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| 1 | 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 |
| 2 | Chemical characteristics of haze particles in Xi'an during Chinese Spring Festival: Impact of fireworks burning显示文摘Fireworks burning releases massive fine particles and gaseous pollutants, significantly deteriorating air quality during Chinese Lunar New Year(LNY) period. To investigate the impact of the fireworks burning on the atmospheric aerosol chemistry, 1-hr time resolution of PM_(2.5) samples in Xi'an during the winter of 2016 including the LNY were collected and detected for inorganic ions, acidity and liquid water content(LWC) of the fine aerosols. PM_(2.5) during the LNY was 167 ± 87 μg/m^3, two times higher than the China National Ambient Air Quality Standard(75 μg/m^3). K^+(28 wt.% of the total ion mass) was the most abundant ion in the LNY period, followed by SO_4^(2-)(25 wt.%) and Cl-(18 wt.%). In contrast, NO_3^-(34 wt.%) was the most abundant species in the haze periods(hourly PM32-2.5> 75 μg/m), followed by SO_4(29.2 wt.%) and NH_4^+(16.3 wt.%), while SO_4^(2-)(35 wt.%) was the most abundant species in the clean periods(hourly PM_(2.5)< 75 μg/m^3), followed by NO_3^-(23.1 wt.%) and NH_4^+(11 wt.%). Being different from the acidic nature in the non-LNY periods, aerosol in the LNY period presented an alkaline nature with a pH value of 7.8 ± 1.3. LWC during the LNY period showed a robust linear correlation with K_2SO_4 and KCl, suggesting that aerosol hygroscopicity was dominated by inorganic salts derived from fireworks burning. Analysis of correlations between the ratios of NO--3/SO_4^(2-) and NH_4^+/SO_4^(2-) indicated that heterogeneous reaction of HNO_3 with NH_3 was an important formation pathway of particulate nitrate and ammonium during the LNY period. | Can Wu Gehui Wang Jiayuan Wang Jianjun Li Yanqin Ren Lu Zhang Cong Cao Jin Li Shuagshuang Ge Yuning Xie Xinpei Wang Guoyan Xue | 2018 | Journal of Environmental Sciences2018，30，9： | 10 |
| 3 | Protonation induced high-T_c phases in iron-based superconductors evidenced by NMR and magnetization measurements显示文摘Chemical substitution during growth is a well-established method to manipulate electronic states of quantum materials, and leads to rich spectra of phase diagrams in cuprate and iron-based superconductors. Here we report a novel and generic strategy to achieve nonvolatile electron doping in series of(i.e.11 and 122 structures) Fe-based superconductors by ionic liquid gating induced protonation at room temperature. Accumulation of protons in bulk compounds induces superconductivity in the parent compounds, and enhances the Tclargely in some superconducting ones. Furthermore, the existence of proton in the lattice enables the first proton nuclear magnetic resonance(NMR) study to probe directly superconductivity. Using Fe S as a model system, our NMR study reveals an emergent high-Tcphase with no coherence peak which is hard to measure by NMR with other isotopes. This novel electric-fieldinduced proton evolution opens up an avenue for manipulation of competing electronic states(e.g.Mott insulators), and may provide an innovative way for a broad perspective of NMR measurements with greatly enhanced detecting resolution. | Yi Cui Gehui Zhang Haobo Li Hai Lin Xiyu Zhu Hai-Hu Wen Guoqing Wang Jinzhao Sun Mingwei Ma Yuan Li Dongliang Gong Tao Xie Yanhong Gu Shiliang Lie Huiqian Luo Pu Yu Weiqiang Yu | 2018 | Science Bulletin2018，63，1： | 7 |
