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Perfect plane-wave source for a high-order symplectic finite-difference time-domain scheme 认领 引用 被引量：5
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作者 王辉 黄志祥 +1 位作者 吴先良 任信钢 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期365-370,共6页
The method of splitting a plane-wave finite-difference time-domain （SP-FDTD） algorithm is presented for the initiation of plane-wave source in the total-field / scattered-field （TF/SF） formulation of high-order sy... The method of splitting a plane-wave finite-difference time-domain （SP-FDTD） algorithm is presented for the initiation of plane-wave source in the total-field / scattered-field （TF/SF） formulation of high-order symplectic finite- difference time-domain （SFDTD） scheme for the first time. By splitting the fields on one-dimensional grid and using the nature of numerical plane-wave in finite-difference time-domain （FDTD）, the identical dispersion relation can be obtained and proved between the one-dimensional and three-dimensional grids. An efficient plane-wave source is simulated on one-dimensional grid and a perfect match can be achieved for a plane-wave propagating at any angle forming an integer grid cell ratio. Numerical simulations show that the method is valid for SFDTD and the residual field in SF region is shrinked down to -300 dB. 展开更多
关键词 splitting plane-wave finite-difference time-domain high-order symplectic finite-differencetime-domain scheme plane-wave source
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Characteristics of carbon emission point sources and industry analysis in the Guangdong-Hong Kong-Macao Greater Bay Area 认领 引用 被引量：2
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作者 Ying Teng Jiajie Li +10 位作者 Yiqi Chen Meiyu Guo Tian Gao Ji Kong Yuze Wang Pengfei Wang Jinlong Zhu Songbai Han Senyou An Jianbo Zhu Heping Xie 《Energy Geoscience》 EI CAS CSCD 2026年第1期179-194,共16页
Carbon Capture,Utilization,and Storage(CCUS)technology has gained widespread attention in recent years as a critical strategy to combat global climate change,particularly in achieving carbon neutrality goals.The Guang... Carbon Capture,Utilization,and Storage(CCUS)technology has gained widespread attention in recent years as a critical strategy to combat global climate change,particularly in achieving carbon neutrality goals.The Guangdong-Hong Kong-Macao Greater Bay Area(GBA),as one of China's most economically active regions,serves as a key engine for economic growth while also facing considerable carbon emission challenges.This study analyzes the industrial emission volume and geographical distribution of key emitting enterprises in the GBA,summarizes their technological processes and main carbonemitting equipment,and provides scientific support for precise mitigation policies and low-carbon development.Based on data from 176 key emitting enterprises,the study reveals that Guangzhou and Dongguan host the largest number of such enterprises.Carbon emissions are primarily concentrated in the power sector,dominated by coal-and gas-fired power units,characterized by significant spatial dispersion and uneven distribution.Beyond the power sector,the paper industry has a high number of enterprises but lower emissions.Key facilities such as boilers,cogeneration systems,and production lines are predominantly located near tributaries rivers in Dongguan and Jiangmen.The building materials sector,primarily cement production,ranks as the second-largest emitter,with hightemperature kilns and grinding equipment,particularly rotary kilns and glass furnaces,as the main sources.The petrochemical and chemical sectors have fewer enterprises and lower emissions in the GBA,mainly located in suburban industrial clusters.Carbon emissions in the GBA exhibit distinct industry concentration and geographical distribution disparities.This study provides crucial data and theoretical insights for the development of targeted emission reduction strategies,optimization of source-sink matching,and the advancement of CCUS technologies in the region,particularly from the GBA to the northern South China Sea. 展开更多
关键词 Greater Bay Area Key emitting enterprise Carbon emission point source Source-sink matching CCUS
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Development of a smart device Android-based decision support system for controlling non-point source nitrogen and phosphorus pollution in an agricultural catchment 认领 引用 被引量：1
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作者 Meihui Wang Wenqian Jiang +5 位作者 Yuxi Fu Yi Wang Xinliang Liu Jianlin Shen Feng Liu Yong Li 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2026年第2期565-576,共12页
Intervention strategies to control non-point source nitrogen(N)and phosphorus(P)pollution in agriculture are expensive and there is a trade-off between engineering cost and treatment effectiveness.Implementing strateg... Intervention strategies to control non-point source nitrogen(N)and phosphorus(P)pollution in agriculture are expensive and there is a trade-off between engineering cost and treatment effectiveness.Implementing strategies often result in unsatisfactory outcomes and massive engineering costs when managing diffusive pollution in agricultural catchments.To address this issue,this paper proposes a robust,handy,catchment N&P decision support system(CNPDSS),an Android-based smartphone system integrated with a web-based geographic information system(GIS).The CNPDSS aims to provide artificial intelligence-driven decisions that minimize N&P loadings and engineering costs for