Search

The Longmaxi Formation in the Sichuan Basin is a hotspot formation for shale gas exploration. In this paper, taking the Longmaxi Formation shale in Yuxi area as an example, a large number of TOC tests, X-diffraction whole-rock mineral fraction tests, electron microscope observations, physical properties, gas content, and CT scanning experiments were carried out, which in turn analyzed the characteristics of the shale gas reservoir and the factors influencing the gas content. The results of the study show that there are seven types of shale facies developed in Yuxi area, which are organic-rich siliceous shale facies (I), organic-rich carbonate-siliceous shale facies (II), organic-rich clayey shale facies (III), organic-poor clayey shale facies (IV), organic-poor carbonate-siliceous shale facies (V), organic-poor siliceous shale facies (VI), and organic-poor siliceous-carbonate shale facies (VII). The microstructural characteristics of the shale reflect that it was disturbed by multiple environmental factors at the time of deposition, and the sources of brittle minerals include both terrestrial clasts and biogenic siliciclastics. The bottom 30 m shale of Longmaxi Formation has good physical properties and gas content, which is a high-quality target section for shale gas exploration and development. TOC, Ro, permeability, quartz content and clay mineral content all have a significant effect on shale gas content and are important control factors for shale gas content. [ABSTRACT FROM AUTHOR]

[Objective] In recent years, high-yield gas wells, such as those in eastern Sichuan, Tarim Oilfield, and Dongfang Gas in the South China Sea, have been increasingly common. However, these wells are not without their challenges. The production pipe string of Sangao gas wells is prone to vibration failure due to the impact of high-speed gas. Taking the Kuqa high-pressure gas area of the Tarim Oilfield as an example, 19 failure incidents have been recorded out of 15 wells, resulting in huge economic property losses and, regrettably, casualties. The primary cause of these failures has been identified as the excessive dynamic load caused by pipe string vibration. Therefore, understanding the vibration characteristics of the production pipe string has become a crucial study area. The production string in oil and gas wells possesses its unique characteristics. Its large slenderness ratio results in a very low overall stiffness, which is difficult to simulate in a typical small experimental system. [Methods] In this study, we established a test bench for large production string evaluation. We developed an extensive, elongated string model using Polyethylene pipe to replicate the vibration characteristics of the production string under high-speed fluid impact. [Results] The experimental results show that the production string in Sangao gas wells vibrates at a constant frequency under the influence of a high-speed fluid. The vibration amplitude is most pronounced in the middle and bottom parts of the string. It was also observed that an increase in gas yield correlates with an increase in the severity of the pipe column's vibration. An effective method of curtailing this vibration amplitude involves increasing the wall thickness of the tubing. However, it is important to note that while this may reduce the tubing amplitude, it does not change the vibration frequency of the tubing string. The packer installation position also plays a pivotal role in vibration suppression. If the packer is installed too high or too low, it fails to effectively suppress vibration. The optimal placement for a single packer has been found to be at the 8/10 position of the string, where it can efficiently suppress vibration. This paper further delves into the analysis of displacement, frequency, and vibration characteristics of simulated tubing when subjected to a high-speed fluid within the tubes. [Conclusions] This study further explores the effects of pipe wall thickness, gas yield, and packer setting positions on the vibration characteristics of simulated tubing. The following conclusions were drawn from the research. When the fluid Reynolds number within the tube reaches 21 430, the simulated tubing presents a second-order vibration mode. This results in a substantial amplitude in the middle and bottom sections of the simulated tubing, which are prone to contact and collision with the casing wall, potentially resulting in pipe string failure. The wall thickness of the tubing exerts little effect on the vibration frequency of the simulated tubing. However, it significantly affects the vibration amplitude. The thicker the tubing, the smaller the vibration amplitude of the simulated tubing. Therefore, tubing vibration can be effectively suppressed by increasing tubing thickness during the actual production process. The larger the gas production, the greater the frequency and amplitude of the simulated tubing vibration. When gas production is excessively large, the tubing is likely to collide severely with the casing wall, thereby increasing the risk of tubing failure. Therefore, it is crucial in the actual production process to determine the daily gas output reasonably, keeping in mind the bearing limit of the tubing. Packers suppress string vibration by limiting the lateral displacement of the string. Installing multiple packers proves to be more effective than a single packer in suppressing vibration. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is an essential staple crop in China. Appropriate storage methods and technology are critical to ensure the quality of seed potatoes, which is closely related to the field performance. So far, the diffused light storage (DLS) technique has been widely applied to potato crop. In this paper, two special potato varieties ('Chuanyu 117' and 'Mira') were treated at DLS for 60 days, and the effects of growth conditions on tuber sprouts and subsequent field performance were evaluated. The results showed that the DLS treatment significantly promoted the greening of potato tubers from highland and simultaneously affected the average sprouting rate, sprout length and number of sprouts at different storage stages, which indicated obvious interacting correlations between DLS treatments and potato varieties. Especially for 'Mira', the shortest average sprout length (2.7 mm) was obtained under 40–200 lx light level, while 'Chuanyu 117' had the shortest average sprout length (1.3 mm) under 5–10 lx and its sprout length was also controlled within 2.3 mm under 200–2000 lx. In the cultivation experiment that followed, the potato tubers with 4–6 mm and 2–3 mm sprout length had the highest yield after 90 days and 110 days planting, respectively. Overall, these results demonstrated that for seed potatoes harvested from the highland area followed by storing for 30 days in the lowland, the sprout length can be better controlled at 2–3 mm to obtain short and strong sprouts when stored under 40–200 lx or 200–2000 lx diffused light for 60 days, which is especially suitable in terms of fast field emergence after planting and final tuber yield for the autumn and winter cultivation of potato in the Chengdu Plain. It is also suggested that the DLS technique on seed potatoes could be used in the mixed single and double-cropping areas in Sichuan and other areas with similar geographical and climatic conditions. The findings of this study have several important implications in the storage, transportation, processing as well as seed potato market for commercial practice. [ABSTRACT FROM AUTHOR]

With the gradual decline of natural gas production, reserve upgrading has become one of the important issues in natural gas exploration and development. However, the traditional reserve upgrade forecasting method is often based on experience and rules, which is subjective and unreliable. Therefore, a prediction method based on neural network is proposed in this paper to improve the accuracy and reliability of reserve upgrade prediction. In order to achieve this goal, by collecting the relevant data of natural gas exploration and development in Sichuan Basin, including geological parameters, production parameters and other indicators, and processing and analyzing the data, the relevant characteristics of reserves increase are extracted. Then, a neural network model based on multi-layer perceptron (MLP) is constructed and trained and optimized using backpropagation algorithm. The results show that the prediction accuracy of the constructed neural network model can reach more than 90% and can effectively predict the reserve upgrading. Experiments show that the model has high accuracy and reliability, and is significantly better than the traditional prediction methods. The method has good stability and reliability, and is suitable for a wider range of natural gas fields. [ABSTRACT FROM AUTHOR]

The exploration and development potential of shale gas reservoirs in the Sichuan Basin is enormous; however, it also faces difficulties such as complex structures, strong heterogeneity, and unclear geophysical response characteristics. Fine prediction of geostress is an important part of shale gas exploration and development, which directly affects the implementation effect of reservoir evaluation, well trajectory design, and fracture reconstruction. The existing geostress prediction techniques lack high-precision seismic data constraints, making it difficult to accurately reflect the planar distribution characteristics of geostress in the block with rapid changes in complex tectonic zones. At the same time, the geophysical response characteristics of geostress in the Sichuan Basin are unknown, and the geostress seismic prediction technology lacks theoretical basis. This paper combines numerical simulation and physical experiments and defines the characteristics of the geophysical response of shale gas reservoirs in the Sichuan Basin changing with the stress field, and technical countermeasures for geostress seismic prediction have been established to provide technical means for accurate prediction of the geostress field in the shale gas block. Based on the geostress sensitive parameters obtained from prestack seismic inversion, the geostress field prediction of a shale gas work area in the Sichuan Basin is realized. [ABSTRACT FROM AUTHOR]

