Particulate matter (PM) pollution within subway systems poses a potential threat to passenger health. Traditional 3D computational fluid dynamics (CFD) simulations using dynamic mesh technology offer high accuracy but incur substantial computational costs, making multi-scenario parametric optimization impractical. This paper proposes a rapid calculation model for PM concentration on subway platforms based on a 2D reduced-dimensional flow field and equivalent PM emission rates. By simplifying complex 3D flow fields into equivalent 2D planes and correcting PM source terms based on train operating conditions, the model significantly reduces computational costs. To validate the model's application value, multi-scenario simulations were conducted for the height of platform screen door (PSD) vents, and a continuous surrogate model was constructed using Gaussian Process Regression (GPR). The results indicate that while maintaining high consistency with 3D simulation results (with errors within allowable ranges), the model improves computational efficiency by 98%. The GPR surrogate model identified an optimal vent height of 0.50 m, which balances PM control with ventilation energy savings. This study provides an efficient numerical tool for real-time monitoring and structural topology optimization of subway ventilation systems.

This study employed PM2.5 concentration data for Xianyang City spanning the years 2014 to 2021, in conjunction with the global data assimilation system （GDAS）. Various analytical techniques, including backward trajectory clustering analysis, potential source contribution function （PSCF）, concentration weighted trajectory analysis （CWT）, and relevant statistical methods, were employed to investigate the temporal and spatial variations in PM2.5 pollution. Furthermore, this research aimed to elucidate the source characteristics and potential areas contributing to PM2.5 pollution within Xianyang City. The results revealed a fluctuation in PM2.5 pollution concentration in Xianyang City from 2014 to 2021, with an initial increase followed by a subsequent decrease. The peak average annual concentration, reaching 81.25 μg·m-3, was recorded in 2016. Seasonal variations indicated higher PM2.5 concentrations in autumn and winter, contrasting with lower levels in spring and summer. Winter exhibited the highest PM2.5 concentration at 116 μg·m-3, while the lowest was recorded in summer at 31.58 μg·m-3. Spatially, the annual mean distribution of PM2.5 in Xianyang City demonstrated heightened pollution in the southern and central regions, juxtaposed with lower pollution in the northern areas. Cluster analysis highlighted that Xianyang City experienced substantial influence from northwest airflow during spring, autumn, and winter, while short-distance transport dominated during the summer months. PSCF and CWT analyses indicated that the high-value potential source contribution areas were most extensive during winter, followed by spring and autumn. Conversely, the high-value area in summer was the smallest. The potential source areas were concentrated within Xianyang City and extended northwest to southeast, encompassing regions in western Inner Mongolia, central and eastern Gansu Province, central and southern Ningxia, and central Henan. In analyzing periods of heavy pollution, the study demonstrated that PM2.5 pollution in Xianyang City was primarily induced by westerly airflow. High PM2.5 concentrations were influenced by the surrounding areas of Xianyang City and the source zone, akin to regions with high potential source values during the winter. As a consequence, mitigating PM2.5 pollution in Xianyang City necessitates stringent control measures for both local and regional pollution sources. Additionally, regional collaborative efforts should be emphasized to prevent external pollution sources from exacerbating persistent pollution episodes in the region.

Conducting Marine Ecological Civilization Construction (MECC) will help to form the coordination of socio-economic, marine ecosystem, and stable marine society. How to evaluate the performance of MECC precisely is an urgent problem in the development of coastal areas. In this study, a comprehensive evaluation indices system consisting of 41 indicators and five dimensions was constructed to reflect the performance of MECC in three coastal cities of Jiangsu Province. Entropy and AHP methods were integrally used to determine the weight of each index, and then, Technique for Order of Preference by Similarity to ideal Solution (TOPSIS) method was applied to depict the relative performance level of marine ecological civilization. The results showed that: (1) From 2011 to 2021, the MECC of Jiangsu coastal regions has gradually increased from 0.3649 to 0.5933, indicating that the development of Jiangsu is undergoing a transformation from resource intensive to environmentally friendly. (2) Different cities had different strengths in marine subsystem layer, with Lianyungang dominated by resource endowment, Yancheng capitalizing on its environmental strengths, and Nantong being significant in marine economic. (3) A decade long dynamic showed that Yancheng achieved the largest improvement by 84.82% from 2011 to 2021, followed by Nantong (69.48%) and Lianyungang (38.15%). (4) For further promoting MECC process, Jiangsu should strategically prioritize land-sea coordination, undertake comprehensive governance and waging a resolute battle for comprehensive marine governance in critical areas. The comprehensive performance evaluation indices system of MECC proposed in this study would be robust and reliable for application in other areas. Meanwhile, the results and recommendations of Jiangsu Province could be valuable for further enhancing MECC development and providing scientific bases for local decision-makers.