| 4 | Seasonal variation and size distribution of biogenic secondary organic aerosols at urban and continental background sites of China显示文摘Size-resolved biogenic secondary organic aerosols(BSOA) derived from isoprene and monoterpene photooxidation in Qinghai Lake, Tibetan Plateau(a continental background site) and five cities of China were measured using gas chromatography/mass spectrometry(GC/MS). Concentrations of the determined BSOA are higher in the cities than in the background and are also higher in summer than in winter. Moreover, strong positive correlations(R2= 0.44–0.90) between BSOA and sulfate were found at the six sites,suggesting that anthropogenic pollution(i.e., sulfate) could enhance SOA formation,because sulfate provides a surface favorable for acid-catalyzed formation of BSOA. Size distribution measurements showed that most of the determined SOA tracers are enriched in the fine mode(< 3.3 μm) except for cis-pinic and cis-pinonic acids, both presented a comparable mass in the fine and coarse(> 3.3 μm) modes, respectively. Mass ratio of oxidation products derived from isoprene to those from monoterpene in the five urban regions during summer are much less than those in Qinghai Lake region. In addition, in the five urban regions relative abundances of monoterpene oxidation products to SOA are much higher than those of isoprene. Such phenomena suggest that BSOA derived from monoterpenes are more abundant than those from isoprene in Chinese urban areas. | Yanqin Ren Gehui Wang Jianjun Li Can Wu Cong Cao Jiayuan Wang Lu Zhang Fan Meng Hong Li | 2018 | Journal of Environmental Sciences2018，30，9： | 4 |
| 5 | Spatial and Temporal Distributions and Sources of Anthropogenic NMVOCs in the Atmosphere of China:A Review显示文摘As the key precursors of O_(3),anthropogenic non-methane volatile organic compounds(NMVOCs)have been studied intensively.This paper performed a meta-analysis on the spatial and temporal variations of NMVOCs,their roles in photochemical reactions,and their sources in China,based on published research.The results showed that both nonmethane hydrocarbons(NMHCs)and oxygenated VOCs(OVOCs)in China have higher mixing ratios in the eastern developed cities compared to those in the central and western areas.Alkanes are the most abundant NMHCs species in all reported sites while formaldehyde is the most abundant among the OVOCs.OVOCs have the highest mixing ratios in summer and the lowest in winter,which is opposite to NMHCs.Among all NMVOCs,the top eight species account for 50%−70%of the total ozone formation potential(OFP)with different compositions and contributions in different areas.In devolved regions,OFP-NMHCs are the highest in winter while OFP-OVOCs are the highest in summer.Based on positive matrix factorization(PMF)analysis,vehicle exhaust,industrial emissions,and solvent usage in China are the main sources for NMHCs.However,the emission trend analysis showed that solvent usage and industrial emissions will exceed vehicle exhaust and become the two major sources of NMVOCs in near future.Based on the meta-analysis conducted in this work,we believe that the spatio-temporal variations and oxidation mechanisms of atmospheric OVOCs,as well as generating a higher spatial resolution of emission inventories of NMVOCs represent an area for future studies on NMVOCs in China. | Fanglin WANG Wei DU Shaojun LV Zhijian DING Gehui WANG | 2021 | Advances in Atmospheric Sciences2021，38，7： | 4 |
| 6 | Tunable optical frequency comb from a compact and robust Er:fiber laser显示文摘We report on a compact and robust self-referenced optical frequency comb with a tunable repetition rate,generated by an all-polarization-maintaining(PM)mode-locked Er-doped fiber laser.The spacing between comb teeth can be tuned above 300 kHz at a repetition rate of 101 MHz.The repetition rate and the carrier-envelope offset of the laser are stabilized separately,and the relative residual phase noises are determined to be 336µrad and 713 mrad(1 Hz-1 MHz).The accurate frequency characteristics and the stable structure show great potential for the use of such a comb in applications of precision measurements. | Zhiwei Zhu Yang Liu Daping Luo Chenglin Gu Lian Zhou Gehui Xie Zejiang Deng Wenxue Li | 2020 | High Power Laser Science and Engineering2020，8，2： | 2 |
| 7 | Maximal subalgebras of the general linear Lie algebra containing Cartan subalgebras显示文摘Let gln(R) be the general linear Lie algebra of all n × n matrices over a unital commutative ring R with 2 invertible, dn(R) be the Cartan subalgebra of gln(R) of all diagonal matrices. The maximal subalgebras of gln(R) that contain dn(R) are classified completely. | WANGDengYin GEHui LIXiaoWei | 2012 | Science China Mathematics2012，55，7： | 2 |
