维普中文期刊产品整合服务
99篇 您的检索式:作者名="Yuesi Wang"
    题名 作者 年代 出处 被引量
1Mechanism for the formation of the January 2013 heavy haze pollution episode over central and eastern China显示文摘In January 2013,a long-lasting episode of severe haze occurred in central and eastern China,and it attracted attention from all sectors of society.The process and evolution of haze pollution episodes were observed by the'Forming Mechanism and Control Strategies of Haze in China'group using an intensive aerosol and trace gases campaign that simultaneously obtained data at 11 ground-based observing sites in the CARE-China network.The characteristics and formation mechanism of haze pollution episodes were discussed.Five haze pollution episodes were identified in the Beijing-Tianjin-Hebei(Jing-Jin-Ji)area;the two most severe episodes occurred during 9–15 January and 25–31 January.During these two haze pollution episodes,the maximum hourly PM2.5mass concentrations in Beijing were 680 and 530μg m 3,respectively.The process and evolution of haze pollution episodes in other major cities in the Jing-Jin-Ji area,such as Shijiazhuang and Tianjin were almost the same as those observed in Beijing.The external cause of the severe haze episodes was the unusual atmospheric circulation,the depression of strong cold air activities and the very unfavorable dispersion due to geographical and meteorological conditions.However,the internal cause was the quick secondary transformation of primary gaseous pollutants to secondary aerosols,which contributed to the'explosive growth'and'sustained growth'of PM2.5.Particularly,the abnormally high amount of nitric oxide(NOx)in the haze episodes,produced by fossil fuel combustion and vehicle emissions,played a direct or indirect role in the quick secondary transformation of coal-burning sulphur dioxide(SO2)to sulphate aerosols.Furthermore,gaseous pollutants were transformed into secondary aerosols through heterogeneous reactions on the surface of fine particles,which can change the particle’s size and chemical composition.Consequently,the proportion of secondary inorganic ions,such as sulphate and nitrate,gradually increased,which enhances particle hygroscopicity and thereby accelerating formation of the haze pollution.WANG YueSi YAO Li WANG LiLi LIU ZiRui JI DongSheng TANG GuiQian ZHANG JunKe SUN Yang HU Bo XIN JinYuan 2014Science China Earth Sciences2014,57,1:189
2Contrasting trends of PM2.5 and surface-ozone concentrations in China from 2013 to 2017显示文摘Although much attention has been paid to investigating and controlling air pollution in China,the trends of air-pollutant concentrations on a national scale have remained unclear.Here,we quantitatively investigated the variation of air pollutants in China using long-term comprehensive data sets from 2013 to 2017,during which Chinese government made major efforts to reduce anthropogenic emission in polluted regions.Our results show a significant decreasing trend in the PM2.5 concentration in heavily polluted regions of eastern China,with an annual decrease of〜7%compared with measurements in 2013.The measured decreased concentrations of SO2>NO2 and CO(a proxy for anthropogenic volatile organic compounds)could explain a large fraction of the decreased PM2.5 concentrations in different regions.As a consequence;the heavily polluted days decreased significantly in corresponding regions.Concentrations of organic aerosol;nitrate;sulfate,ammonium and chloride measured in urban Beijing revealed a remarkable reduction from 2013 to 2017;connecting the decreases in aerosol precursors with corresponding chemical components closely.However;surface-ozone concentrations showed increasing trends in most urban stations from 2013 to 2017;which indicates stronger photochemical pollution.The boundary-layer height in capital c让ies of eastern China showed no significant trends over the Beijing-Tianjin-Hebei,Yangtze River Delta and Pearl River Delta regions from 2013 to 2017;which confirmed the reduction in anthropogenic emissions.Our results demonstrated that the Chinese government was successful in the reduction of particulate matter in urban areas from 2013 to 2017,although the ozone concentration has increased significantly;suggesting a more complex mechanism of improving Chinese air quality in the future.Yonghong Wang Wenkang Gao Shuai Wang Tao Song Zhengyu Gong Dongsheng Ji Lili Wang Zirui Liu Guiqian Tang Yanfeng Huo Shili Tian Jiayun Li Mingge Li Yuan Yang Biwu Chu Tuukka Petaja Veli-Matti Kerminen Hong He Jiming Hao Markku Kulmala Yuesi Wang Yuanhang Zhang 2020National Science Review2020,7,8:51