Deep shale reservoirs (3500–4500 m) exhibit significantly different stress states than moderately deep shale reservoirs (2000–3500 m). As a result, the brittleness response mechanisms of deep shales are also different. It is urgent to investigate methods to evaluate the brittleness of deep shales to meet the increasingly urgent needs of deep shale gas development. In this paper, the quotient of Young's modulus divided by Poisson's ratio based on triaxial compression tests under in situ stress conditions is taken as SSBV (Static Standard Brittleness Value). A new and pragmatic technique is developed to determine the static brittleness index that considers elastic parameters, the mineral content, and the in situ stress conditions (BIEMS). The coefficient of determination between BIEMS and SSBV reaches 0.555 for experimental data and 0.805 for field data. This coefficient is higher than that of other brittleness indices when compared to SSBV. BIEMS can offer detailed insights into shale brittleness under various conditions, including different mineral compositions, depths, and stress states. This technique can provide a solid data-based foundation for the selection of 'sweet spots' for single-well engineering and the comparison of the brittleness of shale gas production layers in different areas. [ABSTRACT FROM AUTHOR]

The Yarlung Zsangbo Grand Canyon (YGC) is an important pathway for water vapor transport from southern Asia to the Tibetan Plateau (TP). This area exhibits one of the highest frequencies of convective activity in China, and precipitation often induces natural disasters in local communities, which can dramatically affect their livelihoods. In addition, the produced precipitation gives rise to vast glaciers and large rivers around the YGC. In 2018, the Second Tibetan Plateau Scientific Expedition and Research Program tasked a research team to conduct an "investigation of the precipitation process in the water vapor channel of the Yarlung Zsangbo Grand Canyon" (INVC) in the southeastern TP. This team subsequently established a comprehensive observation system of land–air interaction, water vapor, clouds, and rainfall activity in the YGC. This paper introduces the developed observation system and summarizes the preliminary results obtained during the first two years of the project. Using this INVC observation network, herein, we focus on the development of rainfall events on the southeastern TP. This project also helps to monitor geohazards in the key area of the Sichuan–Tibet railway, which traverses the northern YGC. The observation datasets will benefit future research on mountain meteorology. [ABSTRACT FROM AUTHOR]

Forest fires have frequently occurred and caused great harm to people's lives. Many researchers use machine learning techniques to predict forest fires by considering spatio-temporal data features. However, it is difficult to efficiently obtain the features from large-scale, multi-source, heterogeneous data. There is a lack of a method that can effectively extract features required by machine learning-based forest fire predictions from multi-source spatio-temporal data. This paper proposes a forest fire prediction method that integrates spatio-temporal knowledge graphs and machine learning models. This method can fuse multi-source heterogeneous spatio-temporal forest fire data by constructing a forest fire semantic ontology and a knowledge graph-based spatio-temporal framework. This paper defines the domain expertise of forest fire analysis as the semantic rules of the knowledge graph. This paper proposes a rule-based reasoning method to obtain the corresponding data for the specific machine learning-based forest fire prediction methods, which are dedicated to tackling the problem with real-time prediction scenarios. This paper performs experiments regarding forest fire predictions based on real-world data in the experimental areas Xichang and Yanyuan in Sichuan province. The results show that the proposed method is beneficial for the fusion of multi-source spatio-temporal data and highly improves the prediction performance in real forest fire prediction scenarios. [ABSTRACT FROM AUTHOR]

The Wenchuan earthquake in 2008 induced thousands of geological hazards. Among them, earthquake-induced landslides are extremely disastrous, causing considerable social and economic losses and damage to the ecology and environment. Therefore, it is of great significance to accurately predict the spatial distribution of earthquake-induced landslides. The research in this paper focuses on ten extremely earthquake-stricken areas of the Wenchuan earthquake; landslide hazard data are collected from the study areas, and the terrain information entropy, distance to rivers, distance to faults, distance to roads, lithology, normalized difference vegetation index (NDVI), peak ground acceleration (PGA) and other landslide conditioning factors are extracted. Combined with a deep neural network (DNN), a landslide hazard spatial prediction model is constructed. Through Dataset 1 and Dataset 2, which are generated randomly, the training dataset (70%) and the validation dataset (30%) are divided to verify the robustness and accuracy of the model, and the landslide susceptibility map of the study area is obtained. Moreover, considering the area under curve (AUC), the impacts of different conditioning factors on the landslide hazard prediction model are analyzed. The research results show that the DNN-based landslide hazard spatial prediction model (AUCMean = 93.66%, RecallMean = 85.70%) has a better prediction performance in the training step. From the validation step, the influences of various factors on the spatial prediction model of landslide hazards established in this paper (from high to low) are as follows: distance to faults, lithology, distance to rivers, PGA, terrain information entropy, NDVI, and distance to roads. The landslide hazard point data and landslide susceptibility map are highly consistent, indicating that the application of a deep learning algorithm in hazard susceptibility assessment is effective and can provide a scientific basis for landslide hazard early warning and disaster prevention and mitigation in mountainous areas prone to earthquake disasters. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Albinism is a kind of anomalous hypopigmentation with a complete white pelage, and it is completely devoid of melanin in the skin, hair follicles and eyes. The present paper firstly reports two cases of adult mole shrews (Anourosorex squamipes) with albinism, which were found in Sichuan province of southwestern China. The two female mole shrews show a complete white pelage. Stained by the soil, the albinistic mole shrews show a yellowish white color. Besides the same morphological characteristics, all the body parameters of the two albinistic mole shrews are within the parameter range of the six normal mole shrews captured at the same site. [ABSTRACT FROM AUTHOR]

Based on sorting out the architectural historical materials of Tang and Song Dynasties reflected in the rock caves of Sichuan and Chongqing area, this paper discusses the evolution of dougong [...], roof forms and architectural groups in the Tang and Five Dynasties Period in this area. At the same time, the paper compares some timber architecture features from Tang to Song Dynasties reflected in rock caves with existing buildings, so as to supplement and demonstrate the development process of some architectural features. The above research reveals the main historical value of these architectural historical materials: firstly, they supplement the absence of ancient wooden structures from Tang to Song Dynasties in Sichuan and Chongqing to some extent; secondly, they witness the spread of some architectural cultures between the northern and southwestern regions from Tang to Song Dynasties. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Geomechanics is the property of Journal of Geomechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The staged and multi-cluster fracturing of horizontal wells is the main fracturing technology used for shale gas reservoir development. Temporary plugging diversion (TPD) is an important technical means to realize a uniform propagation of hydraulic fractures and avoid problems such as frac hits (i.e., well-to-well interference). Although this technology has been extensively used worldwide, field monitoring results have shown that temporary plugging cannot effectively improve the nonuniform propagation of multiple fractures. The fundamental reason is the lack of an organic combination of laboratory research and field application. To solve this problem, this study investigated the reservoir adaptability and plugging performance of three types of temporary plugging agent (TPAs), namely, powder, particle, and fiber, used in the fracturing of wells in the Weiyuan (WY) shale gas field, Sichuan, China, using a pressure-bearing capacity test device for three dimensional (3D)-printing-simulated TPA. A calculation method for the plugging efficiency of the TPA was established, and the ratio and concentration of the TPA were optimized under different fracture widths. The similarity criterion was used to calculate the amount of TPA required for different fracture widths. A field application chart of the TPA was formulated, and a method that connects laboratory research and field application was established. The results showed that the three TPAs have good reservoir adaptability and degradation performance. It is recommended to use 200–400 mesh powder + 6 mm fiber with different concentrations and dosages when performing temporary plugging and fracturing at the front end of 1–3 mm fractures. In the case of inter-cluster TPD for a fracture width of 4–6 mm, a combination of 20 mesh powder + 6 mm fiber + 1–3 mm particles is recommended. The field application results showed that the pressure increased significantly at the front end of the fractures and during inter-cluster temporary plugging when the plugging agent was in place, and there were no frac hits in the adjacent wells. This paper provides a practical research method for hydraulic fracturing involving temporary plugging, from laboratory research to engineering application. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One of the primary tasks for effective disaster relief after a catastrophic earthquake is robust communication. In this paper, we propose a simple logistic method based on two-parameter sets of geology and building structure for the failure prediction of the base stations in post-earthquake. Using the post-earthquake base station data in Sichuan, China, the prediction results are 96.7% and 90% for the two-parameter sets and all parameter sets, respectively, and 93.3% for the neural network method sets. The results show that the two-parameter method outweighs the whole parameter set logistic method and the neural network prediction and can effectively improve the accuracy of the prediction. The weight parameters of two-parameter set by the actual field data significantly show that the failure of base stations after earthquake is mainly due to the geological differences where the base stations are located. It can be envisioned that if the geological distribution between the earthquake source and the base station is parameterized, the multi-parameter sets logistic method can not only effectively solve the failure prediction after earthquakes and the evaluation of communication base stations under complex conditions, but also provide site selection evaluation for the construction of civil buildings and power grid towers in earthquake-prone areas. [ABSTRACT FROM AUTHOR]

