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| 1 | Black carbon aerosols and their radiative properties in the Pearl River Delta region显示文摘The climatic and environmental effects of atmospheric aerosols are a hot topic in global science community, and radiative properties of the aerosols are one of the important parameters in assessing climatic change. Here we studied the black carbon concentration and absorption coefficient measured with aethalometers, scattering coefficient measured with nephelometers, and single scattering albedo derived at an atmospheric composition watch station in Guangzhou from 2004 to 2007. Our main results are as follows. The data of black carbon concentration and absorption coefficients measured with instruments cannot be directly used until they are measured in parallel with internationally accepted instruments for comparison, calibration, and reduction. After evaluation of the data, the result shows that the monthly mean of BC concentration varies 3.1―14.8 μg·m-3 and the concentration decreases by about 1 μg·m-3 in average over the four years; It is higher in the dry season with a multi-year mean of 8.9 μg/m3 and lower in the rainy season with a multi-year mean of 8.0 μg·m-3; The extreme maximum of monthly mean concentration occurred in December 2004 and extreme minimum in July 2007, and a 4-year mean is 8.4 μg·m-3. It is also shown that monthly mean scattering coefficient derived varies 129 -565 Mm-1, monthly mean absorption coefficient 32-139 Mm-1, and monthly mean single scattering albedo 0.71-0.91, with annual mean values of 0.80, 0.82, 0.79 and 0.84 for 2004, 2005, 2006 and 2007, respectively. Three instruments were used to take simultaneous measurements of BC in PM10, PM2.5, and PM1 and the results showed that PM2.5 took up about 90% of PM10 and PM1 accounted for about 68% of PM2.5, and BC aerosols are mainly present in fine particulates. The variability of BC concentrations is quite consistent between the Nancun station (141 m above sea level) and the Panyu station (13 m above sea level), which are 8 km apart from each other. The concentration in higher altitude station (Panyu) is consistently lower than the lower altitude station (Nancun), and the difference of annual mean is about 4 μg·m-3. | WU Dui MAO JieTai DENG XueJiao TIE XueXi ZHANG YuanHang ZENG LiMin LI Fei TAN HaoBo BI XueYan HUANG XiaoYing CHEN Jing DENG Tao | 2009 | Science China Earth Sciences2009,52,8: | 58 |
| 2 | Hygroscopic growth of aerosol scattering coefficient:A comparative analysis between urban and suburban sites at winter in Beijing显示文摘A humidity controlled inlet system was developed to measure the hygroscopic growth of aerosol scattering coefficient in conjunction with nephelometry at an urban site of Chinese Academy of Meteorological Sciences (CAMS) in Beijing and a rural site at Shangdianzi Regional Background Air Pollution Monitoring Station (SDZ) outside Beijing during winter, from December 2005 to January 2006. Measurements were carried out at a wavelength of 525 nm with an Ecotech M9003 nephelometer. The hygroscopic growth function (or factor) of the aerosol scattering coefficient f(RH) increased continuously with increasing relative humidity (RH) and showed no obvious 'step-like' deliquescent behavior at both sites during the experiment. The average growth factor f(RH) at the SDZ site could reach 1.5 when RH increased from less than 40% to 92%, and to 2.1 at the CAMS site when RH increased from less than 40% to 93%. The average hygroscopic growth factor at a relative humidity of 80%, f(RH = 80 ± 1%), was found to be about 1.26 ± 0.15 at CAMS and 1.24 ± 0.11 at SDZ. Further analysis indicated that under relatively polluted conditions, the average hygroscopic growth factor was higher at the CAMS site than that at the SDZ site. However, under relatively clean air conditions, the difference between the two sites was small, showing a hygroscopic growth behavior similar to those of burning biomass or blowing dust. These results reflected the different characteristics of aerosol types at the two sites. | Peng Yan Xiaole Pan Jie Tang Xiuji Zhou Renjian Zhang Limin Zeng | 2009 | Particuology2009,7,1: | 30 |