3Seasonal variation and source apportionment of organic and inorganic compounds in PM_(2.5) and PM_(10) particulates in Beijing,China显示文摘The distribution and source of the solvent-extractable organic and inorganic components in PM 2.5(aerodynamics equivalent diameter below 2.5 microns),and PM 10(aerodynamics equivalent diameter below 10 microns) fractions of airborne particles were studied weekly from September 2006 to August 2007 in Beijing.The extracted organic and inorganic compounds identified in both particle size ranges consisted of n-alkanes,PAHs(polycyclic aromatic hydrocarbons),fatty acids and water soluble ions.The potential emission sources of these organic compounds were reconciled by combining the values of n-alkane carbon preference index(CPI),%waxC n,selected diagnostic ratios of PAHs and principal component analysis in both size ranges.The mean cumulative concentrations of n-alkanes reached 1128.65ng/m3 in Beijing,74% of which(i.e.,831.7ng/m3) was in the PM 2.5 fraction,PAHs reached 136.45ng/m3(113.44ng/m3 or 83% in PM 2.5),and fatty acids reached 436.99ng/m3(324.41ng/m3 or 74% in PM 2.5),which resulted in overall enrichment in the fine particles.The average concentrations of SO42-,NO3-,and NH4+ were 21.3±15.2,6.1±1.8,12.5±6.1μg/m3 in PM 2.5,and 25.8±15.5,8.9±2.6,16.9±9.5μg/m3 in PM 10,respectively.These three secondary ions primarily existed as ammonium sulfate((NH4)2SO4),ammonium bisulfate(NH4HSO4) and ammonium nitrate(NH4NO3).The characteristic ratios of PAHs revealed that the primary sources of PAHs were coal combustion,followed by gasoline combustion.The ratios of stearic/palmitic acid indicated the major contribution of vehicle emissions to fatty acids in airborne particles.The major alkane sources were biogenic sources and fossil fuel combustion.The major sources of PAHs were vehicular emission and coal combustion.Xingru Li Yuesi Wang Xueqing Guo Yingfeng Wang 2013Journal of Environmental Sciences2013,25,4:34
4Carbon Dioxide, Methane, and Nitrous Oxide Emissions from a Rice-Wheat Rotation as Affected by Crop Residue Incorporation and Temperature显示文摘Field measurements were made from June 2001 to May 2002 to evaluate the e?ect of crop residue application and temperature on CO2, CH4, and N2O emissions within an entire rice-wheat rotation season. Rapeseed cake and wheat straw were incorporated into the soil at a rate of 2.25 t hm?2 when the rice crop was transplanted in June 2001. Compared with the control, the incorporation of rapeseed cake enhanced the emissions of CO2, CH4, and N2O in the rice-growing season by 12.3%, 252.3%, and 17.5%, respectively, while no further e?ect was held on the emissions of CO2 and N2O in the following wheat- growing season. The incorporation of wheat straw enhanced the emissions of CO2 and CH4 by 7.1% and 249.6%, respectively, but reduced the N2O emission by 18.8% in the rice-growing season. Signi?cant reductions of 17.8% for the CO2 and of 12.9% for the N2O emission were observed in the following wheat- growing season. A positive correlation existed between the emissions of N2O and CO2 (R2 = 0.445,n = 73,p < 0.001) from the rice-growing season when N2O was emitted. A trade-o? relationship between the emissions of CH4 and N2O was found in the rice-growing season. The CH4 emission was signi?cantly correlated with the CO2 emission for the period from rice transplantation to ?eld drainage, but not for the entire rice-growing season. In addition, air temperature was found to regulate the CO2 emissions from the non-waterlogged period over the entire rice-wheat rotation season and the N2O emissions from the non- waterlogged period of the rice-growing season, which can be quantitatively described by an exponential function. The temperature coe?cient (Q10) was then evaluated to be 2.3±0.2 for the CO2 emission and 3.9±0.4 for the N2O emission, respectively.ZOU Jianwen(邹建文) HUANG Yao(黄耀) ZONG Lianggang(宗良纲) ZHENG Xunhua(郑循华) WANG Yuesi(王跃思) 2004Advances in Atmospheric Sciences2004,21,5:29
