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52篇 您的检索式:作者名="Yujing Mu"
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1Levels,sources and health risks of carbonyls and BTEX in the ambient air of Beijing,China显示文摘The atmospheric concentrations of carbonyls and BTEX (benzene,toluene,ethylbenzene,m,p-xylene and o-xylene) were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010.The average concentrations of the total measured carbonyls during autumn,winter,spring,and summer were 37.7,31.3,39.7,50.5 μg/m 3,respectively,and maximal values for their diurnal variations usually happened at noontime.In contrast to carbonyls,the average concentrations of the total measured BTEX during the four seasons were 27.2,31.9,23.2,19.1 μg/m 3,respectively,andminimal values for their diurnal variations always occurred in the early afternoon.The average concentration for carbonyls increased about 24% from September 2008-August 2009 to September 2009-August 2010,for BTEX,increased about 15%.Integrated life time cancer risks for three carcinogens (benzene,formaldehyde and acetaldehyde) in Beijing exceeded the value of 1E-06,and the hazard quotient (HQ) of non-cancer risk of exposure to formaldehyde exceeded unity.Yujie Zhang Yujing Mu Junfeng Liu Abdelwahid Mellouki 2012Journal of Environmental Sciences2012,24,1:55
2Nitrous oxide emissions from a maize field during two consecutive growing seasons in the North China Plain显示文摘Nitrous oxide (N 2 O) emissions from a maize field in the North China Plain (Wangdu County,Hebei Province,China) were investigated using static chambers during two consecutive maize growing seasons in the 2008 and 2009.The N 2 O pulse emissions occurred with duration of about 10 days after basal and additional fertilizer applications in the both years.The average N 2 O fluxes from the CK (control plot,without crop,fertilization and irrigation),NP (chemical N fertilizer),SN (wheat straw returning plus chemical N fertilizer),OM- 1/2N (chicken manure plus half chemical N fertilizer) and OMN (chicken manure plus chemical N fertilizer) plots in 2008 were 8.51,72.1,76.6,101,107 ng N/(m 2 ·sec),respectively,and in 2009 were 33.7,30.0 and 35.0 ng N/(m 2 ·sec) from CK,NP and SN plots,respectively.The emission factors of the applied fertilizer as N 2 O-N (EFs) were 3.8% (2008) and 1.1% (2009) for the NP plot,3.2% (2008) and 1.2% (2009) for the SN plot,and 2.8% and 2.2% in 2008 for the OM-1/2N and OMN plots,respectively.Hydromorphic properties of the investigated soil (with gley) are in favor of denitrification.The large differences of the soil temperature and water-filled pore space (WFPS) between the two maize seasons were suspected to be responsible for the significant yearly variations.Compared with the treatments of NP and SN,chicken manure coupled with compound fertilizer application significantly reduced fertilizer loss rate as N 2 O-N.Yuanyuan Zhang Junfeng Liu Yujing Mu Zhu Xu Shuwei Pei Xiaoxiu Lun Ying Zhang 2012Journal of Environmental Sciences2012,24,1:15
3Preliminary report on methane emissions from the Three Gorges Reservoir in the summer drainage period显示文摘Recently reported summertime methane (CH4) emissions (6.7 ± 13.3 mg CH4/(m2·hr)) from newly created marshes in the drawdown area of the Three Gorges Reservoir (TGR), China have triggered broad concern in academic circles and among the public. The CH4 emissions from TGR water surfaces and drawdown areas were monitored from 3rd June to 16th October 2010 with floating and static chambers and gas chromatography. The average CH4 emission flux from permanently flooded areas in Zigui, Wushan and Yunyang Counties was (0.33 ± 0.09) mg CH4/(m2·hr). In half of these hottest months of the year, the wilderness, cropland and deforested drawdown sites were aerobic and located above water level, and the CH4 emissions were very small, ranging from a sink at 0.12 mg CH4/(m2·hr) to a source at 0.08 mg CH4/(m2·hr) except for one mud-covered site after flood. Mean CH4 emission in flooded drawdown sites was 0.34 mg CH4/(m2·hr). The emissions from the rice paddy sites in the drawdown area were averaged at (4.86 ± 2.31) mg CH4/(m2·hr). Excepting the rice-paddy sites, these results show much lower emission levels than previously reported. Our results indicated considerable spatial and temporal variation in CH4 emissions from the TGR. Human activities and occasional events, such as flood, may also affect emission levels. Long-term CH4 measurements and modeling in a large region are necessary to accurately estimate greenhouse gas emissions from the TGR.Fei Lu Le Yang Xiaoke Wang Xiaonan Duan Yujing Mu Wenzhi Song Feixiang Zheng Junfeng Niu Lei Tong Hua Zheng Yongjuan Zhou Jiangxiao Qiu Zhiyun Ouyang 2011Journal of Environmental Sciences2011,23,12:13
