检索结果-南通市图书馆

Size-resolved carbonaceous components and water-soluble ions measurements of ambient aerosol in beijing

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2017年第4期29卷 298-313页

作者： Pusheng Zhao Yina Chen Jie Su Institute of Urban Meteorology China Meteorological Administration Environmental Meteorology Forecasting Center of beijing-Tianjin-Hebei State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai University

A MOUDI-120 sampler was used in beijing to collect multi-stage samples in the summer and winter of 2013 to 2015. Thirty-three sample sets were collected during the daytime,nighttime, and different pollution levels. The actual relative humidity in the impactors was calculated for the first time. The carbonaceous components（organic and elemental carbon,OC and EC, respectively） and water-soluble inorganic ions（Na~＋, NH4~＋, K~＋, Mg^（2＋）, Ca^（2＋）, Cl^-, NO3^-,and SO4^（2-）） were analyzed in each sample. The characteristics of the mass concentration distribution and charge balance were discussed. On the basis of relative humidity in the impactors, aerosols less than 1.0 μm were sampled under relatively dry conditions in most cases. The concentration levels for the chemical species were higher in the winter than in the summer. Three modes（condensation mode, droplet mode, and coarse mode） could be identified from the distributions of NH4~＋, NO3^-, SO4^（2-）, Cl^-, K~＋, OC and EC. The distribution characteristics for the pollution dissipation process were different from the pollution accumulation process. NO3^-and NO2^-contributed most of the negative electric charges in the stage below 0.1 μm. In the condensation mode, the cations were dominated by NH4~＋, which was sufficient to balance the anions. In the droplet mode of the heavily polluted samples,the ammonium was not sufficient to balance the anions. In the coarse mode, the positive electric charges were primarily composed of metal cations. The analyzed anions were not sufficient to neutralize the measured cations.

关键词： Size-resolved Carbonaceous Ion Aerosol

Particle size distribution and characteristics of heavy metals in road-deposited sediments from beijing Olympic Park

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2015年第6期27卷 228-237页

作者： Haiyan Li Anbang Shi Xiaoran Zhang Key Lab of Urban Storm-Water System and Water Environment Beijing University of Civil Engineering and Architecture

Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments（RDSs） of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents＇ and tourists＇ health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from beijing Olympic Park in the present study. The results indicated that particles with small grain size（〈150 μm） were the dominant fraction. The length of dry period was one of the main factors affecting the particle size distribution, as indicated by the variation of size fraction with the increase of dry days. The amount of heavy metal（i.e., Cu, Zn, Pb and Cd） content was the largest in particles with small size（〈150 μm） among all samples. Specifically, the percentage of Cu, Zn, Pb and Cd in these particles was 74.7%, 55.5%, 56.6% and 71.3%, *** metals adsorbed in sediments may mainly be contributed by road traffic emissions. The contamination levels of Pb and Cd were higher than Cu and Zn on the basis of the mean heavy metal contents. Specifically, the geoaccumulation index（I geo） decreased in the order：Cd〉Pb〉Cu〉Zn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order： Cd〉Zn≈Pb〉Cu.

关键词： Size distribution Characteristics Heavy metals Road-deposited sediments Contamination assessment beijing Olympic Park

Deposition of water-soluble inorganic ions in PM_(2.5) in a typical forestry system in beijing,China

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2018年第4期5卷 486-497页

作者： Junqi Ding Xiaoxiu Lun Weifang Ma Lu Zhao Yingying Cao Fengbin Sun Renna Li College of Environmental Science and Engineering Beijing Forestry University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Academy of Environmental Sciences School of Soil and Water Conservation Beijing Forestry University

Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and ***: Samples were taken from two sites in beijing from the 7 th to the 15 th May, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron ***: The total deposition flux and total deposition velocity during the daytime were higher than those at *** showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest ***: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry sy

关键词： Fine particle Water-soluble inorganics Forest Dry deposition Deposition velocity

Effectiveness and Acceptability of a Comprehensive Mobile Health-Based Modality for Smoking Cessation-beijing Municipality,China,2022

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2023年第21期5卷 464-468页

作者： Shuilian Chu Hang Jing Di Zhang Yuan Cao Yunliang Qian Xiurong Liu Lin Xiao Zhaohui Tong Lirong Liang Department of Research on Tobacco Dependence Therapies Beijing Institute of Respiratory Medicine and Beijing Chao-Yang HospitalCapital Medical UniversityBeijingChina beijing Center for Disease Prevention and Control BeijingChina Tobacco Control Office Chinese Center for Disease Control and PreventionBeijingChina Department of Respiratory and Critical Care Medicine Beijing Institute of Respiratory Medicine and Beijing Chao-Yang HospitalCapital Medical UniversityBeijingChina