5Variability and reduction of atmospheric pollutants in Beijing and its surrounding area during the Beijing 2008 Olympic Games显示文摘The Beijing-Tianjin-Hebei Atmospheric Environment Monitoring Network was established by the Institute of Atmospheric Physics,Chinese Academy of Sciences.The goals of the network were to monitor and provide warnings of the atmospheric quality in Beijing and its surrounding area during the Beijing 2008 Olympic Games.The results showed that the atmospheric complex pollution exhibited high concentrations of ozone and fine particles and oxidation in summer,with a ubiquitous regional source.The regional mean concentrations of SO2,PM2.5,NO2,and O3_8h max(the maximum daily 8 h mean) and Ox were 22±11,90±40,25±5,136±35 and 112±21 μg/m3 in summer,respectively.During the Olympic Games,the mean concentration of SO2,PM2.5,NO2,O3_8h max,and Ox were 12.5±4,56±28,23±4,114±29,95±17 μg/m3 in the region,respectively,and fell by 51.0%,43.7%,13%,20.2%,and 18.9%,respectively,compared to the prophase mean before the Olympic Games.The concentration of atmospheric pollutants declined significantly and achieved the 'Green Olympics' control goal of air quality.After the Olympic Games,SO2,PM2.5 and NOx increased significantly as the temporary atmospheric pollution control measures were terminated.XIN JinYuan WANG YueSi TANG GuiQian WANG LiLi SUN Yang WANG YingHong HU Bo SONG Tao JI DongSheng WANG WeiFeng LI Liang LIU GuangRen 2010Chinese Science Bulletin2010,55,18:30
6Trends in particulate matter and its chemical compositions in China from 2013–2017显示文摘Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemical components(MI)dropped by 70%,24%and 13%in BTH,the PRD and the Fenhe and Weihe River Plain,respectively.The change in the PM2.5 chemical composition is consistent with the decrease of the PM2.5mass concentration.(3)In 2015,the mean OM concentration contributions to fine particles and coarse particles were 13-46%and 46-57%,respectively,and the mean MI concentration contributions to fine particles and coarse and particles were 31-60%and 39-73%,respectively;these values are lower than the 2013 values from the key regions,which is the most important factor behind the decrease of the particulate matter mass concentration.From 2013 to 2015,among the chemical components of different particle size fractions,the peak value of the coarse particle size fraction decreased significantly,and the fine particle size fractions of SO42-,NO3-,and NH4+decreased with the decrease of the particulate matter mass concentration in different particle size fractions.The fine-particle size peaks of SO42-,NO3-and NH4+shifted from 0.65-1.1μm to the finer size range of0.43-0.65μm during the same time frame.Yuesi WANG Wenjie LI Wenkang GAO Zirui LIU Shili TIAN Rongrong SHEN Dongsheng JI Shuai WANG Lili WANG Guiqian TANG Tao SONG Mengtian CHENG Gehui WANG Zhengyu GONG Jiming HAO Yuanhang ZHANG 2019Science China Earth Sciences2019,62,12:23
7Characterization of volatile organic compounds in the urban area of Beijing from 2000 to 2007显示文摘Beijing is one of the most polluted cities in the world.In this study,the long-term and continuous measurements of volatile organic compounds (VOCs) in the urban area of Beijing,specifically at Beijing 325 m Meteorological Tower,were conducted from 2000 to 2007.The annual record of VOC trends exhibited in two different phases was separated in 2003.Records show that VOC concentrations increased from 2000 to 2003 due to the abrupt increase in vehicle number.Contrarily,since 2003,there had been a decrease in VOCs concentrations as the policy on gasoline and air pollution was implemented.Toluene,benzene,and i-pentane are the chemicals that abound in and are directly related to vehicle activity,such as in vehicle exhaust and gasoline evaporation.Furthermore,records indicate that there had been seasonal variation in VOCs levels in that VOCs level in summer is higher than that in winter.As such,temperature is considered to significantly contribute to VOCs in Beijing.Records also show that VOCs level was high in the morning and during rush hours in the evening.In contrast,VOCs level was low during midday due to photochemical destruction with OH radical and dilution effect.In this study,a particular benzene to toluene ratio range (0.4-1.0) was used as the indicator of air propelled by vehicular exhaust.We also applied the correlation coefficients between BTEX and i-pentane to evaluate evaporation influence to ambient BTEX in the Beijing urban area.Yuesi Wang Xiyan Ren Dongsheng Ji Junqang Zhang Jie Sun Fankun Wu 2012Journal of Environmental Sciences2012,24,1:21