4The levels, sources and reactivity of volatile organic compounds in a typical urban area of Northeast China显示文摘Air concentrations of volatile organic compounds(VOCs) were continually measured at a monitoring site in Shenyang from 20 August to 16 September 2017. The average concentrations of alkanes, alkenes, aromatics and carbonyls were 28.54, 6.30, 5.59 and9.78 ppbv, respectively. Seven sources were identified by the Positive Matrix Factorization model based on the measurement data of VOCs and CO. Vehicle exhaust contributed the most(36.15%) to the total propene-equivalent concentration of the measured VOCs,followed by combustion emission(16.92%), vegetation emission and secondary formation(14.33%), solvent usage(10.59%), petrochemical industry emission(9.89%), petrol evaporation(6.28%), and liquefied petroleum gas(LPG) usage(5.84%). Vehicle exhaust, solvent usage and combustion emission were found to be the top three VOC sources for O_3 formation potential, accounting for 34.52%, 16.55% and 11.94%, respectively. The diurnal variation of the total VOCs from each source could be well explained by their emission characteristics,e.g., the two peaks of VOC concentrations from LPG usage were in line with the cooking times for breakfast and lunch. Wind rose plots of the VOCs from each source could reveal the possible distribution of the sources around the monitoring site. The O_3 pollution episodes during the measurement period were found to be coincident with the elevation of VOCs, which was mainly due to the air parcel from the southeast direction where petrochemical industry emission was found to be dominant, suggesting that the petrochemical industry emission from the southeast was probably a significant cause of O_3 pollution in Shenyang.Zhuobiao Ma Chengtang Liu Chenglong Zhang Pengfei Liu Can Ye Chaoyang Xue Di Zhao Jichen Sun Yiming Du Fahe Chai Yujing Mu 2019Journal of Environmental Sciences2019,31,5:12
5Seasonal and diurnal variations of atmospheric peroxyacetyl nitrate, peroxypropionyl nitrate, and carbon tetrachloride in Beijing显示文摘Atmospheric peroxyacetyl nitrate(PAN), peroxypropionyl nitrate(PPN), and carbon tetrachloride(CCl4) were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to early spring(October to March) with monthly average concentrations ranging from 0.28 to 0.73 ppbV, and increased from early spring to summer(March to August), ranging from 1.37–3.79 ppbV. The monthly variation of PPN was similar to PAN, with low values(below detection limit to 0.18 ppbV) from mid-autumn to early spring, and a monthly maximum in September(1.14 ppbV). The monthly variation of CCl4was tightly related to the variation of temperature, exhibiting a minimum in winter(69.3 pptV) and a maximum of 180.6 pptV in summer. Due to weak solar intensity and short duration, PAN and O3showed no distinct diurnal patterns from morning to night during winter, whereas for other seasons, they both exhibited maximal values in the late afternoon(ca. 15:00 to 16:00 local time) and minimal values during early morning and midnight. Good linear correlations between PAN and PPN were found in autumn(R = 0.91), spring(R = 0.94), and summer(R = 0.81), with slopes of 0.130, 0.222, and 0.133, respectively, suggesting that anthropogenic hydrocarbons dominated the photochemical formation of PANs in Beijing. Positive correlation between PAN and O3 in summer with the low slopes( O3 / PAN) ranging from 9.92 to 18.0 indicated serious air pollution in Beijing, and strong negative correlation in winter reflected strong O3consumption by NO titration and less thermal decompositin of PAN.Gen Zhang Yujing Mu Junfeng Liu Chenglong Zhang Yuanyuan Zhang Yujie Zhang Hongxing Zhang 2014Journal of Environmental Sciences2014,26,1:11