The performance of RAP material directly affects the engineering effect of pavement recycling technology. In this study, the performance of high content RAP recycled mixture was analyzed. Through the extraction and screening of RAP materials, it was found that the viscosity of old asphalt increased significantly, the softening point decreased, and the coarse aggregate was refined seriously. The high, low temperature and water stability of high content plant mixed recycled ATB-25 mixture were studied through laboratory tests with different regenerants. The results showed that, compared with the control group, the dynamic stability, freeze-thaw splitting strength ratio and the maximum flexural tensile strain increase rate were: Type A regenerant: 27.48%, 29.45%, 35.71%; Type B regenerant: 16.76%, 21.28%, 38.96%. Comparing the effects of the two kinds of regenerants, after adding Type A regenerant, the mixture has the best high-temperature and water stability, and Type B regenerant is better than Type A regenerant in improving the low-temperature performance. The high, low temperature and water stability of the mixture after adding the regenerant can meet the specification requirements.

The application of construction waste in road engineering is an effective means to improve the level of resource recycling. Due to the lack of specialized sorting equipment for different types of construction waste and the high cost of manual sorting, resource utilization enterprises mainly rely on mixed crushing and regeneration in production, while there is a lack of systematic research on the application technical indicators of recycled aggregates for brick concrete mixed construction waste. This article proposes a quality evaluation model for construction waste coarse aggregates based on the theory of matter element extension, providing new ideas for quantitative evaluation of the quality status of coarse aggregates, and also providing reference for the rational selection of recycled coarse aggregates and the determination of mechanical parameters of coarse aggregates in the construction process, which is conducive to the evaluation and analysis of the quality status of recycled coarse aggregates.

Vehicle exhaust emissions are posing an increasingly adverse impact on urban air quality. The emission characteristics analysis and health effect assessment of specific air pollution sources can provide scientific evidence for environmental air quality management. The characteristics and health effects of PM2.5 emissions from vehicles and economic losses caused by them in the Beijing-Tianjin-Hebei Region were analyzed from 2010 to 2020. From 2010 to 2020, PM2.5 emissions from vehicles in the Beijing-Tianjin-Hebei Region showed an annual increase at first, followed by a slow decrease. According to the emission sharing ratios of different vehicle types, heavy-duty trucks and buses were the main contributors to PM2.5, with a total contribution rate of over 65.27%. The emission characteristics of vehicle pollutants varied in different cities. The contribution rate of pollutants in Beijing decreased significantly, and the emission reduction in other cities was also dramatic. The evaluation results of the impact of PM2.5 emissions from vehicles on human health showed that the number of health endpoints in the Beijing-Tianjin-Hebei Region was on the rise. In 2020, PM2.5 pollution caused approximately 34337 premature deaths (95% CI:9025-57209), 45500 hospitalizations (95% CI:10800-80200), 282300 outpatients (95% CI:140500-416300), and 439000 people to fall ill (95% CI:160300-679200). Beijing had the largest number of patients that presented different health endpoints. The total health and economic losses caused by PM2.5 emissions from vehicles in 2010, 2015, and 2020 were 27.742 billion yuan (95% CI:8.616-44.643 billion yuan), 90.608 billion yuan (95% CI:28.476-144.050 billion yuan), and 129.965 billion yuan (95% CI:40.829-205.245 billion yuan), respectively. In addition, due to the differences in vehicle ownership, PM2.5 concentrations, population, and economic losses per case of health outcome, the health effects and economic losses varied in different cities within the region. Among these cities, Beijing, Tianjin, Baoding, and Tangshan were at higher health risks and suffered more economic losses. The results of this study will help reduce the adverse effects on health and economic losses caused by pollution discharge and provide scientific evidence for environmental protection authorities to implement targeted pollution prevention and control.