| 3 | Exploration of the formation mechanism and source attribution of ambient ozone in Chongqing with an observation-based model显示文摘An intensive field campaign was conducted in Chongqing during the summer of 2015 to explore the formation mechanisms of ozone pollution. The sources of ozone, the local production rates, and the controlling factors, as well as key species of volatile organic compounds(VOCs), were quantified by integrating a local ozone budget analysis, calculations of the relative incremental reactivity, and an empirical kinetic model approach. It was found that the potential for rapid local ozone formation exists in Chongqing. During ozone pollution episodes, the ozone production rates were found to be high at the upwind station Nan Quan, the urban station Chao Zhan, and the downwind station Jin-Yun Shan. The average local ozone production rate was 30×10^(-9) V/V h^(-1) and the daily integration of the produced ozone was greater than 180×10^(-9) V/V. High ozone concentrations were associated with urban and downwind air masses. At most sites, the local ozone production was VOC-limited and the key species were aromatics and alkene, which originated mainly from vehicles and solvent usage. In addition, the air masses at the northwestern rural sites were NO_x-limited and the local ozone production rates were significantly higher during the pollution episodes due to the increased NOx concentrations. In summary, the ozone abatement strategies of Chongqing should be focused on the mitigation of VOCs. Nevertheless, a reduction in NO_x is also beneficial for reducing the regional ozone peak values in Chongqing and the surrounding areas. | SU Rong LU KeDing YU JiaYan TAN ZhaoFeng JIANG MeiQing LI Jing XIE ShaoDong WU YuSheng ZENG LiMin ZHAI ChongZhi ZHANG YuanHang | 2018 | Science China Earth Sciences2018,61,1: | 24 |
| 4 | Role of secondary aerosols in haze formation in summer in the Megacity Beijing显示文摘A field experiment from 18 August to 8 September 2006 in Beijing, China, was carried out. A hazy day was defined as visibility < 10 km and RH(relative humidity) < 90%. Four haze episodes, which accounted for ~ 60% of the time during the whole campaign, were characterized by increases of SNA(sulfate, nitrate, and ammonium) and SOA(secondary organic aerosol) concentrations. The average values with standard deviation of SO2-+4, NO-3, NH4 and SOA were 49.8(± 31.6), 31.4(±22.3), 25.8(±16.6) and 8.9(±4.1) μg/m3, respectively, during the haze episodes, which were 4.3, 3.4, 4.1, and 1.7 times those in the non-haze days. The SO2-4,NO-3, NH+4, and SOA accounted for 15.8%, 8.8%, 7.3%, and 6.0% of the total mass concentration of PM10 during the non-haze days. The respective contributions of SNA species to PM10 rose to about27.2%, 15.9%, and 13.9% during the haze days, while the contributions of SOA maintained the same level with a slight decrease to about 4.9%. The observed mass concentrations of SNA and SOA increased with the increase of PM10 mass concentration, however, the rate of increase of SNA was much faster than that of the SOA. The SOR(sulfur oxidation ratio) and NOR(nitrogen oxidation ratio) increased from non-haze days to hazy days, and increased with the increase of RH. High concentrations of aerosols and water vapor favored the conversion of SO2 to SO2-4and NO2 to NO-3, which accelerated the accumulation of the aerosols and resulted in the formation of haze in Beijing. | Tingting Han Xingang Liu Yuanhang Zhang Yu Qu Limin Zeng Min Hu Tong Zhu | 2015 | Journal of Environmental Sciences2015,27,5: | 22 |