6Seasonal,diurnal and nocturnal variations of carbonyl compounds in the semi-urban environment of Orléans,France显示文摘Atmospheric carbonyls were measured at a semi-urban site in Orléans, France, from October 2010to July2011. Formaldehyde, acetaldehyde and acetone were found to be the most abundant carbonyls, with average concentrations of 3.1, 1.0, 2.0 ppb, respectively in summer, 2.3, 0.7, 2.2 ppb, respectively in autumn, 2.2, 1.0, 2.1 ppb, respectively in spring,and 1.5, 0.7, 1.1 ppb, respectively in winter. Photo-oxidation of volatile organic compounds(VOCs) was found to make a remarkable contribution to atmospheric carbonyls in the semi-urban site based on the distinct seasonal and diurnal variations of the carbonyls, as well as the significantly positive correlations between the carbonyls and ozone. The significantly negative correlations between NO x and O_3 as well as the carbonyls and the positive correlations between wind speed and O_3 as well as the carbonyls implied that the carbonyls and O_3 at the semi-urban site were probably formed during air mass transport from neighboring cities.Zhaohui Jiang Benoit Grosselin Véronique Daele Abdelwahid Mellouki Yujing Mu 2016Journal of Environmental Sciences2016,28,2:10
7Ambient levels of atmospheric carbonyls in Beijing during the 2008 Olympic Games显示文摘The measurements of atmospheric carbonyls concentrations in Beijing were conducted from 12 July to 8 October, 2008, covering the periods of the 2008 Olympic Games and Paralympic Games. Six carbonyls, including formaldehyde, acetaldehyde, acetone, butyraldehyde, valeraldehyde, and hexaldehyde, were identified in all air samples. The total average concentrations of these carbonyls before, during, and after traffic restriction were (48.1 ± 15.2), (36.6 ± 14.5) and (23.4 ± 12.3) μg/m3, respectively. Compared with the period after traffic restriction, the distinct high concentrations of the carbonyls before and during traffic restriction were primarily ascribed to the remarkable contribution of photochemical reactions. With respect to our previous investigation in the summer of 2005, the reductions of formaldehyde, acetaldehyde and acetone during traffic restriction period were about 64%, 47% and 27%, respectively, indicating that the air cleaning actions adopted by the Chinese government for the two games were efficient. The lowest levels of atmospheric carbonyls and the extremely high composition proportion of acetone after the traffic restriction were mainly attributed to the long-term effect of the control measures for the two games.Zhu Xu Junfeng Liu Yujie Zhang Peng Liang Yujing Mu 2010Journal of Environmental Sciences2010,22,9:6
8Oxidative capacities of size-segregated haze particles in a residential area of Beijing显示文摘The frequent haze days around the Chinese capital of Beijing in recent years have aroused great attention owing to the detrimental efects on visibility and public health. To discover the potential health efects of the haze, oxidative capacities of airborne particles collected in Beijing during haze and clear days were comparably assessed by a plasmid scission assay. Eleven water-soluble trace elements(As, Cd, Cr, Cu, Mn, Ni, Pb, V, Se, Tl, and Zn) in the size-segregated airborne particles were quantitatively analyzed by inductively coupled plasma mass spectrometry, and most of the watersoluble trace elements were found to mainly concentrate in the fine particle size of 0.56–1.0 μm. In comparison with clear days, the mass concentrations of 11 analyzed water-soluble trace elements remarkably increased during haze days, and the oxidative capacities determined by the plasmid scission assay were markedly elevated accordingly during the haze days under the same dosage of particles as for those during clear days. Water-soluble trace elements in airborne particles, such as Cu, V, and particularly Zn, were found to have significantly positive correlations with the plasmid DNA damage rates. Because Cu, V, and Zn have been considered as bioavailable elements, the evident increase of these elements during haze days may be greatly harmful to human health.Zhenquan Sun Longyi Shao Yujing Mu Ying Hu 2014Journal of Environmental Sciences2014,26,1:5
9Impact of dicyandiamide on emissions of nitrous oxide,nitric oxide and ammonia from agricultural field in the North China Plain显示文摘Nitrous oxide(N_2O), nitric oxide(NO) and ammonia(NH_3) emissions from an agricultural field in the North China Plain were compared for three treatments during a whole maize growing period from 26 June to 11 October, 2012. Compared with the control treatment(without fertilization, designated as CK), remarkable pulse emissions of N_2O, NO and NH_3 were observed from the normal fertilization treatment(designated as NP) just after fertilization, whereas only N_2O and NH_3 pulse emissions were evident from the nitrification inhibitor treatment(designated as ND). The reduction proportions of N_2O and NO emissions from the ND treatment compared to those from the NP treatment during the whole maize growing period were 31% and 100%, respectively. A measurable increase of NH_3 emission from the ND treatment was found with a cumulative NH_3 emission of 3.8 ± 1.2 kg N/ha,which was 1.4 times greater than that from the NP treatment(2.7 ± 0.7 kg N/ha).Yizhen Zhou Yuanyuan Zhang Di Tian Yujing Mu 2016Journal of Environmental Sciences2016,28,2:4
