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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 | Source apportionment and secondary organic aerosol estimation of PM_(2.5) in an urban atmosphere in China显示文摘PM2.5 is the key pollutant in atmospheric pollution in China.With new national air quality standards taking effect,PM2.5 has become a major issue for future pollution control.To effectively prevent and control PM2.5,its emission sources must be precisely and thoroughly understood.However,there are few publications reporting comprehensive and systematic results of PM2.5 source apportionment in the country.Based on PM2.5 sampling during 2009 in Shenzhen and follow-up investigation,positive matrix factorization(PMF)analysis has been carried out to understand the major sources and their temporal and spatial variations.The results show that in urban Shenzhen(University Town site),annual mean PM2.5 concentration was 42.2μg m?3,with secondary sulfate,vehicular emission,biomass burning and secondary nitrate as major sources;these contributed30.0%,26.9%,9.8%and 9.3%to total PM2.5,respectively.Other sources included high chloride,heavy oil combustion,sea salt,dust and the metallurgical industry,with contributions between 2%–4%.Spatiotemporal variations of various sources show that vehicular emission was mainly a local source,whereas secondary sulfate and biomass burning were mostly regional.Secondary nitrate had both local and regional sources.Identification of secondary organic aerosol(SOA)has always been difficult in aerosol source apportionment.In this study,the PMF model and organic carbon/elemental carbon(OC/EC)ratio method were combined to estimate SOA in PM2.5.The results show that in urban Shenzhen,annual SOA mass concentration was 7.5μg m?3,accounting for 57%of total organic matter,with precursors emitted from vehicles as the major source.This work can serve as a case study for further in-depth research on PM2.5 pollution and source apportionment in China. | HUANG XiaoFeng YUN Hui GONG ZhaoHeng LI Xiang HE LingYan ZHANG YuanHang HU Min | 2014 | Science China Earth Sciences2014,57,6: | 28 |
| 3 | Aerosol effects on ozone concentrations in Beijing:A model sensitivity study显示文摘Most previous O 3 simulations were based only on gaseous phase photochemistry.However,some aerosol-related processes,namely,heterogeneous reactions occurring on the aerosol surface and photolysis rate alternated by aerosol radiative influence,may affect O 3 photochemistry under high aerosol loads.A three-dimensional air quality model,Models-3/Community Multi-scale Air Quality-Model of Aerosol Dynamics,Reaction,Ionization,and Dissolution,was employed to simulate the effects of the above-mentioned processes on O 3 formation under typical high O 3 episodes in Beijing during summer.Five heterogeneous reactions,i.e.,NO 2,NO 3,N 2 O 5,HO 2,and O 3,were individually investigated to elucidate their effects on O 3 formation.The results showed that the heterogeneous reactions significantly affected O 3 formation in the urban plume.NO 2 heterogeneous reaction increased O 3 to 90 ppb,while HO 2 heterogeneous reaction decreased O 3 to 33 ppb.In addition,O 3 heterogeneous loss decreased O 3 to 31 ppb.The effects of NO 2,NO 3,and N 2 O 5 heterogeneous reactions showed opposite O 3 concentration changes between the urban and extra-urban areas because of the response of the reactions to the two types of O 3 formation regimes.When the aerosol radiative influence was included,the photolysis rate decreased and O 3 decreased significantly to 73 ppb O 3.The two aerosol-related processes should be considered in the study of O 3 formation because high aerosol concentration is a ubiquitous phenomenon that affects the urban-and regional air quality in China. | Jun Xu Yuanhang Zhang Shaoqing Zheng Youjiang He | 2012 | Journal of Environmental Sciences2012,24,4: | 15 |
| 4 | Air quality during the 2008 Beijing Olympic Games显示文摘 | David G. Streets Joshua S. Fu Carey J. Jang Jiming Hao Kebin He Xiaoyan Tang Yuanhang Zhang Zifa Wang Zuopan Li Qiang Zhang Litao Wang Binyu Wang Carolyne Yu | 2006 | Atmospheric Environment2006,,3: | 6 |