mitigating pollution in agricultural catchments.It consists of four components:a general user interface(GUI),GIS,N&P pollution modeling(NPPM),and a DSS.The CNPDSS simplifies the GUI and integrates GIS modules to create a user-friendly interface,enabling non-professional users to operate the system easily through intuitive actions.The NPPM uses straightforward empirical models to predict N&P loadings,enhancing efficiency by avoiding excessive parameters.Taking into account the N&P movement pathway in the catchment,the DSS incorporates three control measures:source reduction in farmland(before migration stage),process retention by ecological ditch(midway transport stage),and down-end purification by constructed wetland(waterbody discharge stage),to formulate a comprehensive ternary controlling strategy.To optimize the cost-effectiveness of any proposed N&P control strategies for sub-catchments,a differential evolution algorithm(DEA)is employed in CNPDSS to carry out a dual-objective decision-making optimization computation.In this study,the CNPDSS is applied to a case study in an agricultural catchment in Central China to develop the most cost-effective ternary N&P control strategies that ensure the catchment water quality within Criterion Ⅲ of the Chinese Surface Water Quality Standard GB3838-2002 is met(total N concentration≤1.0 mg L-1and total P concentration≤0.2 mg L-1).Our results demonstrate that the CNPDSS is feasible and also possesses an adaptive design and flexible architecture to enable its generalization and extension to support strong hands-on applications in other catchments. 展开更多
关键词 decision support system non-point source N&P pollution a ternary controlling strategy dual-objective optimization agricultural catchment
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Source parameters of the 2023 ML 6.4 Jajarkot earthquake in the western Nepal seismic gap zone 认领 引用 被引量：1
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作者 Sanjev Dhakal Ling Bai +7 位作者 Bowen Song Guohui Li Md.Moklesur Rahman Hui Su Zhiwen Chen Shaojun Wang Hongru Li Li Li 《Earthquake Science》 CAS CSCD 2026年第3期273-285,共13页
The 2023 local magnitude(ML)6.4 Jajarkot earthquake was the most destructive event to occur in the source region of the 1505 MW8.2 Lo Mangthang Mustang earthquake in western Nepal.Here we used local seismic stat... The 2023 local magnitude(ML)6.4 Jajarkot earthquake was the most destructive event to occur in the source region of the 1505 MW8.2 Lo Mangthang Mustang earthquake in western Nepal.Here we used local seismic stations deployed in Nepal and southern China,and teleseismic stations with depth phase records to study the earthquake relocation and source rupture process.The Jajarkot earthquake was relocated to an epicenter at 28.828°N,82.110°E and a focal depth of 13 km.The fault plane solution showed a thrust fault earthquake with a north-dipping angle of 21°.The released seismic moment was 3.88×1017N·m,corresponding to a moment magnitude(MW)of 5.7.The rupture area was 25 km along the strike and 20 km along the dip.The rupture nucleated on the ramp structure of the main Himalayan thrust and propagated to shallower depths,causing severe damage to the surrounding region.This study provides new insights into the local geometry of the main Himalayan thrust within the seismic gap zone in western Nepal. 展开更多
关键词 2023 Jajarkot earthquake Main Himalayan Thrust seismic observation earthquake relocation source rupture process
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Intelligent characterization of discontinuities and heterogeneity evaluation of potential hazard sources in high-steep rock slope by TLS-UAV technology 认领 引用 被引量：2
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作者 Changqing Liu Han Bao +5 位作者 Tianyi Wang Jingfeng Zhang Hengxing Lan Shengwen Qi Wei Yuan Shunichi Koshimura 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第1期509-527,共19页
The identification of rock mass hazard sources is fundamental for preventing rockfall and landslide disasters in mountainous regions,with rock mass structural characteristics playing a vital role in hazard assessment.... The identification of rock mass hazard sources is fundamental for preventing rockfall and landslide disasters in mountainous regions,with rock mass structural characteristics playing a vital role in hazard assessment.In this study,terrestrial laser scanning(TLS)and unmanned aerial vehicle(UAV)technologies were integrated to enhance the evaluation methodology for rock mass hazard sources,focusing on the Sichuan Yanjiang Expressway project in China.The findings demonstrate that TLS-UAV technology enhanced both spatial coverage and data density in slope modeling.Through integrated algorithmic analysis,rock discontinuities within heterogeneous datasets were systematically identified,enabling quantitative extraction and statistical analysis of key geometric parameters,including orientation,trace length,spacing,and roughness.Furthermore,quantitative models were developed for cohesion,friction angle and the morphology parameter M of in situ discontinuities,respectively,facilitating efficient mechanical parameter acquisition.A novel rock mass hazard index(RHI)was developed incorporating discontinuity geometric rating(DGR),discontinuity mechanical rating(DMR),and slope mass rating(SMR).Field validation confirmed the methodology's effectiveness in evaluating risk levels and spatial heterogeneity of rock mass hazard sources,revealing the contribution of different discontinuity sets to the rock mass hazard and identifying the primary discontinuity sets controlling instability mechanisms.This study is of great significance for evaluating discontinuity-controlled rock mass hazard sources and preventing rockfall disasters. 展开更多