Summary What is already known on this topic?Mobile health interventions have been demonstrated to be effective in aiding smoking cessation among ***,research on this topic remains limited in *** is added by this report?Following two months of utilizing the services of a comprehensive mobile health(mHealth)-based modality(“Way to Quit”modality)which integrated three online interventions through the WeChat application,29.1%of participating smokers successfully quit *** who used a greater number of online services were more likely to cease *** services were scored highly for satisfaction among *** are the implications for public health practice?This study presents a practical and feasible method to assist Chinese smokers in quitting *** results of this research suggest a promising direction for enhancing the accessibility and utilization of smoking cessation ***,these findings serve as a critical reference for addressing the obstacles faced by smoking cessation services in China.

关键词： smoke services utilizing

Air pollutant emissions from the asphalt industry in beijing,China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2021年第11期33卷 57-65页

作者： Song Qu Shoubin Fan Gang Wang Wanqing He Kangli Xu Lei Nie Yuncheng Zhao Qingchun Zhu Tingting Li Guohao Li Municipal Research Institute of Environmental Protection Beijing 100037China Key Laboratory of beijing on VOC Pollution Control Technology and Application of Urban Atmosphere Beijing 100037China Department of Environmental and Safety Engineering College of Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580China Chuzhou City Ecological Environmental Protection Comprehensive Administrative Law Enforcement Detachment Chuzhou 239000China

Improving our understanding of air pollutant emissions fromthe asphalt industry is critical for the development and implementation of pollution control *** this study,the spatial distribution of potential maximum emissions of volatile organic compounds(VOCs)in the complete life cycle of asphaltmixtures,as well as the particulate matter(PM),asphalt fume,nonmethane hydrocarbons(NMHCs),VOCs,and benzoapyrene(BaP)emissions from typical processes(e.g.,asphalt and concrete mixing stations,asphalt heating boilers,and asphalt storage tanks)in asphalt mixing plants,were determined in beijing in *** results indicated that the potential maximum emissions of VOCs in the complete life cycle of asphalt mixtures were 18,001 ton,with a large contribution from the districts of Daxing,Changping,and *** total emissions of PM,asphalt fume,NMHC,VOCs,and BaP from asphalt mixing plants were 3.1,12.6,3.1,23.5,and 1.9×10^(−3)ton,*** emissions of PMfromasphalt and concretemixing stations contributed themost to the total *** asphalt storage tankwas the dominant emission source of VOCs,accounting for 96.1%of the total VOCs emissions in asphalt mixing plants,followed by asphalt heating *** districts of Daxing,Changping,and Shunyi were the dominant regions for the emissions of PM,asphalt fume,NMHC,and BaP,while the districts of Shunyi,Tongzhou,and Changping contributed the most emissions of VOCs.

关键词： Asphalt mixing plant Particulate matter Asphalt fume Nonmethane hydrocarbon Volatile organic compounds Benzoapyrene

Insights into measurements of water-soluble ions in PM_(2.5)and their gaseous precursors in beijing

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2021年第4期33卷 123-137页

作者： Jie Su Pusheng Zhao Jing Ding Xiang Du Youjun Dou Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300071China

To better understand the characteristics and transformation mechanisms of secondary inorganic aerosols,hourly mass concentrations of water-soluble inorganic ions(WSIIs)in PM_(2.5)and their gaseous precursors were measured online from 2016 to 2018 at an urban site in *** and diurnal variations in water-soluble ions and gaseous precursors were discussed and their gas-particle conversion and partitioning were also examined,some related parameters were ***(TNH_(3))Rich was also defined to describe the variations of the excess NH_(3)in different *** addition,a sensitivity test was carried out by using ISORROPIA II to outline the driving factors of gas-particle *** beijing,the relative contribution of nitrate to PM_(2.5)has increased markedly in recent years,especially under polluted *** the four seasons,only a small portion of NO_(2)in the atmosphere was converted into total nitrate(TNO_(3)),and more than 80%of TNO_(3)occurred in the form of nitrate due to the abundant *** concentration of total ammonia(TNH_(3))was much higher than that required to neutralize acid gases,and most of the TNH_(3)occurred as gaseous NH_(3).The nitrous acid(HONO)concentration was highly correlated with NH_(3)concentration and had increased significantly in beijing compared with previous *** total chloride(TCl)was the highest in winter,andε(Cl^(-))was more sensitive to variations in the ambient temperature(T)and relative humidity(RH)thanε(NO_(3)^(-)).

