Understanding the variations and potential source of air pollution is essential for implementing targeted mitigation actions.However,the distribution and long-term trends of Aerosol Optical Depth(AOD)and its component...Understanding the variations and potential source of air pollution is essential for implementing targeted mitigation actions.However,the distribution and long-term trends of Aerosol Optical Depth(AOD)and its components over the Fenwei Plain(FWP)have not been thoroughly investigated.Furthermore,the potential source contribution of AOD loading is still unclear.Thus,maximum synthesis and Mann-Kendall trend(MK)test with Sen's Slope methods are employed to reveal the spatiotemporal variation characteristics of AOD over the FWP.The Potential Source Contribution Function(PSCF)model was applied to analyze the potential source contribution of AOD over the FWP.Results demonstrated that the AOD in spatial pattern exhibited consistency with the topography.AOD over the FWP fluctuated annually from 2000 to 2020,with an increase in the previous decade followed by a gradual decline after 2011.There was a significant monthly variation in AOD with higher values in August(0.47±0.21)and lower in November(0.29±0.12).A positive AOD trend was confirmed from 2000 to 2010 yet a negative trend is identified from 2011 to 2020.The sulfate aerosol(AODSU)exhibited an increasing trend over an extended period.Clear-sky radiation shows a negative trend at the surface and the top of the atmosphere(TOA)from 2000 to 2010,which is consistent with the trend in AOD.The AOD in FWP was primarily influenced by local emissions,with contributions from northern and northwestern sources.This research offers an enhanced overarching comprehension of the distribution and regional climate effects of aerosols over the FWP.展开更多
The Fenwei Basin, covered by loess, experiences severe ground fissure disasters. These disasters disrupt the continuity of the loess and pose significant threats to engineering construction safety along transportation...The Fenwei Basin, covered by loess, experiences severe ground fissure disasters. These disasters disrupt the continuity of the loess and pose significant threats to engineering construction safety along transportation routes. Nevertheless, the crack characteristics and the influence zone of ground fissures in the loess layer remain inadequately investigated. To effectively prevent and control ground fissure disasters, physical model tests and the PFC(particle flow code) numerical simulation method are used to investigate the crack mechanism of buried ground fissures in the loess layer. The results show that there are two main cracks in the layer profile, which have a Y-shape morphology. As the dip angle of the preset cracks increased from 60° to 90°, the main deformation zone at the surface gradually shifted towards the footwall. The process of crack propagation from depth to surface is divided into five stages. Additionally, the results confirm the accuracy of the width of the rupture zone d2in the footwall calculated by the cantilever beam theory. These findings can offer theoretical guidance for determining the avoidance distance of ground fissures in loess regions, as well as for implementing disaster prevention and corresponding control measures for various stages of buried ground fissure propagation.展开更多
A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,w...A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,we reported the absorption properties and potential source of Br C based on a seven-wavelength aethalometer in the winter of 2018–2019 at an urban site of Sanmenxia in Fenwei Plain in central China.Specifically,the mean value of Br C absorption coefficient was 59.6±36.0 Mm^(-1) at 370 nm and contributed 37.7%to total absorption,which made a significant impact on visibility and regional environment.Absorption coefficients of Br C showed double-peak pattern,and Br C had shown small fluctuations under haze days compared with clean days.As for the sources of Br C,Br C absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols,indicating that most of Br C originated from primary emissions.The linear correlations between trace metal elements(K,As,Fe,Mn,Zn,and Pb)and Br C absorption coefficients further referred that the major sources of Br C were primary emissions,like coal burning,biomass burning,and vehicle emissions.The moderate relationship between Br C absorption coefficients and secondary organic aerosols suggested that secondary production of Br C also played an important role.The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of Br C in and around this area,which inferred most parts of Br C were derived from local emissions.展开更多
There are a series of basins in the Fenwei Graben. Field survey found that there took place several paleolake regressions or intensive stream down-incisions in all basins during the Mid-Late Quaternary. The lowest and...There are a series of basins in the Fenwei Graben. Field survey found that there took place several paleolake regressions or intensive stream down-incisions in all basins during the Mid-Late Quaternary. The lowest and oldest paleosol/Ioess units overlying three of the lacustrine terraces or alluvial ones and some paleomagenetism data from the lacustrine sediment indicate that the onset times of three paleolake regressions or intensive stream down-incisions are synchronous with the formation of Lg, L6 and L2 respectively in the Weihe Basin, $8, S~ and $1 respectively in the Linfen-Taiyuan-Xingding Basins, and Ls, Ls and L1 respectively in the Datong Basin. The difference in the onset time of each lake regressions or intensive stream down-incision in different basins reveals that the farther the basin is from the Tibetan Plateau, the later it took place. Taking these field facts and the former research re- sults in terms of the regional tectonic movement into account, it is inferred that the tectonic movement of the Tibetan Plateau most probably controlled such geomorphological- sedimentary evolution in the graben.展开更多