8Fluxes of CH4 and N_2O from soil under a tropical seasonal rain forest in Xishuangbanna, Southwest China显示文摘从在在 Xishuangbanna 的热带季节的雨林下面的土壤的 CH4 和 N2O 流动,西南中国用关上的静态的房间技术和气体色层法方法被测量一年。三个处理被放在学习的地里:(A) 没有崽,有垃圾的(B) ,和有垃圾和幼苗的(C) 。结果证明在我们的学习的土壤是大气的 CH4 的一个水池和大气的 N2O 的来源。从处理 A, B,和 C 的观察吝啬的 CH4 流动是 50.0 ± 4.0, 35.9 ± 2.8, 31.6 ± 2.8 μ g C/(m2 · h ) ,分别地并且在 2003 的计算年度流动分别地是 4.1, 3.1,和 2.9 kgC/hm2。从处理 A, B,和 C 的观察吝啬的 N2O 流动是 30.9 ± 3.1, 28.2 ± 3.5, 50.2 ± 3 .7 μ g N/(m2 · h ) ,分别地并且在 2003 的计算年度流动分别地是 4.1, 3.1,和 2.9 kgC/hm2。从处理 A, B,和 C 的观察吝啬的 N2O 流动是 30.9 ± 3.1, 28.2 ± 3.5, 50.2 ± 3 .7 μ g N/(m2 · h ) ,分别地并且在 2003 的计算年度流动是 2.8, 2.6,和 3.7 kgN/hm 2 分别地。在 CH4 和 N2O 流动的季节变化在所有三个处理之中是重要的。垃圾的存在减少了 CH4 举起在湿季节期间(P < 0.05 ) ,然而并非在干旱期期间。调停幼苗的 N2O 排出物有类似的增加在期间湿并且干旱期,显示幼苗在两个季节增加了 N2O 排放。一种强壮的积极关系为处理 B 和处理 C 为所有三个处理,和在 CH4 流动和土壤温度之间的弱关系在 CH4 流动和土壤潮湿之间存在。N2O 流动为所有三个处理与土壤温度相关。YAN Yuping SHA Liqing CAO Min ZHENG Zheng TANG Jianwei WANG Yinghong ZHANG Yiping WANG Rui LIU Guangren WANG Yuesi SUN Yang 2008Journal of Environmental Sciences2008,20,2:18
9Meteorological mechanism for a large-scale persistent severe ozone pollution event over eastern China in 2017显示文摘An intensive and persistent regional ozone pollution event occurred over eastern China from 25 June to 5 July 2017.73 out of 96 selected cities,most located in the Beijing-TianjinHebei and the surrounding area(BTHS),suffered severe ozone pollution.A north-south contrast ozone distribution,with higher ozone(199±33μg/m3)in the BTHS and lower ozone(118±25μg/m^3)in the Yangtze River Delta(YRD),was found to be dominated by the position of the West Pacific Subtropical High(WPSH)and mid-high latitude wave activities.In the BTHS,the positive anomalies of geopotential height at 500 hPa and temperature at the surface indicated favorable meteorological conditions for local ozone formation.Prevailing northwesterly winds in the mid-high troposphere and warm advection induced by weak southerly winds in the low troposphere resulted in low-moderate relative humidity(RH),less total cloud cover(TGC),strong solar radiation and high temperatures.Moreover,southerly winds prevailing over the BTHS aggravated the pollution due to regional transportation of O3 and its precursors.On one hand,the deep sinking motion and inversion layer suppressed the dispersion of pollutants.On the other hand,O3-rich air in the upper layer was maintained at night due to temperature inversion,which facilitated O3 vertical transport to the surface in the next-day morning due to elevated convection.Generally,temperature,UV radiation,and RH showed good correlations with O3 in the BTHS,with rates of 8.51(μg/m^3)/℃(within the temperature range of 20-38℃),59.54(μg/m^3)/(MJ/m^2)and-1.93(μg/m^3)/%,respectively.Jia Mao Lili Wang Chuhan Lu Jingda Liu Mingge Li Guiqian Tang Dongsheng Ji Nan Zhang Yuesi Wang 2020Journal of Environmental Sciences2020,32,6:18
10Distribution and sources of solvent extractable organic compounds in PM_(2.5) during 2007 Chinese Spring Festival in Beijing显示文摘The solvent extractable organic compounds (SEOC), including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, anddicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-massspectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs,and organic acids before Chinese Spring Festival Eve (1025.5, 95.9, and 543.3 ng/m3, respectively) were higher than those after (536.6,58.9, and 331.8 ng/m3, respectively). n-Aalkanes and PAHs had much higher concentration in nighttime than those in daytime becauseof high relative humidity and low wind speed during the night. Combustion of coal and exhaust emission were major sources of n-alkanes. It could be concluded by the characteristic ratios that the primary source of PAHs in fine particles was the combustion of coal,but the combustion of gasoline was in the next place. The ratios of C18:0/C16 indicated the contribution of vehicular emissions to thefatty acids. Dicarboxylic and aromatic acids were abundant in daytime than in nighttime because these acids were secondary organicacid and the photochemical degradation of aromatic hydrocarbons was the main source.LI Xingru GUO Xueqing LIU Xinran LIU Chenshu ZHANG Shanshan WANG Yuesi 2009Journal of Environmental Sciences2009,21,2:17
