检索结果-内蒙古大学图书馆

Vertical characteristics and source identification of PM_(10) in Tianjin

Journal of environmental Sciences 2012年第1期24卷 112-115页

作者： Zhimei Xiao Jianhui Wu Suqin Han Yufen Zhang Hong Xu Xiaoyong Zhang Guoliang Shi Yinchang Feng State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and Engineering Nankai University Tianjin 300071 China Tianjin Meteorological Administration Tianjin 300071 China

Ambient PM 10 （particulate matter with a diameter less than 10μm） concentrations were measured on a 255 meter tower in Tianjin,*** samples were collected at four vertical levels （10,40,120 and 220 m）.Vertical characteristics for PM 10 samples were *** results showed that the concentrations of PM 10 and constituent species had a negative correlation with the sampling *** highest concentrations of PM 10 and species were obtained at the 10 m level,and the lowest concentrations were measured at the 220 m *** the fractions of species to total mass,SO 4 2- and NO 3- had higher values （fraction） at greater height;while Ca had a higher fraction at lower *** source categories for the PM 10 ambient dataset were identified by the principal component analysis *** possible source categories included crustal dust,vehicles,cement dust,and incineration as well as secondary sulfate and nitrate *** of meteorological factors on PM 10 concentrations indicated that wind speed and inversion may be the main factors contributing to different concentrations of PM 10 at different heights.

关键词： vertical characteristic PM 10 sources principal component analysis

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

VOCs evaporative emissions from vehicles in China:Species characteristics of different emission processes

引用

environmental Science and Ecotechnology 2020年第1期1卷 9-19页

作者： Hanyang Man Huan Liu He Niu Kai Wang Fanyuan Deng Xiaotong Wang Qian Xiao Jiming Hao State Key Joint Laboratory of ESPC School of EnvironmentTsinghua UniversityBeijing100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing100084China State Key Laboratory of Plateau Ecology and Agriculture Qinghai UniversityXining810003China Fujian Key Laboratory of Pollution Control&Resource Reuse Fujian Normal UniversityFuzhou350007China College of Environmental Sciences and Engineering Peking UniversityBeijing100871China China Automotive Technology and Research Center Beijing100070China

Vehicle evaporation is an essential source of VOCs in cities but is not well understood in *** emission factors from previous studies are not enough for understanding the atmospheric chemical process of vehicular evaporative *** this work,a serious of detailed VOCs speciation profiles are developed based on test processes and emission processes.A mass balance method was used to divide different emission processes during diurnal *** results show that headspace vapor of gasoline cannot represent the real-world vehicle evaporation because of the significant differences in VOCs speciation profiles,especially for *** further distinguish emissions from evaporation and exhaust,only the ratios of MTBE/benzene and MTBE/toluene can serve as indicators when considering species from all evaporative ***,emissions from different sources change significantly with the *** solve these problems,we developed a monthly comprehensive evaporation speciation *** individual profiles at the emission processes are weighted by the emission of the in-use vehicle fleet in Beijing to derive the comprehensive speciation profile of evaporative *** formation potential(OFP)and secondary organic aerosol potential(SOAP)were used to evaluate the environmental *** SOAP,100 g evaporative emissions are equal to 6.05-12.71 g toluene in different months,much higher than that given using headspace vapors,especially in winter(7.2 times higher in December).These findings would improve our understanding of the evaporative VOCs emissions in China and their environmental impacts(e.g.,O3 and SOA formation).

关键词： Vehicle evaporative emission VOC speciation profile Monthly comprehensive profile SOAP Ozone formation potential

来源：评论

学校读者我要写书评

暂无评论

Distributions and sources of n-alkanes in PM_(2.5) at urban,industrial and coastal sites in Tianjin,China

引用

Journal of environmental Sciences 2010年第10期22卷 1551-1557页

作者： Weifang Li Yue Peng Zhipeng Bai State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and Engineering Nankai University Tianjin 300071 China. Tianjin Academy of Environmental Protection Science Tianjin 300191 China Liaoning Provincial Environmental Monitoring Center Shenyang 110031 China

Aliphatic hydrocarbons （n-alkanes） associated with fine particulate matter were determined in the ambient air of urban, industrial and coastal areas in Tianjin, China, where intensive coal burning for industrial and domestic purpose takes place, n-Alkane homologues from C12 to C35 were quantifiable in all samples with C20-C31 being the most abundant species. Average concentrations of the total n-alkanes were 148.7, 250.1 and 842.0 ng/m3 in July, April and January, respectively. Seasonal variations were mainly attributed to ambient temperature changes and coal combustion for residential heating. Among the three studied areas, the highest levels of n-alkanes were observed in the industrial complex in winter and spring, but in summer the coastal alkane concentration moved up to the highest. A mono-modal distribution for n-alkanes was observed in spring and summer with odd carbon number predominance and a maximum centered at C27-C31, suggesting the release of plant wax into the atmosphere. The bimodal distribution with maxima at C22 and C26 observed in winter indicated a substantial influence of fossil fuel sources. All the CPIs （CPI1, CPI2, CPI3） values, varying between 0.64 and 1.97, indicated the influence of anthropogenic emissions on fine organic aerosols. The estimated contributions of plant wax to total n-alkanes were on average of 12.9%, 19.1% and 26.1% for winter, spring and summer, respectively.