10Effect of potential HONO sources on peroxyacetyl nitrate(PAN)formation in eastern China in winter显示文摘As an important secondary photochemical pollutant,peroxyacetyl nitrate(PAN)has been studied over decades,yet its simulations usually underestimate the corresponding observations,especially in polluted areas.Recent observations in north China found unusually high concentrations of PAN during wintertime heavy haze events,but the current model still cannot reproduce the observations,and researchers speculated that nitrous acid(HONO)played a key role in PAN formation.For the first time we systematically assessed the impact of potential HONO sources on PAN formation mechanisms in eastern China using the Weather Research and Forecasting/Chemistry(WRF-Chem)model in February of 2017.The results showed that the potential HONO sources significantly improved the PAN simulations,remarkably accelerated the RO x(sum of hydroxyl,hydroperoxyl,and organic peroxy radicals)cycles,and resulted in 80%–150%enhancements of PAN near the ground in the coastal areas of eastern China and 10%–50%enhancements in the areas around 35–40°N within 3 km during a heavy haze period.The direct precursors of PAN were aldehyde and methylglyoxal,and the primary precursors of PAN were alkenes with C>3,xylenes,propene and toluene.The above results suggest that the potential HONO sources should be considered in regional and global chemical transport models when conducting PAN studies.Jingwei Zhang Yitian Guo Yu Qu Yong Chen Ruipeng Yu Chaoyang Xue Rui Yang Qiang Zhang Xingang Liu Yujing Mu Jing Wang Can Ye Haihan Zhao Qiangqiang Sun Ziwen Wang Junling An 2020Journal of Environmental Sciences2020,32,8:3
11The impact of HS radicals on the measured rate constant of H_2S with OH radicals显示文摘The rate constant for the reaction of OH radicals and hydrogen sulfide (H2S) was studied in different bath gases (including N2, air, O2 and He) by using relative technique at 298 K. The small difference of the measured rate constants between N2 and those with the presence of O2 suggested possible influence of HS self reaction. Further experiments with NOx presence for scavenging HS demonstrated this assumption. The rate constant of (5.48±0.12) ×10-12 cm3 molecule-1 s-1 obtained with 4.09 ×10-4 mol m3 NO presence may be accurate for estimating the atmospheric lifetime of H2S. The results provided circumstantial evidence that the rapid reaction of HS with N2O is suspected.WANG HaiTao ZHU DongSheng WANG WeiPing MU YuJing 2010Chinese Science Bulletin2010,55,26:3
12Serious BTEX pollution in rural area of the North China Plain during winter season显示文摘Atmospheric BTEX compounds(benzene, toluene, ethylbenzene and xylenes) in a rural site of the North China Plain(NCP) were preliminarily investigated in winter, and the outdoor concentrations(25.8–236.0 μg/m3) were found to be much higher than those reported in urban regions. The pollution of BTEX inside a farmer's house was even more serious, with combined concentrations of 254.5–1552.9 μg/m3. Based on the ratio of benzene to toluene(1.17 ± 0.34) measured, the serious BTEX pollution in the rural site was mainly ascribed to domestic coal combustion for heating during the winter season. With the enhancement of farmers' incomes in recent years, coal consumption by farmers in the NCP is rapidly increasing to keep their houses warm, and hence the serious air pollution in rural areas of the NCP during winter, including BTEX, should be paid great attention.Kankan Liu Chenglong Zhang Ye Cheng Chengtang Liu Hongxing Zhang Gen Zhang Xu Sun Yujing Mu 2015Journal of Environmental Sciences2015,27,4:2
13Photooxidation of hydrochlorofluocarbons and hydrofluorocarbons initiated by OH radicals显示文摘PhotooxidationofhydrochlorofluocarbonsandhydrofluorocarbonsinitiatedbyOHradicals¥ZhongJinxian;MuYujing;YangWenxiang(ResearchC...Zhong Jinxian Mu Yujing Yang Wenxiang(Research Center for Eco-Environmental Sciences Chinese Academy of Sciences, Beijing 100085, China)Chen Dazhou(Chinese Center for Certified Reference Materials, Beijing 100013, China) 1996Journal of Environmental Sciences1996,8,2:2
