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| 1 | Contrasting 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 | 2020 | National Science Review2020，7，8： | 51 |
| 2 | Trends 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 | 2019 | Science China Earth Sciences2019，62，12： | 23 |
| 3 | Evolution 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 | 2019 | Journal of Environmental Sciences2019，31，9： | 15 |
| 4 | Characteristics 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 | 2021 | Journal of Environmental Sciences2021，33，2： | 14 |
| 5 | Applications of Acrylate-based Polymer and Silicone Resin on LPFG-based Devices显示文摘Both acrylate based polymer and silicone resin are proposed as recoating materials surrounding LPFGs for purposes of different applications. For the LPFG recoated with a thin layer of acrylate based polymer, the range of wavelength shift as much as 60nm is expected when temperature changes from 0~100℃. As for that with surrounding material of silicone resin, the temperature stability is greatly improved depicted as the maximum wavelength shift of about 0.6nm with the same temperature variation. The former is potentially a broadband tunable band rejection filter or temperature sensor with enhanced sensitivity. And the latter could be applied as temperature insensitive filter, demultiplexer or strain sensor. | 何万迅 Shi Wenkang Gong Xiangyang Ye Ailun GAO Kan Fang Zujie | 2002 | High Technology Letters2002，8，2： | 4 |
| 6 | The empirical relationship between the PM 2.5 concentration and aerosol optical depth over the background of North China from 2009 to 2011显示文摘 | Jinyuan Xin Qing Zhang Lili Wang Chongshui Gong Yuesi Wang Zirui Liu Wenkang Gao | 2014 | Atmospheric Research2014，，： | 1 |
| 7 | Particulate matter trends and quantification of the spring sand-dust contribution in Hohhot,Inner Mongolia,from 2013 to 2017显示文摘2013年9月国务院颁布了《大气污染防治行动计划》.研究其实施前后呼和浩特市大气污染物浓度变化及及原因;同时,分析了春季沙尘天气对于呼和浩特市大气环境颗粒物浓度的定量影响.结果表明:呼和浩特市大气环境质量持续改善,但大气污染物浓度仍然较高.PM_(2.5)和PM10年均浓度分别超过国家二级标准22.9%和35.7%;2013-2017年春季PM_(2.5)和PM10浓度降幅较大,沙尘天气对呼和浩特市PM_(2.5),PM10,和TSP浓度的绝对贡献范围分别在0.6-5.2μg m^(-3),9.0-16.9μg m^(-3)和14.7-30.0μg m^(-3). | Wenkang Gao Lingyun Zhu Zhanyun Ma Qingxian Gao Xuepu Yu Sufen Wu Yu Gu | 2021 | Atmospheric and Oceanic Science Letters2021，14，2： | 1 |
| 8 | Au23(CR)14 nanocluster restores fibril Aβ’s unfolded state with abolished cytotoxicity and dissolves endogenous Aβplaques显示文摘The misfolding of amyloid-β(Aβ)peptides from the natural unfolded state toβ-sheet structure is a critical step,leading to abnormal fibrillation and formation of endogenous Aβplaques in Alzheimer’s disease(AD).Previous studies have reported inhibition of Aβfibrillation or disassembly of exogenous Aβfibrils in vitro.However,soluble Aβoligomers have been reported with increased cytotoxicity;this might partly explain why current clinical trials targeting disassembly of Aβfibrils by anti-Aβantibodies have failed so far.Here we show that Au23(CR)14(a new Au nanocluster modified by Cys-Arg(CR)dipeptide)is able to completely dissolve exogenous mature Aβfibrils into monomers and restore the natural unfolded state of Aβpeptides from misfoldedβ-sheets.Furthermore,the cytotoxicity of Aβ40 fibrils when dissolved by Au23(CR)14 is fully abolished.More importantly,Au23(CR)14 is able to completely dissolve endogenous Aβplaques in brain slices from transgenic AD model mice.In addition,Au23(CR)14 has good biocompatibility and infiltration ability across the blood–brain barrier.Taken together,this work presents a promising therapeutics candidate for AD treatment,and manifests the potential of nanotechnological approaches in the development of nanomedicines. | Wenkang Zhang Guanbin Gao Zhongjie Ma Zhuoying Luo Meng He Taolei Sun | 2020 | National Science Review2020，7，4： | 0 |
