1,453 results
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2. Evaluating the green development level of global paper industry from 2000-2030 based on a market-extended LCA model.
- Author
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Shang, Di, Lu, Haiyan, Liu, Chang, Wang, Dong, and Diao, Gang
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SUSTAINABLE development , *GREEN technology , *PAPER industry , *TEXT mining , *INDUSTRIALIZATION ,DEVELOPING countries - Abstract
As a traditional energy and carbon intensive sector, it becomes imperative for the global paper industry to realize green development. This paper aims to provide guidance for the green transformation of global paper industry by evaluating the global paper industry green development level in a systematic and dynamic way. This paper employs text-mining method to develop paper industry green development evaluation indicator system and adopts market-extended LCA model and entropy-TOPSIS method to calculate the paper industry green development level of 48 countries/regions. The results show that during 2000–2030 the paper industry green development level of developing countries improves faster than developed countries, where those of developing and developed countries increase from 0.3369 to 0.3938 and from 0.5120 to 0.5517 respectively and the gap between them narrows from 0.1751 to 0.1579. The comparative analysis reveals that the paper industries of developed and developing countries are in different green development stages. Developing countries, represented by China, improve greatly in economic and social dimensions, but decline seriously in ecological dimension due to enlarging resource consumption and environmental damages. On the contrary, developed countries tend to saturate in economic and social dimensions and have been improving fast in ecological dimension, gradually realizing the decoupling of industrial economic development and environmental damages. To further promote the global paper industry green development, developing countries should focus on promoting the coordinated development between economic growth and environment protection and developed countries should play a leading role in the global green transformation by promoting optimal allocation of resources and cross-regional communications of green technologies. • A paper industry green development indicator system is developed based on text mining. • A global paper industry green development model is built with market-extended LCA. • Complex interactions among the indicators are internalized in the evaluation. • A spatial-temporal analysis is performed on global paper industry green development level. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. Evaluating the green development level of global paper industry from 2000-2030 based on a market-extended LCA model.
- Author
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Shang, Di, Lu, Haiyan, Liu, Chang, Wang, Dong, and Diao, Gang
- Subjects
- *
SUSTAINABLE development , *GREEN technology , *PAPER industry , *TEXT mining , *INDUSTRIALIZATION ,DEVELOPING countries - Abstract
As a traditional energy and carbon intensive sector, it becomes imperative for the global paper industry to realize green development. This paper aims to provide guidance for the green transformation of global paper industry by evaluating the global paper industry green development level in a systematic and dynamic way. This paper employs text-mining method to develop paper industry green development evaluation indicator system and adopts market-extended LCA model and entropy-TOPSIS method to calculate the paper industry green development level of 48 countries/regions. The results show that during 2000–2030 the paper industry green development level of developing countries improves faster than developed countries, where those of developing and developed countries increase from 0.3369 to 0.3938 and from 0.5120 to 0.5517 respectively and the gap between them narrows from 0.1751 to 0.1579. The comparative analysis reveals that the paper industries of developed and developing countries are in different green development stages. Developing countries, represented by China, improve greatly in economic and social dimensions, but decline seriously in ecological dimension due to enlarging resource consumption and environmental damages. On the contrary, developed countries tend to saturate in economic and social dimensions and have been improving fast in ecological dimension, gradually realizing the decoupling of industrial economic development and environmental damages. To further promote the global paper industry green development, developing countries should focus on promoting the coordinated development between economic growth and environment protection and developed countries should play a leading role in the global green transformation by promoting optimal allocation of resources and cross-regional communications of green technologies. • A paper industry green development indicator system is developed based on text mining. • A global paper industry green development model is built with market-extended LCA. • Complex interactions among the indicators are internalized in the evaluation. • A spatial-temporal analysis is performed on global paper industry green development level. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
4. Comment on the paper 'Soil microplastic pollution under different land uses in tropics, southwestern China'.
- Author
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Chia, Rogers Wainkwa, Lee, Jin-Yong, and Cha, Jihye
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SOIL pollution , *FILTER paper , *SOIL science , *DISSECTING microscopes , *LAND use , *SUBSOILS - Abstract
Research on soil microplastics is currently at an early stage, and there is no widely approved sampling protocol. Even so, any basic research should minimize errors to ensure that they are not amplified in future research. This paper examines some weaknesses of the original research paper 'Soil microplastic pollution under different land uses in tropics, southwestern China' recently published in this journal. The authors neglected to report the equipment used for soil sampling and did not use field blank samples. There is also a soil layer that was incorrectly named. The type and pore size of filter paper used for filtration during pre-analytical soil sample preparation is very important. In this paper the nature of the filter paper used, and its larger pore sizes are questionable by today's scientists. In addition, the authors in the original paper also overlooked reporting the statistical package used for statical analysis and ensuring if all data sets obey normality, homogeneity, and equality before running the one-way ANOVA test. This statistical step is widely considered mandatory, especially in the soil science community. So, this makes it difficult to trust the results documented. Furthermore, in the original paper, the needle and stereo microscope instruments used to sort microplastic-like materials prior to proper analysis are not reliable. [Display omitted] • A dissecting needle and stereo microscope shouldn't be used to sort out soil microplastics. • Gold-coated filter paper with smaller pore size is better than nitrocellulose filter paper. • The 0–10cm is the top soil layer and 10–20cm is the subsoil layer not a deep soil layer. • The statistical package used for analysis must be documented accordingly. • If the dataset is a normal distribution prior to ANOVA testing, it must be confirmed and reported. [ABSTRACT FROM AUTHOR]
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- 2022
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5. Spatial disturbance grey model of nonlinear impact on carbon emissions under urbanization policies.
- Author
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Zhao, Kai and Wu, Lifeng
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CARBON emissions , *URBANIZATION , *CITIES & towns , *PERTURBATION theory , *ECONOMIC development , *CARBON isotopes - Abstract
Urbanization and the release of carbon emission are two significant features of contemporary economic and social progress in China. However, there are few studies that consider how urbanization policy goals affect carbon emission. This paper aims to study the nonlinear effects of urbanization policy goals on carbon emission in 13 cities of the Beijing-Tianjin-Hebei region. In this paper, a multi-dimensional spatial disturbance grey model is proposed. Based on matrix perturbation theory, this paper explores the spatial perturbation bounds of the novel model and verifies that the spatial property of the model is consistent with the viewpoint of the First Law of Geography. Then, the novel model is used to predict the urban carbon emission under different urbanization policy goal scenarios. The results showed that the novel model has spatial regional correlation in spatial region prediction. With the development of urbanization level, carbon emissions show a downward trend in more than 50% of cities from 2022 to 2025. In addition, the improvement of urbanization policy goals will promote the carbon peak time of most cities. The carbon emission intensity will exhibit an inverted U-shaped trend distribution in space. The research results are conducive to providing scientific guidance for the formulation of new-type urbanization policies and helping to achieve the dual carbon goals. • A multi-dimensional spatial disturbance grey model is proposed. • The novel grey model is consistent with the viewpoint of the First Law of Geography. • The spatial distribution of carbon intensity showed an inverted U-shaped pattern. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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6. A hybrid model for TEC prediction using BiLSTM and PSO-LSSVM.
- Author
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Li, Dengao, Jin, Yan, Wu, Fanming, Zhao, Jumin, Min, Pengfei, and Luo, Xinyu
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GLOBAL Positioning System , *HILBERT-Huang transform , *STANDARD deviations , *PREDICTION models , *SUPPORT vector machines , *FORECASTING - Abstract
High precision ionospheric Total Electron Content(TEC) prediction is of great significance for improving the accuracy of Global Navigation Satellite System(GNSS), preventing natural disasters, and ensuring wireless communication. Given the varying frequencies of TEC signals, a hybrid CEEMDAN-BiLSTM-PSO-LSSVM-FE model for predicting ionospheric TEC content is proposed in this paper. Firstly, complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is used to decompose the extracted hourly TEC sequence and calculate the fuzzy entropy (FE) of the subsequences. Then, the signal is divided into high-frequency and low-frequency parts based on the fuzzy entropy value, for the high-frequency component, Bidirectional Long Short-Term Memory network (BiLSTM) is used for prediction; for the low-frequency component, Particle Swarm Optimization-based Least Squares Support Vector Machine (PSO-LSSVM) is used for prediction. The hourly TEC values collected from six evenly distributed GPS stations in China are used as the main input variable for the proposed model, with solar and geomagnetic activity data used as auxiliary data, using the TEC data from the previous 48 h to forecast the TEC content for the next hour. The performance of the model is evaluated by comparing it with other models under different geographical locations, seasons, solar and geomagnetic activity conditions. Experimental results show that the proposed hybrid model outperforms other models, with a correlation coefficient R2 and root mean square error (RMSE) of 0.99 and 0.20 TECU, respectively. The model effectively overcomes the problem of low TEC prediction accuracy and can provide more precise ionospheric delay correction services. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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7. Variable stiffness design for the soft landing of a 2016HO3 asteroid probe.
- Author
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Ding, Jianzhong, Zhou, Shiming, Yu, Haoran, and Wang, Chunjie
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ASTEROIDS , *NEAR-earth asteroids - Abstract
• Variable stiffness design for a 3-legged asteroid probe. • Landing dynamics for soft landing on the 2016HO3 asteroid is modeled. • Response surface surrogate model is established for optimization. • Variable stiffness leg and pressing force are optimized. China plans to launch a probe to detect and sampling on the near-Earth asteroid 2016HO3 around 2025. In view of this, this paper discusses an alternative landing strategy with passive variable stiffness landing gears, which help to land the probe stably on the asteroid for sufficient sampling time. First, a three-legged lander is introduced, following which, a four-bar-linkage-based variable stiffness leg is designed considering the design constraint of landing clearance. Then, a numerical model of the probe for landing simulation is established. Moreover, a surrogate model is obtained using the second-order response surface method (RSM) to improve computational efficiency. Based on the surrogate, the variable stiffness leg and the pressing force are optimized to reduce the impact forces at touchdown and the landing time. Finally, the optimal solution is validated using the dynamics analysis model. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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8. Logistic model for pattern inference of subway passenger flows based on fare collection and vehicle location data.
- Author
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Li, Chunya, Xiong, Shifeng, Xiong, Hui, Sun, Xuan, and Qin, Yong
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LOCATION data , *SUBWAYS , *TRANSPORTATION demand management , *EXPECTATION-maximization algorithms , *PARAMETER estimation , *PASSENGERS , *TRAVEL time (Traffic engineering) - Abstract
With large volume of passengers boarding and alighting through subway platforms, the stations are getting crowded, resulting in drops in the level of service and safety concerns, especially for subway systems operating at capacity during peak hours. Thus, it is crucial for subway agencies to sense changes in travel demand and adjust their management schemes accordingly. In this paper we propose a statistical approach to estimate dynamic passenger flows with automated data. First, we develop a dynamic logistic model for calculating passenger tap-out times, which can be employed to infer passenger flow characteristics at the aggregate level. In addition, a new passenger-to-train assignment model for any subway route is derived based on the dynamic model. Subsequently, we apply an expectation-maximization algorithm to estimate the model parameters with automated fare collection and automated vehicle location data. Finally, a cross-validation method is employed to validate our approach with data obtained from several routes in Beijing subway system in China. Results of 95% prediction intervals indicate the effectiveness of the models and the proposed estimation methods. • Propose a dynamic logistic model for inferring and predicting subway passenger tap-out times. • Apply an expectation-maximization algorithm for model parameters estimation. • Develop a novel passenger-to-train assignment strategy. • No prior distributions of parameters or additional information required in the proposed methods. • Results show good effectiveness of the models and acceptable accuracy of the prediction methods. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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9. Applications of satellite technologies within China's legal system – A review.