With the increase of shale gas resource exploitation in our country during recent decades, the situations of low gas production, fast production decline rate, and low flowback rate have been appearing in field production. It is an urgent problem to be solved in shale gas production and it is therefore necessary to study the interaction of the shale gas reservoir and the detained fracturing fluid. In this paper, the Longmaxi Formation shale samples of Sichuan Basin were selected for a water invasion experiment. The fracture propagation law, the water invasion front location, and the water invasion thickness of deep and shallow shale reservoirs after water invasion were compared and analyzed by CT scanning technology. Based on the analysis of the experimental mechanism, a numerical simulation model was established. The dimensionless permeability and thickness of the fracturing fluid invasion layer were introduced to analyze the positive and negative effects of fracturing fluid retention on the reservoir. The results show that during the hydraulic fracturing of shale gas wells, fracturing fluid can quickly enter the complex fracture network, and then slowly enter the shale matrix under various mechanisms to form the fracturing fluid invasion layer. Compared with shallow shale reservoirs, deep shale reservoirs have lower porosity and permeability, which propagates microfractures in the matrix induced by fracturing fluid retention, and results in a smaller fracturing fluid invasion layer thickness. Both the negative effect of fracturing fluid retention on shale damage and the positive effect of microfracture formation and propagation exist simultaneously. The higher the dimensionless fracturing fluid invasion layer permeability, the more complex the fracture network formed in the fractured reservoir will be, resulting in a longer stable production period and a better development effect. When the dimensionless fracturing fluid invasion layer permeability is greater than 1, that is, when the positive effect of fracturing fluid retention is greater, and the thicker the dimensionless fracturing fluid invasion layer is, the better the development effect will be. Combining reservoir characteristics and fracture development, the key to obtaining high productivity of a shale gas well is to optimize the soaking time and the speed of flowback in order to extend the stable production period. In this paper, the characteristics of the fracturing fluid invasion layer and the influence of fracturing fluid retention on gas well productivity are deeply studied, which provides a certain theoretical basis for the optimization of shale gas extraction technology and the improvement of the gas–water two-phase productivity prediction method for fractured horizontal wells. [ABSTRACT FROM AUTHOR]

Promoting quality certification of agricultural products is a matter of the sustainable development of agriculture and the transformation of the global agri-food system, and cooperatives are an important carrier to achieve the above policy goals. However, few scholars have included external resources and cooperative quality certification behavior in an analytical framework from the perspective of resource embedding. This study combines resource dependence theory and embeddedness theory, based on survey data from 230 agricultural cooperatives in six counties of Sichuan Province, China. This paper constructs a theoretical analysis framework of government resources, market resources and cooperative quality certification, and uses binary Logit regression model to empirically study the correlation between external resources and cooperative quality certification. The results show that: (1) Cooperatives do not receive a high proportion of external resource support, with 30% and 47% receiving support from the government and market respectively; the proportion of cooperatives carrying out product quality certification was relatively low, about 29.57%. (2) Government resources and market resources have a significant positive effect on improving the quality certification of cooperatives, and the promotion effect of the market is greater than that of the government. (3) Mechanism analysis shows that government resources promote quality certification in cooperatives mainly through regulations on agricultural inputs, while market resources can jointly play a role on regulations on agricultural inputs and market expectations for certified agricultural products. [ABSTRACT FROM AUTHOR]

Farmers' participation in public affairs is the combined effect of informal and formal institutions. In order to improve the current situation of low willingness of Chinese farmers to participate in living environment improvement, and to enhance the motivation of farmers and the effectiveness of living environment improvement, this paper incorporates the clan network in the informal institution and the perceivable authority of village chiefs in the formal institution into a unified analytical framework, divides the clan network into two dimensions (scale and strength) and explores the influence of the clan network and the perceivable authority of village chiefs on farmers' participation in rural living environment improvement. Finally, an empirical test is conducted using survey data from 683 farming households in the provinces of Henan, Shaanxi and Sichuan. The results show that the strength of the clan network and the perceivable authority of the village chiefs have a significant positive effect on the farmers' participation in rural living environment improvement, while the scale of the clan network does not have a significant effect on farmers' behavior. The perceivable authority of the village chief has a positive moderating effect between the clan network and farmers' participation in rural living environment improvement, while the heterogeneity analysis shows that the positive effect of the clan network on farmers' participation in the rural living environment is reduced for those who have worked outside, far away from the village. It is suggested that the protection of traditional clan relations should be emphasized, and the positive role of clan agents and their influence should be effectively utilized in promoting the improvement of the rural living environment at the grassroots level. Moreover, it is necessary to carry out timely training of professional knowledge and skills for grassroots leaders, propagandize and interpret policies, thus increasing the enthusiasm of farmers to participate in the improvement of the rural living environment. [ABSTRACT FROM AUTHOR]

The preference of biofloculants over chemical flocculants in water and wastewater remediation systems has gained wider attention due to their biodegradability, innocuousness, safety to human and environmental friendliness. The present study aimed to evaluate research outputs on bioflocculant potentials in wastewater remediation from 1990 to 2019 using bibliometric analyses. To the best of our knowledge, this is the first bibliometric report in bioflocculant research. The subject bibliometric dataset was extracted from the Web of Science Core Collection (WoSCC) and Scopus using the Boolean, 'bioflocculant* and waste*' and analysed for indicators such as a yearly trend, productivity (authors, articles, country, institution and journal source), conceptual framework and collaboration network. We found 119 documents with 347 authors from 78 journal sources on the subject, an annual growth rate of 12·1%, and average citations/document of 15·08. Guo J. and Wang Y. were the top researchers with 15 and 12 outputs respectively. China (42%) and South Africa (9·24%) ranked the top two dominant countries in the field. The top journals were Bioresource Technology (9 papers, 506 citations), Applied Microbiology and Biotechnology (5 papers, 268 citations), whereas, the top institution was Chengdu University of Information and Technology (n = 9 documents) followed by Sichuan Univ. Sci. & Engn, China (n = 8 documents). This study found that lack of intercountry collaboration and research funding adversely affects research participants in the field. [ABSTRACT FROM AUTHOR]