11Evolution of boundary layer ozone in Shijiazhuang,a suburban site on the North China Plain显示文摘The structure of the boundary layer affects the evolution of ozone(O3), and research into this structure will provide important insights for understanding photochemical pollution.In this study, we conducted a one-month observation(from June 15 to July 14, 2016) of the boundary layer meteorological factors as well as O3 and its precursors in Luancheng County,Shijiazhuang(37°53′N, 114°38′E). Our research showed that photochemical pollution in Shijiazhuang is serious, and the mean hourly maximum and mean 8-hr maximum O3 concentrations are 97.9 ± 26.1 and 84.4 ± 22.4 ppbV, respectively. Meteorological factors play a significant role in the formation of O3. High temperatures and southeasterly winds lead to elevated O3 values, and at moderate relative humidity(40%–50%) and medium boundary layer heights(1200–1500 m), O3 production sensitivity occurred in the transitional region between volatile organic compounds(VOC) and nitrogen oxides(NOx) limitations,and the O3 concentration was the highest. The vertical profiles of O3 were also measured by a tethered balloon. The results showed that a large amount of O3 was stored in the residual layer, and the concentration was positively correlated with the O3 concentration measured the previous day. During the daytime of the following day, the contribution of O3 stored in the residual layer to the boundary layer reached 27%± 7% on average.Wei Zhao Guiqian Tang Huan Yu Yang Yang Yinghong Wang Lili Wang Junlin An Wenkang Gao Bo Hu Mengtian Cheng Xingqin An Xin Li Yuesi Wang 2019Journal of Environmental Sciences2019,31,9:15
12In situ measurement of PM_1 organic aerosol in Beijing winter using a high-resolution aerosol mass spectrometer显示文摘Organic aerosol (OA) is a crucial component of atmospheric fine particles. To achieve a better understanding of the chemical characteristics and sources of OA in Beijing, the size-resolved chemical composition of submicron aerosols were measured in-situ using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer in the winter of 2010, with a high time resolution of 5 min. During this study, the mean OA mass concentration was 20.9±25.3 μg/m3, varying between 1.9 and 284.6 μg/m3. Elemental analysis showed that the average H/C, O/C and N/C (molar ratio) were 1.70, 0.17, and 0.005, respectively, corresponding to an OM/OC ratio (mass ratio of organic matter to organic carbon) of 1.37. The average mass-based size distributions of OA present a promi- nent accumulation mode peaking at approximately 450 nm. The prominent presence of ultrafine particles (Dva < 100 nm) was mainly from the fresh emissions of combustion sources. A Positive Matrix Factorisation (PMF) analysis of the organic mass spectral dataset differentiated the OA into three components, including hydrocarbon-like (HOA), cooking-related (COA), and oxygenated (OOA) organic aerosols, which, on average, accounted for 26.9%, 49.7% and 23.4%, respectively, of the total organic mass. The HOA and COA likely corresponded to primary organic aerosol (POA) associated with combustion-related and cooking emissions, respectively, and the OOA components corresponded to aged secondary organic aerosol (SOA).LIU Quan SUN Yang HU Bo LIU ZiRui AKIO Shimono WANG YueSi 2012Chinese Science Bulletin2012,57,7:14
13Characteristics of PM_(2.5) pollution in Beijing after the improvement of air quality显示文摘Following the implementation of the strictest clean air policies to date in Beijing,the physicochemical characteristics and sources of PM_(2.5) have changed over the past few years.To improve pollution reduction policies and subsequent air quality further,it is necessary to explore the changes in PM_(2.5) over time.In this study,over one year(2017-2018)field study based on filter sampling(TH-150C;Wuhan Tianhong,China)was conducted in Fengtai District,Beijing,revealed that the annual average PM_(2.5) concentration(64.8±43.1μg/m^3)was significantly lower than in previous years and the highest PM_(2.5) concentration occurred in spring(84.4±59.9μg/m^3).Secondary nitrate was the largest source and accounted for 25.7%of