- Author
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Zhang, Max, Cao, Xingguo, and Sun, Aidi
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JUSTICE administration , *SPACE law , *COURT system , *MODERN society , *LEGAL evidence - Abstract
In contrast to the rising technological applications of China's satellite systems, their applications and impacts in modern Chinese Society, particularly in the legal and administrative forums, have largely escaped under the radar. Specifically, the use of satellite outputs can now be found within a number of administrative and legal activities within China - including policy and rule-making, administrative investigations, and the production of court evidence. At the same time however, outdated legal practices, ambiguous status, and lack of guidance has prevented China's legal system from fully capitalizing on the advantages of satellite technologies. Therefore, to fill these legislative gaps, this review provides a comprehensive overview on the applications of satellite technologies within China's legal system, and provide important insights as to their current developments, legal framework, and legal issues. Additionally, having identified the aforementioned issues, this paper offers policy recommendations for the purposes of legislation. • Satellite applications in China's policy and rule-making processes. • Investigatory applications of satellite technologies within China's administrative organs. • Emerging evidentiary applications of satellite technologies in Chinese court systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Modeling and analysis for coupled multi-zone flow of frac hits in shale reservoirs.
- Author
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Wang, Wendong, Zhang, Qian, Yu, Wenfeng, Su, Yuliang, Li, Lei, and Hao, Yongmao
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SHALE gas reservoirs , *HORIZONTAL wells , *SHALE oils , *SHALE , *OIL shales , *GAS wells , *OIL wells - Abstract
• The model for multiple horizontal wells considers heterogeneous fracture network. • The number of frac hits is determined by pressure differentials and derivatives. • Higher conductivity promotes inter-well pressure equilibrium. • Lower conductivity is beneficial to extended interference testing. Frac hits can significantly impact the final development results. Therefore, accurately and quickly understanding the frac-hit interference between wells is crucial for efficient development. At present, traditional pressure/production data analysis methods and numerical simulation methods can characterize the frac-hit interference. However, challenges such as quantitatively assess interference, high uncertainty in modeling parameters and computational time still exist. A quantitative evaluation method for the interference between wells with complex fracture networks has not been reported yet. This paper takes shale oil reservoir with three production wells as an example and establishes a semi-analytical model (frac-hit semi-analytical model, FSM) based on the linear flow characteristics. The model accurately characterizes the non-uniform distribution of complex fracture networks in the stimulated reservoir volume by introducing fractal theory. A quantitative evaluation index, interference coefficient, is defined to assess the interference. The coupled flow model is applied to evaluate the effects of interference in three typical wells in a continental shale oil field in China. We can see from the actual data fitting of the FSM model that the interference coefficients between target well A and adjacent wells B and C are 0.1 and 0.05, respectively, which means there are about 8–10 and 3–5 frac hits, respectively. Comprehensive analysis for the effects of interference shows that the current inter-well interference is beneficial for production in low-pressure areas but detrimental to new well production. Based on this, sensitivity analysis is generated to illustrate the relationship between the conductivity of combined fractures arising from hits and the interference coefficient. As the interference increases, the propagation of inter-well pressure accelerates, significantly reducing the time required for inter-well pressure equilibrium. The research findings have important guiding implications for the quantitative evaluation of inter-well interference in field operations of horizontal shale oil and gas wells and optimization of fracturing operations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Study of the deorbit sail damage under the combined effects of atomic oxygen erosion and material defects.
- Author
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Fu, Yulei, Gong, Ruifeng, Ding, Zhiang, Zeng, Zhankui, Wei, Guoning, and Xiao, Yuzhi
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SPACE debris , *MATERIAL erosion , *MONTE Carlo method , *FOLDS (Geology) , *SPACE environment , *OXYGEN , *SAILS - Abstract
In order to help control the spread of space debris and junk, deorbit sail devices have been used for deorbiting techniques; however, this approach is still considered risky due to potential failure or malfunction as it need to be exposed to the harsh space environment for a prolonged period of time, particularly in low-Earth orbit. China has made new strides forward in managing space junk, as it has successfully unfolded a 25-square-meter deorbit sail developed by the Shanghai Academy of Spacecraft Technology in-orbit for the payload capsule of a recently launched rocket. Accordingly in this paper, a full life-cycle modelling based on Monte Carlo method is developed to reveal the damage behavior of the 25-square-meter deorbit sail surface under the combined effects of atomic oxygen erosion and deorbit sail defects. The simulation results show that as the atomic oxygen fluence increases and the material defect width widens, the interaction effect of the two factors becomes more and more pronounced, which decisively influences the erosion rate of the sail surface. Morphological characterization of aluminized film PET material, activated silanisation modified material and plasma-polymerization coating material before and after atomic oxygen erosion combined defects is carried out and the atomic oxygen erosion of the deorbit sail surfaces is quantitatively assessed. The assessment results show that compared to the PET material and activation silanisation surface modification material, the plasma polymeric coated material showed much better flexibility, folding resistance and irradiation resistance to prevent geological fold and to shield from the atomic oxygen erosion in space. The atomic oxygen erosion combined defects assessment method studied in this paper provides valuable reference data for the subsequent serialisation of deorbit sail products and other typical lightweight film materials for space applications. • Introduction of Monte Carlo method for material surface damage simulation analysis. • Compare the performance of off-orbit sail surface materials under different protection treatments. • Standardize the process of space flexible film material performance evaluation system. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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12. Validation of long arc orbit determination method based on orbital residuals analysis and determination of coordinates of Chinese SLR stations using the LAGEOS satellites.
- Author
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Zhou, Chongchong, Wang, Junao, Zhong, Shiming, Peng, Bibo, Zhang, Jie, Han, Jinyang, and Guo, Zhao
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ORBIT method , *LASER ranging , *ORBIT determination , *ORBITS (Astronomy) , *GEODESY - Abstract
Satellite Laser Ranging (SLR) technology is one of the main technologies in the field of space geodesy, it has played an extremely important role in laser ranging data application and research. As a commonly used geodynamic satellites, the main contribution of LAGEOS and LAGEOS-2 is the solution of orbit determination and station coordinates. At present, there are 8 analysis centers of the International Laser Ranging Service (ILRS) to release the precise orbit products for the two LAGEOS satellites. However, there is currently no relevant research on the analysis of the consistency of these orbits. So, the authors would evaluate the accuracies of them, and the results show that the orbital accuracies of the two LAGEOS satellites are 3 ∼ 5 cm. SLR is regarded as one of the important input data of the International Terrestrial Reference Frame (ITRF), the analysis center of ILRS provides weekly solutions of station coordinates for ITRF. But, due to the limitation of SLR observation conditions, for example most observations of Chinese SLR stations can be made at night, and laser ranging test cannot be conducted in rainy days, the orbit solution of the seven-day arc may have the problem of less data. Therefore, this paper proposed a method for computing the station coordinates based on long arc orbit determination, and we developed the LAODGEO software (Long Arc Orbit Determination Software for Geodynamic Satellite), which is used to solve the orbits of two LAGEOS satellites and station coordinates of five SLR stations in China. The results show that the obtained orbital precision is basically superior to 3.70 cm, and the 3DRMS values between station coordinates solved by us and the coordinates published by SLRF2014 are mostly smaller than 0.013 m, which is consistent with research results domestic and overseas. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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13. A quantitative analysis of latitudinal variation of ionospheric total electron content and comparison with IRI-2020 over China.
- Author
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Yang, Yuyan, Liu, Libo, Zhao, Xiukuan, Han, Tingwei, Arslan Tariq, M., Chen, Yiding, Zhang, Hui, Le, Huijun, Zhang, Ruilong, Li, Wenbo, Sun, Wenjie, and Li, Guozhu
- Subjects
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SOLAR activity , *GLOBAL Positioning System , *SPRING , *QUANTITATIVE research , *ELECTRONS - Abstract
Many studies have investigated the spatial variations of the ionosphere, but the quantitative characteristics of the ionosphere are rarely reported. In this paper, we utilize the total electron content (TEC) data to evaluate the latitudinal gradient of the ionosphere within 10°-50° N over the China sector. It is found that the magnitudes of latitudinal gradient are significantly higher within 10°-40° N and 45°-50° N, respectively. The database of TEC from 1 November 2018 to 31 October 2022 is processed to figure out the local time, seasonal, and solar activity dependency of the latitudinal gradient. The results suggest that the gradient within 10°-40° N is higher in the daytime and during high solar activity period. They are more noticeable in the spring and autumn, and least visible in the summer. Conversely, the gradient within 45°-50° N strengthens in the nighttime and under lower solar activity, and has larger values in the summer months. Furthermore, the International Reference Ionosphere (IRI-2020) model is assessed in terms of the reproducibility of latitudinal gradient. The IRI-2020 basically represents the latitudinal gradient within 10°-40° N, whereas it overestimates the gradient in the low solar activity period and misses the gradient features near 45°–50° N. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Longitudinal variations of ionospheric responses to the February and April 2023 geomagnetic storms over American and Asian sectors.
- Author
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Arslan Tariq, M., Liu, Libo, Shah, Munawar, Yang, Yuyan, Sun, Wenjie, Ali Shah, M., Zhang, Ruilong, and Yoshikawa, Akimasa
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MAGNETIC storms , *GLOBAL Positioning System , *THERMOSPHERE , *ELECTRIC fields - Abstract
This paper investigates the ionospheric responses to the February and April 2023 geomagnetic storms using Total Electron Content (TEC) derived from the 10 Global Navigation Satellite System (GNSS) stations at the transition of low to mid-latitudes (Approx. 20 ∼ 30°N) across different longitudes in the American and Asian sectors. Significant variations in both sectors were recorded during the recovery phase and were mainly attributed to the Prompt Penetration Electric Field (PPEF), Disturbance Dynamo Electric Field (DDEF) and the thermospheric neutral composition changes as O/N 2 depletion. Similarly, the American and Asian sectors showed TEC enhancements, primarily attributed to the PPEF, during the main phase of the April storm. The negative TEC variations during the recovery phase were observed due to the DDEF and changes in O/N 2. In the Asian sector, positive and negative variations were recorded over Pakistan and China, respectively, during the main phase of the April storm. These variations resulted in high and low concentrations of the O/N 2 ratio due to Magnetosphere-Ionosphere-Thermosphere coupling. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Real-time GNSS tropospheric parameter prediction of extreme rainfall events in China based on WRF multi-source data assimilation.
