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This paper proposes a novel aviation CO 2 emissions reduction method by introducing a market-based incentive mechanism. An aviation carbon emissions prediction model is proposed to characterize both the microscopic flight dynamics and the macroscopic air traffic demand trend. Based on emissions prediction, a linear climate response model is applied to evaluate the environmental impact of the aviation carbon emissions. Finally, a market-based framework for aviation CO 2 emissions reduction is established based on a two-phase carbon trading model, which provides a piecewise charge method through emission taxation and cap-and-trade. A case study is carried out to demonstrate the effectiveness of the proposed framework using a real-world dataset from the Hefei Air Traffic Control Zone in China. Three scenarios are defined to describe the possible development speed of sustainable aviation fuel application in the future: not applied, medium-speed development, and high-speed development. The results show that the carbon peak will be reached in 2025 in the high-speed development scenario, when the emission amount and associated environmental impact will be reduced by 23.7% and 22.3%, respectively. Thus, the market-based framework proposed in this paper can effectively reduce aviation CO 2 emissions and mitigate the effects of global warming. • An aviation CO 2 emissions prediction model is proposed considering both microscopic flight dynamics and macroscopic traffic demand. • A more efficient market-based CO 2 emission reduction framework is developed based on a two-phase carbon trading model by means of taxation and cap-and-trade. • Case study shows that the proposed method has a more optimal incentive for CO 2 emission reduction. [ABSTRACT FROM AUTHOR]

Information on the vertical distribution of air pollutants is essential for understanding their spatiotemporal evolution underlying urban atmospheric environment. This paper presents the SO 2 profiles based on ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements from March 2018 to February 2019 in Hefei, East China. SO 2 decrease rapidly with increasing heights in the warm season, while lifted layers were observed in the cold season, indicating accumulation or long-range transport of SO 2 in different seasons might occur at different heights. The diurnal variations of SO 2 were roughly consistent for all four seasons, exhibiting the minimum at noon and higher values in the morning and late afternoon. Lifted layers of SO 2 were observed in the morning for fall and winter, implying the accumulation or transport of SO 2 in the morning mainly occurred at the top of the boundary layer. The bivariate polar plots showed that weighted SO 2 concentrations in the lower altitude were weakly dependent on wind, but in the middle and upper altitudes, higher weighted SO 2 concentrations were observed under conditions of middle-high wind speed. Concentration weighted trajectory (CWT) analysis suggested that potential sources of SO 2 in spring and summer were local and transported mainly occurred in the lower altitude from southern and eastern areas; while in fall and winter, SO 2 concentrations were deeply affected by long-range transport from northwestern and northern polluted regions in the middle and upper altitudes. Our findings provide new insight into the impacts of regional transport at different heights in the boundary layer on SO 2 pollution. [Display omitted] [ABSTRACT FROM AUTHOR]

Hefei, the capital city of Anhui Province, is located in China's central region. A city with over 2200 years of history, Hefei was still a middle-sized city at the end of 1970s. Over the past decade, however, the city had experienced a dramatic spatial expansion and economic growth. This paper discusses Hefei's history of development, its achievement in socioeconomic and spatial development, and its challenges with regard to future development. Urban researchers have largely ignored cities in China's central region; as such, this paper will serve to enrich the international literature in this field and enable readers to better understand the urbanization and industrialization efforts of a typical emerging city in inland China. [ABSTRACT FROM AUTHOR]