To reduce the adverse effects of traditional domestic solid fuel,the central government began implementing a clean heating policy in northern China in 2017.Clean coal is an alternative low-cost fuel for rural househol...To reduce the adverse effects of traditional domestic solid fuel,the central government began implementing a clean heating policy in northern China in 2017.Clean coal is an alternative low-cost fuel for rural households at the present stage.In this study,18 households that used lump coal,biomass,and clean coal as the main fuel were selected to evaluate the benefits of clean heating transformation in Tongchuan,an energy city in the Fenwei Plain,China.Both indoor and personal exposure(PE)samples of fine particulate matter(PM_(2.5))were synchronically collected.Compared with the lump coal and biomass groups,the indoor PM_(2.5)concentration in the clean coal group is 43.6%and 20.0%lower,respectively,while the values are 16.8%and 21.3%lower,respectively,in the personal exposure samples.PM_(2.5)-bound elements Cd,Ni,Zn,and Mn strongly correlated with reactive oxygen species(ROS)levels in all fuel groups,indicating that transition metals are the principal components to generate oxidative stress.Using a reliable estimation method,it is predicted that after the substitution of clean coal as a household fuel,the all-cause,cardiovascular,and respiratory disease that causes female deaths per year could be reduced by 16,6,and 3,respectively,in the lump coal group,and 22,8,and 3,respectively,in the biomass group.Even though the promotion of clean coal has led to impressive environmental and health benefits,the efficiencies are still limited.More environmental-friendly energy sources must be promoted in the rural regions of China.展开更多
基金supported by the National Natural Science Foundation of China(No.41905016)the Key Research and Development Program of Shaanxi Province(No.2024SF-YBXM-583)+1 种基金the Key Research and Development Project of Shaanxi Province(No.2021ZDLSF-05-07)the National Key Research and Development Plan of China(No.2017YFC0212206).
文摘Understanding the variations and potential source of air pollution is essential for implementing targeted mitigation actions.However,the distribution and long-term trends of Aerosol Optical Depth(AOD)and its components over the Fenwei Plain(FWP)have not been thoroughly investigated.Furthermore,the potential source contribution of AOD loading is still unclear.Thus,maximum synthesis and Mann-Kendall trend(MK)test with Sen's Slope methods are employed to reveal the spatiotemporal variation characteristics of AOD over the FWP.The Potential Source Contribution Function(PSCF)model was applied to analyze the potential source contribution of AOD over the FWP.Results demonstrated that the AOD in spatial pattern exhibited consistency with the topography.AOD over the FWP fluctuated annually from 2000 to 2020,with an increase in the previous decade followed by a gradual decline after 2011.There was a significant monthly variation in AOD with higher values in August(0.47±0.21)and lower in November(0.29±0.12).A positive AOD trend was confirmed from 2000 to 2010 yet a negative trend is identified from 2011 to 2020.The sulfate aerosol(AODSU)exhibited an increasing trend over an extended period.Clear-sky radiation shows a negative trend at the surface and the top of the atmosphere(TOA)from 2000 to 2010,which is consistent with the trend in AOD.The AOD in FWP was primarily influenced by local emissions,with contributions from northern and northwestern sources.This research offers an enhanced overarching comprehension of the distribution and regional climate effects of aerosols over the FWP.
基金supported by National Natural Science Foundation of China (Grant NOs. 41877250, 41272284)the Key Laboratory of Earth Fissures Geological Disaster, Ministry of Natural Resources (No. EFGD20240601)the Natural Science Foundation of Shaanxi Province-General Project (grant number 2023-JC-YB-231)-Suitability Evaluation of Precast Prestressed Underground Comprehensive Pipe Gallery Crossing Active Ground Fissure。
文摘The Fenwei Basin, covered by loess, experiences severe ground fissure disasters. These disasters disrupt the continuity of the loess and pose significant threats to engineering construction safety along transportation routes. Nevertheless, the crack characteristics and the influence zone of ground fissures in the loess layer remain inadequately investigated. To effectively prevent and control ground fissure disasters, physical model tests and the PFC(particle flow code) numerical simulation method are used to investigate the crack mechanism of buried ground fissures in the loess layer. The results show that there are two main cracks in the layer profile, which have a Y-shape morphology. As the dip angle of the preset cracks increased from 60° to 90°, the main deformation zone at the surface gradually shifted towards the footwall. The process of crack propagation from depth to surface is divided into five stages. Additionally, the results confirm the accuracy of the width of the rupture zone d2in the footwall calculated by the cantilever beam theory. These findings can offer theoretical guidance for determining the avoidance distance of ground fissures in loess regions, as well as for implementing disaster prevention and corresponding control measures for various stages of buried ground fissure propagation.