Eco-efficiency is a practical approach to promote sustainable industrial development, as it emphasizes fewer environmental impacts alongside increased economic benefits. This study applies the super-minimum distance to a strong efficient frontier–Malmquist–Luenberger model to assess the static and dynamic eco-efficiency of 37 industrial sectors in China during 2003–2015 and analyzes how input redundancy, an excess of undesirable outputs, and a shortage of economic output influence industrial eco-efficiency. The results show that China’s overall static industrial eco-efficiency has steadily risen but remains inefficient. Furthermore, the inefficiency performance of inputs and outputs present fluctuating downward trends, and the inefficiency being more severe than output inefficiency. Moreover, clear discrepancies exist in the input and output inefficiency levels in the 37 industrial sectors. Manufacture of electrical machinery and equipment and other four sectors have achieving eco-efficiency in input, while mining of other ores is under inefficiency in input. Meanwhile, utilization of waste resources industries and other six sectors perform well in output, while the performance of mining of other ores is the worst. The average total-factor productivity of China’s industrial eco-efficiency is 0.995, which is close to the production frontier but leaves considerable room for improvement. The change is due mainly to the increased technical efficiency of production and the lag in the technological progress of production—the latter factor is emerging as a contributor to improved eco-efficiency even as the positive reinforcement of technical efficiency is reducing. The paper shares relevant policy suggestions to improve eco-efficiency and foster sustainable economic development.

结合2014～2020年临汾市臭氧逐小时质量浓度和同期气象数据、再分析数据以及潜在源贡献函数法(PSCF)对临汾市O3污染时空变化特征、与气象因子的关系以及传输路径及潜在源分布开展研究.结果表明,临汾市近年来臭氧污染日益严重,O3_8h_max年均质量浓度整体呈现上升趋势,2020年相对于2014年增加78.79％;月变化特征呈现"M"双峰型,季节变化峰值出现在夏季,而日变化受近地面大气光化学过程影响显著,呈较为明显的单峰单谷分布,峰值出现在14:00～16:00.O3浓度与气温和日照时数呈显著线性正相关,当研究区相对湿度为40％～60％,气温高于20℃,风速区间为2～6m/s时易出现高浓度O3污染.聚类分析表明临汾市O3重污染天气期间以短距离输送气流为主,高O3浓度除受到本地生成影响外,还受到省内临近城市及陕西省中部、河南省北部重工企业排放的大量NOx和VOCs传输的影响.因此,针对临汾市O3污染在严格控制本地污染源排放的前提下,必须加强汾渭平原地区的联防联控,才能有效缓解该区域大气污染的连片发生.

The deriving of mangrove biophysical parameters in a cost-effective manner, at a fine spatial scale and over relatively large areas remains a significant challenge. This study aims to provide a comprehensive integrated technical method to map mangrove landscape biophysical characteristic parameters (height, canopy area, canopy perimeter and volume) of two typical mangrove areas in China based on unmanned aerial vehicle (UAV) techniques. In this study, initially, response surface methodology (RSM) was applied to seek the optimal flight parameters for obtaining good-quality synthesized the orthophoto digital composite images. Afterward, a digital surface model (DSM) and a dense photogrammetric point cloud technical method were utilized to derive the mangrove parameters, and artificial visual interpretation was applied to carry out species discrimination and mangrove community canopy coverage. The results showed that the most efficient combination of flight parameters for mangrove extraction is UAV vertical shooting at 30 m altitude and a 75% overlap ratio, which could cover a maximum mangrove investigation area of 0.51 ha during low tide within a day. (2) The integrated technical methods demonstrated good performance in retrieving high-precision mangrove landscape parameters by taking the Dongwei and Daguansha mangrove areas as examples. (3) Transact analysis showed an inverted Ucurve of height, canopy area, and volume from the seaward mangrove edge to the landward mangrove edge. Overall, the UAV system with high-resolution (8 cm pixel) images has the potential to enable satisfactory extraction of mangrove landscape parameters by using multisoftware processing. The study will be helpful to the policy-makers, ecologists and environmentalists to formulate and implement various sustainable development programs in mangrove ecosystems.