- Author
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Wei, Pengzhi, Liu, Jianhui, Ye, Shirong, Sha, Zhimin, and Hu, Fangxin
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GLOBAL Positioning System , *PRECIPITABLE water , *RAINFALL , *BRIGHTNESS temperature - Abstract
In recent years, extreme rainfall events have frequently occurred frequently, and heavy rainfall can cause drastic changes in the troposphere. Therefore, achieving to achieve real-time high-precision numerical prediction of key tropospheric parameters during heavy rainfall has become a major problem in global navigation satellite system (GNSS) meteorology. In this paper, two extreme rainfall events in southern China (Guangdong region) and northern China (Shandong region) in 2022 are used as case studies. Twenty-four-hour real-time numerical forecasts of key tropospheric parameters (atmospheric weighted mean temperature (Tm), precipitable water vapor (PWV), and GNSS zenith tropospheric delay (ZTD)) are obtained using three models, namely, the HGPT2, GPT3, and WRF models. Two optimization models, i.e., WRFDA (am) and WRFDA (pre), are then constructed by assimilating two types of data (global upper air and surface weather observations and daily advanced microwave sounding unit A (AMSU-A) brightness temperature) based on the WRF model. The experimental results for heavy rainfall show that (1) the WRF model predicts the key tropospheric parameters with better accuracy than the HGPT2 and GPT3 models, and the WRFDA (pre) model predicts PWV and ZTD with the highest accuracy; (2) the WRFDA (pre) model achieves a higher accuracy than the WRF model in predicting PWV and ZTD, where the PWV prediction accuracy is improved relative to the WRF model (in the south: MAE: 32.7 %; RMSE: 33.9 %; MAPE: 36.8 %; in the north: MAE: 27.3 %; RMSE: 24.2 %; MAPE: 28.0 %); this model achieves an MAE of 2.17 cm and an RMSE of 2.70 cm in 24-h ZTD prediction in the south, while the MAE reaches 2.48 cm, and the RMSE is 3.18 cm in the north; (3) the models provide a higher forecast accuracy in the southern region than in the northern region for heavy rainfall. The WRFDA (pre) model provides a favourable ZTD accuracy at GNSS stations near the ocean, while the WRFDA (am) model provides a satisfactory ZTD accuracy at inland GNSS stations, and the WRFDA (am) model provides the highest ZTD prediction accuracy at GNSS stations above 100 m. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Spatial correlation and coupling between industrial enterprise agglomeration and water pollutant discharge.
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Wang, Yazhu, Deng, Yawen, Duan, Xuejun, Zou, Hui, and Wang, Lingqing
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WATER pollution , *INDUSTRIAL clusters , *INDUSTRIAL wastes , *PAPER products industry , *POLLUTION - Abstract
Industrial wastewater discharge has become the main cause of water pollution in China. However, the spatial interaction mechanism between industrial structure and water pollution is still unclear. Accordingly, we evaluated and analyzed spatiotemporal changes of the agglomeration pattern of pollution-intensive industrial enterprises and the evolution of the water environmental pollution pattern, as well as the correlation between them. The study results show that the polluting industrial enterprises were located mainly along the Yangtze River and Taihu Lake Basin in southern Jiangsu in 2013 and 2018. However, we observed a spatial trend of pollution transfer to northern Jiangsu. The industrial water pollution discharge presents the distribution pattern of facing rivers, seas, lakes and cities. Papermaking and paper products industry are the leading factors of COD and NH 3 –N pollution, with explanatory power of 0.3666 and 0.6201 respectively. The spatial positive coupling effect between the concentration degree of polluting enterprises and the intensity of water environment pollution discharge is 94.95% of the region. The spatial agglomeration of polluting industrial enterprises is an important cause of water environment pollution. They promote and couple each other, proving the existence of "Pollution haven" and "Porter hypothesis". [Display omitted] • The polluting industrial enterprises are located mainly along the Yangtze River and Taihu Lake Basin. • Papermaking and paper products industry are the leading factors of COD and NH 3 –N pollution. • The spatial agglomeration of polluting industrial enterprises is a significant cause of water environment pollution. • This study proves the existence of "Pollution haven" and "Porter hypothesis". • This study fills the gap in the spatial response mechanisms of different industrial structures and pollutants. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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17. Comparative analysis of paddy straw-degrading consortia in China using high-throughput sequencing.
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Ban, Yunhe, Li, Xiang, Li, Yuqi, Li, Xinyu, Li, Xu, Wang, Xiujuan, Su, Zhencheng, and Zhang, Huiwen
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NUCLEOTIDE sequencing , *FILTER paper , *COMPARATIVE studies , *BACTERIAL communities , *MICROBIAL communities - Abstract
Nine paddy straw-degrading microbial consortia were isolated from 253 paddy straw samples from northern China and the Yangtze River Valley, which are two major rice production regions in China. The microbial consortia completely degraded filter paper within 15 d at 25 °C. The V4 region of the microbial consortia 16S rRNA gene was amplified, and the amplicons were sequencing using the Illumina Miseq high-throughput platform. Compilobacterota and Bacteroidota were the predominant phyla in the samples. At the genus level, the relative abundance of Macellibacteroides was the highest in Y2, and Arcobacter was predominant in the other samples. Analysis of the microbial community structure revealed that the diversity and richness in samples from the Yangtze River Valley were significantly higher compared with those of the samples from northern China, and the community structure of the four microbial consortia from the northern region had higher similarity than the five consortia from the Yangtze River Valley. • Campilobacterota and Bacteroidetes were the predominant phyla of microbial consortia. • The major genera in the two regions were significantly different. • Pseudomonas , Comamonas , Fibrobacter , Sphingobacterium , Ruminiclostridium , and Ruminococcus are the functional bacteria. • The northern bacterial community richness and diversity were lower than the Yangtze River Valley. • The northern microbial community structure was higher in similarity than the Yangtze River Valley. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
18. Ionospheric foF2 nowcast based on a machine learning GWO-ALSTM model.
- Author
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Yang, Zheng, Qiao, Lei, Su, Mingkun, Hu, Zhenhua, Teng, Xuyang, and Wang, Jiayi
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MACHINE learning , *MAGNETIC storms , *IONOSONDES - Abstract
The ionospheric foF2 prediction model GWO-ALSTM is proposed in this paper, which combines the Gray Wolf Optimization (GWO) algorithm and the attention mechanism based on the long short-term memory (LSTM) model. The datasets used in this model were obtained from the oblique ionosondes of the China Ground-based Seismo-ionospheric Monitoring Network. The data from 2010 to 2012 was used for training, and the data of 2013 was used for verification. The input parameters of the model include local time, day number, sunspot number, F10.7 solar flux, Ap index, Dst index, and foF2 at the previous moment, and the output parameter is foF2 at the current moment. The IRI2016 model, GABP model, LSTM model and GWO-ALSTM model were compared with the observed results for analysis. The results show that the GWO-ALSTM model is superior to the LSTM model, the GABP model and the IRI2016 model. Meanwhile, the comparative analyses of the diurnal variations of foF2 show that the curve of the GWO-ALSTM model fits the observed values more closely than the curve of any other model under the geomagnetic quiet and storm conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. Dynamics of microbial communities associated with flavor formation during sour juice fermentation and the milk fan drying process.
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Chen, Chen, Yao, Wenqian, Yu, Haiyan, Yuan, Haibin, Guo, Wei, Huang, Ke, and Tian, Huaixiang
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DRIED milk , *MICROBIAL communities , *MICROBIAL metabolism , *PEARSON correlation (Statistics) , *FLAVOR , *FERMENTATION , *MICROBIAL diversity - Abstract
Milk fan is an acid-curd cheese with strong national characteristics (a traditional dairy product of the Bai nationality with a shape like a piece of paper) and a long history in Yunnan province, China. In our previous study, we characterized the microbial community diversity of milk fan, but the succession of microorganisms associated with flavor formation in milk fan is still unknown. Therefore, we examined the predominant microorganisms and their correlations with the formation of flavor in the fermentation of sour juice and drying of milk fan by gas chromatography mass spectrometry, high-throughput 16S rDNA sequencing, intergenic spacer sequencing and metatranscriptome analysis. We found that the relative abundances of Lactobacillus and Issatchenkia initially decreased and then increased with time during the fermentation of sour juice. However, the relative abundances of Acetobacter , Leuconostoc , Lactococcus, Geotrichum , and Dipodascus initially increased and then decreased. During the drying step, the relative abundances of Lactobacillus and Issatchenkia continuously increased and became the dominant microorganisms in the milk fan. The metatranscriptomes generated from the milk fan showed that "carbohydrate metabolism," "translation," and "signal transduction" were the main metabolic functions of the microbial communities. Rhodotorula and Yarrowia contained more differentially expressed genes than other genera, which indicated they may be associated with the production of the characteristic flavor. Furthermore, a Pearson correlation analysis showed that Lactococcus , Rhodotorula , Candida , Cutaneotrichosporon , and Yarrowia were significantly positively correlated with more aroma-active compounds, mainly ethyl acetate, 2-heptanone, isovaleraldehyde, butyric acid, nonanal, and hexanal. In conclusion, these findings contribute to a better understanding of the flavor production mechanism during the production of milk fan. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2023
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20. A recyclable, up-scalable and eco-friendly radiative cooling material for all-day sub-ambient comfort.
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Sun, Haodong, Tang, Fengjie, Chen, Qunfeng, Xia, Linmin, Guo, Chenyue, Liu, He, Zhao, Xinpeng, Zhao, Dongliang, Huang, Liulian, Li, Jianguo, and Chen, Lihui
- Subjects
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CELLULOSE fibers , *THERMAL comfort , *PAPER pulp , *RENEWABLE energy sources , *ENERGY consumption , *PAPERMAKING , *SOLAR radiation - Abstract
• A simple, large-scale fabrication of cooling paper via pulping and papermaking technology. • The cooling paper is facilely deconstructed and regenerated to architect the secondary cooler. • The cooling paper features a high solar reflectance of 94% and emissivity of 0.95. • The cooling paper shows the sub-ambient temperature drop of 6 ∼ 8.8 °C under directly solar radiation at daytime. Passive radiative cooling materials provide coldness without energy consumption for all-day thermal comfort by reflecting solar irradiation and emitting heat into the 3 K universe. However, the conventional radiative cooling materials involve complex multilayer structures and unsustainable polymers, showing the non-recyclable disadvantage, which induces resource waste and environmental issues. Herein, we reported a low-cost, scalable, and eco-friendly radiative cooling material (namely cooling paper), consisting of the delignified, fibrillated cellulose fibers and nano-sized hydroxyapatite (HA) via the mature pulping and papermaking process. The resulting cooled paper can be recycled, and it can be easily deconstructed to harvest cellulose fibers and HA, individually. The recovered source materials can be reused to prepare secondary products that show comparable performance to the original cooling paper, including a high solar reflectance of ∼94% and an infrared emissivity of ∼0.95 in the atmospheric transparency window. Such cooling paper enables superior cooling performance with the temperature drop of 6 ∼ 8.8 °C under directly solar radiation. Based on the EnergyPlus simulation, our cooling paper shows a average cooling energy saving of ∼29 % in buildings across China. The recyclable cooling paper with high cooling capability and scalability, as well as environmental friendliness, shows promising potential for sustainable energy-efficient buildings. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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21. Synergizing carbon trading and water management for urban sustainability: A city-level multi-objective planning framework.