基金supported by The National Key Research and Development Program of China(No.2017YFC0209500)the National Natural Science Foundation of China(Nos.91744204,41822703,and 91844301)National research program for key issues in air pollution control(No.DQGG-0103)。
文摘A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,we reported the absorption properties and potential source of Br C based on a seven-wavelength aethalometer in the winter of 2018–2019 at an urban site of Sanmenxia in Fenwei Plain in central China.Specifically,the mean value of Br C absorption coefficient was 59.6±36.0 Mm^(-1) at 370 nm and contributed 37.7%to total absorption,which made a significant impact on visibility and regional environment.Absorption coefficients of Br C showed double-peak pattern,and Br C had shown small fluctuations under haze days compared with clean days.As for the sources of Br C,Br C absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols,indicating that most of Br C originated from primary emissions.The linear correlations between trace metal elements(K,As,Fe,Mn,Zn,and Pb)and Br C absorption coefficients further referred that the major sources of Br C were primary emissions,like coal burning,biomass burning,and vehicle emissions.The moderate relationship between Br C absorption coefficients and secondary organic aerosols suggested that secondary production of Br C also played an important role.The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of Br C in and around this area,which inferred most parts of Br C were derived from local emissions.
基金Foundation： National Natural Science Foundation of China, No.41371021
文摘There are a series of basins in the Fenwei Graben. Field survey found that there took place several paleolake regressions or intensive stream down-incisions in all basins during the Mid-Late Quaternary. The lowest and oldest paleosol/Ioess units overlying three of the lacustrine terraces or alluvial ones and some paleomagenetism data from the lacustrine sediment indicate that the onset times of three paleolake regressions or intensive stream down-incisions are synchronous with the formation of Lg, L6 and L2 respectively in the Weihe Basin, $8, S~ and $1 respectively in the Linfen-Taiyuan-Xingding Basins, and Ls, Ls and L1 respectively in the Datong Basin. The difference in the onset time of each lake regressions or intensive stream down-incision in different basins reveals that the farther the basin is from the Tibetan Plateau, the later it took place. Taking these field facts and the former research re- sults in terms of the regional tectonic movement into account, it is inferred that the tectonic movement of the Tibetan Plateau most probably controlled such geomorphological- sedimentary evolution in the graben.
基金supported by the National Natural Science Foundation of China(Grant Nos.41877376 and 41877404)the open fund of the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environm ent,Chinese Academy of Sciences(SKLLQG2110)。
文摘To reduce the adverse effects of traditional domestic solid fuel,the central government began implementing a clean heating policy in northern China in 2017.Clean coal is an alternative low-cost fuel for rural households at the present stage.In this study,18 households that used lump coal,biomass,and clean coal as the main fuel were selected to evaluate the benefits of clean heating transformation in Tongchuan,an energy city in the Fenwei Plain,China.Both indoor and personal exposure(PE)samples of fine particulate matter(PM_(2.5))were synchronically collected.Compared with the lump coal and biomass groups,the indoor PM_(2.5)concentration in the clean coal group is 43.6%and 20.0%lower,respectively,while the values are 16.8%and 21.3%lower,respectively,in the personal exposure samples.PM_(2.5)-bound elements Cd,Ni,Zn,and Mn strongly correlated with reactive oxygen species(ROS)levels in all fuel groups,indicating that transition metals are the principal components to generate oxidative stress.Using a reliable estimation method,it is predicted that after the substitution of clean coal as a household fuel,the all-cause,cardiovascular,and respiratory disease that causes female deaths per year could be reduced by 16,6,and 3,respectively,in the lump coal group,and 22,8,and 3,respectively,in the biomass group.Even though the promotion of clean coal has led to impressive environmental and health benefits,the efficiencies are still limited.More environmental-friendly energy sources must be promoted in the rural regions of China.