| 5 | Study of Oxygen Vacancies on Different Facets of Anatase TiO2显示文摘Anatase TiO2 samples with different ratios of {101} to {001} facets were prepared with hydrothermal method and further treated under three specific calcination atmospheres (air,H2,N2).The characterization results indicate that {001} facets may generate more oxygen vacancies and more Ti3+ species than {101} facets. | Yanan Wu Yingyi Fu Li Zhang Yuanhang Ren Xueying Chen Bin Yue Heyong He | 2019 | Chinese Journal of Chemistry2019,37,9: | 4 |
| 6 | Understanding PM_(2.5) sources in China:challenges and perspectives显示文摘INTRODUCTION China is experiencing severe air pollution,with extremely high levels of fine particulate matter(PM_(2.5)),especially common during the fall and winter seasons in northern China over recent years.Large-scale and long-lasting regional haze episodes occurred | Mei Zheng Caiqing Yan Shuxiao Wang Kebin He Yuanhang Zhang | 2017 | National Science Review2017,4,6: | 3 |
| 7 | Mode demultiplexing hybrids for mode-division multiplexing coherent receivers显示文摘We propose a mode demultiplexing hybrid(MDH) that integrates mode demultiplexing, local oscillator power splitting, and optical 90-deg mixing using multi-plane light conversion(MPLC). We demonstrate the realization of a three-mode MDH using four phase plates, one more than what is required for an MPLC-based mode demultiplexer, via numerical simulations. The performance of the three-mode MDH is comparable to that of commercial single-mode 90-deg hybrids. This multiple-functionality device enables simplification of the coherent optical front end of mode-division multiplexing receivers. | HE WEN HUIYUAN LIU YUANHANG ZHANG PENG ZHANG GUIFANG LI | 2019 | Photonics Research2019,7,8: | 3 |
| 8 | Identification of secondary organic aerosols based on aerosol mass spectrometry显示文摘Secondary organic aerosol (SOA) is one of the major components of aerosols in the atmosphere and has not been well understood so far.Due to the complex chemical composition of organic aerosols,the identification of SOA has been a hotspot and difficult issue in the field of aerosol study.This study attempts to quantitatively identify SOA in winter of Shenzhen based on positive matrix factorization (PMF) analysis.Major sources were resolved and SOA was identified subsequently according to the characteristic ion fragments measured by highly time-resolved aerosol mass spectrometer measurement.It showed that in the winter of Shenzhen the average SOA concentration was 9.41±6.33 g/m 3,accounting for 39.9±21.8% of the total organic mass.Compared with primary organic aerosol (POA),the SOA concentrations had no large variation,suggestive of characteristics of regional secondary pollutants.The ratio of SOA/BC had pronounced diurnal variation,similar to that of O x (O3+NO2),indicating SOA formation was significantly controlled by activity of photochemistry in the atmosphere.The most effective period for SOA formation was from 9 am~3 pm since the SOA/BC ratio increased by 122% during this period.This study provides a new technical method and a new idea for SOA investigation. | HUANG XiaoFeng 1,ZHAO QianBiao 1,2,HE LingYan 1,HU Min 2,BIAN QiJing 3,XUE Lian 1 & ZHANG YuanHang 2 1 Key Laboratory for Urban Habitat Environmental Science and Technology School of Environment and Energy,Peking University Shenzhen Graduate School,Shenzhen 518055,China 2 State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China 3 Division of Environment,Hong Kong University of Science & Technology,Hong Kong,China | 2010 | Science China Chemistry2010,53,12: | 2 |
| 9 | Scalable non-mode selective Hermite–Gaussian mode multiplexer based on multi-plane light conversion显示文摘Non-mode-selective(NMS) multiplexers(muxes) are highly desirable for coherent power combining to produce a high-power beam with a shaped profile(wavefront synthesis) from discrete, phase-locked emitters. We propose a design for a multi-plane light conversion(MPLC)-based NMS mux, which requires only a few phase masks for coherently combining hundreds of discrete input beams into an output beam consisting of hundreds of Hermite–Gaussian(HG) modes. The combination of HG modes as a base can further construct a beam with arbitrary