the measured PM_(2.5).Vehicular emission,the second largest source(17.6%),deserves more attention when considering the increase in the number of motor vehicles and its contribution to gaseous pollutants.In addition,the contribution from coal combustion to PM_(2.5) decreased significantly.During weekends,the contribution from EC and NO3−increased whereas the contributions from SO4^2−,OM,and trace elements decreased,compared with weekdays.During the period of residential heating,PM_(2.5) mass decreased by 23.1%,compared with non-heating period,while the contributions from coal combustion and vehicular emission,and related species increased.With the aggravation of pollution,the contribution of vehicular emission and secondary sulfate increased and then decreased,while the contribution of NO3−and secondary nitrate continued to increase,and accounted for 34.0%and 57.5%of the PM_(2.5) during the heavily polluted days,respectively.Xiaojuan Huang Guiqian Tang Junke Zhang Baoxian Liu Chao Liu Jin Zhang Leilei Cong Mengtian Cheng Guangxuan Yan Wenkang Gao Yinghong Wang Yuesi Wang 2021Journal of Environmental Sciences2021,33,2:14
14Soil respiration in tropical seasonal rain forest in Xishuangbanna, SW China显示文摘With the static opaque chamber and gas chromatography technique, from January 2003 to January 2004 soil respiration was investigated in a tropical seasonal rain forest in Xishuangbanna, SW China. In this study three treatments were applied, each with three replicates: A (bare soil), B (soil+litter), and C (soil+litter+seedling). The results showed that soil respiration varied seasonally, low from December 2003 to February 2004, and high from June to July 2004. The annual average values of CO2 efflux from soil respiration differed among the treatments at 1% level, with the rank of C (14642 mgCO2· m-2. h-1)>B (12807 mgCO2· m-2. h-1)>A (9532 mgCO2· m-2. h-1). Diurnal variation in soil respiration was not apparent due to little diurnal temperate change in Xishuangbanna. There was a parabola relationship between soil respiration and soil moisture at 1% level. Soil respiration rates were higher when soil moisture ranged from 35% to 45%. There was an exponential relationship between soil respiration and soil temperature (at a depth of 5cm in mineral soil) at 1% level. The calculated Q1o values in this study,ranging from 2.03 to 2.36, were very near to those of tropical soil reported. The CO2 efflux in 2003was 5.34 kgCO2· m-2. a-1 from soil plus litter plus seedling, of them 3.48 kgCO2· m-2. a-1 from soil (accounting for 62.5%), 1.19 kgCO2· m-2. a-1 from litter (22.3%) and 0.67 kgCO2·m-2. a-1 from seedling (12.5%).SHA Liqing, ZHENG Zheng, TANG Jianwei, WANG Yinghong, ZHANG Yiping, CAO Min, WANG Rui, LIU Guangren, WANG Yuesi & SUN Yang Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China Graduate School of Chinese Academy of Sciences, Beijing 100039, China 2005Science China Earth Sciences2005,48,z1:12
15Haze insights and mitigation in China: An overview显示文摘The present article provides an overview of the chemical and physical features of haze in China, focusing on the relationship between haze and atmospheric fine particles, and the formation mechanism of haze. It also summarizes several of control technologies and strategies to mitigate the occurrence of haze. The development of instruments and the analysis of measurements of ambient particles and precursor concentrations have provided important information about haze formation. Indeed, the use of new instruments has greatly facilitated current haze research in China. Examples of insightful results include the relationship between fine particles and haze, the chemical compositions and sources of particles, the impacts of the aging process on haze formation, and the application of technologies that control the formation of haze. Based on these results, two relevant issues need to be addressed: understanding the relationship between haze and fine particles and understanding how to control PM2.5.Xuliang Zhuang Yuesi Wang Hong He Jianguo Liu Xinming Wang Tingyu Zhu Maofa Ge Ju Zhou Guiqian Tang Jinzhu Ma 2014Journal of Environmental Sciences2014,26,1:12