| 9 | Assessment of health benefit of PM_(2.5) reduction during COVID-19 lockdown in China and separating contributions from anthropogenic emissions and meteorology显示文摘The national lockdown policies have drastically disrupted socioeconomic activities during the COVID-19 pandemic in China,which provides a unique opportunity to investigate the air quality response to such anthropogenic disruptions.And it is meaningful to evaluate the potential health impacts of air quality changes during the lockdown,especially for PM_(2.5) with adverse health effects.In this study,by using PM_(2.5) observations from 1388 monitor-ing stations nationwide in China,we examine the PM_(2.5) variations between the COVID-19 lockdown(February and March in 2020)and the same period in 2015-2019,and find that the national average of PM_(2.5) decreases by 18 μg/m^(3),and mean PM_(2.5) for most sites(about 75%)decrease by 30%-60%.The anthropogenic and meteorological contributions to these PM_(2.5) variations are also determined by using a stepwise multiple linear regression(MLR)model combined with the Kolmogorov-Zurbenko filter.Our results show that the change of anthropogenic emissions is a leading contributor to those widespread PM_(2.5) reductions,and meteorological conditions have the negative influence on PM_(2.5) reductions for some re-gions,such as Beijing-Tianjin-Hebei(BTH).Additionally,the avoided premature death due to PM_(2.5) reduction is estimated as a predicted number based on a log-linear concentration-response function.The total avoided premature death is 9952 in China,with dominant con-tribution(94%)from anthropogenic emission changes.For BTH,Yangtze River Delta,Pearl River Delta and Hubei regions,the reductions of PM_(2.5) are 24.1,24.3,13.5 and 29.5 μg/m^(3),with the avoided premature deaths of 1066,1963,454 and 583,respectively. | Heming Bai Wenkang Gao Yuanpeng Zhang Li Wang | 2022 | Journal of Environmental Sciences2022，34，5： | 0 |
| 10 | Characterization and source identification of submicron aerosol dur ing ser ious haze pollution periods in Beijing显示文摘Submicron aerosol is of extensive concern not only due to its significant impact on air quality but also because it is detrimental to human health.In this study,we investigated the characteristics,sources and chemical processes of submicron aerosol based on realtime online measurements of submicron aerosols(NR-PM 1)during December 2015 at an urban site in Beijing.The average mass concentration of NR-PM 1 was 92.5±84.9μg/m^(3),the hourly maximum was 459.1μg/m^(3) during the entire observation.The organic aerosol(OA)(55%)was the largest contributor to NR-PM 1.The average mass concentration of PAHs was 0.217±0.247μg/m^(3),exhibiting the highest concentration at night and the lowest levels in the daytime.The average mass concentration of organic nitrate was 2.52±2.36μg/m^(3) and that of inorganic nitrate was 7.62±8.22μg/m^(3),accounting for 36%and 64%,respectively,of the total nitrate mass.Positive matrix factorization(PMF)differentiated the OA into five chemical components including LV-OOA,SV-OOA,COA,HOA and CCOA,accounting for 22%,16%,13%,25%and 24%respectively,of the total OA.The average NR-PM 1 mass concentration on the heavy polluted days(HPD)was 182.8±70.2μg/m^(3),which was approximately 9 times that on clean days(CD).The enhanced secondary formation of SNA was evident on HPD,especially the rapid increase of sulfate(23%)and nitrate(19%). | Peng Xu Yuan Yang Junke Zhang Wenkang Gao Zirui Liu Bo Hu Yuesi Wang | 2022 | Journal of Environmental Sciences2022，34，2： | 0 |
| 11 | 2014-2017年华北平原PM_(2.5)组分消光与能见度对比研究显示文摘华北平原大气污染与低能见度状况一直是人们关切的问题.本文通过分析2014-2017年PM_(2.5)化学成分的浓度和消光效果,研究了华北平原典型城市保定市的大气污染特征.结果表明,PM_(2.5)分的年均浓度显示下降趋势,水溶性无机离子,碳质气溶胶和金属元素分别减少了11μgm^(-3),23μg m^(-3)和1796 ngm^(-3).NH_(4)^(+),NO_(3)^(-)和SO_4^(2-)是PM_(2.5)污染的主要污染物,三者之和占总离子浓度的82.9%.基于IMPROVE方程对细颗粒物进行重构,在观测期间PM_(2.5)质量浓度平均为93±69μgm^(-1),春季,夏季,秋季和冬季的消光系数分别为373.8±233.6 Mm^(-1)±,405.3±300.1 Mm^(-1),554.3±378.2 Mm^(-1)和1005.2±750.3 Mm^(-1).硫酸铵,硝酸铵和有机物对消光的贡献最大,不同季节下占比达55%~77%.通过PM_(2.5)组分进行重构,利用IMPROVE算法计算得到Rb_(sca),用能见度测量值转换得到Vb_(sca),二者具有较高的相关性(r^(2)=0.84);但存在Vb_(sca)的高值被低估,Vb_(sca)的低值被高估的现象;特别是当Rb_(sca)>1123 Mm^(-1)(对应能见度约小于2.0 km)时,Vb_(sca)的值被低估了17.6%.高浓度PM_(2.5)和高湿度对IMPROVE算法结果有显著的影响. | Xinrui Wu Jinyuan Xin Xiaoling Zhang Ruirui Si Guangjing Liu An’na Li Tianxue Wen Zirui Liu Shigong Wang Guangzhou Fan Yuesi Wang Lili Wang Wenkang Gao | 2021 | Atmospheric and Oceanic Science Letters2021，14，2： | 0 |
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