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Zhou, Yang, Han, Jingcheng, and Zhou, Ya
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- *
WATER management , *MUNICIPAL water supply , *CARBON offsetting , *CLIMATE change mitigation , *CARBON emissions , *PAPER products industry - Abstract
The ever-increasing challenges related to water security and climate mitigation underscore the pressing need for forward-thinking systems planning tools to drive urban sustainability transitions. In this study, we propose a novel city-level multi-objective planning framework that explores the nexus between carbon trading and water management, with the aim of facilitating water-efficient urban industrial restructuring. The framework integrates cap-and-trade mechanisms into a two-layered optimization model, creating an integrated approach to optimizing carbon emissions and generating economic opportunities for improving water efficiency. To illustrate the potential application of this framework, we conducted a case study focusing on Dongguan City, a water-stressed industrial metropolis in southern China. The results illustrate potential synergies between water planning strategies and carbon trading schemes, which could be harnessed to enable targeted reductions in water usage and carbon emissions. Furthermore, our findings identify the textile, apparel, and paper products manufacturing industries as primary candidates for strategic production scale reduction, emphasizing the importance of sustained support for the development of the computer and electronic manufacturing sector as a catalyst for urban sustainability transitions. By pioneering this new nexus-based perspective, our study offers valuable insights into long-term strategic planning for a low-carbon and resource-efficient urban economy. • Synergizing carbon trading and water management within a novel integrated planning framework. • Implementing resource-efficiency-driven optimization for water- and carbon-intensive manufacturing sectors. • Gaining insights into the specific roles of key manufacturing sectors in water management and carbon trading. • Introducing carbon trading systems may help in promoting water-efficient industrial restructuring. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2024
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22. Using weighted entropy to measure the recyclability of municipal solid waste in China: Exploring the geographical disparity for circular economy.
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Tong, Xin, Yu, Haofan, and Liu, Tao
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SOLID waste , *PAPER recycling , *TACIT knowledge , *WASTE recycling , *DIVISION of labor , *VALUE capture , *REGIONAL disparities - Abstract
Solid waste recycling in developing countries has been largely relying on the informal recycling sector which intelligently uses the tacit knowledge within the hierarchical network of labor division to capture the value from the geographically uneven distribution of waste generation and demands on secondary materials. Previous studies on solid waste recycling mainly have a material-centric view on economic value. In this paper, an entropy-weighted recyclability index (EWRI) is developed to quantify the recyclability of Municipal Solid Waste (MSW) in China at the prefectural city level by integrating the road transportation density and regional recycling capability into the categories of waste physical components regarding the cost to deliver the waste from generating sources to the conversion sites for recycling. The result confirms the existence of an east-west gradient regional disparity in recyclability of Municipal Solid Waste (MSW) among cities for the recyclable components. The 339 prefectural cities were classified into 4 grades, namely "best, good, normal, and difficult" for the recyclability of local MSW with guidelines for planning of regional recycling infrastructure, respectively. In conclusion, general guidelines for the building of wise-waste city infrastructure to fit the local context in developing countries is advised. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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23. Comparing the power resources critical to international rulemaking in outer space: China and the United States.
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Li, Xiaodao
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POWER resources , *OUTER space , *SPACE law , *EXTRATERRESTRIAL resources , *EXTRATERRESTRIAL beings ,CHINA-United States relations - Abstract
The rapid growth of China's national resources in the space domain may change the gap in power between China and the United States in relevant international rulemaking. This article proposes an analytical framework for identifying, comparing, and analyzing states' power resources critical to international rulemaking and uses the framework to compare the relevant resources between China and the United States in the space domain. First, this paper develops a method for identifying resources crucial to international rulemaking in outer space. The relevant resources of the two countries are then compared in this article. Finally, the article explores comparative advantages, consensus, differences, and cooperation possibilities of the two countries in specific international space rules. The framework could be adapted to compare diverse nations' resources critical to international rulemaking in other fields; it contributes to research on space law, international legislation, and national power. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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24. A combined prediction model based on secondary decomposition and intelligence optimization for carbon emission.
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Yang, Hong, Wang, Maozhu, and Li, Guohui
- Subjects
- *
CARBON emissions , *PREDICTION models , *OPTIMIZATION algorithms , *HILBERT-Huang transform , *SUPPORT vector machines , *MACHINE learning - Abstract
• An improved singular spectrum decomposition is proposed. • High complexity components are secondarily decomposed to reduce its complexity. • An improved prediction model of optimization algorithm is proposed. • Intelligent weighting strategy is introduced to overcome traditional weighting problem. • A combined prediction model for carbon emission is proposed. Accurate prediction of carbon emission is critical for the development of low-carbon economy. However, most carbon emission prediction studies use a single model with low prediction accuracy, and do not consider the instability of carbon emission. Therefore, this paper proposes a combined prediction model of carbon emission. Firstly, the original data is decomposed by singular spectrum decomposition to obtain a limited amount of singular spectrum components. Secondly, high complexity components are secondarily decomposed by variational mode decomposition. Then, chameleon swarm algorithm and carnivorous plant algorithm are used to train the regularization coefficients and kernel parameters of kernel extreme learning machine and least squares support vector machine respectively, and the trained model is used to predict the decomposition components. Finally, induced ordered weighted averaging operator is used to calculate the weight of single model, and error correction is introduced to further promote the prediction accuracy. The carbon emission data of China and the United States is used to make a prediction experiment. The results indicate that the proposed model is superior to other comparative models in different indexes, which provides a new idea for carbon emission prediction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. The short-term effects of the Cosmos 1408 fragmentation on neighboring inhabited space stations and large constellations.
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Pardini, Carmen and Anselmo, Luciano
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- *
SPACE stations , *SPACE debris , *TELECOMMUNICATION satellites , *GLOBAL Positioning System , *ORBITS (Astronomy) , *CONFORMANCE testing ,UNIVERSE - Abstract
In terms of cataloged debris produced, the anti-satellite test carried out by Russia, in November 2021, at an altitude of about 480 km, leading to the destruction of the old satellite Cosmos 1408, was the second worst to date and represented the third worst fragmentation in orbit. It generated more than 1/4 of the cataloged debris produced over 55 years by all such tests and almost twice as many as were produced by all previous Soviet tests. After placing this event in its historical context, this paper analyzes in detail how the evolution of the Cosmos 1408 debris cloud affected the environment below 600 km in the first seven months, focusing on the two operational space stations and the Starlink large constellation of satellites. During the first six months following the test, the Cosmos 1408 cloud of fragments nearly doubled the average flux of cataloged objects on the International Space Station and increased by about 3/4 that on China's Tiangong. In the same period, the Starlink large constellation saw an average increase in the flux of cataloged objects of about 20%. Some orbital planes, the "counter-rotating" ones with respect to the Cosmos 1408 debris cloud, were more affected than others, and the affected planes gradually changed over time, due to the differential precession of cloud and constellation nodes. However, being the Starlink constellation 70 km higher up, the flux of Cosmos 1408 cataloged debris steadily decreased over the period analyzed, due to the cloud orbital decay, reducing to just over a quarter of its extrapolated initial value after seven months. • A review of ASAT tests as a source of orbital debris was presented. • The impact of the Cosmos 1408 destruction was put into context. • The cataloged debris flux increase on space stations was computed and discussed. • The debris flux increase and evolution on Starlink orbit planes was analyzed. • A moratorium on this type of ASAT tests was recommended, including low LEO. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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26. Historical poem-quoting interaction: An interaction-speech act-ritual integrative study of fù in ancient China.
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Liao, Guohai and Xia, Dengshan
- Subjects
- *
POLITICAL affiliation , *CARDINAL virtues , *SOCIAL interaction , *SPRING , *SOCIAL action , *AUTUMN , *VIRTUE - Abstract
Drawing on the interaction-speech act-ritual integrative approach, this paper investigates the pragmatic properties, functions and socio-cultural mechanism of fù 賦, a special kind of historical poem-quoting 賦詩 interaction in the Spring and Autumn Period of ancient China, from the historical sociopragmatic perspective. The study shows that, firstly, the historical interaction of fù features both rituality and strategicality. The rituality manifests how fù is used to initiate the ritual speech acts of Greet and Leave-take in the opening and closing phases of interaction. The use of fù as a greeting compulsorily calls for another fù as a response, violation of which will incur negative evaluation while the use of fù as a leave-taking potentially evokes positive evaluation; the strategies are shown in the core phase where fù performs the informative speech act of Opine to express political orientation on the one hand and the attitudinal speech acts of Request, Refusal and Resolve to strategically achieve diplomatic negotiation on the other. Secondly, fù mainly performs in interaction as three social actions: institution-maintaining for bureaucratic institutes and hierarchies, virtue-favoring for the five moral virtues of Confucianism, "Gong" 恭, "Ken" 寬, "Xi" 信, "Min" 敏, and "Hui" 惠 and face-upholding for self and others to re-enact the institutionalized and interpersonal aspects of moral order of li in interaction. Third, the moral order of li in turn provides the basis for the evaluation of fù as social action, between which the dynamic socio-cultural mechanism of fù in interaction emerges. • The study provides the interaction-speech act-ritual evidences on fù historical Chinese poem-quoting interaction. • Fù interaction contains both ritual and strategical aspects. • Fù performs as the institution-maintaining, virtue-favoring and face-upholding actions to re-enact the moral order of li. • The moral order of li provides the basis for the evaluation of fù , from which its socio-cultural mechanism emerges. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. China's emerging commercial space industry: Current developments, legislative challenges, and regulatory solutions.
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Zhang, Max and Yang, Xiaonan
- Subjects
- *
SPACE industrialization , *SPACE law , *LEGAL instruments , *EMERGING industries , *COMMUNITIES , *FOOD chains , *PUBLIC spaces - Abstract
With commercial participants now undertaking an ever-expanding role within the development and supply-chains of China's space industry post Document No. 60, the resulting legal challenges relating to this emerging industry status-quo has garnered much academic discussion. Specifically, while China's space industry has grown at a rapid pace within the past few decades, China's legislative framework has remained largely silent over matters relating to space. Instead, China continues to remain as the only major space-faring nation without a national space law and regime. This substantive legislative gap over China's space related activities has negatively impacted the industry's current deregulation process. While it has been the academic community's primary solution to address the industry's current substantive legislative gap through coordinated rulemaking activities, this paper aims to advance the current academic discussion by taking an alternative approach and arguing that the fundamental legislative challenge and solution to China's emerging commercial space industry, is not substantive, but rather procedural by nature. Importantly, by reconceptualizing the industry's substantive gap from one that is determined by the number of missing legal instruments, to one determined by the rate of legislative activity i.e., the pace of law-making activities vis-à-vis commercial expansion, this paper argues that only through the implementation of legal procedural rulemaking mechanisms will China's space law regime be able to sufficiently address the current substantive legislative gap at a pace matching commercial expansion. • The deregulation of China's space industry. • Regulatory structure and legal challenges of China's space industry. • A procedural argument to resolve China's substantive space law gap. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Q-SAT for atmosphere and gravity field detection: Design, mission and preliminary results.