16Organic composition of gasoline and its potential effects on air pollution in North China显示文摘When gasoline is burned to power an automotive engine, a portion of the fuel remains unburned or is partially burned and leaves the engine as hydrocarbon and oxygenated compounds. In addition, a small portion of the fuel can escape the vehicle through evaporation. Changes in alkanes, olefins and aromatics each affect emissions differently, which could complicate control strategies for air pollution. In this study, we collected 31 gasoline samples over five provinces and cities(Beijing, Tianjin, Hebei, Shandong, and Shaanxi) in North China between 2012 and 2013. The organic composition of the gasoline samples was analyzed using the gas chromatography-mass spectrometry(GC-MS) method, and the aniline compounds were analyzed by solvent extraction and the GC-MS method. The ratios of alkanes, aromatics, olefins and other organic compounds in gasoline were 40.6%, 38.1%, 12.9% and 8.4%, respectively. The aromatic and benzene exceedances were 15 and 8 based on the China's gasoline standards(III), and they accounted for 48.4% and 25.8% of all the gasoline samples, respectively. Strong carcinogen aniline compounds were detected in all 31 samples, and the content of aniline compounds in 3 samples exceeded 1%. The high proportion of aromatics and olefins in the gasoline increased the emissions of carbon monoxide(CO) and toxics, as well as the atmospheric photochemical reactivity of exhaust emissions, which could hasten the formation of secondary pollutants. Our results are helpful for redefining government strategies to control air pollution in North China and relevant for developing new refining technology throughout China.Guiqian Tang Jie Sun Fangkun Wu Yang Sun Xiaowan Zhu Yejun Geng Yuesi Wang 2015Science China Chemistry2015,58,9:10
17Trend,seasonal and diurnal variations of atmospheric CO_2 in Beijing显示文摘The concentration of atmospheric CO2 in Beijing increased rapidly at a mean growth rate of 3.7%·a-1 from 1993 to 1995. After displaying a peak of (409.7±25.9) μmol·mol-1 in 1995, it decreased slowly. Both the almost stable anthropogenic CO2 source and increasing biotic CO2 sink contribute to the drop of CO2 concentration from 1995 to 2000. The seasonal variation of CO2 concentration exhibits a clear cycle with a maximum in winter, averaging (426.8± 20.6)μmol·mol-1, and a minimum in summer, averaging (369.1±6.1)μmol·mol-1. The seasonal variation of CO2 concentration is mainly controlled by phenology. The mean diurnal variation of atmospheric CO2 concentration for a year in Beijing is highly clear: daily maximum CO2 concentration usually occurs at night, but daily minimum CO2 concentration does in the daytime, with a mean diurnal difference more than 34.7μmol·mol-1. It has been revealed that the interannual variations of atmospheric CO2 concentration in winter and autumn regulated theWANG Yuesi, WANG Changke, GUO Xueqing, LIU Guangren & HUANG YaoLAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100083, China Department of Chemistry, Capital Normal University, Beijing 100037, China 2002Chinese Science Bulletin2002,47,24:8
18Validation of MODIS aerosol products by CSHNET over China显示文摘The Chinese Sun Hazemeter Network (CSHNET) provides the necessary ground-based observation to validate and assess the applicability of MODIS aerosol optical depth (AOD) products over different ecological and geographic regions in China for the first time. The validation results show that the comprehensive utilization ratio and applicability of MODIS products varied very much over different regions and seasons from August 2004 to July 2005. On the Tibetan Plateau, the comprehensive utili- zation ratio of MODIS data was low: MODIS products only accounted for 16% of the ground-based observation; on average, 31% to 45% of MODIS products fell within the retrieval errors issued by NASA. A similar result was found in northern desert areas with the ratio of MODIS to observation ranging from 15% to 55%, with 7% to 39% of MODIS products within errors. In the remote northeast corner of China, low ratios of MODIS to observation were also found ranging from 14% to 46%, with 49% to 69% of MODIS within errors. The forested sites exhibited moderate ratios of MODIS to observation ranging from 46% to 65%, with 30% to 59% of MODIS within errors. This was similar to numbers observed at sites along eastern seashore of China and inland urban sites with the ratio of MODIS to observation between 63% to 75%, with 25% to 67% of MODIS within errors for sites along eastern seashore of China and 43% to 78%, with 35% to 75% of MODIS within errors for inland urban sites. The ratio of MODIS to observation over agricultural areas ranged from 61% to 89%; 59%-88% of MODIS fell within the retrieval errors. At homogeneous and well vegetated areas, the comprehensive utilization ratio of MODIS products was over 80% and above 70% of MODIS products fell within the retrieval errors in growing season.WANG LiLi XIN JinYuan WANG YueSi LI ZhanQing WANG PuCai LIU GuangRen WEN TianXue 2007Chinese Science Bulletin2007,52,12:7