| 5 | Single whispering-gallery mode lasing in polymer bottle microresonators via spatial pump engineering显示文摘Single-mode lasing in whispering-gallery mode(WGM)microresonators is challenging to achieve.In bottle microresonators,the highly non-degenerated WGMs are spatially well-separated along the long-axis direction and provide mode-selection capability.In this work,by engineering the pump intensity to modify the spatial gain profiles of bottle microresonators,we demonstrate a simple and general approach to realizing single-mode WGM lasing in polymer bottle microresonators.The pump intensity is engineered into an interference distribution on the bottle microresonator surface.By tuning the spacing between axial positions of the interference pump patterns,the mode intensity profiles of single-bottle WGMs can be spatially overlapped with the interference stripes,intrinsically enabling single-mode lasing and selection.Attractive advantages of the system,including high sidemode suppression factors 420 dB,large spectral tunability 48 nm,low-lasing threshold and reversible control,are presented.Our demonstrated approach may have a variety of promising applications,ranging from tunable single-mode lasing and sensing to nonlinear optics. | Fuxing Gu Fuming Xie Xing Lin Shuangyi Linghu Wei Fang Heping Zeng Limin Tong Songlin Zhuang | 2017 | Light(Science & Applications)2017,6,1: | 17 |
| 6 | The GW2-WG1-OsbZIP47 pathway controls grain size and weight in rice显示文摘Regulation of seed size is a key strategy for improving crop yield and is also a basic biological question.However,the molecular mechanisms by which plants determine their seed size remain elusive.Here,we report that the GW2-WG1-OsbZIP47 regulatory module controls grain width and weight in rice.WG1,which encodes a glutaredoxin protein,promotes grain growth by increasing cell proliferation.Interestingly,WG1 interacts with the transcription factor OsbZIP47 and represses its transcriptional activity by associating with the transcriptional co-repressor ASP1,indicating that WG1 may act as an adaptor protein to recruit the transcriptional co-repressor.In contrary,OsbZIP47 restricts grain growth by decreasing cell proliferation.Further studies reveal that the E3 ubiquitin ligase GW2 ubiquitinates WG1 and targets it for degradation.Genetic analyses confirm that GW2,WG1,and OsbZIP47 function in a comm on pathway to control grain growth.Taken together,ourfindi ngs reveal a genetic and molecular framework for the control of grain size and weight by the GW2-WG1-OsbZIP47 regulatory module,providing new targets for improving seed size and weight in crops. | Jianqin Hao Dekai Wang Yingbao Wu Ke Huang Penggen Duan Na Li Ran Xu Dali Zeng Guojun Dong Baolan Zhang Limin Zhang Dirk Inze Qian Qian Yunhai Li | 2021 | Molecular Plant2021,14,8: | 14 |
| 7 | Characteristics and formation mechanism of regional haze episodes in the Pearl River Delta of China显示文摘To investigate the characteristics and the specific mechanism of continuous haze,comprehensive measurements were conducted from 15 October to 19 November in the Atmospheric Environment Monitoring Super-Station in Heshan of Guangdong province.Five haze episodes occurred in October and November 2014 in the Pearl River Delta(PRD)region. The meteorological parameters, gas data, chemical compositions, and optical parameters of the aerosols were obtained. Among these events, the second haze episode,with the highest concentration of PM2.5 of 187.51 μg/m^3, was the most severe. NO^3-was always higher than SO_4^(2-), which indicated that motor vehicles played an important role in the haze, even though the oxidation rate from SO_2 to SO_4^(2-)was faster than that of NOXto NO_3^-. The difference between the hourly averages of Na+and K+during the haze episode and clean days was small, implying that straw combustion and sea salt had no significant effect on the occurrence of haze, and the backward trajectories of the air masses also conformed with this result. The air pollutants were difficult to disperse because of the significant decrease in the planetary boundary layer(PBL) height. Relative humidity played a crucial role in the formation of haze by leading to hygroscopic growth of the diameter of aerosols. | Wenguang Li Xingang Liu Yuanhang Zhang Kang Sun Yusheng Wu Rui Xue Limin Zeng Yu Qu Junling An | 2018 | Journal of Environmental Sciences2018,30,1: | 11 |