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Zhaokui, Wang, Dapeng, Han, Boxin, Li, Yunhan, He, Qi, Zhang, Guangwei, Wen, and Yulin, Zhang
- Subjects
- *
GRAVIMETRY , *UPPER atmosphere , *ATMOSPHERIC density , *GRAVITY , *ATMOSPHERIC models - Abstract
Q-SAT, a small spherical satellite designed and developed by Tsinghua university, was successfully launched on Aug 6, 2020 at Jiuquan satellite launch center in China. The mission of Q-Sat is the joint measurement of long-wavelength Earth gravity field and upper atmosphere density, which is of great significance for improving spacecraft orbit prediction and promoting the development of satellite gravity measurement technology. The satellite is designed in spherical shape innovatively and deploys high dynamic dual-frequency GPS as the main payload. On-orbit data shows that the atmospheric density detection precision is in the order of 10−14kg/m3 and the gravity recovery precision achieves the level of 30 orders. All mission success criteria and objectives were achieved. This paper presents the design, space mission, key technologies, science capabilities and preliminary results of the satellite. • Q-SAT, a spherical satellite for the joint measurement of long-wavelength Earth gravity field and upper atmosphere density, was launched in 2020. • An electromagnetic separation system with point connection-release structure is designed for the Q-Sat. • As secondary payload a powerful GPU module is implemented to validate artificial intelligence computing capabilities in orbit. • Modifications for the Jacchia-Roberts atmospheric density model are proposed in the paper. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
29. Drag-free design based on Embedded Model Control for TianQin project.
- Author
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Xiao, Chunyu, Canuto, Enrico, Hong, Wei, Zhou, Zebing, and Luo, Jun
- Subjects
- *
MULTI-degree of freedom , *CENTER of mass , *GRAVITATIONAL waves , *LASER interferometers , *SOLAR radiation , *LANDSAT satellites , *ARTIFICIAL satellite attitude control systems - Abstract
With the ability to detect low-frequency gravitational waves (GWs), space-borne detectors will play an important role in exploring the universe in the future. The TianQin project proposed in China participates in this challenge by aiming to detect millihertz GWs. The TianQin GW detector consists of three spacecraft forming a triangular constellation. Each spacecraft carries a pair of test masses (TM) which, inside shielding cages, are left to free fall along the local geodesic. In this way, a pair of TMs on two separate spacecraft can be each other aligned to become the gravitational references of the GW detector, made by an inter-satellite laser interferometer. Each free-falling TM is limited by parasitic forces to be appropriately bounded. The relevant acceleration bound has been fixed to 10−15 m/s2/ Hz within the TianQin measurement bandwidth (MBW) ranging from 0.1 mHz to 0.1 Hz. In turn, TM to cage fluctuations must be kept below 4nm/ Hz to limit the stiffness coupling with the spacecraft displacement caused by non-gravitational disturbances, such as solar radiations and the thruster noise. Suppression of such disturbances calls for a challenging drag-free control technology, since the center of mass (CoM) of a single spacecraft cannot track the separated CoMs of two TMs simultaneously, and consequently tracking must be limited to three degrees of freedom (DoF): two non-orthogonal sensitive axes (one for each TM) and the perpendicular direction to their plane. Control design and simulated tests of this paper will be restricted to the drag-free control along the sensitive axes. The remaining nine DoFs of the two TMs (position and attitude) are controlled by electrostatic suspensions, not to be treated here, but accounted for in the simulated trials. The design of the two-DoF drag-free control relies on a model-based control methodology, the Embedded Model Control (EMC), capable of predicting and suppressing unknown disturbances within the required bandwidth and of decoupling the TM dynamics along the non-orthogonal sensitive axes. The paper starts with the nonlinear model of the TM to cage dynamics, followed by the relevant EMC design, restricted to the sensitive axes. Numerical simulations are employed to validate closed-loop performance and robust stability. Simulated results show that the residual TM to cage fluctuations can be kept below 3nm/ Hz , which leaves a margin within the required spectral bound. The EMC methodology discussed in the paper can provide a reference for future developments and implementations. • Test mass dynamics can be decoupled by 'thruster coupling' or 'sensor coupling'. • Embedded Model Control predicts and compensates unknow disturbances. • Reference generator smooths test mass centering process. • Test mass to cage displacement has satisfied TianQin requirement. • Monte Carlo trails have validated the closed-loop robust stability. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
30. A novel grey prediction model with four-parameter and its application to forecast natural gas production in China.
- Author
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Song, Nannan, Li, Shuliang, Zeng, Bo, Duan, Rui, and Yang, Yingjie
- Subjects
- *
NATURAL gas production , *PREDICTION models , *DIFFERENCE equations , *DIFFERENTIAL equations - Abstract
Due to the non-homology problem and the simple structural characteristics, a grey prediction model will have defects in modeling. In this paper, the structure of the GM (1 , 1 , x (1) ) model is deformed, and additional parameters are added. A novel four-parameter grey prediction model NFGM(1,1) is established to avoid the non-homology problem. The accumulation order of the NFGM(1,1) model is optimized to enhance its performance. This paper first introduces a nonlinear term and a linear term into the GM (1 , 1 , x (1) ) model to compensate for its structural defects, which can enhance the accuracy of the model in modeling complex modeling sequences. Secondly, a simplified basic formula of the model is proposed to estimate its parameters and iteratively establish the model, which can avoid the problem of non-homologous errors during modeling. Then a novel four-parameter grey prediction model NFGM(1,1) is constructed. Thirdly, the unbiasedness of NFGM(1,1) is proved and verified by matrix theory. Fourthly, by optimizing the order of the NFGM(1,1) model, the model is more flexible and adjustable, and a novel fractional-order four-parameter grey prediction model FNFGM(1,1) can be obtained. Finally, the FNFGM(1,1) model is applied to the prediction of natural gas production in China. The model results show that the FNFGM(1,1) model exhibits superior performance compared to the NFGM(1,1), TWGM(1,1), TDGM(1,1), DGM(1,1), and GM(1,1) models, with the mean relative simulation/prediction/comprehensive percentage errors of 0.92%/1.42%/1.07%, respectively. According to the predicted results, China's natural gas production will reach 3542.9 × 108 m3 in 2027 and some relevant policy recommendations are put forwarded. • On the basis of GM (1 , 1 , x (1) ) , a nonlinear term and a linear term are introduced to expand the model structure, and a novel four-parameter grey prediction model is proposed. • In order to avoid the non-homology problem of the differential equation and difference equation in traditional modeling, this paper uses the simplified basic formula of the model to estimate parameters, and does not directly derive the time response, but directly uses the iterative recurrence method to model. • The new model is proved to be unbiased by the matrix theory method and verified by arithmetic examples. • According to the objective function and constraints of fractional-order solving, PSO algorithm is used to optimize the order of the new model, which makes the model parameters changeable and improves the model performance. • The comprehensive performance of the new model is verified by a case study, the new model is applied to forecast China's natural gas production in the context of Xi Jinping's new era, and the results show that the new model has better accuracy, and the results obtained can help the government to formulate relevant policies. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Does mobile payment foster low-carbon lifestyles? Evidence from Alipay's "collecting five blessings" campaign.
- Author
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Li, Tong, Jiang, Yi, and Zhao, Yue
- Subjects
- *
MOBILE commerce , *CARBON nanofibers , *CARBON emissions , *PANEL analysis , *CONSUMPTION (Economics) , *DIGITAL technology - Abstract
The widespread use of digital technology has driven a huge change in the way payments are made. Based on the micro-data of the China Family Panel Studies (CFPS), this paper explores the relationship between mobile payment and carbon emissions from the consumption side. With the exogenous impact of Alipay's "Collecting Five Blessings" campaign, this paper finds that mobile payment significantly increases household consumption carbon emissions, but the marginal effect is gradually decreasing. Mechanism analysis shows that mobile payment mainly realizes the above impact through promoting the increase of consumption expenditure and upgrading of consumption structure. Further analysis indicates that carbon reduction policies introduced by the Chinese government in the personal consumption sector can mitigate the carbon emissions growth associated with mobile payments. Still, there is a need to strengthen policy measures further to effectively address the issue of rising carbon emissions from household consumption. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Battery recycling models selection and contractual incentives: From an information sharing perspective.
- Author
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Feng, Lin, Qu, Mengru, Ng, Adolf K.Y., Jia, Peng, and Kuang, Haibo
- Subjects
- *
ELECTRIC vehicle batteries , *INFORMATION sharing , *ELECTRIC vehicle industry , *ELECTRIC vehicles , *RIDESHARING - Abstract
As the battery recycling market in China is still in an embroynic stage, the mechanisms, channels, pricing, and efficiency of battery recycling are shrouded in opacity. Battery recycling in China is currently dominated by electric vehicle manufacturer, supplemented by other market players such as battery producers and electric vehicle retailers. Due to the lack of information, battery recycling lacks cooperation and communication, and the whole market is dealing with "Information Island." Therefore, based on information sharing and channel competition, this paper designs a Stackelberg game model with an electric vehicle manufacturer, an electric vehicle retailer, and a third-party recycler as the primary participants. This study found that effective information sharing can reduce intensified market competition and promote the transformation of market players into "collaboration state". To promote partnership in the battery recycling market, this paper proposes a revenue-sharing contract incentive for the electric vehicle retailer to share demand information about battery recycling. It finds a revenue-sharing contract based on information sharing can help companies and competitors make appropriate behavioral choices in the battery recycling market. This study demonstrates that information sharing benefits the electric vehicle manufacturer and the third-party recycler while offering no advantages to the electric vehicle retailer. The decreasing accuracy of demand signals results in the diminishing value of information sharing for the electric vehicle manufacturer and the third-party recycler. The revenue-sharing contract can incentivize the electric vehicle retailer to share information. [Display omitted] • A battery recycling mode of electric vehicles is constructed. • Effective information sharing would encourage market players to be more collaborative. • A revenue-sharing contract is designed to incentivize the electric vehicle retailer to share information. • Inaccurate information and channel competition reduce the attractiveness of information sharing. • Inter-firm information sharing is beneficial for building an efficient battery recycling system. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Machine learning for power outage prediction during hurricanes: An extensive review.
- Author
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Fatima, Kehkashan, Shareef, Hussain, Costa, Flavio Bezerra, Bajwa, Abdullah Akram, and Wong, Ling Ai
- Subjects
- *
HURRICANE forecasting , *HURRICANE damage , *RESEARCH personnel , *HURRICANES , *MACHINE learning - Abstract
The surge of machine learning (ML) applications and increasing usage of data driven approach for resilience enhancement provide great opportunities for applying ML techniques to power outage prediction (POP) during hurricanes. Considering the substantial damage that wind hazards can cause to power system network (PSN) in countries such as the USA and China, researchers have devised numerous approaches for disaster prevention to reduce their susceptibility. Since the selection of optimal ML algorithms for POP during hurricanes is a complex task, this paper helps researchers easily comprehend the numerous prediction techniques used worldwide for power outages during hurricanes. The paper provides a brief review of several categories of hurricanes and the damage it causes to the PSN more specifically to distribution side, the necessary measures to improve the PSN resilience, and finally a sequential approach for optimal ML model selection techniques that researchers and engineers can use to improve the POP during hurricanes. In this study the effectiveness of ML algorithms has been explored with the help of performance evaluation metrics which serve as the basic deciding criteria for optimal model selection. This research also highlights some of the key issues and challenges of integrating machine learning algorithms with existing PSN. • Reviewed various ML algorithms used for distribution system POP during hurricanes. • Effects of damage experienced by power system networks during hurricanes are widely investigated. • Provides an insight into the measures for improving power system resilience against hurricanes. • Provides a stepwise approach for using various ML algorithms in the context of POP. • Identification of key issues, challenges, and discussion of possible future research directions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Machine learning for power outage prediction during hurricanes: An extensive review.