关键词 High-steep slope Rock mass hazard source Discontinuities Intelligent characterization Terrestrial laser scanning(TLS) Unmanned aerial vehicle(UAV)
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Sources of total and dissolved aerosol iron at Xi’an,Northwest China:implications for solubility of aerosol iron from different sources 认领 引用
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作者 Yizhu Chen Tianyu Zhang +9 位作者 Zhenyu Wang Zhenming Zhu Yifan Zhang Mingyuan Liu Fu Wang Yan Ren Guoliang Shi Guohua Zhang Xinming Wang Mingjin Tang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第7期29-37,共9页
Dissolved aerosol iron(Fe)significantly impacts marine biogeochemical cycles,human health,and atmospheric multiphase reactions.However,up to now very few studies have quantified its sources.This work employed a recept... Dissolved aerosol iron(Fe)significantly impacts marine biogeochemical cycles,human health,and atmospheric multiphase reactions.However,up to now very few studies have quantified its sources.This work employed a receptor model to investigate the sources of total and dissolved aerosol Fe in coarse and fine particles at Xi’an,an inland city in Northwest China.Total aerosol Fe mainly originated from the dust source which contributed 56%and 73%to total Fe for coarse and fine particles,followed by the industry and anthropogenic sources.In contrast,even at Xi’an which is quite close to deserts,the contribution of dust to dissolved aerosol Fe was still very limited(6%and 5%for coarse and fine particles).Instead,dissolved aerosol Fe originated predominantly from secondary(61%and 42%),anthropogenic(30%and 38%)and industry sources(3%and 15%).Furthermore,this work proposed a novel method to retrieve solubility of aerosol Fe for different sources,and utilized this method to analyze field data collected at Xi’an and Qingdao.For a given source,Fe solubility values estimated using our method agree very well at these two locations,and are also in broad agreement with previous direct measurements.This method provides a new and promising perspective for understanding the solubility of aerosol Fe for various sources,and can help modeling work to better constrain the contribution of different sources to dissolved aerosol Fe over larger spatial and temporal scales. 展开更多
关键词 Aerosol iron Source apportionment Desert dust Non-dust sources Fractional solubility
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Mobile MAX-DOAS measurements and source analysis of NO2,HCHO,and HONO during the Chengdu 2023 FISU world university games 认领 引用
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作者 Qijin Zhang Chengzhi Xing +8 位作者 Miao Feng Yinshuo Ding Zhongmou Sun Yikai Li Haochen Peng Wei Tan Zhiguo Zhang Tianjun Du Cheng Liu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第2期517-527,共11页
To maintain air quality during the 31st World University Games,Chengdu employed a range of monitoring and control strategies in 2023.High-resolution regional pollutant distributions were reconstructed by integrating t... To maintain air quality during the 31st World University Games,Chengdu employed a range of monitoring and control strategies in 2023.High-resolution regional pollutant distributions were reconstructed by integrating the vertical column densities(VCDs)from mobile MAX-DOAS measurements with Gaussian process regression analysis.The correlation between the spatial distribution derived from MAX-DOAS and that of GEMS and TROPOMI satellite data exceeded 0.6.This paper explores the impact of air quality improvements during the games on the sources of HCHO and the formation process of HONO.During the control period,primary emissions and secondary formations of HCHO contributed 50.85%±24.24%and 42.81%±7.57%to the total atmospheric HCHO,respectively.The study indicates that with improved air quality,HCHO primary emissions decrease while secondary emissions and atmospheric radiation transmission intensities rise.It is found that HONO always appears under the condition of high aerosol optical depth(AOD)and NO2,but high NO2 concentration and AOD are not necessarily accompanied by high concentrations of HONO.To assess the influence of temperature and humidity on the formation of HONO from NO2,we calculated the emission ratesΔHONO∕ΔNO2 to quantify the impact of primary sources on total HONO concentrations.The analysis results show that the turning point of relative humidity is 65%(60%–70%)and the turning point of temperature is 31℃(30–32℃).Lower temperatures and higher humidity levels were found to decrease the rate of secondary HONO formation from NO2. 展开更多
关键词 Mobile MAX-DOAS Pollutant reconstruction Primary source and secondary source of HCHO Heterogeneous reaction
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The order of accuracy related to the error from source approximation in the method of characteristics for purely absorbing materials in planar geometry 认领 引用
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作者 Ji-Pu Wang Zhen-Wen Wei +5 位作者 Can Huang William Martin Brendan Kochunas Qi-Cang Shen Si-Juan Chen Martin Pilch 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第6期257-270,共14页