| 8 | Efficacy of capecitabine-based combination therapy and singleagent capecitabine maintenance therapy in patients with metastatic breast cancer显示文摘Objective: The purpose of this study was to observe the efficacy and toxicities of capecitabine-based chemotherapy and capecitabine monotherapy as maintenance therapy in the treatment of metastatic breast cancer(MBC).Patients and methods: A total of 98 MBC patients were treated with capecitabine combined with vinorelbine(NX). Results: The median number of treatment was 6 cycles(1-7 cycles). There were two cases of complete remission(CR), 58 partial remission, 27 stable disease(SD), 11 progression disease. The overall response rate(ORR)(CR + PR) was 61.2%. The clinical benefit rate(CBR) was 75.5%. Fifty of effective patients received with capecitabine monotherapy as maintenance therapy. The ORR(CR + PR) was 4%. The CBR was 48%. The median progression-free survival(PFS) was 12 months. In maintenance therapy or not, the median post metastasis survival rate(MSR) was 63 and 28 months, respectively. In the combination therapy group, the major grade 3/4 toxicities included hand-foot syndrome(3.1%), skin pigmentation(2.0%), diarrhoea and abdominal distension(5.1%), stomatitis(1.0%), and leukopenia(20.4%).Conclusions: Capecitabine-based combination therapy and single-agent capecitabine maintenance therapy were well tolerated and effective to MBC. | Huimin Lv Min Yan Mengwei Zhang Limin Niu Huiai Zeng Shude Cui | 2014 | Chinese Journal of Cancer Research2014,26,6: | 8 |
| 9 | Investigation of carbonyl compound sources at a rural site in the Yangtze River Delta region of China显示文摘Carbonyl compounds are important intermediates in atmospheric photochemistry, but their primary sources are still not understood well. In this work, carbonyls, hydrocarbons,and alkyl nitrates were continuously measured during November 2011 at a rural site in the Yangtze River Delta region of China. Mixing ratios of carbonyls and hydrocarbons showed large fluctuations during the entire measurement. The average level for total measured volatile organic compounds during the pollution episode from 25 th to 27 th November, 2011 was 91.6 ppb, about 7 times the value for the clean period of 7th–8th, November, 2011. To preliminarily identify toluene sources at this site, the emission ratio of toluene to benzene(T/B) during the pollution episode was determined based on photochemical ages derived from the relationship of alkyl nitrates to their parent alkanes. The calculated T/B was5.8 ppb/ppb, significantly higher than the values of 0.2–1.7 ppb/ppb for vehicular exhaust and other combustion sources, indicating the dominant influence of industrial emissions on ambient toluene. The contributions of industrial sources to ambient carbonyls were then calculated using a multiple linear regression fit model that used toluene and alkyl nitrates as respective tracers for industrial emission and secondary production. During the pollution episode, 18.5%, 69.0%, and 52.9% of measured formaldehyde, acetaldehyde, and acetone were considered to be attributable to industrial emissions. The emission ratios relative to toluene for formaldehyde, acetaldehyde, and acetone were determined to be 0.10, 0.20 and0.40 ppb/ppb, respectively. More research on industrial carbonyl emission characteristics is needed to understand carbonyl sources better. | Ming Wang Wentai Chen Min Shao Sihua Lu Limin Zeng Min Hu | 2015 | Journal of Environmental Sciences2015,27,2: | 8 |
| 10 | Daytime HONO formation in the suburban area of the megacity Beijing, China显示文摘Nitrous acid(HONO),as a primary precursor of OH radicals,has been considered one of the most important nitrogencontaining species in the atmosphere.Up to 30%of primary OH radical production is attributed to the photolysis of HONO.However,the major HONO formation mechanisms are still under discussion.During the Campaigns of Air Quality Research in Beijing and Surrounding Region(CAREBeijing2006)campaign,comprehensive measurements were carried out in the megacity Beijing,where the chemical budget of HONO was fully constrained.The average diurnal HONO concentration varied from 0.33 to 1.2 ppbv.The net OH production rate from HONO,POH(HONO)net,was on average(from 05:00 to 19:00)7.1×106 molecule/(cm3 s),2.7 times