- Author
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Fatima, Kehkashan, Shareef, Hussain, Costa, Flavio Bezerra, Bajwa, Abdullah Akram, and Wong, Ling Ai
- Subjects
- *
HURRICANE forecasting , *HURRICANE damage , *RESEARCH personnel , *HURRICANES , *MACHINE learning - Abstract
The surge of machine learning (ML) applications and increasing usage of data driven approach for resilience enhancement provide great opportunities for applying ML techniques to power outage prediction (POP) during hurricanes. Considering the substantial damage that wind hazards can cause to power system network (PSN) in countries such as the USA and China, researchers have devised numerous approaches for disaster prevention to reduce their susceptibility. Since the selection of optimal ML algorithms for POP during hurricanes is a complex task, this paper helps researchers easily comprehend the numerous prediction techniques used worldwide for power outages during hurricanes. The paper provides a brief review of several categories of hurricanes and the damage it causes to the PSN more specifically to distribution side, the necessary measures to improve the PSN resilience, and finally a sequential approach for optimal ML model selection techniques that researchers and engineers can use to improve the POP during hurricanes. In this study the effectiveness of ML algorithms has been explored with the help of performance evaluation metrics which serve as the basic deciding criteria for optimal model selection. This research also highlights some of the key issues and challenges of integrating machine learning algorithms with existing PSN. • Reviewed various ML algorithms used for distribution system POP during hurricanes. • Effects of damage experienced by power system networks during hurricanes are widely investigated. • Provides an insight into the measures for improving power system resilience against hurricanes. • Provides a stepwise approach for using various ML algorithms in the context of POP. • Identification of key issues, challenges, and discussion of possible future research directions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Maintaining ecological connectivity in highly urbanized areas: Optimal strategy, key patches and protection policy.
- Author
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Wang, Xiuming, Wen, Ding, Liu, Piao, Wei, Chentao, Zhao, Peng, and Xu, Naizhong
- Subjects
- *
LANDSCAPE ecology , *METROPOLITAN areas , *CORRIDORS (Ecology) , *LAND use ,REPRODUCTIVE isolation - Abstract
• A practical and feasible protection strategy for EC maintaining in highly urbanized areas was proposed. • Key patches for EC maintaining were identified by using stepping stone and complex network theories. • The protection rate for key patches by the new policies were assessed. Maintaining and restoring ecological connectivity (EC) are important measures of mitigating habitat isolation caused by urbanization. Considering the prominent contradiction of land use in highly urbanized areas, the EC protection measures proposed in the previous studies, such as expanding the ecological sources and widening the ecological corridors, are unrealistic. By using the stepping-stone and complex network theories, this paper simulated the ecological network (EN), evaluated the centrality of each ecological source and stepping-stone, and analysed the network robustness under different damage scenarios, then identified the optimal strategy and key patches for EC maintaining. Meanwhile, this paper evaluated whether the key patches are protected by China's new policies, which are, Ecological Protection Red Line (EPRL) and the Three Lines One Permit (TLOP). The results were as follows: (1) The EN is composed of 53 ecological sources and 291 stepping-stones, with 591 links between them. (2) The network stability can be optimally maintained by prioritizing the protection of stepping-stones with high centrality. (3) The 53 ecological sources and 51 stepping-stones with the highest centrality can ensure the stable operation of the EN, that is, they are key patches for EC maintaining. (4) Compared with EPRL, the protection rate for ecological sources and stepping-stones are significantly improved by TLOP; however, stepping-stones with high centrality require stronger protection. This study enriched the research cases of complex network theory applied in landscape ecology, and provided references for the improvement of policies in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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36. County zoning and optimization paths for trade-offs and synergies of ecosystem services in Northeast China.
- Author
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Wang, Shihao, Shi, Huading, Xu, Xinliang, Huang, Lin, Gu, Qingbao, and Liu, Hanbing
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ECOSYSTEM services , *ENVIRONMENTAL security , *RESTORATION ecology , *LAND degradation , *BLACK cotton soil , *GRAIN - Abstract
• Ecosystem services are quantified at large scales and long time series in NE China. • The trade-offs and synergies among ecosystem services are characterized. • Human activities are the dominant driving factors of provisioning services. • Synergistic optimization paths of production-ecological functions are proposed. In Northeast (NE) China, the largest commodity grain base and natural forest area in China, both agricultural production and ecological protection require attention. In recent years, land degradation in NE China has increased, seriously affecting the production-ecology synergy. In this paper, four key ecosystem services (ESs) in NE China are quantified: provisioning, water conservation (WC), soil conservation (SC) and sand fixation (SF), and the spatiotemporal evolution characteristics and trade-offs and synergies (T&S) of ESs are analyzed. The driving factors of provisioning services and the characteristics of T&S are considered, and the county zoning scheme and the corresponding production-ecological function synergistic optimization paths are proposed. The results show that (1) the provisioning, WC and SF services in NE China have slightly increased in the past 20 years, and the provisioning in the Greater-Khingan-Mountains-Region (GKMR) and Lesser-Khingan-Mountains-Region (LKMR), the WC in the LKMR, and the SF in the Liao-River-Plain (LRP) have more obviously increased. The SC service has slightly decreased, especially in the Changbai-Mountains-Region (CBMR). (2) The provisioning service in NE China mainly shows a synergistic relationship with WC and SF, accounting for 79.1 % and 62.9 % of the area, respectively, and a trade-off relationship with SC, accounting for 52.54 % of the area. (3) Human activities (HA) are the dominant driving factor of the provisioning service change in NE China, with an impact degree of 62.65 %. The LKMR is an exception, as climate change (CC) dominates. The LRP, Songnen-Plain (SNP) and GKMR have high degrees of HA. (4) The number of synergistic optimized (SO), light optimized (LO) and trade-off limited (TL) counties accounted for 19.0 %, 61.7 % and 19.3 %, respectively. Among them, the SO type counties should prioritize improving provision and grain production capacity, the LO type counties should protect basic farmland and decrease trade-offs between ESs, and the TL type counties should improve ecological functions and strengthen ecological protection and restoration. This paper clarifies the main contradictions of ESs in NE China and provides an important scientific basis for ecological protection and restoration, which is important for ensuring food and ecological security and realizing the ecological and efficient sustainable utilization of black soil. [ABSTRACT FROM AUTHOR]
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- 2024
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37. Efficient agricultural water research under elevated global carbon dioxide concentration – Based on bibliometric analysis.
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Bai, Jiaming, Li, Rui, Jiang, Yu, Zhang, Jiarui, Li, Dayong, Cai, Zelin, and Zhang, Zhi
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BIBLIOMETRICS , *ATMOSPHERIC carbon dioxide , *CARBON dioxide , *GREENHOUSE gases , *AGRICULTURAL research - Abstract
Freshwater resources are scarce globally, and the increase in carbon dioxide (CO 2) concentration leads to both a decrease in soil moisture and arid climate, further limiting agricultural production. Therefore, it is critical to achieve water efficiency in agriculture under elevated CO 2 concentration. A comprehensive analysis was conducted on the research topic of efficient agricultural water under elevated CO 2 concentration using bibliometric methods. The results show that the number of papers on this research has changed from an accumulation phase (1992–2005, 395) to a growth phase (2006–2023, 963). "Carbon dioxide", "water-stress", "growth", "photosynthesis", "yield", and other keywords have been the focus of past research in this area. Kimball BA and Ainsworth EA are the most influential authors in this area. Leakey's (2009) paper in "Experimental Botany" was the most contributing study, summarizing six lessons about the effects of CO 2 enrichment on the relationship among carbon, nitrogen, and water in plants. The United States and China were the most influential countries. Over time, research has shifted from an early focus on atmospheric CO 2 change itself to the response of crops to elevated CO 2 in agricultural production. The efficient crop production strategy under the interaction of environmental factors is becoming a hot spot for future research, and the emission and use of greenhouse gases, the improvement of crop quality, and the efficient guidance of models are also worth exploring. Overall, this study presents a quantitative analysis and comprehensive review of past research conducted on the effect of water and fertilizer on agricultural production under CO 2 enrichment. It also offers suggestions and expectations for future research on the hot spot direction of efficient crop production under climate change. • The continuous research attention is closely related to climate change caused by CO 2 enrichment. • The main research fields included CO 2 enrichment, water stress, crop growth and photosynthesis. • The co-citation analysis reveals broad research clusters in the literature. • The new research focus will be interactive climatic factors, greenhouse gas recycling, and modeling. [ABSTRACT FROM AUTHOR]
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- 2024
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38. Firm's position in global value chains and its impact on pollutant emissions: Evidence from Chinese manufacturing firms.
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Lu, Yue, Yan, Fei, Xue, Jinjun, Zhang, Haotian, and Sun, Qian
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- *
VALUE chains , *GLOBAL value chains , *ENVIRONMENTAL protection , *POLLUTANTS , *SUPPLY chain disruptions , *FACTOR structure , *FACTORS of production - Abstract
This paper studies examines how a firm's position in the global value chain affects its pollutant emissions. This paper integrates China's firm-level trade data into China's multi-regional input-output tables to provide an index to measure a firm's position in global value chains. Based on a firm-level pollution dataset (2000–2014) in China, this paper conducts an empirical analysis and find that the most-downstream firms on the global value chain have lower pollutant emission intensity. Our results also suggest that the production factor structure effect, the knowledge absorption effect and the abatement investment effect together contribute to the emission intensity gap between the most-upstream firms and the most-downstream firms. These novel results are significant in guiding firms towards reducing their emissions and promoting a green global value chain, with the ultimate goal of achieving multinational environmental protection. [Display omitted] • The most-downstream firms have lower pollutant emission intensity. • A supply chain disruption shock is used as an instrumental variable. • Factor structure, knowledge absorption and abatement investment are channels. • Effects on firms with diverse ownership and trade patterns are heterogeneous. [ABSTRACT FROM AUTHOR]
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- 2024
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39. Does oil future increase the network systemic risk of financial institutions in China?