19Vehicular emissions in China in 2006 and 2010显示文摘Vehicular emissions in China in 2006 and 2010 were calculated at a high spatial resolution based on the data released by the National Bureau of Statistics, by taking the emission standards into consideration. China's vehicular emissions of carbon monoxide(CO),nitrogen oxides(NO_x), volatile organic compounds(VOCs), ammonia(NH_3), fine particulate matters(PM_(2.5)), inhalable particulate matters(PM_(10)), black carbon(BC), and organic carbon(OC) were 30,113.9, 4593.7, 6838.0, 20.9, 400.2, 430.5, 285.6, and 105.1 Gg, respectively, in 2006 and 34,175.2, 5167.5, 7029.4, 74.0, 386.4, 417.1, 270.9, and 106.2 Gg, respectively, in 2010. CO,VOCs, and NH_3 emissions were mainly from motorcycles and light-duty gasoline vehicles,whereas NO_X, PM_(2.5), PM_(10), and BC emissions were mainly from rural vehicles and heavyduty diesel trucks. OC emissions were mainly from motorcycles and heavy-duty diesel trucks. Vehicles of pre-China Ⅰ(vehicular emission standard of China before phase Ⅰ) and China Ⅰ(vehicular emission standard of China in phase Ⅰ) were the primary contributors to all of the pollutant emissions except NH_3, which was mainly from China Ⅲ and China Ⅳ gasoline vehicles. The total emissions of all the pollutants except NH_3 changed little from2006 to 2010. This finding can be attributed to the implementation of strict emission standards and to improvements in oil quality.Guiqian Tang Na Chao Yuesi Wang Jiashan Chen 2016Journal of Environmental Sciences2016,28,10:7
20Chemical characteristics and source apportionment of PM_(2.5) in a petrochemical city: Implications for primary and secondary carbonaceous component显示文摘To study the pollution features and underlying mechanism of PM_(2.5) in Luoyang, a typical developing urban site in the central plain of China, 303 PM_(2.5) samples were collected from April 16 to December 29, 2015 to analyze the elements, water soluble inorganic ions, organic carbon and elemental carbon. The annual mean concentration of PM_(2.5) was 142.3 μg/m^(3), and 75% of the daily PM_(2.5) concentrations exceeded the 75 μg/m^(3). The secondary inorganic ions, organic matter and mineral dust were the most abundant species, accounting for 39.6%, 19.2% and 9.3% of the total mass concentration, respectively. But the major chemical components showed clear seasonal dependence. SO_(4)^(2-) was most abundant specie in spring and summer, which related to intensive photochemical reaction under high O_3 concentration. In contrast, the secondary organic carbon and ammonium while primary organic carbon and ammonium significantly contributed to haze formation in autumn and winter, respectively. This indicated that the collaboration effect of secondary inorganic aerosols and carbonaceous matters result in heavy haze in autumn and winter. Six main sources were identified by positive matrix factorization model: industrial emission, combustion sources, traffic emission, mineral dust, oil combustion and secondary sulfate, with the annual contribution of 24%, 20%, 24%, 4%, 5% and 23%, respectively. The potential source contribution function analysis pointed that the contribution of the local and short-range regional transportation had significant impact. This result highlighted that local primary carbonaceous and precursor of secondary carbonaceous mitigation would be key to reduce PM_(2.5) and O_3 during heavy haze episodes in winter and autumn.Guangxuan Yan Puzhen Zhang Jie Yang Jingwen Zhang Guifen Zhu Zhiguo Cao Jing Fan Zirui Liu Yuesi Wang 2021Journal of Environmental Sciences2021,33,5:6
返回顶部 每页显示:
共5页 首页 上一页 第1页 下一页 末页 /5 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费