higher than from O3 photolysis.This production rate demonstrates the important role of HONO in the atmospheric chemistry of megacity Beijing.An unknown HONO source(Punknown)with an average of 7.3×106molecule/(cm3 s)was derived from the budget analysis during daytime.Punknown provided four times more HONO than the reaction of NO with OH did.The diurnal variation of Punknown showed an apparent photo-enhanced feature with a maximum around 12:00,which was consistent with previous studies at forest and rural sites.Laboratory studies proposed new mechanisms to recruit NO2 and J(NO2)in order to explain a photo-enhancement of of Punknown.In this study,these mechanisms were validated against the observation-constraint Punknown.The reaction of exited NO2 accounted for only 6%of Punknown,and Punknown poorly correlated with[NO2](R=0.26)and J(NO2)[NO2](R=0.35).These results challenged the role of NO2 as a major precursor of the missing HONO source. | YANG Qiang SU Hang LI Xin CHENG YaFang LU KeDing CHENG Peng GU JianWei GUO Song HU Min ZENG LiMin ZHU Tong ZHANG YuanHang | 2014 | Science China Chemistry2014,57,7: | 8 |
| 11 | Study on Steel-Mushy Al-20Sn Alloy Bonding显示文摘Steel-mushy Al-20Sn alloy bonding was studied for the first time. The relationship model about preheat temperature of steel plate, solid fraction of Al-20Sn alloy mushy, rolling speed and interfacial shear strength of bonding plate could be established by artificial neural networks perfectly. This model could be optimized with a genetic algorithm. The optimum bonding parameters were: 505’C for preheat temperature of steel plate, 34.3% for solid fraction of Al20Sn alloy musry and 10 mm/s for rolling speed, and the largest interfacial shear strength of bonding plate was 71.2 MPa. | Peng ZHANG, Yunhui DU and Daben ZENG Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China Jianzhong CUI Metal Forming Department, NEU, Shenyang 110006, China Limin BA Anshan Automobile Fittings Factory, Anshan 114014, China | 2001 | Journal of Materials Science & Technology2001,17,2: | 7 |
| 12 | Overactive bladder symptom score to evaluate efficacy of solifenacin for the treatment of overactive bladder symptoms显示文摘 | Liu Ming Wang Jianye Yang Yong An Ruihua Wen Jianguo Guan Zhichen Zheng Shaobin Wang Dongwen Song Bo Liao Limin Guo Hongqian Xiao Jiaquan Sun Yinghao Shen Zhoujun Kong Chuize He Dalin Huang Yiran Wang Xiaofeng Zhang Xu Li Hanzhong Huang Jian Zhao Xiaokun Zeng Puqing Song Xishuang Ye Zhangqun | 2014 | Chinese Medical Journal2014,,2: | 7 |
| 13 | Community structures and population dynamics of “Candidatus Accumulibacter” in activated sludges of wastewater treatment plants using ppk1 as phylogenetic marker显示文摘Candidatus Accumulibacter has been identified as dominant polyphosphate-accumulating organisms(PAOs) in enhanced biological phosphorus(P) removal(EBPR) from wastewater.This study revealed the relevance of community structure, abundance and seasonal population dynamics of Candidatus Accumulibacter to process operation of wastewater treatment plants(WWTPs) in China using ppk1 gene as phylogenetic marker. All sludge samples had properties of denitrifying P removal using nitrate as an electron acceptor.Accumulibacter abundance in the anaerobic-anoxic-oxic(A^2O) process was the highest(26%of total bacteria), and higher in winter than in summer with a better EBPR performance.Type-II was the dominant Accumulibacter in all processes, and type-I accounted for a small proportion of total Accumulibacter. The abundance of Clade-IIC as the most dominant clade reached 2.59 × 10~9 cells/g MLSS and accounted for 87.3% of total Accumulibacter. Clade IIC mainly contributed to denitrifying P removal. Clades IIA, IIC and IID were found in all processes, while clade-IIF was only found in oxidation ditch process through phylogenetic analysis. High proportion of clade IID to total Accumulibacter led to poor performance of aerobic P-uptake in inverted A^2O process. Therefore, Accumulibacter clades in WWTPs were diverse, and EBPR performance was closely related to the clade-level community structures and abundances of Accumulibacter. | Wei Zeng Limin Zhang Pengchao Fan Jingjing Guo Yongzhen Peng | 2018 | Journal of Environmental Sciences2018,30,5: | 6 |