14An unexpected large continental source of reactive bromine and chlorine with significant impact on wintertime air quality显示文摘Halogen atoms affect the budget of ozone and the fate of pollutants such as hydrocarbons and mercury.Yet their sources and significances in polluted continental regions are poorly understood.Here we report the observation of unprecedented levels(averaging at 60 parts per trillion)of bromine chloride(BrCl)at a mid-latitude site in North China during winter.Widespread coal burning in rural households and a photo-assisted process were the primary source of BrCl and other bromine gases.BrCl contributed about 55%of both bromine and chlorine atoms.The halogen atoms increased the abundance of'conventional'tropospheric oxidants(OH,HO_(2) and RO_(2))by 26%-73%,and enhanced oxidation of hydrocarbon by nearly a factor of two and the net ozone production by 55%.Our study reveals the significant role of reactive halogen in winter atmospheric chemistry and the deterioration of air quality in continental regions where uncontrolled coal combustion is prevalent.Xiang Peng Weihao Wang Men Xia Hui Chen A.R.Ravishankara Qinyi Li Alfonso Saiz-Lopez Pengfei Liu Fei Zhang Chenglong Zhang Likun Xue Xinfeng Wang Christian George Jinhe Wang Yujing Mu Jianmin Chen Tao Wang 2021National Science Review2021,8,7:2
15A large-scale outdoor atmospheric simulation smog chamber for studying atmospheric photochemical processes:Characterization and preliminary application显示文摘Understanding the formation mechanisms of secondary air pollution is very important for the formulation of air pollution control countermeasures in China.Thus,a large-scale outdoor atmospheric simulation smog chamber was constructed at Chinese Research Academy of Environmental Sciences(the CRAES Chamber),which was designed for simulating the atmospheric photochemical processes under the conditions close to the real atmospheric environment.The chamber consisted of a 56-m^(3) fluorinated ethylene propylene(FEP) Teflon film reactor,an electrically-driven stainless steel alloy shield,an auxiliary system,and multiple detection instrumentations.By performing a series of characterization experiments,we obtained basic parameters of the CRAES chamber,such as the mixing ability,the background reactivity,and the wall loss rates of gaseous compounds(propene,NO,NO_(2),ozone) and aerosols(ammonium sulfate).Oxidation experiments were also performed to study the formation of ozone and secondary organic aerosol(SOA),including α-pinene ozonolysis,propene and 1,3,5-trimethylbenzene photooxidation.Temperature and seed effects on the vapor wall loss and SOA yields were obtained in this work:higher temperature and the presence of seed could reduce the vapor wall loss;SOA yield was found to depend inversely on temperature,and the presence of seed could increase SOA yield.The seed was suggested to be used in the chamber to reduce the interaction between the gas phase and chamber walls.The results above showed that the CRAES chamber was reliable and could meet the demands for investigating tropospheric chemistry.Junling Li Hong Li Xuezhong Wang Weigang Wang Maofa Ge Hao Zhang Xin Zhang Kun Li Yan Chen Zhenhai Wu Fahe Chai Fan Meng Yujing Mu Abdelwahid Mellouki Fang Bi Yujie Zhang Lingyan Wu Yongchun Liu 2021Journal of Environmental Sciences2021,33,4:2
16Nitric oxides and nitrous oxide fluxes from typical vegetables cropland in China: Effects of canopy, soil properties and field management显示文摘Xiaobing Pang Yujing Mu Xinqing Lee Shuangxi Fang Juan Yuan Daikuan Huang 2009Atmospheric Environment2009,,16:2
17Seasonal and diurnal variations of carbonyl compounds in Beijing ambient air 显示文摘Pang Xiaobing Mu Yujing 2006Atmospheric Environment2006,40,33:1
18Characteristics of carbonyl compounds emission from a diesel - engine using biodiesel - ethanol - diesel as fuel 显示文摘Xiaobing Pang Xiaoyan Shi Yujing Mu 2006Atmospheric Environment2006,40,:1
19Emission reduction potential of using ethanol - biodiesel - diesel fuel blend on a heavyduty diesel engine 显示文摘Xiaoyan Shi Xiaobing Pang Yujing Mu 2006Atmospheric Environment2006,40,:1
20Nitric oxides and nitrous oxide fluxes from typical vegetables cropland in China: Effects of canopy, soil properties and field management 显示文摘Pang Xiaobing Mu Yujing Lee Xinqing 2009Atmospheric Environment2009,43,16:1
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