Knowledge of vertical distribution of air pollutants is important for understanding the mechanisms underlying haze pollution. In this paper, we characterize the vertical structure of air pollutants based on ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements in the wintertime in Hefei, East China. Both NO 2 and aerosol show exponentially decreasing profile with high concentrations concentrated close to the surface, suggesting the major emissions are at ground level. SO 2 profiles extend to slightly higher altitudes than NO 2 , which might be due to the SO 2 emissions from elevated point sources (e.g., power plants). Elevated HCHO was observed in the middle layer during noon time, probably indicating that the larger effect of the photochemical formation of atmospheric HCHO rather than direct HCHO emissions. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) models were used to evaluate the potential sources of Hefei's air pollution in the lower, middle and upper boundary layer. The results revealed that the major regional source of NO 2 and aerosol were located in the northern and eastern part of Anhui and the transport mainly occured in the lower layer. Transported SO 2 from the northwestern regions in the middle layer made great contribution to SO 2 in Hefei. HCHO was mostly produced locally while the transport of HCHO from potential source areas was negligible. To further explore the potential source contributions affecting haze pollution, PSCF and CWT analysis for heavy haze episodes suggested that the potential source areas for aerosol were almost located in the northern region, the northwestern region, and the YRD region. Our findings provide a more comprehensive understanding for regional transport through the study on potential sources at different altitudes, which are useful for designing collaborative air pollution control strategies on a regional scale. • Vertical distribution of air pollutants is investigated to identify potential sources at different altitudes during winter. • Both NO 2 and aerosol show exponentially decreasing profile with high concentrations concentrated close to the surface. • SO 2 and HCHO profile typically extended to higher altitudes than NO 2 and aerosol did during winter. • The main potential sources for aerosol were located in the northern region, the northwestern region, and the YRD region. • This study is useful for designing collaborative air pollution control strategies on a regional scale. [ABSTRACT FROM AUTHOR]

Nowadays industrial parks have played a massive role in promoting regional economic development. However, due to intensive industrial activities and enormous energy consumption, industrial parks have become the main areas for pollution emissions. China has carried out the National Demonstration Eco-industrial Parks program to solve such challenges. Industrial symbiosis is the kernel of industrial ecological construction. It aims at promoting several companies to gather in a same geographical site to share services, utility, and by-products in order to decrease environmental impacts of their industrial activities. However how to quantify the impact of industrial symbiosis on improving the sustainability of an industrial park is rarely studied. This study proposed an emergy analysis to conduct an assessment on Hefei economic and technological development area to quantify the performance of industrial symbiosis. Comparing with conventional evaluation methods, emergy analysis can reflect the real contribution of local ecosystem by focusing on nature's free investment, not only the economic value or the resources supplied to the industrial system. Research results show that industrial symbiosis operations improve the study area's sustainable development ability by 33%. Specifically, non-renewable inputs, imported resource inputs, and associated services could be saved by 99.71%, 25.64%, and 9.82%, and the ratio of the money saving to the total gross domestic product of the industrial park would be 29.71%. By examining industrial symbiosis practices in detail within the system, this paper can describe the process of the industrial symbiosis and how these industrial symbiosis practices influence the overall performance of the industrial park. This study indicates that industrial symbiosis could effectively reduce raw materials and energy consumption and improve the overall sustainability, which can help policy-makers make decisions. [ABSTRACT FROM AUTHOR]

Based on the principle of light propagation, it is necessary to obtain the ratio (R MN) of atmospheric aerosol mass concentration to the imaginary part of the atmospheric equivalent refractive index for measuring aerosol mass vertical flux. In this paper, the factors affecting the R MN values are analyzed by numerical calculation under an ideal state and by using observational data. Numerical calculations show that the R MN is mainly determined by the aerosol particle size distribution (PSD), hygroscopicity parameters and relative humidity. With the same relative humidity, the smaller the geometric mean diameter (Dg) is, the larger the R MN , and when the aerosol particle hygroscopicity parameter is greater than 0.14, the greater the relative humidity is, the smaller the R MN. Comprehensive experiments were conducted in urban Hefei, and the results of observations at Hefei confirm the numerical results. Data from ten cities across China also confirm the numerical results. The order of geometric mean diameter of aerosol particles at the ten sites can be determined by the order of R MN , and the order of hygroscopicity parameters at the ten sites can be determined by the order of the change rate of R MN with relative humidity. The geometric mean diameters of aerosol particles are different among the ten sites, while the hygroscopicity parameters are similar. • The ratio (R MN) of TSP mass concentration to the imaginary part of the atmospheric equivalent refractive index is defined • The R MN is mainly affected by aerosol particle size distribution, relative humidity and hygroscopicity parameter. • The order of geometric mean diameter of aerosol particles at the ten sites can be determined by the order of R MN. • The variation of R MN with relative humidity reflects hygroscopicity parameter (α) of the aerosol particles. [ABSTRACT FROM AUTHOR]