At present, the quality of material life and richness of the Chinese residents have been improved. Some people have high requirements for quality of their personal lives and put forward the problem of health preservation. Honey, as a nutritious food, is deeply loved by people. There are a large number of trace elements in honey, such as VC, VA, VD, VB1, and VB2. The honey from the Chinese honeybee has a very high nutritional value and plays an important role in the pollination and reproduction of some plants. Therefore, the Chinese honeybee plays a very significant role in the ecological environment. Moreover, it is protected as the main species resource of the country, which also fully proves the importance of the Chinese honeybee. Chinese bees can survive in various ecological and geographical environments in China and have strong heat as well as cold resistance. They can survive in the hot environment in the south and withstand the dynamics of severe cold in the north. At the same time, they can make full use of a small number of honey sources and have strong resistance to a variety of diseases and pests. In fact, there will be a variety of insect invasion problems in the beehive culture of Chinese bees, and it is necessary to accurately detect various diseases and pests during the breeding of Chinese bees. However, there are a large amount of insect invasion and various disease sources in the breeding stage of the Chinese bees. Therefore, in this paper, we use a deep learning algorithm to detect the insect invasion of the Chinese beehive culture and analyze the bee colonies in six bee farms in the province of Sichuan. In addition, we measure the common insect and disease indexes of the Chinese bee and analyze the parasitism rate, microsporidia infection rate, virus infection rate, and virus infection titer of bee colonies in overwintering and spring breeding. The experimental results show that the anti-insect invasion situation of bees in the six bee farms is significantly different; however, the antimite ability is basically the same. [ABSTRACT FROM AUTHOR]

Identifying the types of disasters and analyzing the distribution pattern of and the spatial correlation between villages and disasters are important prerequisite for the disaster prevention and mitigation of traditional villages. Taking Aba Tibetan and Qiang Autonomous Prefecture as an example and using the tools of kernel density evaluation and spatial statistics, this paper analyzes the distribution pattern of and the spatial correlation between traditional villages and typical geological disasters on the three spatial scales of Aba Prefecture, village agglomeration area, and village administrative area with necessary explanations. It concludes that most of the traditional villages in Aba Prefecture agglomerate in the middle- and high-level alpine gorges and some are clustered at either the border area or the central hinterland of counties; with the increase of maximum seismic intensity and frequency of earthquakes, it appears there is an increase of traditional villages and their trend of agglomeration, which implies an overlap of the areas of dense traditional villages and high-density geological disasters, as well as the synchronous increase of traditional village density and geological disaster density; and the traditional villages in Aba Prefecture are affected by multiple disasters, in particular landslide and debris flow. Finally, the paper discusses the issue of disaster prevention and mitigation in the protection and development planning of traditional villages. [ABSTRACT FROM AUTHOR]

The relationship between government intervention and cooperative development has always been a source of controversy in the developing world. This paper aims to examine the rationale and successful conditions of government intervention to promote cooperative development in poor areas of rural China. In the context of the "targeted poverty alleviation" program (2015–2020), a government-led campaign covering all poverty-stricken villages in west China, cooperative development was listed by the central government as a criterion for evaluating successful intervention at the county government level. Accordingly, the central questions of this paper are: why is government intervention necessary to initiate a process of cooperative development in poor areas of China; and under what conditions can government intervention be successful, leading to sustainable cooperative development? Bearing in mind the complexity of government intervention with mixed results, both successful and failed, the above questions are addressed through a case study of XM Beekeeping Cooperative, representing one type of successful government intervention in poverty-stricken and ethnic-minority-dominated regions of China. Overall, government intervention is crucial in building cooperative ecosystems in poor regions of China. However, government intervention is not invariable because the approaches can be modified to accommodate the effect of the intervention. [ABSTRACT FROM AUTHOR]

Early work on China's Two-Child Policy identified cost as a major disincentive to having a second child, but financial constraints may work in tandem with cultural factors to shape childbearing desire. In addition, most research has excluded men from the sample. This paper develops Yan's (2003) concepts of 'new' and 'traditional' fertility cultures to childbearing desire, a key component of fertility decision-making that is poorly understood (Hayford & Agadjanian, 2017). In particular, we focus on how differing conceptions of children's needs relate to perceptions of cost. This paper reports on semi-structured interviews with 29 men and women in Chengdu, the capital of Sichuan province. We found that interviewees who espoused views consistent with a traditional fertility framework were more interested in having a second child, and were less concerned about cost. In addition, men were more likely to espouse views consistent with a traditional fertility cultural framework. [ABSTRACT FROM AUTHOR]

Several possible lithosphere–atmosphere–ionosphere coupling mechanisms before earthquake occurrence are presented in the literature. They are described by several models with different interaction channels (e.g., electromagnetic, mechanics, chemical, thermal), sometimes in conflict with each other. In this paper, we search for anomalies six months before the Lushan (China) 2013 earthquake in the three geo-layers looking for a possible view of the couplings and testing if one or another is more reliable to describe the observations. The Lushan earthquake occurred in China's Sichuan province on 20 April 2013, with a magnitude of Mw = 6.7. Despite the moderate magnitude of the event, it caused concern because its source was localized on the southwest side of the same fault that produced the catastrophic Wenchuan event in 2008. This paper applies a geophysical multi-layer approach to search for possible pre-earthquake anomalies in the lithosphere, atmosphere, and ionosphere. In detail, six main increases in the accumulated seismic stress were depicted. Anomalous geomagnetic pulsations were recorded in the Chengdu observatory, sometimes following the increased stress. Atmosphere status and composition were found to be anomalous in several periods before the earthquake, and, spatially, the anomalies seem to appear firstly far from the upcoming earthquakes and later approaching the Longmenshan fault where the Lushan earthquakes nucleated. The Formosat-3 data identified interesting anomalies in the altitude or electron content of the ionospheric F2 peak in correspondence with seismic and atmospheric anomalies 130 days before the earthquake. In addition, the total electron content showed high anomalous values from 12 to 6 days before the earthquake. We compared the anomalies and tried to explain their correspondences in different geo-layers by the lithosphere–atmosphere–ionosphere coupling models. In particular, we identified three possible couplings with different mechanisms: a first, about 130 days before the earthquake, with a fast (order of one day) propagation delay; a second, about 40 days before the earthquake occurrence, with a propagation delay of few days and a third from 2.5 weeks until one week before the event. Such evidence suggests that the geo-layers could interact with different channels (pure electromagnetic or a chain of physical-chemical processes) with specific propagation delays. Such results support the understanding of the preparation for medium and large earthquakes globally, which is necessary (although not sufficient) knowledge in order to mitigate their impact on human life. [ABSTRACT FROM AUTHOR]

In the face of the new reform of China's "unified electricity market", the frequency regulation ancillary service market in each region of China is still divided between using the MCP and PAB pricing mechanisms. The purpose of this paper is to explore the different impact the laws of the above two pricing mechanisms have on the frequency regulation market and to provide relevant suggestions for this electricity market reform. This paper simulates the competitive activities of the frequency regulation market based on the multi-agent simulation model, conducts a comparative experiment by changing the pricing mechanism to a single variable based on the rules of the Sichuan frequency regulation market in China, and concludes that MCP can make the market fast and stable, and that its market settlement price is low, which is suitable for the "unified electricity market". Although PAB makes the market settlement price high, it can ensure the retention of high-performance units in the market, and the stable settlement price makes this model able to accurately reflect the "price signal", making it suitable for late adoption in the "unified electricity market". [ABSTRACT FROM AUTHOR]