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Chen, Chuanglian, Zhou, Lichao, Sun, Chuanwang, and Lin, Yuting
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ENERGY futures , *SYSTEMIC risk (Finance) , *FINANCIAL risk , *FINANCIAL institutions , *FOREIGN exchange market - Abstract
The fluctuation of oil futures price greatly influences the market investment sentiment, which can cause credit risk and capital pressure risk of various financial institutions, and ultimately affect the idiosyncratic risk and systemic risk of financial institutions. This paper adopts MES to measure the systemic risk of Chinese financial institutions and proposes a high-dimensional time-varying parameter spillover network matrix to identify the infection route and source of systemic risk. Finally, the paper investigates the mechanism by that oil futures affect the contagion effect of systemic risk across institutions. The results show that banking financial institutions are the main exporters of risk while insurance is the main absorber, and after the outbreak of COVID-19, the risk contagion capacity of institutions generally increased, the network structure became more complex, and the risk spillover level was pro-cyclical. The empirical results show that the rise of oil futures will promote the (net) risk spillover capacity of institutions and inhibit the risk absorption capacity, and the above process can be transmitted through the stock market, bond market, and foreign exchange market. • Banking institutions are transmitters of risk, while insurance are receivers; • Financial institutions' risk contagion network becomes more complex after COVID-19; • The systemic risk spillover level of Chinese financial institutions has obvious pro-cyclical; • Higher oil futures price promotes the (net) risk spillover capacity of institutions and inhibit the risk absorption capacity; • The above impacts involve three possible transmission mechanisms: the stock market, bond market and foreign exchange market; [ABSTRACT FROM AUTHOR]
- Published
- 2024
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40. Decarbonizing prefabricated building waste: Scenario simulation of policies in China.
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Zhao, Wenbo, Hao, Jian Li, Gong, Guobin, Ma, Wenting, Zuo, Jian, and Di Sarno, Luigi
- Subjects
- *
CONSTRUCTION & demolition debris , *CARBON dioxide mitigation , *CARBON emissions , *CONCRETE waste , *GREENHOUSE gas mitigation , *CARBON offsetting - Abstract
Compared to cast-in-situ construction, prefabricated construction reduces the generation of construction waste; however, construction waste cannot be entirely eliminated through prefabrication and can be generated at each stage of its life cycle. This paper generates a system dynamics model, comprising two causal-loop diagrams and one stock-flow diagram, to simulate the effectiveness of policies on decarbonizing prefabricated concrete building waste. The model can predict the annual and total construction waste, along with the associated carbon emissions, under different policy scenarios in China by 2030. This paper focuses on prefabricated concrete buildings in China, with specific attention to the wastage of concrete, bricks, mortar, and metal. In single-factor scenario simulations, increasing landfilling fee is the most effective policy for waste decarbonization, potentially reducing carbon emissions by 31%. Increasing prefabrication rate and enhancing regulation degree at the design phase of prefabrication can directly reduce prefabricated building waste generation, subsequently resulting in an 18% and 7% carbon emissions reduction. Multi-factor scenario simulations demonstrate that the simultaneous application of all four policies is most effective, achieving a 44% reduction in carbon emissions. This research establishes a theoretical framework for prefabricated concrete building waste management and provides the Chinese government with practical insights on optimizing policies for waste decarbonization in the dynamic landscape of prefabrication. • This paper develops the prefabricated building waste generation and disposal systems. • The model predicts the construction waste and associated carbon emissions by 2030. • Raising landfill fee is an effective policy for decarbonizing construction waste by 31.06%. • Prefabrication rate reaching 100% can reduce 18.04% of carbon emissions from waste. • Applying all policies is most effective, achieving a 44.34% carbon emissions reduction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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41. Technical transformation of heavy/ultra-heavy oil production in China driven by low carbon goals: A review.
- Author
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Xiong, Ruiying, Guo, Jixiang, Kiyingi, Wyclif, Gao, Chenhao, Wang, Li, Luo, Junjie, Song, Hanxuan, and Wang, Xiwen
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- *
HEAVY oil , *PETROLEUM , *SUSTAINABILITY , *ENVIRONMENTAL economics , *EXTRACTION techniques , *ENVIRONMENTAL protection , *CARBON offsetting - Abstract
With the growing global energy demand and limited production of conventional crude oil, the extraction of unconventional heavy and extra-heavy oil is receiving unprecedented attention. China is the fourth largest producer of heavy oil. High viscosity and complex formation environments increase the difficulty of exploiting heavy oil. To alleviate the economic cost and environmental pollution pressure brought by heavy oil production, China has achieved significant advancement in the innovation of heavy oil recovery, including accelerating the transformation of thermal technology to non-thermal technology and the use of new energy technology to achieve the goal of low-carbon economy and green environmental protection. Based on the background of heavy oil in China, this paper recharacterizes the high-viscosity mechanism of heavy oil. From different aspects, including basic principles, main characteristics, applicability, limitations, and challenges, this paper comprehensively reviews existing heavy oil recovery technologies, including thermal recovery, in-situ upgrading, cold recovery, and new energy technologies. Currently, in China, the main target of heavy oil recovery is achieving the "carbon peaking and carbon neutrality" goals, which can be described as low energy consumption, low emission, and low pollution. To facilitate the low-carbon transition in the extraction of heavy/extra-heavy oil and attain environmental sustainability goals, it is essential to increase the proportion of non-thermal factors in thermal recovery technologies, develop efficient in-situ catalysts, adopt clean cold extraction techniques, and advance the development of new energy technologies. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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42. Green finance and food production: Evidence from cities in China.
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Lee, Chien-Chiang and Song, Ting
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CITIES & towns , *FOOD production , *SUSTAINABLE development , *ENVIRONMENTAL policy , *ECONOMIC expansion - Abstract
In the domain of global socio-economic dynamics, the pivotal role of food production (FP) cannot be overstated. It constitutes the bedrock of fundamental human necessities while being inexorably linked with critical aspects such as economic expansion, societal equilibrium, and geopolitical interplays. The multifaceted nature of FP appears through its direct impact on macroeconomic indicators and its latent influence on international relations and policy-making. This critical nexus underscores the imperative for a comprehensive understanding and strategic management of food production processes to sustain and enhance global socio-economic stability and growth. Investigating the nexus between green finance (GF) and FP is pivotal for ensuring national security and promoting sustainable economic development. This research thus paper examines GF's impact on FP in China as outlined in the 2017 green finance policies. It employs the difference-in-differences (DID) method and analyzes a balanced panel dataset comprising 282 cities in China from 2009 to 2020. The results show that GF has an inhibitory effect on FP, and this remains valid after a range of reliability checks, including parallel trend assessments and placebo tests. Further findings of transmission mechanism analysis indicate that non-agricultural factors and financial exclusion are critical for GF's inhibitory effect on FP. Heterogeneity analyses show that GF's inhibitory effect on FP is more pronounced in the main food-producing areas, the main food-marketing areas, and cities with better infrastructure. The empirical results of this paper comprehensively illustrate GF's impact on FP and how it contributes to the achievement of food security objectives. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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43. A novel evaluation method for renewable energy development based on improved sparrow search algorithm and projection pursuit model.
- Author
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Leng, Ya-Jun, Zhang, Huan, and Li, Xiao-Shuang
- Subjects
- *
ENERGY development , *RENEWABLE energy sources , *SEARCH algorithms , *EVALUATION methodology , *CARBON emissions - Abstract
With global climate change posing a major threat to human society, a growing number of countries have taken "carbon-neutral" as a national strategy and proposed a vision of carbon-free future. As an important supplement to traditional fossil energy, renewable energy is the main force to reduce the use of high-carbon energy and carbon dioxide emissions, which will become the trend of social development in the future. Finding the optimal renewable energy source is of particular significance for achieving the net zero emissions. However, the existing evaluation methods of renewable energy sources have obvious shortcomings. In terms of weight calculation methods, such as the randomness of the subjective method is strong and the index weights do not reflect the small changes of the evaluation matrix, which affect the reliability and accuracy of the evaluation result. The existing ranking methods can only achieve the complete ranking of the different objects, but cannot classify the renewable energy technical alternatives into different grades. Given this background, this paper proposes a novel evaluation method for renewable energy plans based on improved sparrow search algorithm and projection pursuit model. Firstly, this paper improves the traditional sparrow search algorithm from three aspects: population initialization, population update and population variation. Then, the projection pursuit model is constructed, and the improved sparrow search algorithm is applied to optimize the projection target to find the optimal projection direction, so as to determine the weight values of each evaluation index. Finally, the weighted rank-sum ratio method is used to select the best renewable energy technical plan, which can not only realize the complete ranking of different plans, but also classify the technical plans into different levels. Based on the actual renewable energy development data from a province in China, experiments were carried out to investigate the effectiveness of the proposed method. Experimental results show that the proposed method performs better than some existing evaluation methods of renewable energy technical plans. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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44. Formulation and heuristic method for urban cold-chain logistics systems with path flexibility – The case of China.
- Author
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Leng, Longlong, Wang, Zheng, Zhao, Yanwei, and Zuo, Qiang
- Subjects
- *
HEURISTIC , *PERISHABLE goods , *EVOLUTIONARY algorithms , *CUSTOMER satisfaction , *AUTOMOTIVE fuel consumption , *CARBON emissions ,TRUCK fuel consumption - Abstract
The focus of this paper is on achieving a win-win situation regarding the economic, environmental, and social impacts of the cold chain logistics terminal distribution system. This paper proposes three multi-objective models to investigate the above effects by incorporating soft time windows, heterogeneous fleets, and path flexibility, with defining the objectives of examining logistics costs, fuel consumption, carbon emissions, quality damage to perishable commodities, and customer satisfaction using six evaluation functions. To solve the proposed models, an efficient optimization framework is developed by combining domain operators with versatile multi-objective evolutionary algorithms (MOEA) to obtain Pareto solutions. Extensive experiments are conducted to test the validity of the concerned model and algorithms. The results demonstrate that: (1) the proposed algorithm is effective in solving the proposed model; (2) the proposed multi-path strategy can effectively improve the performance of cold-chain logistics systems compared to single-path strategies; (3) evaluation functions that assess customer satisfaction greatly affect the performance of cold-chain logistics systems; and (4) the trade-off relationship between the objectives should be investigated to define the model. The paper also provides valuable managerial insights for improving the efficiency and sustainability of cold-chain logistics operations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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45. SWAP 50 years: Advances in modelling soil-water-atmosphere-plant interactions.
- Author
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Heinen, Marius, Mulder, Martin, van Dam, Jos, Bartholomeus, Ruud, de Jong van Lier, Quirijn, de Wit, Janine, de Wit, Allard, and Hack - ten Broeke, Mirjam
- Subjects
- *
CROP development , *WATER in agriculture , *CROP growth , *OXYGEN in water , *SUBIRRIGATION - Abstract
This paper highlights the evolution and impact of the SWAP model (Soil – Water – Atmosphere – Plant), which was initiated by R.A. Feddes and colleagues fifty years ago, in 1974. Since then, the SWAP model has played a crucial role in the advancement of agrohydrology. This paper highlights some major advances that have been made, especially focussing on the last fifteen years. The domain of the SWAP model deals with the simulation of the soil water balance in both unsaturated and saturated conditions. The model solves the Richards equation using the water retention and hydraulic conductivity functions as described by the Van Genuchten – Mualem equations. Bimodal extensions of the Van Genuchten - Mualem relationships have been implemented, as well as modifications near saturation and addressing hysteresis. An important sink term in the Richards equation is root water uptake. Crop development plays an important role in a robust simulation of root water uptake. That is why a link has been made with the dynamic crop growth model WOFOST. Instead of using a prescribed crop development, a distinction between potential and actual crop development is calculated by reducing the potential photosynthesis as a result of water or oxygen stress. Since the early days of SWAP, empirical and macroscopic concepts have been used to simulate root water uptake. Recently two process-based concepts of root water uptake and oxygen stress have also been implemented. Another important sink-source term in the Richards equation is the interaction with artificial drains. In SWAP, drainage can be simulated by either using prescribed or simulated drain heads and simulation of controlled drainage with subirrigation is possible. Finally, we briefly elaborate on three studies using SWAP: water stresses in agriculture in the Netherlands, regional water productivity in China, and controlled drainage with subirrigation. We finish discussing promising developments for the near future. • Advances in soil-vegetation-atmosphere transfer modelling in the SWAP model. • Coupling of soil water dynamics with dynamic crop growth model. • Process-based root water uptake and oxygen uptake functions. • Climate-adaptive drainage with subirrigation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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46. Preschool and child health: Evidence from China's universal child care reform.