The method of characteristics(MoC)is a well-established tool for lattice physics calculations,offering advantages such as accurate representation of both lattice geometry and boundary conditions.The flat source(FS)app... The method of characteristics(MoC)is a well-established tool for lattice physics calculations,offering advantages such as accurate representation of both lattice geometry and boundary conditions.The flat source(FS)approximation is the most commonly used approach,whereas the linear source(LS)approximation enhances the accuracy by preserving the higherorder spatial moments of the neutron source.However,determining the order of accuracy(OoA)for spatial discretization in the MoC is challenging,particularly for the LS approximation.This complexity arises because MoC employs two spatial meshes:the fission source region(FSR)mesh and a set of characteristic rays used to integrate the transport equation over the FSR mesh.In this study,we analyzed the spatial order of accuracy of the MoC in planar geometry for both FS and LS approximations in relation to the distributed source.Our theoretical predictions are consistent with the numerical results obtained using the Method of Manufactured Solutions(MMS).The results demonstrate that the FS approximation achieves second-order accuracy,whereas the LS approximation attains fourth-order accuracy. 展开更多
关键词 Method of characteristics Order of accuracy Flat source approximation Linear source approximation Method of manufactured solutions
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Distribution characteristics,source apportionment and risk assessment of heavy metal pollution in typical redevelopment sites in Jinshan District,Shanghai,China 认领 引用
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作者 Cheng Shen Chenyan Sha +7 位作者 Tianhao He Zhongchun Yan Xiurong Chen Kuangfei Lin Haichao Chen Jian Wu Ye Li Min Liu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第5期197-208,共12页
As urban renewal accelerates,heavy metals(HMs)pollution resulting from industrial activities in urban areas must be considered.This study examines 36 representative redevelopment industrial sites in the Jinshan Distri... As urban renewal accelerates,heavy metals(HMs)pollution resulting from industrial activities in urban areas must be considered.This study examines 36 representative redevelopment industrial sites in the Jinshan District of Shanghai,where the concentrations of eight HMs in the soil were assessed.Based on this data,the characteristics of heavy metal concentrations and their sources in the region were investigated,followed by a risk assessment of HMs pollution.The results indicate that the soil in the study area exhibits low levels of pollution,with moderate ecological risks.Using Pearson correlation analysis and the Absolute Principal Component Score-Multiple Linear Regression(APCS-MLR)source apportionment model,the HMs were categorized into several sources:An industrial source dominated by Cu(74.84%),a traffic source dominated by Zn(67.51%),a natural source dominated by Cr and As(66.50%and 64.98%,respectively),and a mixed source.A probabilistic risk assessment was conducted using Monte Carlo simulation,which incorporates the probability distributions of various assessment parameters,thereby reducing uncertainty in the results.The findings show that the non-carcinogenic risk for all populations in the study area(children,adult females,and adult males)remains within acceptable limits.However,the carcinogenic risk proportional probabilities for these populations were found to be 48.13%,32.49%,and 11.41%,respectively,indicating a notable risk level.Uncertainty analysis results suggest that the heavy metals Cd and As exhibit high sensitivity in the model.This study provides theoretical support for the prevention and control of soil pollution during urban renewal. 展开更多
关键词 Redevelopment site Heavy metal Source apportionment Risk assessment
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Temporal variations and source analysis of ambient carbonyls in Hangzhou:A city-level study in the Yangtze River Delta region,China 认领 引用
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作者 Haonan Xu Xiaobing Pang +4 位作者 Danyun Chen Zhongjian Wei Yu Lu Huiyi Yang Lian Yu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第2期629-639,共11页
Carbonyls play an important role in the atmospheric chemistry as the main precursor for reactive radicals and peroxyacetyl nitrate.However,little research has been conducted so far on the seasonal variations of carbon... Carbonyls play an important role in the atmospheric chemistry as the main precursor for reactive radicals and peroxyacetyl nitrate.However,little research has been conducted so far on the seasonal variations of carbonyls in China’s urban atmosphere.In this study,ambient carbonyls were 24-hourly observed in four seasons in Hangzhou,a mega-city in the Yangtze River Delta Region,China.The concentration of total carbonyls was the highest in summer(44.35μg/m3),the second in winter(44.05μg/m3),the third in spring(29.31μg/m3)and autumn(27.11μg/m3).The most abundant species were found to be acetone in spring,summer,and winter,while formaldehyde in autumn.Rainfall can significantly reduce the concentrations of most ambient carbonyls,with the largest decrease observed in the wet precipitation events occurring in spring and summer,while acetone concentrations remained invariable due to its lower water solubility.Multiple linear regression analysis and carbonyls ratios indicated that anthropogenic emissions were the predominant sources of carbonyls,and atmospheric formaldehyde was mainly emitted from primary sources other than secondary sources.Vehicular exhaust was identified as the primary source of ambient carbonyls,particularly in winter,and its contribution reached 92.80%to formaldehyde.Additionally,photochemical reactions were closely associated with the secondary production of formaldehyde in summer.Carbonyls showed strong ozone formation potential in all four seasons.Based on the health risk assessment,the exposure to ambient carbonyls is harmful to outdoor pedestrians.The results could provide essential information and references for simulating regional air quality and analyzing ozone pollution,which is essential for improving air quality in the Yangtze River Delta region. 展开更多