A World Natural Heritage Site, Jiuzhaigou, is the first nature reserve in China whose primary purpose is to protect natural scenery. On August 8, 2017, a Ms 7.0 earthquake caused many unstable slopes in Jiuzhaigou, Sichuan Province, China. In the extreme storm conditions that follow, the unstable slopes tend to develop into potential landslides, which can cause many casualties and property losses in scenic areas. Sentinel-1A ascending orbit data were obtained in this paper to establish a SAR database. The large-scale deformation rate map of the study area was obtained using a small baseline set InSAR technology. The potential landslides in the deformation area are preliminarily confirmed with remote sensing interpretation. The field verification is further carried out by studying the deformation information of the characteristic points on the potential landslides. The results show that 13 deformation zones were preliminarily identified, and three typical deformation zones were selected for coupling verification and identified as potential landslides. At the same time, further analysis shows that the four potential landslides have been in continuous linear deformation for a long time since the earthquake, posing a severe threat to the safety of local people's lives and property. The research results provide a reference for the early identification and warning of potential landslides in earthquake-prone regions. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In Sichuan Province, China, most coal seams that are mined are steeply inclined; their roadways' surrounding rocks are asymmetric, with non-equilibrium deformations and unstable anchorage structures, thus making major safety hazards highly likely. Using field observations and a universal distinct element code (UDEC) numerical simulation method, this paper analyzed the time-dependent failure of the ventilation roadway of Working Face 1961 of the Zhaojiaba Mine, revealing the preconditions for such damage and a bidirectional deterioration mechanism for the deformation as well as stress of surrounding rocks. Moreover, this paper built an anchorage mechanical model for the thick layer of the roadway roof and proposed a cross-boundary anchor-grouting (CBAG) differential support technique. Calculations proved that the new support was particularly effective in restraining the expansion of tension cracks, thus preventing the slipping and dislocation deformations of rock masses on the curved roof side. The feedback of engineering applications showed that the maximum development depths of cracks in the arc roof and straight inclined roof of the roadway 150 m behind the working face are only 1.5 m and 1.10 m, decreasing by 61.3% and 47.6%, respectively, compared with the primary support. The proposed technology offers an overall thick-layer bearing structure for the surrounding rocks of roadways, effectively restraining the non-equilibrium large deformations of roadways in steeply inclined coal seams. [ABSTRACT FROM AUTHOR]

The rapid and accurate extraction of wide-area coseismic landslide locations is critical in earthquake emergencies. At present, the extraction of coseismic landslides is mainly based on post-earthquake site investigation or the interpretation of human–computer interactions based on remote sensing images. However, the identification efficiency is low, which seriously delays the earthquake emergency response. On the basis of the available multisource and multiscale remote sensing data, numerous studies have been carried out on the methods of coseismic landslide extraction, such as pixel analysis, object-oriented analysis, change detection, and machine learning. However, the effectiveness of coseismic landslide extraction was low in wide areas with complex topographic and geomorphic backgrounds. Therefore, this paper offers a comprehensive study of the factors influencing coseismic landslides and researches rapid and accurate wide-area coseismic landslide extraction methods with multisource remote sensing and geoscience technology. These techniques include digital elevation modeling (DEM) and its derived slopes and aspects. An embedded multichannel spectral–topographic feature fusion model for coseismic landslide extraction based on DeepLab V3+ is proposed, and a knowledge-enhanced deep learning information extraction method integrating geological knowledge is formed. Using the Jiuzhaigou Ms7.0 earthquake (seismic intensity VIII) in Sichuan Province, China, a comparison of landslide extraction models and strategies is carried out. The results show that the model proposed in this paper achieves the best balance in the accuracy and efficiency of wide-area extractions. Using multiple feature data of coseismic landslides, the problem of mixed pixels is solved. The rate of the misidentification of landslides as clouds, snow, buildings, and roads is significantly lower than in other methods. The identified landslide boundaries are smoother and more accurate, and the connectivity is better. Compared with other methods, ours can more accurately eliminate landslides not triggered by the Jiuzhaigou earthquake. While using the image block strategy to ensure extraction efficiency, it also improves the extraction accuracy of wide-area coseismic landslides in complex backgrounds. [ABSTRACT FROM AUTHOR]

Background: On September 5, 2022, an Ms 6.8 earthquake occurred in Luding County, Ganzi Tibetan Autonomous Prefecture, Sichuan, China. The casualties and economic losses caused by the earthquake are huge. Most of the landslides triggered by this earthquake are small and medium-sized rock collapses and destructive debris flows, with a small number of large-scale landslides. Results: There are 5007 coseismic landslides in the Luding earthquake VII-degree area and above, with a total area of 17.36 km2. The landslides are generally distributed along the NW-SE direction. The highest landslide area density is 13.8%, and the highest point density of the landslide is 35.73 km2. High-density area is mainly concentrated in the IX-degree area and the northeast side of the seismogenic fault. Coseismic landslides are more likely to develop in the area with the slope more than 40°, the slope direction of 67.5-112.5 degree, and vegetation coverage of 40–50%. More landslides are developed in granite areas and forest areas. The closer distance to active faults, the more the coseismic landslides develop. The correlation between coseismic landslide development and the distance from the active faults is better than that between coseismic landslide development and the distance from the seismogenic faults. Conclusion: The landslide database used in this paper is the most perfect at present, and the research results have also been verified by fieldwork. This is also the first applied study of this landslide inventory, which indirectly confirmed the accuracy of the inventory. The results obtained in the manuscript will provide an important guideline for future disaster prevention and mitigation in southwest China. [ABSTRACT FROM AUTHOR]

With the continuous emphasis of the country on the construction of ecological civilization, promoting the utilization of straw resources has become an important measure to achieve green agricultural development. Based on the survey data of 540 households in Sichuan Province and under the guidance of the theory of planned behavior, this paper constructed the IV-Probit model to explore the impact of land transfer on the straw resource utilization of households. The results show that: (1) land transfer in and land transfer out can significantly promote the utilization of straw resources by farmers. (2) Heterogeneity analysis showed that land transfer in had a positive effect on crop straw utilization of the new generation and large-scale farmers. (3) Land transfer in can promote the utilization of straw resources by improving farmers' economic cognition and efficacy cognition; land transfer out can promote the utilization of straw resources by improving farmers' efficacy cognition. Accordingly, the government should improve the land transfer market, increase technology propaganda, and create an excellent policy environment to promote farmers' participation in straw resource utilization. [ABSTRACT FROM AUTHOR]

In this paper, based on Sina Weibo data, a natural language processing (NLP) analysis method was used to analyze the temporal and spatial sequence characteristics of people's attention and the characteristics of text content with the help of microblogs posted by people within 6 days after the 2022 Lushan M6.1, Maerkang M5.8 and Luding M6.8 earthquakes. Moreover, the same analysis method was used on the content of comments on microblogs posted by official media outlets within 6 days after the earthquakes to analyze the changes in people's sentiments and the differences in the sentiments in various regions, and the influencing factors were also analyzed. The results of this research show the following: In terms of the spatial and temporal distributions, people's attention was affected by the earthquakes themselves and their social impacts, and the first 2 h was often a period of an outbreak of attention, with the publishing areas mainly concentrated in Sichuan and Guangdong. In terms of people's sentiments, the overall microblogging sentiment of the three earthquakes was positive, and the sentiment value of the people in Sichuan was generally low compared with that of the people in the other regions. Not only was the fluctuation in sentiment affected by the influence of the region, but it was also positively related to the sentiment of official microblogs. The results of this research provide reference for guiding people's sentiments after earthquakes in the new media era. [ABSTRACT FROM AUTHOR]