采用对数平均迪氏指数方法,区分生产和生活两个体系,构建时空分解分析模型,追踪了福建省9个设区市2011-2019年水污染物排放变化的关键驱动力及其贡献的时空差异.结果显示:研究期内福建省工业废水污染物排放持续减少,并且各驱动力贡献的区域差距明显变小,趋于平衡;生活污水污染物排放量仍保持高位,各驱动力贡献的区域差距基本保持不变.其中,经济规模扩张是福建省水污染物排放的主导驱动力,主要源于福州、厦门、泉州经济赶超发展影响;城镇化发展对区域生活污水污染物排放的驱动影响表现为增排效应,以福州和厦门尤为显著;工业化发展对区域工业废水污染物排放的影响效应由正驱动逐渐转变为负驱动,这主要归功于三明和泉州产业结构调整优化的拉动效应;技术效应一直是福建省水污染物排放控制的重要驱动力,但部分地区已逐渐步入生活污染物技术减排攻坚期.

China has been undergoing rapid economic growth since its reform and opening-up at the expense of resource depletion and environmental pollution. We estimated the monetary costs of resource depletion and environmental pollution in China over the past 14 recent years by establishing integrated mathematical models with System for Integrated Environmental and Economic Accounting (SEEA) framework. Results showed four points. Firstly, the total temporal costs of natural resource depletion and environmental pollution witnessed an inverted ‘U’ shape pattern with the turning point in 2012. The relationship between cost of mineral resource depletion, as well as water pollution cost, and per capita GDP were found to follow the Inverted-U shape environmental Kuznets curve (EKC). Secondly, the average annual share of natural resources of the total costs was more than 80%, indicating that the rapid economic growth of China is highly dependent on resource depletion. Thirdly, Although China still has the highest worldwide in its total energy consumption and CO2 emission, China's struggles with adjustment of industrial & energy consumption structure, and pollution controls have resulted in a general temporal decline of the share of resource and environmental costs to China's GDP. The green GDP of China is growing at an average rate of 14.76%. Finally, although in the process of manufactured goods for the whole world, China has reduced environmental pollution and left it at home as much as possible. Driving forces behind the progress in green GDP of China were analyzed by using Differences-in-Differences method and Spearman rank correlation analysis.

The research on spatial pattern and optimization of regional ecological carrying capacity is especially necessary to promote the overall development of economic transformation, upgrading and ecological protection and restoration. This study chose the natural, social and economic complex ecosystem of Jiangsu coastal area as subject. The concept model of pressure-state-potential (PSP) of ecological carrying capacity was established. A total of 15 indices were used to represent the interaction of three level states. With the support of GIS and other space technologies, the magnitude, spatial variation of regional ecological carrying capacity were examined through comprehensive evaluation of multiple indices and analysis of single index. Results showed that the spatial pattern of the suitability of single factor ecological carrying capacity in Jiangsu coastal area showed a variety of trends. There were significant differences in the area, proportion and layout of the same index across different cities and counties. The spatial differentiation of pressure and state superposition index showed that low pressure suitable bearing, low pressure generally suitable bearing, low pressure unsuitable bearing, high pressure suitable bearing, high pressure generally suitable bearing, bearing high pressure unsuitable bearing area was 3971.42, 6885.21, 3705.23, 4597.03, 6853.26, and 6403.97 km2, accounting for 12.3%, 21.2%, 11.4%, 14.2%, 21.1% and 19.8% of the total area, respectively. The results of spatial differentiation of superposition index of state and potential showed that the area integral of low potential suitable bearing, low potential general sui-table bearing, low potential unsuitable bearing, high potential suitable bearing, high potential general sui-table bearing and high potential unsuitable bearing was 3030.79, 6545.30, 5874.31, 3253.31, 7614.38, and 6097.83 km2, accounting for 9.4%, 20.2%, 18.1%, 10.0%, 23.5% and 18.8% of the total area, respectively. Most areas showed distribution characteristics of low pressure bearing area corresponding to high potential bearing area and high pressure bearing area corresponding to low potential bearing area in spatial pattern. There was an interaction of mutual influence, mutual promotion and collaborative promotion between pressure and state superposition index and state and potential superposition index.