关键词 Carbonyls Seasonal variations Wet deposition Source analysis Hangzhou
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Modeling particle number concentrations and sources in the Beijing and Shanghai metropolitan areas with the UCD/CIT model 认领 引用
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作者 Yanhong Zhu Jianjiong Mao +6 位作者 Kangjia Gong Xiaodong Xie Qiong Liao Zelong Wang Huaiqiu Xiao Hongguang Liao Jianlin Hu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第8期723-732,共10页
Particle number concentration(PNC)is a crucial parameter for evaluating the environment,climate,and health effects of particulate matter.Although PNC observation studies have been conducted at various locations,its sp... Particle number concentration(PNC)is a crucial parameter for evaluating the environment,climate,and health effects of particulate matter.Although PNC observation studies have been conducted at various locations,its spatiotemporal variations and source contributions in China remain unclear.In this study,the University of California,Davis/California Institute of Technology air quality model was updated and applied to predict the concentrations and source contributions of particle number in the Beijing and Shanghai metropolitan areas in2017(April and July).The comparison of the average of binary and ternary nucleation results against observations shows that good agreement is found for Beijing in April(the normalized mean bias(NMB)=-0.12)and for Shanghai in April(NMB=0.28)and July(NMB=-0.10).Nucleation is the largest source of PNC in nucleation mode,contributing>90%(except for 40%in July of Beijing,likely due to other unaccounted nucleation schemes such as organic nucleation).For PNC in Aitken mode,the two largest sources are transportation(28%-45%in Beijing,15%-35%in Shanghai)and nucleation(14%-45%,27%-73%).In addition,residential(18%-22%)is also important in Beijing.For PNC in accumulation mode,industry is the largest source,contributing over38%.PNC from power plant and industry is high near the sources and shows sharp spatial gradient.PNC from residential and transportation is high in urban centers,while PNC from nucleation is higher in relatively clean suburban regions than in the polluted urban center regions in the two cities.Modeling PNCs and sources are useful in future control strategies and epidemiological studies. 展开更多
关键词 Particle number concentration Spatiotemporal variation Source contribution Nucleation
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Distribution,assessment,and sources of nutrients in river water in the headwaters of the Shule River Basin,Northeastern Qinghai-Tibet Plateau 认领 引用
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作者 Qin Yang Donghui Shangguan +2 位作者 Tianding Han Da Li Asim Qayyum Butt 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第1期502-511,共10页
Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in a... Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in alpine mountains with climate change.Hence,94 samples of river water were collected from 2018 to 2020 in the headwaters of the Shule River Basin to assess the nutrients spatiotemporal distribution and combined ap-proach of water quality index to assess water quality and potential sources.The findings depict that high nutrient concentrations were found to coincide with snowmelt and glacial meltwater and rainfall recharge periods,while total flux peaked from June to September due to increased runoff.Notably,total nitrogen(TN)concentrations were significantly higher near the town,primarily attributed to the replenishment of nitrate(NO3‒-N)from live-stock manure.The high total P(TP)was near the glacier,which was attributed to the transportation of glacial sediments into the river,and pH was another critical factor.N was the primary nutrient limiting factor for the growth of phytoplankton in river water.Although the migration and transport of nutrients have altered with climate change,river water quality is good in alpine mountains based on an overall evaluation.These findings contribute to enriching nutrient datasets and highlight the importance of water resource management and water quality assessment in sensitive and fragile alpine mountains. 展开更多
关键词 Nutrients Spatiotemporal distribution Water quality assessment Potential sources Alpine mountains
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Particle size-driven rare earth elements pollution,source and child health risks in Beijing kindergarten dust 认领 引用
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作者 Peng Wang Jian Hu +5 位作者 Wenmin Ma Qian Zhang Liyan Tian Tingyi Liu Houyi Zheng Guilin Han 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第7期589-596,共8页