wavefront. The low number of phase masks is attributed to the identical zero-crossing structure of the Hadamard-coded input arrays and of the output HG modes, enabling the practicality of such devices. An NMS mux supporting 256 HG modes is designed using only seven phase masks, and achieves an insertion loss of-1.6 d B, mode-dependent loss of 4.7 d B, and average total mode crosstalk of-4.4 d B. Additionally, this design,featuring equal power for all input beams, enables phase-only control in coherent power combining, resulting in significant simplifications and fast convergence compared with phase-and-amplitude control. | HE WEN YUANHANG ZHANG RACHEL SAMPSON NICOLAS K.FONTAINE NING WANG SHENGLI FAN GUIFANG LI | 2021 | Photonics Research2021,9,2: | 2 |
| 10 | Air quality during the 2008 Beijing Olympic Games显示文摘 | David G. Streets Joshua S. Fu Carey J. Jang Jiming Hao Kebin He Xiaoyan Tang Yuanhang Zhang Zifa Wang Zuopan Li Qiang Zhang Litao Wang Binyu Wang Carolyne Yu | 2006 | Atmospheric Environment2006,,3: | 1 |
| 11 | Perovskite films with gradient bandgap for self-powered multiband photodetectors and spectrometers显示文摘Bandgap-graded materials present varying spectral responses at different positions,making them possible to be used as an alternative to photoactive materials array in multi-spectral responsive devices,thus miniaturizing the apparatus.However,the preparation of bandgap-graded materials usually requires complicated deposition process.Here we report a facile lowtemperature solution process to make films with lateral bandgap gradients,which form spontaneously via self-spreading and interdiffusion of solutions.We show lead halide perovskite films with MAPbCl_(3)-MAPbBr_(3)and MAPbBr_(3)-MAPbI_(3)gradients,which exhibit light absorption onsets ranging from 410 to 781 nm.The bandgap-graded films were used to make self-powered multiband photodetectors,which show different spectral responses at different positions without applying bias voltage.Furthermore,self-powered spectrometers were made by using the multiband photodetectors. | Chuantian Zuo Lixiu Zhang Xiyan Pan He Tian Keyou Yan Yuanhang Cheng Zhiwen Jin Chenyi Yi Xiaoliang Zhang Wu-Qiang Wu Qinye Bao Liyuan Han Liming Ding | 2023 | Nano Research2023,16,7: | 1 |
| 12 | miR-141 regulates TGF-β1-induced epithelial-mesenchymal transition throughrepression of HIPK2 expression in renal tubular epithelial cells显示文摘 | Yuanhang Huang Junrong Tong Feng He Xinpei Yu Liming Fan Jing Hu Jiangping Tan Zhengliang Chen | 2015 | International Journal of Molecular Medicine2015,,2: | 1 |
| 13 | Preliminary study on diagnostic techniques for transient plasma generated by hyperve- locity impact显示文摘 | Tang Enling Zhang Qingming He Yuanhang | 2008 | Plasna Science and Technology2008,10,6: | 1 |
| 14 | Response of soil respiration to environmental and photosynthetic factors in different subalpine forest-cover types in a loess alpine hilly region显示文摘Soil respiration(Rs)is important for transport-ing or fixing carbon dioxide from the atmosphere,and even diminutive variations can profoundly influence the carbon cycle.However,the R_(s) dynamics in a loess alpine hilly region with representative sensitivity to climate change and fragile ecology remains poorly understood.This study investigated the correlation and degree of control between R_(s) and its photosynthetic and environmental factors in five subalpine forest cover types.We examined the correlations between R_(s) and variables temperature(T_(10)) and soil moisture content at 10 cm depth(W_(10)),net photosynthetic rate(P_(n))and soil properties to establish multiple models,and the variables were measured for diurnal and monthly vari-ations from September 2018 to August 2019.The results showed that soil physical factors are not the main drivers of R_(s) dynamics at the diel scale;however,the trend in the monthly variation in R_(s) was consistent with that of T_(10)and P_(n).Further,R_(s) was significantly affected by pH,providing further evidence that coniferous forest leaves contribute to soil acidification,thus reducing R_(s).Significant exponential and linear correlations were established between R_(s) and T_(10)and W_(10),respectively,and