- Author
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Ren, Meiqing
- Subjects
- *
SERVICES for caregivers , *PRESCHOOL children , *CHILD care , *CHILDREN'S health , *EARLY childhood education , *PRESCHOOL education , *EDUCATIONAL change - Abstract
Early childhood education programs have been found to effectively promote children's social and cognitive development. However, the health impact of these programs is less understood. Using a quasi-experiment of the first universal child care reform in China from 2010, this paper aims to identify whether the preschool reform produces any short-term effects on health-related outcomes of preschoolers (3-6 years old). Specifically, this reform expands access to affordable preschools that provide full-day center-based education, with school meals and essential health services on campus. I exploit the variation in the number of newly established preschools across provinces and implement difference-in-differences and triple-difference strategies. Results confirm the effectiveness of this reform by showing a strong and positive impact on preschool attendance. This paper then documents the benefits to alleviating underweight among preschoolers. Estimates show a larger effect in rural areas, suggesting that the reform narrows rural-urban disparities in education access and undernutrition prevention. I also explore the impact on caregivers' health consciousness and find improved health-seeking behavior when children get sick. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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47. Concavity-convexity of distribution system security region. Part II: Mathematical principle, judgment, and application.
- Author
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Jiao, Heng, Xiao, Jun, Zu, Guoqiang, Song, Chenhui, Lv, Zihan, Bao, Zhenyu, and Qiu, Zekai
- Subjects
- *
SECURITY systems , *TOPOLOGICAL property , *MATHEMATICAL models - Abstract
This paper is the second in a two-part series on the concavity-convexity of the distribution system security region (DSSR). In Part I, the concave-convex characteristics and mechanism of DSSR are revealed by observing many case grids. In Part II (this paper), the concave-convex principle of DSSR is revealed through mathematical deduction. Firstly, the relevant concepts of sub-regions are proposed, and a DSSR model based on the union of sub-regions is developed. Secondly, the concave-convex principle of DSSR is proposed. The proposed criteria show that the security region of a distribution system with a single load transfer path for each feeder is convex, while that with multiple load transfer paths for some feeders can be concave or convex. Thirdly, the proposed criteria are deduced mathematically. Fourthly, based on the criteria, a method is proposed to judge whether a DSSR is concave or convex. Fifthly, the proposed criteria and method are verified through several cases, and the DSSR concavity-convexity of real distribution systems in China is also analyzed. Finally, the applications of DSSR concavity-convexity are illustrated. This work lays a mathematical foundation for the research of the topological properties of DSSR and is also useful for the application of DSSR. • The DSSR mathematical model based on the union of sub-regions is developed. • Three criteria are proposed and proved, revealing the concave-convex principle of DSSR. • A judgment method for DSSR concavity-convexity is proposed based on these criteria. • The DSSR concavity-convexity of real distribution systems in China is analyzed. • The application values of DSSR concavity-convexity are demonstrated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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48. Numerical modeling of the mineralizing processes within the Shaxi porphyry-type Cu-Au deposit, Eastern China: Influence and restriction from physical and chemical characteristics of host rocks.
- Author
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Gao, Lixiang, Li, Xiaohui, Yuan, Feng, Wang, Shiwei, Ord, Alison, Zhang, Rulin, Hu, Xunyu, and Li, Yue
- Subjects
- *
ORE deposits , *METALLOGENY , *ROCK permeability , *ROCK properties , *PROSPECTING , *FINITE element method , *FLUID flow - Abstract
Here we present our workflow, numerical models and results of the spatial distribution of chalcopyrite mineralization under the different porosity and permeability conditions of the host rocks of the Shaxi deposit. During the numerical modeling research, we tried to coupling heat transfer, fluid flow, material migration, mineralization reaction, and their coupling with porosity and permeability of rock. The results show that the porosity and permeability of the host rocks play a significant role in the mineralization of porphyry-type systems. The chemical properties of the strata restrict significantly on mineralization intensity and spatial extent rather than affecting the depth of mineralization. This paper also indicates that the numerical modeling method employed in this study can be used to predict the mineralization depth and spatial location of deep concealed porphyry-type deposits, aiding research in deep-seated mineral exploration. [Display omitted] • The porosity and permeability of the host rocks play a significant role in the mineralization of Shaxi porphyry-type deposit. • The chemical properties of the strata restrict significantly on mineralization intensity and spatial extent rather than affecting the depth of mineralization. • The numerical modeling may be used to predict the mineralization depth and spatial location of deep concealed porphyry-type deposits. The Shaxi porphyry-type Cu-Au deposit is located in the northwestern outer margin of the Luzong volcanic basin, which is situated in the Middle-Lower Yangtze River Metallogenic Belt (MLYRMB), Eastern China. It is a large porphyry-type Cu-Au deposit with confirmed copper resources exceeding 1 Mt and gold resources exceeding 40 tons. Previous studies have extensively investigated the genesis, controlling structures, geochemical characteristics, fluid evolution, alteration zone, and ages of mineralization and host rocks in this deposit. However, research on the influence of the physical and chemical properties of the host rocks on the mineralizing processes has not been explored in detail. This study employs the finite element method to apply numerical modeling of multiple physical and chemical fields, interlinking heat transfer, fluid flow, material migration, mineralization reaction, and their coupling with porosity and permeability of rock, to investigation of the influence of different porosities, permeabilities, and chemical properties of the host rocks on the mineralizing processes in the Shaxi deposit. The results show that the porosity and permeability of the host rocks play a significant role in the mineralization of porphyry-type systems. The different porosity and permeability of the intrusions and strata control the depth, the mineralization intensity, the morphology of the ore bodies, and the spatial location of the mineralization center. The chemical properties of the strata significantly restrict the mineralization intensity and horizontal spatial rather than affecting the depth of mineralization. Furthermore, the formation of skarn-type deposits may require a longer period of time than that of porphyry-type deposits under the same mineralization conditions and ore grade. This paper also indicates that the numerical modeling method employed in this study can be used to predict the mineralization depth and spatial location of deep concealed porphyry-type deposits, aiding research in deep-seated mineral exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Nonlinear impact of unconventional water use on water resource sustainability in China: A perspective on water poverty.
- Author
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Wang, Ruifang, Wu, Fengping, Ji, Yingwen, and Feng, Chen
- Subjects
- *
WATER use , *WATER supply , *SUSTAINABILITY , *EVIDENCE gaps , *WATER management - Abstract
• Most of China still faces notable water poverty with obvious spatial variations. • Unconventional water use does not always have a positive impact on water poverty. • The impact shows an inverted U-shaped tendency as per capita GDP increases. • Sustainable water management plans should be tailored to local economy. Unconventional water serves as a bridge to water sustainability. However, many developing nations still have a long way to go in terms of unconventional water utilization. Different regional characteristics lead to different consumption capacities for unconventional water. Consequently, more unconventional water use (UWU) may not necessarily be positive for alleviating water poverty. However, there is a significant research gap in this field. This paper aims to answer three key questions: "Whether UWU consistently alleviates water poverty?" "Is this effect spatially heterogeneous?" and "What role do economic factors play in addressing water poverty?" For that, this paper focused on 30 provinces in China, with the sample period spanning from 2006 to 2021. To identify the mechanisms through which UWU alleviates water poverty, this paper employed a panel fixed-effects model using the Water Poverty Index (WPI) as the dependent variable and the square of UWU amount as an independent variable. The results indicate a non-linear impact of UWU on WPI, with the significance of impact influenced by GDP per capita (PGDP). Furthermore, threshold regressions were conducted with PGDP as the threshold variable. The results revealed a double-threshold effect of PGDP in the impact of UWU on WPI, displaying "U" or inverted "U" shape as PGDP develops: When PGDP is less than or equal to RMB 13,574, UWU demonstrates a negative effect on WPI; when PGDP ranges from RMB 13,574 to RMB 53,653, the effect turns positive; however, when PGDP exceeds RMB 53,653, the effect turns back to negative. The findings confirm that more UWU is not always better. Sustainable utilization plans of water resources must be tailored to local conditions, especially considering the unique characteristics of the regional economy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Spatiotemporal evolution and drivers of carbon inequalities in urban agglomeration: An MLD-IDA inequality indicator decomposition.
- Author
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Yu, Bolin, Xu, Zhenci, Du, Congcong, Xu, Jinghang, Pan, Yuling, Zhou, Junfang, and Shan, Yuli
- Subjects
- *
EMISSIONS (Air pollution) , *CARBON emissions , *CITIES & towns , *CARBON offsetting , *ECONOMIC structure , *SPACE - Abstract
[Display omitted] • Measure carbon emission inequalities (CEIs) of urban agglomerations under rapid urbanization. • Identify the key factors determining CEIs within the three urban agglomerations. • Account for the differences between adjacent or distant urban agglomerations. • The declining CEI is mainly due to changes in industrial structure and economic development. • CEI in the upper reaches of the YREB increases due to the changes in energy intensity. Increasing countries are articulating ambitious goals of carbon neutrality. However, large inequalities in regional emissions within a country may hinder progress toward a carbon–neutral future, as the unequal distribution of reduction responsibilities among regions could impair just transition and exacerbate uneven development, which necessitates an in-depth understanding of the mechanism of multi-scale carbon inequalities within country, region, and city. Yet, the evolution of carbon inequalities within urban agglomerations and the differences between adjacent or distant urban agglomerations have not been well understood, especially in countries undergoing rapid urbanization. Using the data of 89 cities in China's Yangtze River Economic Belt (YREB) during 2006–2021, this paper quantifies carbon emissions inequality (CEI) at different scales in a systematic regional-urban agglomeration-city hierarchical structure. Then, under the integrated mean logarithmic deviation-logarithmic mean Divisia index (MLD-LMDI) decomposition framework, multi-scale CEIs are perfectly decomposed into six interrelated drivers, i.e., industrial emission structure, energy emission intensity, industrial energy mix, energy intensity, industrial structure, and economic development. The results show that economic development, energy intensity, and industrial energy mix disparities are the main determinants accounting for CEIs at different scales. The decreasing CEI in YREB is mainly due to the changes in industrial structure and economic development, while the energy intensity effect partially hinders the mitigation of CEI. In the upper reaches of the YREB, the energy intensity effect accounts for over 94% growth of CEI during 2006–2021, while the decline in CEIs in middle and lower reaches is primarily caused by the effects of industrial energy mix and industrial structure, respectively. Further spatial decomposition analysis reveals more refined city-level heterogeneous effects and emphasizes the prioritized emission reduction direction for each city. This paper offers implications for reducing carbon inequality and insights into coordinated carbon emissions mitigation at the regional level for a carbon–neutral future. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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