The concentrations and sources of rare earth elements(REEs) in urban dust are strongly affected by particle size.This study investigates the contamination,sources,and health risks of REEs in re-suspended dust(RPD)and ... The concentrations and sources of rare earth elements(REEs) in urban dust are strongly affected by particle size.This study investigates the contamination,sources,and health risks of REEs in re-suspended dust(RPD)and fine dust(FD) from Beijing kindergartens.Results indicate Ce and Eu concentrations in RPD,and La,Ce,Pr,Nd,Sm,Eu,Gd,and Tb concentrations in FD slightly exceed local background levels.Both RPD and FD are classified as non-polluted levels,with notable enrichment of light rare earth elements(LREEs).Although RPD and FD share similar anthropogenic and natural sources,their contributions differ significantly:RPD reflects stronger anthropogenic influences on RPD and FD demonstrate heightened REE affinity due to its finer particle size.Health risk assessments reveal that children face higher exposure to health risks than adults,primarily through with oral ingestion.Despite elevated risks associated with FD compared to RPD,both remain within negligible thresholds.These findings underscore the importance of implementing particle-specific strategies for mitigating REE pollution in urban environments,providing a scientific foundation for safeguarding children's health in kindergarten settings. 展开更多
关键词 Particle size effect Source differences Health risks Rare earth elements Dust
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Experimental and theoretical study of the smoke back-layering length in a tunnel with cross-passage:effects of longitudinal fire source locations 认领 引用
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作者 Zhisheng Li Yuchun Zhang +2 位作者 Maozhen Qiao Yunji Gao Yule Huang 《Railway Engineering Science》 EI 2026年第1期184-199,共16页
The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,... The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,despite the fact that the scenario exists in practice.A series of laboratory-scale experiments were conducted in this study to investigate the smoke back-layering length in a model tunnel with cross-passage.The heat release rate,the velocity of longitudinal air flow,and the location of the fire source were all varied.It was found that the behavior of smoke backflow for the fire source located at the upstream of bifurcation point resembles a single-hole tunnel fire.As the fire source’s position shifts downstream from the bifurcation point,the length of smoke back-layering progressively increases.A competitive interaction exists between airflow diversion and smoke diversion during smoke backflow,significantly affecting the smoke back-layering length in the main tunnel.The dimensionless smoke back-layering length model was formulated in a tunnel featuring a cross-passage,taking into account the positions of longitudinal fire sources.The dimensionless smoke back-layering length exhibits a positive correlation with the 17/18 power of total heat release rate Q and a negative correlation with the 5/2 power of longitudinal ventilation velocity V. 展开更多
关键词 Tunnel fire Cross-passage Smoke back-layering length Fire source location Longitudinal ventilation
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Candidate injector design for the Southern Advanced Photon Source based on linac and booster 认领 引用
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作者 Liang-Sheng Huang Yan-Liang Han +5 位作者 Wei-Hang Liu Jian-Liang Chen Sheng Wang Yi Jiao Xiao Li Jia-Xin Chen 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第2期67-78,共12页
The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that ... The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that the injected beam has a short bunch length and low emittance,and the preferred injector should offer high stability and low cost.Therefore,an injector based on a booster synchrotron was developed.The proposed injector includes a 250 MeV linac,a booster synchrotron that ramps the beam energy to 3.5 GeV,and two beam transport lines to ensure efficient beam delivery and beam quality preservation.The linac utilizes a thermionic high-voltage DC gun for reliable operation and features a bunching system with an advanced focusing system to preserve the emittance.To meet the injection requirements of the SAPS,a comprehensive design for the booster has been conducted.The booster synchrotron employs a threefold lattice structure,incorporating modified theoretical minimum emittance cells with a small momentum compaction factor and a high voltage to achieve an emittance of 3.98 nm rad and a bunch length of 4.8 mm.The injector has the potential to deliver a high charge,reducing the injection period of the storage ring to less than 1 min.Simulations demonstrated the expected performance,with a transmission efficiency of 90%,confirming its capability to meet the injection requirement of the SAPS storage ring.This design offers a stable and efficient solution for the SAPS. 展开更多
关键词 Southern Advanced Photon Source Longitudinal injection Booster synchrotron Emittance Bunch length
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Multi-media distribution,sources,and ecological risk of per-and poly-fluoroalkyl substances(PFAS)in the Weihe River Basin,China 认领 引用
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作者 TANG Bin SONG Jinxi +5 位作者 LU Aoran ZHANG Zhuo MAO Ruichen YANG Chenxi LI Nan FENG Jiayuan 《Journal of Arid Land》 SCIE CAS CSCD 2026年第4期632-656,共25页