| 14 | An online monitoring system for atmospheric nitrous acid(HONO) based on stripping coil and ion chromatography显示文摘A new instrument for measuring atmospheric nitrous acid(HONO) was developed,consisting of a double-wall glass stripping coil sampler coupled with ion chromatography(SC-IC).SC-IC is featured by small size(50 × 35 × 25 cm) and modular construction,including three independent parts:the sampling unit,the transfer and supporting unit,and the detection unit.High collection efficiency(> 99%) was achieved with 25 μmol/L Na2CO3 as absorption solution even in the presence of highly acidic compounds.This instrument has a detection limit of 8 pptv at 15 min time resolution,with a measurement uncertainty of 7%.Potential interferences from NOx,NO2+SO2,NO2+VOCs,HONO+O3,HNO3,peroxyacetyl nitrite(PAN) and particle nitrite were quantified in laboratory studies and were found to be insignificant under typical atmospheric conditions.Within the framework of the 3C-STAR project,inter-comparison between the SC-IC and LOPAP(long path liquid absorption photometer) was conducted at a rural site in the Pearl River Delta.Good agreement was achieved between the two instruments over three weeks.Both instruments determined a clear diurnal profile of ambient HONO concentrations from 0.1 to 2.5 ppbv.However,deviations were found for low ambient HONO concentrations(i.e.< 0.3 ppbv),which cannot be explained by previous investigated interference species.To accurately determine the HONO budget under illuminated conditions,more intercomparison of HONO measurement techniques is still needed in future studies,especially at low HONO concentrations. | Peng Cheng Yafang Cheng Keding Lu Hang Su Qiang Yang Yikan Zou Yanran Zhao Huabing Dong Limin Zeng Yuanhang Zhang | 2013 | Journal of Environmental Sciences2013,25,5: | 5 |
| 15 | Th17 cells were recruited and accumulated in the cerebrospinal fluid and correlated with the poor prognosis of anti-NMDAR encephalitis显示文摘Anti-N-methyI-D-aspartate-receptor (NMDAR)encephalitis is an autoimmune disorder characterized by memory deficits,psychiatric symptoms,and autonomic instability.The lack of suitable biomarkers targeting anti-NMDAR encephalitis makes the immunotherapy and prognosis challenging.In this study,we found that the Th17 cells were significantly accumulated in the cerebrospinal fluid (CSF)of anti-NMDAR encephalitis patients than that of control individuals.The concentration of the cytokines and chemokines including interleukin (IL)-1β,IL-17,IL-6,and CXCL-13 were significantly increased in the CSF of anti-NMDAR encephalitis patients.IL-6 and IL-17 were found to promote the differentiation of CD4+T cells into Th17 lineage.The chemotaxis assay showed that CCL20 and CCL22 play essential roles in the migration of Th17 cells.Notably,the correlation between the expression of IL-17 and the outcome of anti-NMDAR encephalitis patients was analyzed.The data showed that high level of IL-17 was significantly correlated with the limited response to the treatment and relapse of anti-NMDAR encephalitis patients.Our results suggested the potential important involvement of IL-17 in anti-NMDAR encephalitis. | Chaosheng Zeng Lin Chen Bocan Chen Yi Cai Pengxiang Li Limin Yan Dehua Zeng | 2018 | Acta Biochimica et Biophysica Sinica2018,50,12: | 5 |
| 16 | Developing chemical signatures of particulate air pollution in the Pearl River Delta region, China显示文摘PM 2.5 samples were collected in a regional sampling network with three sites in Hong Kong and four sites in the adjacent inland Pearl River Delta (PRD) or Guangdong Province during four months/seasons from 2002–2003. Trans-boundary transport between Hong Kong and the inland PRD is inevitable under the influence of Asian monsoon. In summer, Hong Kong serves as the upwind site of the inland PRD while during other seasons it is under the influence of continental emissions. Previous studies have recognized the importance of using chemical signatures to differentiate