关键词： PM_(2.5) Water-soluble ion Gaseous precursor Secondary formation Gas-particle partitioning

Numerical Simulations of Impacts of Urbanization on Heavy Rainfall in beijing Using Different Land-Use Data

在线全文

学校读者我要写书评

暂无评论

Acta meteorologica Sinica 2007年第2期21卷 245-255页

作者：江晓燕刘伟东 Institute of Urban Meteorology CMA

A summer strong convective precipitation event on 10 July 2004 over beijing is numerically simulated in this paper, and the impact of urban heat island （UHI） on summer convective rain is investigated. The analysis reveals that a mesoscaie convective cloud cluster system leads to this heavy rainfall event, suggesting the supply of moisture by the large scale circulation before the initiation of precipitation, a generally weaker UHI of 2-3℃ existed in the urban area. Much like a sea breeze, the anomalously warm urban air created relatively low pressure, inducing the inflow of cooler rural air towards the urban center, which is favorable to the ascending motion and the formation of convective precipitation over the urban area. In addition, the numerical simulation of the strong convective precipitation event suggests that the simulated result of precipitation using the 2002 LANDSAT-7 land-use data with 30-m resolution is much better than that using the 1992-1993 USGS land-use data with 1-km resolution, whether in the magnitude of rainfall or in the location of precipitation. The simulation confirms to some extent that the UHI has a significant role in causing extreme rainfall event.

关键词： urban heat island (UHI) heavy rainfall numerical simulation land-use data

Assessment of Land Suitability Potentials for Selecting Winter Wheat Cultivation Areas in beijing,China,Using RS and GIS

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2011年第9期10卷 1419-1430页

作者： WANG Da-cheng LI Cun-jun SONG Xiao-yu WANG Ji-hua YANG Xiao-dong HUANG Wen-jiang WANG Jun-ying ZHOU Ji-hong Institute of Agricultural Remote Sensing and Information Technology Zhejiang University Hangzhou 310029 P.R. China beijing Research Center for Information Technology in Agriculture Beijing 100097 P.R.China Agricultural Technology Extension Station in beijing Beijing 100029 P.R.China

It is very important to provide reference basis for winter wheat quality regionalization of cultivation area. The aim of this article was based on factors affecting wheat quality and setting realistic spatial models in each part of the land for assessment of land suitability potentials in beijing, China. The study employed artificial neural network （ANN） analysis to select factors and evaluate the relative importance of selected environment factors on wheat grain quality. The spatial models were developed and demonstrated their use in selecting the most suitable areas for the winter wheat cultivation. The strategy overcomes the non-accurate traditional statistical methods. Satellite images, toposheet, and ancillary data of the study area were used to find tillable land. These categories were formed by integrating the various layers with corresponding weights in geographical information system （GIS）. An integrated land suitability potential （LSP） index was computed considering the contribution of various parameters of land suitability. The study demonstrated that the tillable land could be categorized into spatially distributed agriculture potential zones based on soil nutrient and assembled weather factors using RS and GIS as not suitable, marginally suitable, moderately suitable, suitable, and highly suitable by adopting the logical criteria. The sort of land distribution map made by the factors with their weights showed more truthfulness.

关键词： LSP ANN suitable areas wheat RS and GIS

Foliar Particulate Matter Distribution in Urban Road System of beijing, China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2019年第4期29卷 591-600页

作者： BAO Le MA Keming XU Xiaowu YU Xinxiao beijing Laboratory of Urban and Rural Ecological Environment College of Soil and Water Conservation Beijing Forestry University Beijing 100083 China State Key Laboratory of Urban and Regional Ecology Research Centre for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Particulate matter(PM), one of the most important pollutants of traffic emission, threatens the health of urban ecosystems and citizens. Roadside trees play an important role in trapping PM, and the foliar PM load is a useful indicator for air PM pollution in road systems. To detect the relationships of foliar PM load with road structures, urbanization, and meteorology in road systems, we studied a widely-planted tree Sophora japonica L. in 100 roads and 10 yards of beijing, China, and found that the foliar PM loads increased with the distances from the urban centre(DUC) linearly, while decreased with the road density. All-subsets regression analysis indicated that DUC, average monthly relative humidity, average monthly wind speed, and mean annual wind speed were the most important factors in predicting foliar PM load, rather than general situation of buildings and road cleanliness. The monthly relative humidity and monthly wind speed had a negative correlation to foliar PM, while the annual relative humidity and annual wind speed had a positive correlation to foliar PM. Suburban areas and these effective factors should be highlighted in PM control in beijing.

关键词： distance from the urban centre road width road density relative humidity wind speed number of lanes roadside tree road cleanliness