Per-and poly-fluoroalkyl substances(PFAS)have garnered significant global attention due to their widespread presence and potential environmental and health risks.However,research on the occurrence and environmental be... Per-and poly-fluoroalkyl substances(PFAS)have garnered significant global attention due to their widespread presence and potential environmental and health risks.However,research on the occurrence and environmental behavior of PFAS across different media remains limited.We analyzed the occurrence,distribution,sources,and ecological risks of 32 PFAS across multiple media in the Weihe River,China.The concentrations of PFAS ranged from 5.89 to 472.84 ng/L in the pore water and from 9.93 to 459.50 ng/L in surface water,exhibiting significant spatial variability(P0.05).Vertically,concentrations in 33.00%of pore water samples exceeded those in surface water,showing a heterogeneous vertical distribution with enrichment at depths of 40-60 cm.The physical-chemical characteristics of PFAS and the hydrological and sedimentary processes at the basin scale were responsible for PFAS partitioning between the aquatic environment and sediments.Four major sources were identified through integrated source apportionment:industrial and domestic wastewater(58.25%),aqueous film-forming foam(18.07%),combined input from household pollution and metal plating(8.70%),and stormwater runoff and landfill leachate(14.98%).The ecological risk assessment revealed negligible risks from short-chain PFAS in surface water and pore water,whereas long-chain PFAS posed low to moderate ecological risks.Furthermore,the discharge of PFAS from the Weihe River to the Yellow River was estimated up to 708.20 kg/a.This study provides critical data informing strategies for mitigating PFAS pollution in rivers across typical arid and semi-arid areas of China. 展开更多
关键词 per-and poly-fluoroalkyl substances multi-media distribution source apportionment ecological risk Weihe River
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Identication and Analysis of Aerodynamic Sound Sources in Wind Turbines Based on the Integration of Time-Domain De-Doppler and Orthogonal Matching Pursuit Techniques 认领 引用
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作者 Peng Wang Zhiying Gao +4 位作者 Yongyan Chen Rina Su Yefei Bai Jianlong Ma Tianhao Zhang 《Energy Engineering》 EI 2026年第6期292-315,共24页
We propose a novel procedure,Time-Domain De-Dopplerized Orthogonal Matching Pursuit deconvolution approach for the mapping of acoustic sources(TD-OMP-DAMAS),for separating aerodynamic noise sources distributed across ... We propose a novel procedure,Time-Domain De-Dopplerized Orthogonal Matching Pursuit deconvolution approach for the mapping of acoustic sources(TD-OMP-DAMAS),for separating aerodynamic noise sources distributed across wind turbine blades(WTB),a task that is typically hindered by mutual interference and spatial mixing.e proposed procedure is a two-stage,hybrid de-Doppler/sparse-reconstruction algorithm based on timedomain de-Doppler(TD,Stage 1)and an orthogonal matching pursuit(OMP)-based deconvolution scheme(Stage 2),enabling sparse-reconstruction techniques to be eectively applied in rotating-source scenarios.e method is validated using both simulated rotating-source data and wind-tunnel measurements,and its performance is systematically compared with several conventional approaches,including conventional beamforming(CBF),time-domain de-Doppler beamforming(TD-BF),and time-domain de-Doppler deconvolution approach for the mapping of acoustic sources(TD-DAMAS).Numerical results demonstrate that TD-OMP-DAMAS achieves the smallest localization error and the highest spatial resolution among all tested algorithms,while also maintaining strong robustness under low signal-to-noise ratio conditions and requiring signicantly fewer iterations than TD-DAMAS to accurately converge to the true source positions.Wind-tunnel tests further show that,under an inow velocity of 6 m/s and a tip-speed ratio of 4.5,the method improves spatial resolution by approximately 89%compared with CBF,conrming its superior capability in separating aerodynamic sources located on dierent WTB. 展开更多
关键词 Wind turbine noise source identication DAMAS orthogonal matching pursuit
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Source analysis of atmospheric ozone in a typical industry city:Highlighting the role of coal chemical industry in ozone formation 认领 引用
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作者 Dongmei Hu Qiuhong Tao +4 位作者 Yueyuan Niu Yulong Yan Wen Yan XingXiao Gong Lin Peng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第4期543-551,共9页
The coal chemical industry(CCI)plays a critical role in China’s economy by supplying a substantial share of nation’s energy and chemical products.However,the traditional CCI processes,such as coal pyrolysis and gasi... The coal chemical industry(CCI)plays a critical role in China’s economy by supplying a substantial share of nation’s energy and chemical products.However,the traditional CCI processes,such as coal pyrolysis and gasification,release substantial and complex emissions of volatile organic compounds(VOCs).The impact of CCI on the formation of ozone(O3)in cities is currently unclear.To address this issue,this study focused on a typical industrial city characterized by coal-based nitrogen fertilizer production as the dominant industry to quantitatively analyze O3sources.The results indicated alkanes(70%)were the dominant VOCs component,with their concentration significantly exceeding those observed in other typical industrial cities in China,particularly for isobutane and n-butane.Observation-based model simulation results revealed alkenes and C4-C5 alkanes significantly contributed to the formation of organic peroxyl radicals(RO2⋅).These species,primarily emitted by CCI,drive radical circulation and accelerate O3formation.Additionally,alkenes,especially C4-C5 alkenes,can react with O3to produce Criegee intermediates,which rapidly decompose into large quantities of RO x radicals(hydroxyl,hydroperoxyl radicals,and RO2⋅).O3source apportionment analysis identified that industrial processes were the primary contributor(48%),followed by vehicle emissions(34%).These findings highlight the significant influence of VOCs emitted from CCI on photochemical reaction cycles and O3formation.To effectively mitigate O3formation,targeted control of highly reactive VOC species is crucial.For CCI-dominated cities,transiting from traditional CCI to advanced gasification technologies is essential to reduce VOCs emissions at the source for sustainable development. 展开更多