R_(s) was positively correlated with P_(n).Accordingly,we established a two-factor model and a three-factor model,and the correlation coefficients(R_(2))was improved to different degrees compared with models based only on T_(10) and W_(10).Moreover,temperature sensitivity(Q_(10))was the highest in the secondary forest and lowest in the Larix principis-rupprechtii forest.Our findings suggest that the control of R_(s) by the environment(moisture and tempera-ture)and photosynthesis,which are interactive or comple-mentary effects,may influence spatial and temporal homeo-stasis in the region and showed that the models appropriately described the dynamic variation in R_(s) and the carbon cycle in different forest covers.In addition,total phosphorus(TP)and total potassium(TK)significantly affected the dynamic changes in R_(s).In summary,interannual and seasonal variations in forest R_(s) at multiple scales and the response forces of related ecophysiological factors,especially the interactive driving effects of soil temperature,soil moisture and photo-synthesis,were clarified,thus representing an important step in predicting the impact of climate change and formulating forest carbon management policies. | Yuanhang Li Sha Lin Qi Chen Xinyao Ma Shuaijun Wang Kangning He | 2022 | Journal of Forestry Research2022,33,2: | 1 |
| 15 | Fine particle emissions from on-road vehicles in the Zhujiang tunnel 显示文摘 | Lingyan He Min Hu Yuanhang Zhang | 2008 | China Environmental Science and Technology2008,42,: | 1 |
| 16 | Progress in quantitative research on the relationship between atmospheric oxidation and air quality显示文摘Atmospheric oxidizing capacity(AOC)is an essential driving force of troposphere chemistry and self-cleaning,but the definition of AOC and its quantitative representation remain uncertain.Driven by national demand for air pollution control in recent years,Chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC research.This paper will give a brief review of these developments.First,AOC indexes were established that represent apparent atmospheric oxidizing ability(AOIe)and potential atmospheric oxidizing ability(AOIp)based on aspects of macrothermodynamics and microdynamics,respectively.A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing,and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the country.In addition,the detection of ground or vertical profiles for atmospheric OH·,HO_(2)·,NO_(3)·radicals and reservoir molecules can now be obtained with domestic instruments in diverse environments.Moreover,laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O_(3)and NO_(2),which are typical oxidants in the surface/interface atmosphere,and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies,multiphase and multi-interface conditions were obtained.Finally,based on the GRAPES-CUACE adjoint model improved by Chinese scholars,simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been optimized.Normalized numerical simulations of AOIe and AOIp were performed,and regional coordination of AOC was adjusted.An optimized plan for controlling O_(3)and PM2.5was analyzed by scenario simulation. | Yuesi Wang Xin Jin Zirui Liu Gehui Wang Guiqian Tang Keding Lu Bo Hu Shanshan Wang Guohui Li Xinqin An Chao Wang Qihou Hu Lingyan He Fenfen Zhang Yuanhang Zhang | 2023 | Journal of Environmental Sciences2023,,1: | 1 |
| 17 | The synergy of modulated surface polarity and oxygen vacancy for CO_(2) to methanol over Zn(δ-)-Ti(δ+)Ovacancy显示文摘Bi-functional catalysts,which can be traced back to 1960s,are widely applied in energy conversion and chemical transformation[1].Generally,the enhanced performance of the bi-functional catalyst comes from the local geometry or electron density change after the second component introduced.These changes facilitate the reaction at the structure or electron density level[2].In fact,it is a great challenge to understand and control those effects[3]. | Junfu Zhou Lin Ye Daofeng Huang Meiyin Wang Yuanhang Ren Bin Yue Heyong He | 2021 | Journal of Energy Chemistry2021,30,5: | 0 |