Population is a major production factor in rural development in China, which makes the study of rural population distribution patterns at different times and the factors influencing the population distribution an important foundation for understanding the issues in rural China and moving forward with the implementation of rural revitalization strategies. This paper analyzed the spatial evolution of the population in rural China based on population census data for the People's Republic of China by county in 1990, 2000 and 2010. Applying the geographical detector method, this paper also delved into the contributing factors that influenced the distribution based on the natural, social and economic data, such as the potential crop productivity, the average slope, the urbanization rate and the time cost to reach the nearest cities. The results indicate that the migration of the population from the rural areas into the cities, which was a result of rapid urbanization, did not change the original population distribution in rural China significantly. The rural population was still concentrated in the eastern plains, basins and deltas, and the North China Plain and Sichuan Basin still house the bulk of rural residents, but the population density of rural residents in the North China Plain and Sichuan Basin decreased from 1990 to 2010. The rural population in China tended to be distributed around the cities. Seventy-four percent of the rural population lived in an area within a 60-minute driving distance from the surrounding cities. The areas with dense rural population were basically consistent with the locations of the current major urban agglomerations in China. The current distribution of the rural population in China was a result of natural, social and economic conditions and location factors. Among them, natural factors such as the potential crop productivity and the degree of surface fragmentation had the most significant influence. [ABSTRACT FROM AUTHOR]

The exploration and comprehensive assessment of fractured-vuggy reservoir information have perennially constituted focal points and challenges within the domain of oil and gas reservoir evaluation. The verification of geological phenomena, identification of various fracture and hole types, and the quantitative characterization thereof currently present pressing challenges. This study meticulously examines the deep carbonate reservoirs within the Dengying Formation in the Penglai gas region of the Sichuan Basin. The Core Rolling Scan images reveal five discernible features: unfilled holes, filled holes, filled fractures, open fractures, and algae. The analysis pinpoints three primary challenges in semantic segmentation recognition: the amalgamation of feature scales, class imbalance, and the scarcity of datasets with substantial sample sizes. To address these challenges, this paper introduces a Multi-Scale Feature Aggregation Pyramid Network model (MFAPNet), achieving a pixel accuracy of 68.04% in recognizing the aforementioned five types. Lastly, the model is employed in calculating core porosity, exposing a scaling relationship between wellbore image porosity and core porosity ranging from 1.5 to 3 times. To a certain extent, it reveals the correlation between the wellbore image logging data and the actual formation of the Dengying Formation in the Penglai Gas Field of the Sichuan Basin, and also provides a basis for the subsequent logging evaluation of the formation. The partial code and CHA355 dataset are publicly available at https://github.com/zyng886/MFAPNet. [ABSTRACT FROM AUTHOR]

Landslides are common natural disasters that cause serious damage to ecosystems and human societies. To effectively prevent and mitigate these disasters, an accurate assessment of landslide hazards is necessary. However, most traditional landslide hazard assessment methods rely on static assessment factors while ignoring the dynamic changes in landslides, which may lead to false-positive errors in the assessment results. This paper presents a novel landslide hazard assessment method for the Zagunao River basin, China. In this study, an updated landslide inventory was obtained for the Zagunao River basin using data from interferometric synthetic aperture radar (InSAR) and optical images. Based on this inventory, a landslide susceptibility map was developed using a random forest algorithm. Finally, an evaluation matrix was created by combining the results of deformation rates from both ascending and descending data to establish a hazard level that considers surface deformation. The method presented in this study can reflect recent landslide hazards in the region and produce dynamic assessments of regional landslide hazards. It provides a basis for the government to identify and manage high-risk areas. [ABSTRACT FROM AUTHOR]

Siliceous minerals of the Dengying Formation in the Gaoshiti–Moxi area in the central Sichuan Basin exhibit four types of quartz crystals (cryptocrystalline quartz, chalcedony, microcrystalline quartz, and megacrystalline quartz) and three structural types: cryptocrystalline, microcrystalline, and mosaic (laminated mosaic, window-hole interrupted mosaic, and arc-laminated mosaic). Siliceous minerals have a great influence on the storage performance of the reservoirs in the Dengying Formation. According to the petrophysical parameters of the Dengying Formation and porosity intersection diagrams, the siliceous dolomite and the reservoirs have low impedance characteristics, which makes it difficult to distinguish between them and leads to difficulties in the characterization and prediction of the reservoirs. The transverse wave velocity is favorable for reservoir characterization. Currently, the main method used to estimate the transverse wave velocity is petrophysical modeling, which establishes a relationship between the elastic and physical parameters of the reservoir. In this paper, the siliceous minerals in the dolomite in the study area are regarded as solid inclusions, and the calculation method of the rock matrix modulus is improved by using solid replacement. Then, an improved petrophysical model is constructed by combining the KT (Kuster–Toksöz) model, the DEM (Discrete Element Method) model, the Gassmann equation, and the Wood equation. The transverse wave velocity is estimated using the improved model under the constraint of the longitudinal wave velocity. The shapes of the transverse wave velocity curves obtained by the improved model and the deviations from the measured velocities are significantly better than those of the Xu–Payne model and other models. The results show that the improved model can effectively estimate the transverse wave velocity of the reservoir in this area, which provides a basis for future reservoir predictions in this area. [ABSTRACT FROM AUTHOR]

As flexible resources, cascaded hydropower stations can regulate the fluctuations caused by wind and photovoltaic power. Constructing pumped-storage units between two upstream and downstream reservoirs is an effective method to further expand the capacity of flexible resources. This method transforms cascaded hydropower stations into a cascaded pumped-hydro-energy storage system. In this paper, a flexibility reformation planning model of cascaded hydropower stations retrofitted with pumped-storage units under a hybrid system composed of thermal, wind, and photovoltaic power is established with the aim of investigating the optimal capacity of pumped-storage units. First, a generative adversarial network and a density peak clustering algorithm are utilized to generate typical scenarios to deal with the seasonal fluctuation of renewable energy generation, natural water inflow, and loads. Then, a full-scenario optimization method is proposed to optimize the operation costs of multiple scenarios considering the variable-speed operation characteristics of pumped storage and to obtain a scheme with better comprehensive economy. Meanwhile, the proposed model is retransformed into a mixed-integer linear programming problem to simplify the solution. Case studies in Sichuan province are used to demonstrate the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

The frequent fluctuation of pork prices has seriously affected the sustainable development of the pork industry. The accurate prediction of pork prices can not only help pork practitioners make scientific decisions but also help them to avoid market risks, which is the only way to promote the healthy development of the pork industry. Therefore, to improve the prediction accuracy of pork prices, this paper first combines the Sparrow Search Algorithm (SSA) and traditional machine learning model, Classification and Regression Trees (CART), to establish an SSA-CART optimization model for predicting pork prices. Secondly, based on the Sichuan pork price data during the 12th Five-Year Plan period, the linear correlation between piglet, corn, fattening pig feed, and pork price was measured using the Pearson correlation coefficient. Thirdly, the MAE fitness value was calculated by combining the validation set and training set, and the hyperparameter "MinLeafSize" was optimized via the SSA. Finally, a comparative analysis of the prediction performance of the White Shark Optimizer (WSO)-CART model, CART model, and Simulated Annealing (SA)-CART model demonstrated that the SSA-CART model has the best prediction of pork price (compared with a single decision tree, R2 increased by 9.236%), which is conducive to providing support for pork price prediction. The accurate prediction of pork prices with an optimized machine learning model is of great practical significance for stabilizing pig production, ensuring the sustainable growth of farmers' income, and promoting sound economic development. [ABSTRACT FROM AUTHOR]

In this paper we update the knowledge on the species of Serica McLeay, 1819 (sensu lato) occurring in Yunnan, Sichuan, and Shaanxi provinces, China. Three new species are described: Serica allonanhua Liu, Ahrens, Li & Su, sp. nov., S. breviantennalis Liu, Ahrens, Li & Su, sp. nov., and S. fengensis Liu, Ahrens, Li & Su, sp. nov. The key to the species groups and species is updated. The habitus and male genitalia of the new species are illustrated, and a map showing their distribution is provided. New distributional data are given for four species. [ABSTRACT FROM AUTHOR]