关键词 Volatile organic compounds(VOCs) Ozone pollution Formation mechanism Source apportionment Coal chemical industry
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Changes in source-specific health risks of PM2.5-bound trace elements after the residential“coal-to-gas”conversion measure in urban Beijing 认领 引用
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作者 Wei Yuan Ru-Jin Huang +6 位作者 Jing Duan Jie Guo Wenjuan Cao Ting Wang Jingye Ren Yanan Zhan Wei Xu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第8期436-442,共7页
The concentration of atmospheric fine particles(PM2.5)has been considerably lowered in Beijing as a result of the implementation of a number of air pollution control initiatives.Nevertheless,the understanding of th... The concentration of atmospheric fine particles(PM2.5)has been considerably lowered in Beijing as a result of the implementation of a number of air pollution control initiatives.Nevertheless,the understanding of the impact of clean air measures on the health risks of PM2.5-bound trace elements is still limited.In this study,the concentrations and chemical fractionation of 14 trace elements in PM2.5 in Beijing after the"coal-to-gas"conversion measure were measured and compared with our previous study in Beijing before the measure.The major elements changed from Fe,Zn,and Pb before the measure to Fe,Ti,and Cu after the measure.The bioavailability of Pb,Zn,Cu,Sr,Ba,and Cr increased by approximately 5%-44%after the measure,while the bioavailability of Cd,Mn,As,Co,V,Fe,Ni,and Ti decreased by approximately 0.5%-31%,which may be mainly attributed to changes in their emission sources.After the measure,the relative contribution of traffic-related emissions to the total concentration of 14 elements increased by 12.1%,and coal combustion decreased by 17.5%.Trafficrelated emissions(92.8%)were the primary causes of carcinogenic risk after the measure,while traffic-related emissions(52.2%)and coal combustion(41.4%)dominated before the measure.This study elucidates changes in concentrations,chemical fractionation,bioavailability,sources,and health risks of PM2.5-bound trace elements in Beijing before and after the“coal-to-gas”conversion measure and suggests that traffic-related emissions should still be the main focus in the future. 展开更多
关键词 Trace elements Chemical fractionation Emission sources Health risks “Coal-to-gas”conversion measure
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Characterization,sources,and driving factors of particulate matter(PM)pollution in a desert hinterland city:Insights from Hotan,China 认领 引用
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作者 Bei Jiang Yayi Cai +4 位作者 Yumo Shi Qilian Zhai Haibao Huang Long Peng Junlei Zhan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第3期209-219,共11页
Atmospheric particulate matter(PM)pollution is severe in southern Xinjiang,especially near the Taklimakan Desert,where air quality is affected by both dust and anthropogenic emissions.This study employs explainable ma... Atmospheric particulate matter(PM)pollution is severe in southern Xinjiang,especially near the Taklimakan Desert,where air quality is affected by both dust and anthropogenic emissions.This study employs explainable machine learning in Hotan to identify distinct mechanisms underlying haze and dust events.Results confirm severe PM pollution in Hotan.Annual mean PM10and PM2.5reached 327.39 and 102.02μg/m3,respectively.Dust events originated mainly from the central desert,while haze was dominated by local and nearby sources.Emission contributions averaged 405.84μg/m3for PM10and 114.56μg/m3for PM2.5annually.Meteorological stagnation increased PM10and PM2.5by 138.37 and 44.51μg/m3,respectively,and transport added another 138.04 and43.20μg/m3.The mechanisms showed significant diurnal and seasonal differences.Diurnal analysis revealed that haze pollution exhibits a double-peak pattern linked to stable stratification under high surface pressure(SP),whereas dust pollution shows irregular peaks driven by afternoon wind resuspension.Seasonal analysis revealed that haze-season PM was driven by high NO2and low solar radiation(SSR),reflecting precursor accumulation and stagnant weather,with transport contributions from regional pollution convergence via air mass history.Dust-season PM was triggered by high SP,strong 10-m u-component of wind(U10),and strong SSR,with nearsource transport dominated by dust sources.Overall,PM pollution manifests as“static accumulation”during haze and“dynamic excitation”during dust events.This study validates the“de-weathering-SHAP”model for PM attribution in arid regions,providing a scientific basis for targeted prevention strategies in“Belt and Road”dust-affected zones. 展开更多
关键词 Atmospheric particulate matter(PM) Dust source Explainable machine learning Meteorology Emissions Transport
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