Solar energy is a sustainable and inexhaustible renewable energy. Solar-powered PV systems contribute to the cleanest and the most cost-effective electrical energy. However, PV systems are confronted with a nonlinear maximum power point tracking (MPPT) problem caused by partial shading (PS). PS causes the loss of available power. This paper presents a novel Harris hawk optimization (HHO) based MPPT controller to effectively track maximum power under all weather conditions. The effectiveness of the proposed HHO based MPPT is supplemented by a comparative study with perturb and observe algorithm (P&O), dragonfly optimization algorithm (DFOA), particle swarm optimization (PSO), cuckoo search (CS) and grey wolf optimization (GWO). The analytical and statistical analysis is made based on 4 different cases, including fast varying irradiance, PS, complex-PS (CPS), and field atmospheric data of Hefei city of China, to solidify the effectiveness of HHO based MPPT for PV systems in real-world applications. The proposed HHO shows superior performance in tracking maximum power point and faster convergence at the global maximum power point. The improvement of 10–30% in tracking time and more than 90% in random oscillations are effectively achieved by the proposed MPPT technique. Faster maximum power point (MPP) tracking, lower computational burden and higher efficiency are the key contributions of the HHO based MPPT technique. • Novel Harris hawk optimizations (HHO) based MPPT control of PV system is proposed. • HHO is compared with P&O, PSO, GWO, CSA, and DFOA through field atmospheric data and case studies. • HHO outperform competing techniques with 10-30% faster tracking, 4-6% more energy harvest and oscillation reduction 95.45%. • Statistical and quantitative analysis confirms the superior performance of the proposed HHO. [ABSTRACT FROM AUTHOR]

• Bayesian network model for buried gas pipeline failure analysis is presented. • The pipeline failure caused by corrosion and external interference is analyzed. • Failure frequency and leakage size are analyzed based on pipeline characteristics. • The pipeline in the city of Hefei is used to state the practicability of the model. • Critical pipeline parameters can be identified using this model. The unintentional release of urban buried gas pipeline may cause crucial consequences to the economy, society and environment. Corrosion and external interference are primary causes of pipeline failure incidents. Due to the complexity and unpredictability of outside influence on the buried gas pipeline, this paper presents an approach to analyze pipeline failure frequency and leakage size caused by corrosion and external interference based on pipeline characteristics. Bayesian network method is used to construct a knowledge model. Pipeline characteristics statistics and failure data are collected to build the relationships among variables in the model and verify the applicability of the model. Results show that the proposed model can estimate buried gas pipeline failure frequency and leakage size caused by corrosion and external interference. It is also capable of highlighting the critical parameters to pipeline failure. Practical application of the model is demonstrated on the underground gas pipeline in the City of H, China. Results indicate that proposed model can explicitly quantify uncertainties and then put forward practical measures for buried gas pipeline parameter design, laying plan and operating maintenance. [ABSTRACT FROM AUTHOR]

• A new Infrared beamline was constructed at HLS II. • Details of the optics and experimental techniques at the beamline. • High performance of the infrared beamline and endstations. National Synchrotron Radiation Laboratory (NSRL) owns the first dedicated synchrotron radiation facility in China, Hefei Light Source (HLS). The HLS was fully upgraded to HLS II in 2016. Following the machine upgrade, the infrared beamline was reconstructed to match the new storage ring and improved its performance. The infrared radiation is extracted from a bending magnet (1 degree port) with an acceptance angle of 65(H) × 55(V) mrad2, which including edge radiation and constant field radiaton. Two endstations were reconstructed. One is for spectroscopy experiment covering from far to near infrared, the other one is for mid-infrared microspectroscopy and imaging experiment. In this paper, we introduce the new infrared beamline and endstations in detail, including optics, experimental techniques developed at two endstations. [ABSTRACT FROM AUTHOR]