local vs. regional contributions to air pollutants in Hong Kong such as the CO/NOx ratio, ratios of different VOC species. In this study, detailed chemical speciation by gas chromatography-mass spectrometry was performed with PM 2.5 samples to identify new chemical signatures to distinguish aerosols in Hong Kong from those from the inland PRD. Since Hong Kong is not influenced by the continental emissions from the inland PRD during summer, comparison focused on chemical data obtained from this season for chemical signatures. The new ratios developed from the current study include LCPI/HCPI ratio of alkanes (0.39 ± 0.02 in Hong Kong vs. 0.78 ± 0.08 in the inland PRD), pyrene to benzo[ghi]perylene ratio (0.97 ± 0.21 in Hong Kong compared to 0.20 ± 0.06 in the inland PRD), and the ratio of 1,2-benzenedioic acid to 1,4-benzenedioic acid (1.8 ± 0.1 in Hong Kong vs. 0.6 ± 0.05 in the inland PRD). Results from this study also revealed that Hong Kong was impacted by ship emissions as reflected by substantially high V/Ni ratio (9 ± 2) while this ratio was about 1–2 at all sites in the inland PRD, which is very close to typical ratios from residual oil combustion. | Mei Zheng Yuan Cheng Limin Zeng Yuanhang Zhang | 2011 | Journal of Environmental Sciences2011,23,7: | 3 |
| 17 | Peroxyacetyl nitrate observed in Beijing in August from 2005 to 2009显示文摘Measurements of peroxyacetyl nitrate(PAN) were made at a Beijing urban site each August from2005 to 2009. Over this 5-year period, the average PAN concentration for August in each year increased from 3(2005) to 11.7 μg/m3(2007); however, it decreased rapidly in 2008(4.1 μg/m3).Generally, the variation over the 5 years showed a rise in the first part of the study period,followed by a decline. We considered two categories of local and regional air masses in this study, which revealed that the PAN concentration in Beijing was affected mainly by southeastern air masses. The August PAN variation was influenced predominantly by local air masses in 2005,but by 2009 regional air masses had become more important. This study showed the level and variation of PAN in the month of August in 5 consecutive years for the first time, and proved that control measures are useful in decreasing photochemical pollution; hence, these measures are probably feasible for other megacities too. Furthermore, this method of analyzing regional and local impacts might be useful for other studies as well. | Tianyu Gao Li Han Bin Wang Guang Yang Zhenqiang Xu Limin Zeng Jianbo Zhang | 2014 | Journal of Environmental Sciences2014,26,10: | 3 |
| 18 | Seasonal trends in PM2.5 source contributions in Beijing, China显示文摘 | Mei Zheng Lynn G. Salmon James J. Schauer Limin Zeng C.S. Kiang Yuanhang Zhang Glen R. Cass | 2005 | Atmospheric Environment2005,,22: | 3 |
| 19 | Ground-level ozone in the Pearl River Delta and the roles of VOC and NO x in its production显示文摘 | Min Shao Yuanhang Zhang Limin Zeng Xiaoyan Tang Jing Zhang Liuju Zhong Boguang Wang | 2007 | Journal of Environmental Management2007,,1: | 3 |
| 20 | Estimation of dry deposition fluxes of major inorganic species by canopy throughfall approach显示文摘Dry deposition in China has not yet been intensively studied even though it constitutes an important pathway for acid deposition. The total deposition was monitored at Tieshanping catchment, a regional remote site in Chongqing City. The dry deposition loads of sulphur, calcium and nitrogen are estimated by using a canopy throughfall approach. The results indicate that the annual dry deposition loads of sulphur and calcium at Tieshanping site are much higher than those measured in forestry areas in other countries, while the dry deposition flux of ni- trogen is at a comparable level. The dry deposition loads of sulphur, calcium and nitrogen are all higher than the wet deposition loads. Applying a canopy budget model has proven that the routine, simplified canopy throughfall approach may underestimate the dry deposition flux of nitrogen-containing species. | JIN Lei SHAO Min ZENG Limin ZHAO Dawei TANG Dagang | 2006 | Chinese Science Bulletin2006,51,15: | 2 |