| 18 | Synthesis of Cs_(2.5)H_(0.5)PW_(12)O_(40)/TiO_(2) Nanocomposites with Dominant TiO_(2){001}Facets and Related Photocatalytic Properties显示文摘TiO_(2) nanosheets with dominant{001}facets,coupled with Cs_(2.5)H_(0.5)PW_(12)O_(40),were successfully synthesized by a one-step hydrothermal reaction.The photocatalytic activity of nanocatalysts was evaluated by the degradation of Rhodamine B under UV light irradiation.The results showed that both the addition of Cs_(2.5)H_(0.5)PW_(12)O_(40) and the exposed{001}facets of TiO_(2) have a positive effect on the photocatalytic activity.The improved photoactivity of nanocomposites in comparison with that of TiO_(2) nanosheets could be attributed to the synergistic effect between Cs_(2.5)H_(0.5)PW_(12)O_(40) and TiO_(2) which facilitates the separation of photo-induced hole-electron pairs. | Yichen Hu Yuanhang Ren Gangfeng Tang Cheng Wang Min Tang Bin Yue Heyong He | 2014 | Chinese Journal of Chemistry2014,32,11: | 0 |
| 19 | Advances in nanomaterials for the diagnosis and treatment of head and neck cancers:A review显示文摘Nanomaterials(NMs)have increasingly been used for the diagnosis and treatment of head and neck cancers(HNCs)over the past decade.HNCs can easily infiltrate surrounding tissues and form distant metastases,meaning that most patients with HNC are diagnosed at an advanced stage and often have a poor prognosis.Since NMs can be used to deliver various agents,including imaging agents,drugs,genes,vaccines,radiosensitisers,and photosensitisers,they play a crucial role in the development of novel technologies for the diagnosis and treatment of HNCs.Indeed,NMs have been reported to enhance delivery efficiency and improve the prognosis of patients with HNC by allowing targeted delivery,controlled release,responses to stimuli,and the delivery of multiple agents.In this review,we consider recent advances in NMs that could be used to improve the diagnosis,treatment,and prognosis of patients with HNC and the potential for future research. | Cheng Yu Long Li Shiwen Wang Yuanhang Xu Lu Wang Yongbiao Huang Ahmed Hieawy He Liu Jingzhi Ma | 2023 | Bioactive Materials2023,,7: | 0 |
| 20 | Improving Catalytic Stability and Coke Resistance of Ni/Al_(2)O_(3) Catalysts with Ce Promoter for Relatively Low Temperature Dry Reforming of Methane Reaction显示文摘A series of Ni catalysts supported on alumina with different Ce contents(1.0%–6.0%,mass fraction)was prepared by the impregnation method and used for dry reforming of methane(DRM)at a relatively low temperature of 650°C.The promotion effect of Ce with different loading amounts on the physicochemical properties of the catalysts was systematically characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD),N_(2) adsorption-desorption,thermo elemental IRIS Intrepid inductively coupled plasma atomic emission spectrometer(ICP-AES),UV-visible diffuse reflectance spectroscopy(UV-Vis DRS),Fourier transformation infrared(FTIR)spectra,H_(2)-temperature programmed reduction(H_(2)-TPR)analysis,H_(2)-temperature programmed desorption(H_(2)-TPD),and The X-ray photoelectron spectroscopy(XPS)techniques.The results indicate that all the catalysts mainly exist in the NiAl_(2)O_(4) phase after being calcined at 750°C with small Ni particle sizes due to the strong metal-support interaction derived from the reduction of the NiAl_(2)O_(4) phase.The Ce-promoted catalysts show better catalytic performance as well as the resistance against sintering of Ni particles and deposition of carbon compared to the Ni/Al_(2)O_(3) catalyst.The Ni-6Ce/Al_(2)O_(3) exhibits the best catalytic stability and coke resistance among the four catalysts studied,which is due to its small Ni nanoparticles sizes,excellent reducibility as well as high amount of active oxygen species.In a 400 h stability test for DRM reaction at 650°C,Ni-6Ce/Al_(2)O_(3) exhibits less coke deposition and small growth of Ni nanoparticles.This work provides a simple way to preparing the Ni-Ce/Al_(2)O_(3) catalyst with enhanced catalytic performance in DRM.The Ni-6Ce/Al_(2)O_(3) catalyst has great potential for industrial application due to its anti-sintering ability and resistance to carbon deposition. | HE Lulu CHEN Xin REN Yuanhang YUE Bin TSANG Shik Chi Edman HE Heyong | 2022 | Chemical Research in Chinese Universities2022,38,4: | 0 |