| 8 | Ammonia in urban atmosphere can be substantially reduced by vehicle emission control:A case study in Shanghai, China显示文摘To investigate the impact of emission controls on ammonia(NH_(3)) pollution in urban atmosphere, observation on NH_(3)(1 hr interval) was performed in Shanghai before, during and after the 2019 China International Import Expo (CIIE) event, along with measurements on inorganic ions, organic tracers and stable nitrogen isotope compositions of ammonium in PM_(2.5). NH_(3)during the CIIE period was 6.5±1.0μg/m^(3), which is 41% and 32% lower than that before and after the event, respectively. Such a decrease was largely ascribed to the emission controls in nonagricultural sources, of which contribution for measured NH_(3)in control phase abated by ~20% compared to that during uncontrol period. Molecular compositions of PAHs and hopanes further suggested a dominant role of the reduced vehicle emissions in the urban NH_(3)abatement during the CIIE period. Our results revealed that vehicle exhaust emission control is an effective way to mitigate NH_(3)pollution and improve air quality in Chinese urban areas. | Can Wu Shaojun Lv Fanglin Wang Xiaodi Liu Jin Li Lang Liu Si Zhang Wei Du Shijie Liu Fan Zhang Jianjun Li Jingjing Meng Gehui Wang | 2023 | Journal of Environmental Sciences2023，，4： | 1 |
| 9 | Chemical Characterization of Water-soluble Compositions of PMm and PM2s Atmospheric Aerosols in Five Locations of Nanjing, China 显示文摘 | Gehui Wang Hui Wang Yajuan Yu | 2003 | Atmospheric Environment2003，37，21： | 1 |
| 10 | Characterization of water-soluble species of PM10 and PM2.5 aerosols in urban area in Nanjing, China显示文摘 | Gehui Wang Liming Huang Shixiang Gao Songting Gao Liansheng Wang | 2002 | Atmospheric Environment2002，，8： | 1 |
| 11 | Molecular, sea sonal,and spatial distributions of organic aerosols from four teen Chinese cities显示文摘 | WANG Gehui KAWAMURA K LEE S | 2006 | Environmental Science and Technolo-gy2006，40，15： | 1 |
| 12 | Impact of PM 2.5 chemical compositions on aerosol light scattering in Guangzhou — the largest megacity in South China显示文摘 | Jun Tao Leiming Zhang Kinfai Ho Renjian Zhang Zejian Lin Zhisheng Zhang Mang Lin Junji Cao Suixing Liu Gehui Wang | 2014 | Atmospheric Research2014，，： | 1 |
| 13 | Significant coal combustion contribution to water-soluble brown carbon during winter in Xingtai, China: Optical properties and sources显示文摘To understand the characteristics of atmospheric brown carbon(BrC),daily PM2.5 samples in Xingtai,a small city in North China Plain(NCP),during the four seasons of 2018-2019,were collected and analyzed for optical properties and chemical compositions.The light absorption at 365 nm(abs λ=365 nm)displayed a strong seasonal variation with the highest value in winter(29.0±14.3 M/m),which was 3.2∼5.4-fold of that in other seasons.A strong correlation of abs λ=365 nm with benzo(b)fluoranthene(BbF)was only observed in winter,indicating that coal combustion was the major source for BrC in the season due to the enhanced domestic heating.The mass absorbing efficiency of BrC also exhibited a similar seasonal pattern,and was found to correlate linearly with the aerosol pH,suggesting a positive effect of aerosol acidity on the optical properties and formation of BrC in the city.Positive matrix factorization(PMF)analysis further showed that on a yearly basis the major source for BrC was biomass burning,which accounted for 34% of the total BrC,followed by secondary formation(26.7%),coal combustion(21.3%)and fugitive dust(18%).However,the contribution from coal combustionwas remarkably enhanced in winter,accounting for∼40%of the total.Our work revealed that more efforts of“shifting coal to clean energy”are necessary in rural areas and small cities in NCP in order to further mitigate PM2.5 pollution in China. | Dapeng Li Can Wu Si Zhang Yali Lei Shaojun Lv Wei Du Shijie Liu Fan Zhang Xiaodi Liu Lang Liu Jingjing Meng Yuesi Wang Jian Gao Gehui Wang | 2023 | Journal of Environmental Sciences2023，，2： | 1 |