通过建立综合指标评价体系,运用熵权法、产业聚集指数,对淮河生态经济带25个地级市产业承接能力和承接行业进行了研究,并采用GIS空间技术,揭示了产业承接能力及其各影响要素的空间格局.结果显示:(1)淮河生态经济带内产业承接能力整体呈东高西低的分布格局,三大片区中,中西部内陆崛起区产业承接能力最差.(2)地区发展水平、科技创新能力和市场潜力对产业承接能力的影响最为显著,较低的产业发展成本是经济带吸引产业转入的主要优势之一.(3)经济带当前的产业承接方向以劳动密集型行业为主,结合国家相关政策,建议淮河生态经济带产业承接方向由劳动密集型向战略新兴产业转变.

为研究长三角城市群机动车污染物排放特征,本研究应用COPERTⅣ模型估算1999-2017年长三角城市群机动车污染物CO、NMVOC、NOx、PM2.5、PM10、CO2、CH4、N2O、NH3和SO2排放因子,建立排放清单,并对其排放特征展开分析,结果表明:1999-2017年不同污染物时间变化趋势存在差异,污染物CO、NMVOC、NOx、PM2.5、PM10和CH4排放量呈现先增长后下降的趋势,但开始下降的年份不同,CO2和NH3排放量增长趋势显著,2017年相对于1999年分别增加621％和3925％,N2O和SO2排放量总体呈上升趋势并在特定年份下降明显;污染物排放空间分布与路网分布基本一致,沿海地区的排放强度要明显大于内陆地区,特别是长江下游、杭州湾和太湖附近的城市最为明显;轻型客车为污染物CO、NMVOC、CO2、CH4、N2O和NH3的主要贡献车型,重型货车和重型客车为污染物NOx、PM2.5、PM10和SO2主要贡献车型;长三角城市群各城市机动车污染物排放量的差别主要与各城市机动车保有量有关,上海市各污染物贡献率下降幅度明显,机动车污染物主要贡献城市除了省会城市和直辖市之外,其余城市的污染物排放也不容忽视.

Urban green spaces and water bodies play major roles in effectively alleviating the urban heat island (UHI) effect by decreasing temperature. Here, statistical correlation and regression analyses were carried out to examine the relationships between metrics (vegetation coverage, water coverage, area, leaf area (LA), and patch shape index (PSI)) and land surface temperature (LST) or cooling effect intensity. Besides, the cooling ranges of green spaces and water bodies were explored by sampling and thresholds detection. Landsat satellite images were used to derive land cover map and LST map. Results show that: (1) average LST within given residential area decreases with the vegetation coverage and water coverage increasing; (2) area and LA are both significantly positively correlated with the cooling effect beneficial to people entering green spaces; (3) increasing the vegetation coverage in the range from approximately 0-28 % can effectively and economically alleviate the thermal environment of residential areas, and the economical optimal green space area and LA are both 0.26 ha; and (4) from 2010 to 2017, the cooling range of green spaces in the central districts of Nanjing is around between 180 and 810 m with the average value of 540 m, while the cooling range of water bodies ranges approximately from 510 to 1260 m with the average value of 840 m.