关键词： PM2.5 n-alkanes distribution pattern CPIs plant wax

来源：评论

学校读者我要写书评

暂无评论

Measurement of air exchange rates in different indoor environments using continuous CO_2 sensors

引用

Journal of environmental Sciences 2012年第4期24卷 657-664页

作者： Yan You Can Niu Jian Zhou Yating Liu Zhipeng Bai Jiefeng Zhang Fei He Nan Zhang State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Sciences and EngineeringNankai UniversityTianjin 300071China Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China

A new air exchange rate （AER） monitoring method using continuous CO2 sensors was developed and validated through both laboratory experiments and field studies. controlled laboratory simulation tests were conducted in a 1-m3 environmental chamber at different AERs （0.1-10.0 hr-1）. AERs were determined using the decay method based on box model assumptions. Field tests were conducted in classrooms, dormitories, meeting rooms and apartments during 2-5 weekdays using CO2 sensors coupled with data loggers. Indoor temperature, relative humidity （RH）, and CO2 concentrations were continuously monitored while outdoor parameters combined with on-site climate conditions were recorded. Statistical results indicated that good laboratory performance was achieved： duplicate precision was within 10%, and the measured AERs were 90%-120% of the real AERs. Average AERs were 1.22, 1.37, 1.10, 1.91 and 0.73 hr-l in dormitories, air-conditioned classrooms, classrooms with an air circulation cooling system, reading rooms, and meeting rooms, respectively. In an elderly particulate matter exposure study, all the homes had AER values ranging from 0.29 to 3.46 hr-1 in fall, and 0.12 to 1.39 hr-1 in winter with a median AER of 1.15.

关键词： air exchange rate continuous CO2 sensor steady-state method decay method particulate matter indoor-outdoorconcentration relationship

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

Influence of environmental temperature and relative humidity on photocatalytic oxidation of toluene on activated carbon fibers coated TiO_(2)

引用

Frontiers of environmental Science & Engineering 2008年第2期2卷 224-229页

作者： Ting GUO Zhipeng BAI Can WU Tan ZHU State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300071China

TiO_(2) supported on active carbon fiber(TiO_(2)/ACF),an absorbable photocatalyst,is a new kind of material applied in air *** this paper,the influence of environmental temperature(T)and relative humidity(RH)on the gas-solid adsorption of toluene and the photocatalytic oxidation(PCO)efficiency of adsorbed toluene on TiO_(2)/ACF were studied,and then,the purification capability of TiO_(2)/ACF was *** results showed that although the PCO efficiency increased under high RH and T levels,the amount of adsorption of toluene ***,quantitative analysis results of intermediates indicated that more environmental risk emerged when PCO of toluene was carried out at higher environmental T and RH levels because more toxic intermediates would be accumulated on the TiO_(2)/***,it is significant to control the environmental T and RH conditions in the application of the PCO technique.T 525uC and RH530% is the optimal condition for purifying toluene in our experimental system.

关键词： environmental temperature relative humidity TiO_(2)/ACF photocatalytic oxidation toluene

来源：评论

学校读者我要写书评

暂无评论

air pollutant emissions induced by rural-to-urban migration during China's urbanization(2005-2015)

引用

environmental Science and Ecotechnology 2022年第2期10卷 45-53页

作者： Guang Shi Xi Lu Hongxia Zhang Haotian Zheng Zhonghua Zhang Shi Chen Jia Xing Shuxiao Wang State Key Joint Laboratory of Environment Simulation and Pollution Control and School of Environment Tsinghua UniversityBeijing100084PR China Institute for Carbon Neutrality Tsinghua UniversityBeijing100084PR China Beijing Laboratory of Environmental Frontier Technologies Tsinghua UniversityBeijing100084PR China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing100084PR China School of Applied Economics Renmin University of ChinaBeijing100872PR China