Background: Scutellaria amoena (SA) is the root of S. amoena C.H. Wright of Labiatae, also known as Scutellaria southwestern. This is mainly distributed in Sichuan, Yunnan, and Guizhou in China. In southwest China, SA is used as an alternative method to genuine medicine for the treatment of allergy, diarrhea, inflammation, hepatitis, and bronchitis. Thus far, studies on the effects of SA on non-alcoholic steatohepatitis (NASH) are lacking. This paper investigated the effect of SA on the regulation of gut microbiota and its metabolites in NASH rats by inhibiting the NOD-like receptor 3 (NLRP3)/apoptosis-associated specklike protein (ASC)/caspase-1 axis. Methods: A NASH rat model was induced by a high-fat diet (HFD) for 12 weeks, and rats were orally given different doses of SA extracts (150 and 300 mg/kg/d) for 6 weeks. Changes in histological parameters, body weight, organ indexes, cytokines, and biochemical parameters related to NLRP3 in NASH rats were checked. 16S rRNA gene sequencing and UPLC-MS/MS technology were used to analyze the changes in the gut microbiota composition and its metabolites in NASH rats. Results: SA significantly inhibited the HFD-induced increase in body weight, lipid levels, and inflammatory infiltration. SA notably inhibited the HFD-induced increase in the upper and lower factors of NLRP3, such as transforming growth factor (TGF)-β, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-18, pro-IL-18, IL-1β, pro-IL-1β, NLRP3, ASC, and caspase-1. Additionally, mRNA expressions of caspase-1, NLRP3, and ASC were significantly downregulated after SA treatment. The results of the intestinal flora showed that SA could increase the diversity of flora and change its structure and composition in NASH rats by reducing Firmicutes/Bacteroidetes (F/B) ratio, Blautia (genus), Lachospiraceae (family), and Christensenellaceae R-7 group (genus), and increasing Muribaculaceae (family) and Bacteroides (genus). The metabolomics revealed that 24 metabolites were possibly the key metabolites for SA to regulate the metabolic balance of NASH rats, including chenodeoxycholic acid, xanthine, and 9-OxoODE. Nine metabolic pathways were identified, including primary bile acid biosynthesis, bile secretion, purine metabolism, and secondary bile acid biosynthesis. Conclusion: SA can regulate the intestinal microbial balance and metabolic disorder by inhibiting the NLRP3/ASC/caspase-1 axis to relieve NASH. [ABSTRACT FROM AUTHOR]

Music expresses thoughts and emotions in artistic form and is made up of different components including harmony, rhythm, and melody. Several musical elements are tied together during the songwriting process in order to generate melodies that are harmonic. A music melody is the essential element of any music to generate strong feelings from listeners and capture their interest. In the process of music appreciation, melody controls the emotional changes of music. It is an efficiently perceived part and the tone of a song. In recent years, Sichuan unvoiced music has developed rapidly and attracted much attention. This paper selects Sichuan unvoiced music as the main research theme and constructs a melody generation algorithm by utilizing the state-of-the-art techniques of deep learning (DL) and evolutionary algorithms (EAs) such as recurrent neural network-long short-term memory (RNN-LSTM) and genetic algorithm (GA). Firstly, this paper briefly describes the concept of DL algorithms, the deep generation model, and sequence to sequence model, as they constitute the technological foundation for this research. Secondly, this paper proposes a melody generation algorithm that utilizes RNN-LSTM for melody generation and GA for melody optimization. More specifically, the melody is generated by preprocessing data, creating, and training the RNN-LSTM model. A GA was used to determine the melodic fitness function for eight songs as the fitness function directly affects the selected termination condition. The fitness function can be thought of as either a person or an evolutionary rule. Finally, the average score of these songs, before and after evolution, is calculated, which demonstrates that the analysis and rotation creation methods are more precise and that the song's average melody score is higher. The method proposed in this study has been thoroughly compared to the existing approaches proposed in earlier studies, and it was found that the approach we propose is more effective in terms of accuracy and the average melody score. [ABSTRACT FROM AUTHOR]

As a typical rock, shale's reservoir depth is about 1500–4000 m, and the temperature of the shale reservoir at this depth is 150 °C. Therefore, in order to study the dynamic strength of shale at this temperature, it is necessary to consider the effects of temperature and strain rate on the dynamic strength of shale, and then establish the damage constitutive model of shale. This paper took black shale from the Sichuan Basin as the research object, combined it with the separated Hopkinson bar experiment and temperature control system, and conducted the Hopkinson bar experiment on shale at room temperature, 60 °C, 90 °C, 120 °C, and 150 °C, and at three groups of air pressures of 0.2 MPa, 0.3 MPa, and 0.4 MPa. The stress–strain curves of shale at the same strain rate and different temperature and at the same temperature and different strain rate were obtained. In the temperature difference range of this experiment, the dynamic strength of the sample presented two opposite trends (increasing and decreasing) with the increase in temperature, which was determined via the direction of the bedding. The peak strength linearly increased with the increase in strain rate. Based on the Weibull statistical distribution and the D–P failure criterion, a statistical damage constitutive model of shale dynamic strength considering the effects of temperature and strain rate was obtained. By modifying the parameters F0 and m, the dynamic strength statistical damage constitutive model of shale was in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The optimal choice of the planetary boundary layer (PBL) parameterization scheme is of particular interest and urgency to a wide range of scholars, especially for many works involving models. At present, there have been many works to evaluate the PBL schemes. However, little research has been conducted into a more comprehensive and systematic assessment of the performance capability of schemes in key regions of China, especially when it comes to the differences in the mechanisms of the schemes themselves, primarily because there is scarcely sufficient observational data, computer resources, and storage support to complete the work. In this companion paper (i.e., Part 1), four typical schemes (i.e., YSU, ACM2, BL, and MYJ) are selected to systematically analyze and evaluate near-surface meteorological parameters, PBL vertical structure, PBL height (PBLH), and turbulent diffusion coefficient (TDC) in five key regions of China (i.e., North China Plain, NCP; Yangtze River Delta, YRD; Sichuan Basin, SB; Pearl River Delta, PRD and Northwest Semi-arid region, NS) in different seasons (i.e., January, April, July, and October). The differences in the simulated 2 m temperatures between the nonlocal closure schemes are mainly affected by the downward shortwave radiation, but to compare the nonlocal closure schemes with the local closure schemes, the effect of sensible heat flux needs to be further considered. The 10 m wind speed is under the influence of factors like the momentum transfer coefficient and the integrated similarity functions at night. The wind speeds are more significantly overestimated in the plains and basin, while less overestimated or even underestimated in the mountains, as a result of the effect on topographic smoothing in the model. Moreover, the overestimation of small wind speeds at night is attributable to the inapplicability of the Monin–Obukhov similarity theory (MOST) at night. The model captures the vertical structure of temperature well, while the wind speed is outstandingly overestimated below 1000 m, largely because of the TDC. The difference between the MOST and the mixing length theory, PBLH, and Prandtl number is cited as the reason for the difference between the TDC of the YSU and ACM2 schemes. The TDCs of the BL and MYJ schemes are affected by the mixing length scale, which of BL is calculated on the basis of the effect of buoyancy, while MYJ calculates it with the consideration of the effect of the total turbulent kinetic energy. The PBLH of the BL scheme is better than the other schemes because of the better simulation results of temperature. In general, to select the optimal scheme, it is necessary to offer different options for different regions with different focuses (heat or momentum). The first focus is on the temperature field. The BL scheme is recommended for January in the NCP region, especially for Beijing, and the MYJ scheme is better for the other 3 months. The ACM2 scheme would be a good match for the YRD region, where the simulation differences between the four schemes are small. The topography of the SB region is more complex, but for most of the areas in the basin, the MYJ scheme is proposed, and if more stations outside the basin are involved, the BL scheme is recommended. The MYJ scheme is applied to the PRD region in January and April, and the BL scheme in July and October. The MYJ scheme is counseled for the NS region. The second focus is the wind field. The YSU scheme is recommended if the main concern is the near-surface layer, and the BL scheme is suggested if focusing on the variation in the vertical direction. The final evaluation of the parameterization scheme and uncertainties will lay the foundation for the improvement of the modules and forecasting of the GRAPES_CUACE regional model developed independently in China. [ABSTRACT FROM AUTHOR]