China has put forward CO2 emissions reduction target (committing to achieve CO2 emissions peak or plateau by 2030) to prevent global climate change. With Jiangsu Province as a case, we explored whether China could achieve the 2030 CO2 emissions reduction target. We predicted the peak volume and time of CO2 emission in three scenarios, i.e., quick scenario, medium scenario, slow scenario, respectively, based on the long-range energy alternatives planning system (LEAP) model and the logarithmic mean Divisia index decomposition approach. The results showed that, during the period 2000 to 2015, the economic scale effect was the most important driver, whose contribution to the increase of total CO2 emissions was as high as 147.4%. The technology progress effect was the main mitigation factor for CO2 emissions, which caused CO2 emissions to decrease by 60.4%. In addition, the contributions of energy structure effect, industrial structure effect, per capita income effect and population scale effect to CO2 emissions were -5.3%, 9.7%, 11.0%, and 0.6% respectively. In quick and medium scenarios, the peak CO2 emissions of Jiangsu Province would be 701 million tons in 2025, and 795 million tons in 2029, respectively. In slow scenario, however, Jiangsu Province could not achieve the 2030 CO2 emissions reduction target. To achieve the 2030 target, Jiangsu Province needs to adopt some strategies, including actively developing the tertiary industry to balance the economic structure, continuously promoting energy saving and emissions reduction technologies to reduce energy consuming intensity, and vigorously deploying clean energy to optimize the energy consuming structure.

Vehicular emissions have become one of the important sources of air pollution, and their effective control is essential to protect the environment. The Chengdu-Chongqing Urban Agglomeration (CCUA), a less developed area located in the southwest of China with higher vehicle population and special topographic features, was selected as the research area. The aims of this study were to establish multi-year vehicular emission inventories for ten important air pollutants in this area and to analyze emission control policy scenarios based on the inventories. The results showed that the ten vehicular pollutant emissions had differences during the past decade, and CO2 and NH3 increased markedly between 1999 and 2015. Chengdu and Chongqing were the dominant contributors of vehicular emissions in the CCUA. Eight scenarios based on these inventories were designed and the alternative energy replacement scenario was studied from the life-cycle perspective. Compared with the business as usual scenario, elimination of substandard vehicles scenario is the most effective policy to control NOx, PM2.5, PM10, and CH4 emissions; the radical alternative energy replacement scenario could decrease the vehicular NMVOC, CO2, N2O, and NH3 emissions; the elimination of motorcycles scenario could decrease the vehicular CO emissions; and the raising fuel standards scenario could reduce vehicular SO2 emissions significantly (by 94.81%). The radical integrated scenario (combining all of the reduction control measures mentioned above) would achieve the maximum emission reduction of vehicular pollutants CO, NMVOC, NOx, PM2.5, PM10, CO2, N2O, and NH3 compared with any scenario alone.

Ecological compensation is an effective means to adjust relationships among stakeholders in order to conserve and/or sustainably use ecosystem services. The current ecological compensation standards (ECS) do not well reflect the differences in ecological, social, and economic development. Thus, we took a typical urbanization area (the Suzhou–Wuxi–Changzhou region) in China as an example, because of its prominent contradiction between rapid socio-economic development and fragile ecosystem. Combined with the ecological, economic, and social conditions, the methods of ecosystem service value (ESV) evaluation, cluster analysis, and scenario analysis were used to propose an optimized spatial zoning method and optimal development scenario. Then, the ECS by different zones were determined by using ESV assessment, cost-benefit analysis, and contingent valuation method. The results showed that (1) the regions were divided into two categories, with a total of four zones: ESV output areas (synergetic development zones (SDZ) and ecological conservation zones (ECZ)) and ESV input areas (ecological degradation zones (EDegZ) and economic development zones (EDevZ)); (2) among five scenarios, the best development mode in the future was the protection and development scenario, which was consistent with the existing planning; and (3) the ECS for the SDZ should be paid about 1.94 billion Yuan/year, the ECZ should be paid about 0.80 billion Yuan/year, the ECS for the EDegZ should pay about 2.20–2.25 million Yuan/year, and the EDevZ should pay about 0.06–7.33 million Yuan/year. By feasibility analysis, the ESV input areas were fully capable of inter-regional compensation, which could promote the effective purchase of ecological services. The developed evaluation framework of ECS in this study can accurately provide a scientific basis for the determination of ecological compensation regulations and policies in the future.