As the world's most populous country,China has witnessed rapid urbanization in recent decades,with population migration from rural to urban(RU)regions as the major driving *** to the large gap between rural and urban consumption and investment level,large-scale RU migration impacts air pollutant emissions and creates extra uncertainties for air quality ***,we integrated population migration assessment,an environmentally extended inputeoutput model and structural decomposition analysis to evaluate the NOx,SO2 and primary PM2.5 emissions induced by RU migration during China's urbanization from 2005 to *** results show that RU migration increased air pollutant emissions,while the increases in NOx and SO2 emissions peaked in approximately 2010 at 2.4 Mt and 2.2 Mt,accounting for 9.2%and 8.7%of the national emissions,*** primary PM2.5 emissions induced by RU migration also peaked in approximately 2012 at 0.3 Mt,accounting for 2.8%of the national *** indirect emissions embodied in consumption and investment increased,while household direct emissions *** widening gap between urban and rural investment and consumption exerted a major increasing effect on migration-induced emissions;in contrast,the falling emission intensity contributed the most to the decreasing effect benefitting from end-of-pipe control technology applications as well as improving energy *** peak of air pollutant emissions induced by RU migration indicates that although urbanization currently creates extra environmental pressure in China,it is possible to reconcile urbanization and air quality improvement in the future with updating urbanization and air pollution control policies.

关键词： Urbanization Population migration air pollutant emission reduction Inputeoutput model Structural decomposition analysis

来源：评论

学校读者我要写书评

暂无评论

Low-condensation diesel use contributes to winter haze in cold regions of China

引用

environmental Science and Ecotechnology 2024年第6期22卷 226-232页

作者： Weiwei Song Mengying Wang Yixuan Zhao Yu Bo Wanying Yao Ruihan Chen Xianshi Wang Xiaoyan Wang Chunhui Li Kebin He State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing100029China Harbin Ecological and Environmental Monitoring Center Harbin150076China Collaborative Innovation Center for Regional Environmental Quality Beijing100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing100084China

The application of low-condensation diesel in cold regions with extremely low ambient temperatures(−14 to−29℃)has enabled the operation of diesel ***,it may contribute to heavy haze pollution in cold regions during *** we examine pollutant emissions from low-condensation diesel in *** measure the emissions of elemental carbon(EC),organic carbon(OC),and elements,including heavy metals such as arsenic(As).Our results show that low-condensation diesel increased EC and OC emissions by 2.5 and 2.6 times compared to normal diesel fuel,*** of vehicular sources,including EC,As,lead(Pb),cadmium(Cd),chromium(Cr),nickel(Ni),and manganese(Mn),increased by approximately 20.2-162.5%when using low-condensation *** variation of vehicular source indicators,observed at road site ambient environments revealed the enhancement of PM2.5 pollution by the application of low-condensation diesel in *** findings suggest that−35#diesel,a low-cetane index diesel,may enhance air pollution in winter,according to a dynamometer test conducted in *** raises questions about whether higher emissions are released if−35#diesel is applied to running vehicles in real-world cold ambient environments.

关键词： Low condensation diesel Carbonaceous matterHeavy metal Dynamometer Cold regions

来源：评论

学校读者我要写书评

暂无评论

Strong metal-support interaction (SMSI) in environmental catalysis: Mechanisms, application, regulation strategies, and breakthroughs

引用

environmental Science and Ecotechnology 2024年第6期22卷 7-24页

作者： Fuyuan Qi Jianfei Peng Zilu Liang Jiliang Guo Jiayuan Liu Tiange Fang Hongjun Mao Tianjin Key Laboratory of Urban Transport Emission Research&State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin300071China

The strong metal-support interaction(SMSI)in supported catalysts plays a dominant role in catalytic degradation,upgrading,and remanufacturing of environmental *** studies have shown that SMSI is crucial in supported catalysts'activity and ***,for redox reactions catalyzed in environmental catalysis,the enhancement mechanism of SMSI-induced oxygen vacancy and electron transfer needs to be ***,the precise control of SMSI interface sites remains to be fully *** we provide a systematic review of SMSI's catalytic mechanisms and control strategies in purifying gaseous pollutants,treating organic wastewater,and valorizing biomass solid *** explore the adsorption and activation mechanisms of SMSI in redox reactions by examining interfacial electron transfer,interfacial oxygen vacancy,and interfacial acidic ***,we develop a precise regulation strategy of SMSI from systematical perspectives of interface effect,crystal facet effect,size effect,guest ion doping,and modification ***,we point out the drawbacks and breakthrough directions for SMSI regulation in environmental catalysis,including partial encapsulation strategy,size optimization strategy,interface oxygen vacancy strategy,and multi-component *** review article provides the potential applications of SMSI and offers guidance for its controlled regulation in environmental catalysis.

关键词： environmental catalysis Metal oxide supported catalysts Strong metal-support interaction(SMSI) Interfacial site regulation Electron transfer

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：