| 14 | Molecular, seasonal, and spatial distributions of organic aerosols from fourteen Chinese cities 显示文摘 | Wang Gehui Kawamura Kimitaka Lee Shuncheng | 2006 | Environmental Science and Technology2006，40，15： | 1 |
| 15 | Molecular composition and size distribution of sugars, sugar-alcohols and carboxylic acids in airborne particles during a severe urban haze event caused by wheat straw burning显示文摘 | Gehui Wang Chunlei Chen Jianjun Li Bianhong Zhou Mingjie Xie Shuyuan Hu Kimitaka Kawamura Yan Chen | 2011 | Atmospheric Environment2011，，15： | 1 |
| 16 | Decoration of C_(60) nanorods with nickel and their magnetic properties显示文摘We studied the coating of C60 nanorods with nickel by electroless plating method and investigated their magnetic properties. The morphology and structure of the nickel layer coated on C60 nanorods were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Raman spectroscopy. The coated nickel is in the form of nano-sized crystals and becomes a continuous layer as reaction time increases. The hysteresis loop shows a super paramagnetic characteristic similar to that of nanometer-sized nickel particle. These results suggest that the average size of nickel particles on C60 rods is below 10 nm. Our study has shown that electroless plating is an efficient and simple method for coating C60 nanorods with nickel. | CHEN Ao LIU BingBing HOU YuanYuan WEN GeHui LIU DeDi LU ShuangChen LI ZePeng LI XiangLin ZOU YongGang ZOU Bo LI DongMei CUI Tian ZOU GuangTian | 2009 | Chinese Science Bulletin2009，54，14： | 1 |
| 17 | Optimizing noise characteristics of mode-locked Yb-doped fiber laser using gain-induced RIN-transfer dynamics显示文摘Gain-parameter-dependent transfer functions and phase-noise performances in a mode-locked Yb-doped fiber laser are measured in this study.It is discovered that the corner frequency in the amplitude and phase domains is determined by the absorption coefficient of the gain fiber,when the total absorption and other cavity parameters are fixed.This shows that an oscillator using gain fiber with higher dopant concentration accumulates more phase noise.Furthermore,we present net cavity dispersion-dependent transfer functions to verify the effect of dispersion management on the frequency response.We derive a guideline for optimizing mode-locked fiber laser design to achieve low phase noise and timing jitter. | Jiangshuoxue Han Yang Liu Zejiang Deng Gehui Xie Daping Luo Chenglin Gu Lian Zhou Wenxue Li | 2021 | High Power Laser Science and Engineering2021，9，3： | 1 |
| 18 | Aliphatic alkanes and polycylic aromatic hydrocarbons in atmospheric PMjo aerosols from Baoji, China: implications for coal burning 显示文摘 | XIE Mingjie WANG Gehui HU Shuyuan | 2009 | Atmospheric Research2009，93，4： | 1 |
| 19 | Mid-infrared optical frequency comb in the 2.7-4.0μm range via difference frequency generation from a compact laser system显示文摘We report on the generation of a mid-infrared(mid-IR)frequency comb with a maximum average output power of250 mW and tunability in the 2.7-4.0μm region.The approach is based on a single-stage difference frequency generation(DFG)starting from a compact Yb-doped fiber laser system.The repetition rate of the near-infrared(NIR)comb is locked at 75 MHz.The phase noise of the repetition rate in the offset-free mid-IR comb system is measured and analyzed.Except for the intrinsic of NIR comb,environmental noise at low frequency and quantum noise at high frequency from the amplifier chain and nonlinear spectral broadening are the main noise sources of broadening the linewidth of comb teeth,which limits the precision of mid-IR dual-comb spectroscopy. | Lian Zhou Yang Liu Gehui Xie Chenglin Gu Zejiang Deng Zhiwei Zhu Cheng Ouyang Zhong Zuo Daping Luo Bin Wu Kunfeng Chen Wenxue Li | 2020 | High Power Laser Science and Engineering2020，8，4： | 1 |
| 20 | Organic molecular compositions and size distributions of Chinese summer and autumn aerosols from Nanjing: characteristic haze event caused by wheat straw burning 显示文摘 | WANG Gehui KAWAMURA K XIE Mingjie | 2009 | Environ Sei Technol2009，43，17： | 1 |
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