Previous scientific research on reservoirs of the Deng IV Member in the Gaoshiti-Moxi area, the main production area of the Anyue gas field with reserves of tens of billions of cubic metres, has focused on karst palaeogeomorphology reconstruction, the facies distribution on platform margins, and their effects on creating favourable reservoirs. However, the quality of microbial carbonate reservoirs is also closely related to their original depositional environments on both inner and marginal platforms. Therefore, this paper attempts to reveal favourable microbial carbonate reservoir characteristics and the sedimentary effects on their distribution and prediction based predominantly on a synthetic analysis of the sequence stratigraphy and depositional facies. The results show that favourable reservoirs of the Deng IV Member are classified into three types according to their reservoir spaces: fracture-cavity, pore-cavity and pore reservoirs. Secondary dissolution pores and cavities are primary reservoir spaces developed mainly in nonskeletal grain dolomites with sparry cements, thrombolites, and stromatolites. The physical properties of the fracture-cavity and pore-cavity types of reservoirs are better than those of pore reservoirs and have porosities between 1 and 5% and permeabilities between 0.01 × 10–3 and 1 × 10–3 μm2. Vertically, favourable reservoirs are developed mainly in parasequence set 6 (PSS6) and PSS7 and are laterally distributed in well zone MX9-MX19-MX1 for the fracture-cavity type, MX105-MX110-GS20 for the pore-cavity type and MX17-MX107-MX41-MX102-GS102 for the pore type. Moreover, depositional effects on reservoirs in terms of depositional sequences, seismic facies, microfacies and microfacies associations indicate that to some extent, the fracture-cavity type of reservoir is constrained by the top boundaries of PSS7, PSS2, parasequence 17 (PS17) and PS14; the pore-cavity type of reservoir is constrained by the top boundaries of PSS7, PSS4, PS18 and PS12; and the pore type of reservoir is constrained by the top boundaries of PSS7, PSS6, PSS3, PSS2, PS18, PS17, PS14, and PS12. Seismic facies associated with shoals and mound-flat complexes are related to the facies distributions of pore cavities and pore reservoirs. MA1, MA3, MA7, and MA8 are predominant microfacies associations of favourable reservoirs of the Deng IV Member in the Gaoshiti-Moxi area. The above results are significant for further petroleum exploration and exploitation of ultradeep microbial carbonate reservoirs in this area. [ABSTRACT FROM AUTHOR]

Anthropogenic forcing caused the biodiversity loss and stability decline of communities. There is still controversy over whether the decline in biodiversity will lead to a decrease in community stability. The stability of biological communities is related to both biodiversity and structure, and this paper aims to reveal the human impacts on diatom communities' biodiversity and structure. We studied the richness, β‐diversity and network distance of diatom communities in Qinghai‐Xizang, Yunnan‐Sichuan and Lower Yangtze River Basin, China through empirical dataset and simulation method. The results showed that the diatoms richness in the Qinghai‐Xizang and the Yunnan‐Sichuan region was lower and the network distance was higher than that of the Lower Yangtze River Basin. β‐diversity in the Lower Yangtze River Basin was the lowest and the diatom network distance responds negatively to human population densities in China. The simulation showed that the network distance kept constant during random species loss, and declined while specialist species were lost or replaced by generalist species. The results suggested diatom communities' homogeneity and stability decline were associated with human activities. Human impacts may cause biodiversity loss targeted to specialist species or no biodiversity loss while generalist species replace those specialist species. This study showed that how diversity changes determined ecological stability depends on the type of species changes. [ABSTRACT FROM AUTHOR]

The ion-adsorption rare earth deposit developed on the Mosuoying granite in the Panxi area of southwestern China represents a significant advancement in the exploration of ion-adsorption rare earth deposits in Sichuan. Being the first and currently the sole ion-adsorption rare earth deposit in Sichuan, studying its rare earth mineralization characteristics holds great importance. This paper aims to investigate the geochemical properties of the Mosuoying granite and its overlying weathered crust using rock geochemical methods based on field geological investigations. The findings reveal that the deposit belongs to the light rare earth type, with the ore-forming parent rock attributed to the high-potassium calc-alkaline series. It exhibits a high rock REE content ranging from 419 to 578 ppm, indicating favorable mineralization potential. Hydrothermal alteration reduces the REE content of the parent rock, leading to a notable increase in the LREE/HREE ratio, thus impacting the partitioning of rare earth elements and subsequent ore formation. The distribution characteristics of rare earth elements in each layer of the weathered crust are controlled by the parent rock and exhibit a light rare earth distribution pattern. The completely weathered layer is the main enrichment zone for rare earth elements, and the migration and enrichment patterns of rare earth elements in the weathered crust are evident. From the semi-weathered layer to the completely weathered layer, all REEs were gained, with a higher degree of migration for LREE. From the completely weathered layer to the clay layer, all REEs were lost, and the vertical distribution of rare earth content shows a "low-high-low" pattern. [ABSTRACT FROM AUTHOR]

Sichuan kahalo Jinsha River Bridge is a suspension bridge with a main span of 1030 m, and the anchorages on both sides are gravity anchorages. In order to adapt to special terrain and geological conditions, anchorage of Sichuan bank pioneered the use of frame structure as the anchorage foundation. The soil and the frame structure jointly bear the vertical load and resist the horizontal component of the main cable to form a "frame soil" community and fully mobilize the role of the undisturbed soil. In order to ensure the integrity of the frame structure, the indirect head of the slot section adopts a rigid joint. At the same time, the distributed grouting technology is used to strengthen the soil around the frame structure, so as to further improve the safety factor. This paper introduces the topography and geology of the anchorage position, compares and selects different anchorage foundation schemes, and explains in detail the design concept, structure size and construction technology of the frame foundation. The research shows that using frame structure as anchor foundation is not only reasonable, safe, good economy, but also environmentally friendly. It has solved the difficult problem of anchorage design under poor terrain and geological conditions, and will provide a good reference for the design of mountainous suspension bridges in similar condition. [ABSTRACT FROM AUTHOR]

Incorporating wind energy on a large scale into power systems presents challenges for the operation and control of the grid. To enhance the safety of power grid operation, accurate short-term forecasting of wind power is necessary, as it minimizes the impact of randomness. Considering the uncertainty and prediction issues associated with wind power, this paper introduces a CNN–GRU ultra-short-term wind power prediction model. This model relies on multichannel signals, including data such as wind speed, wind direction, climate conditions, and historical power outputs collected from wind farms. These data types contribute to the formation of a comprehensive multichannel signal for wind power. Following that, the CNN method extracts both global and partial features from these signals. Concurrently, features are extracted from past power outputs based on their time series. These features are then combined with the ones obtained from the convolution process. Subsequently, these combined features are input into a fully connected network. This step is crucial for blending multichannel information and generating forecast results. To validate the model, it was tested using data from a wind farm located in a specific region of Sichuan Province. According to our experimental results, the model demonstrates a high level of accuracy in computation and robust generalization ability. [ABSTRACT FROM AUTHOR]

Copyright of Trans/Form/Ação is the property of Trans/Form/Acao and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)