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PM_(2.5) and PM_(10-2.5) chemical composition and source apportionment near a Hong Kong roadway

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Particuology 2015年第1期13卷 96-104页

作者： Yan Cheng Shuncheng Lee Zhaolin Gu Kinfai Ho Yunwei Zhang Yu Huang Judith C.Chow John G.Watson Junji Cao Renjian Zhang Department of Environmental Science and Technology School of Human Settlements and Civil EngineeringXi'an Jiaotong University State Key Laboratory of Loess Quaternary Geology Institute of Earth and EnvironmentChinese Academy of Sciences Department of Civil and Structural Engineering Research Center for Environmental Technology and ManagementThe Hong Kong Polytechnic University School of Public Health and Primary Care The Chinese University of Hong Kong Division of Atmospheric Sciences Desert Research Institute Key Laboratory of Regional Climate-Environment research for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of Sciences

Twenty-four-hour PM2.5 and PM10 samples were collected simultaneously at a highly trafficked road-side site in Hong Kong every sixth day from October 2004 to September 2005. The mass concentrations of PM2.5, PMlo-2.5 （defined as PM10 - PM2.5）, organic carbon （OC）, elemental carbon （EC）, water-soluble ions, and up to 25 elements were determined. Investigation of the chemical compositions and potential sources revealed distinct differences between PM2.5 and PM10-2.5. The annual average mass concentrations were 55.5 ＋ 25.5 and 25.9±15.7μg/m^3 for PM2.5 and PM10-2.5, respectively. EC, OM （OM = OC × 1.4）, and ammonium sulfate comprised over -82% of PM2.5, accounting for -29%, -27%, and -25%, respectively, of the PM2.5 mass. Low OC/EC ratios （less than 1） for PM2.5 suggested that fresh diesel-engine exhaust was a major contributor. Seven sources were resolved for PM2.5 by positive matrix factorization （PMF） model, including vehicle emissions （-29%）, secondary inorganic aerosols （-27%）, waste incinera- tor/biomass burning （-23%）, residual oil combustion （-10%）, marine aerosols （-6%）, industrial exhaust （-4%）, and resuspended road dust （-1%）. EC and OM comprised only -19% of PM10-2.5. The average OC/EC ratio of PM10-2.5 was 7.8± 14.2, suggesting that sources other than vehicular exhaust were important contributors. The sources for PM10-2.5 determined by the PMF model included -20% traffic-generated resuspension （e.g., tire dust/brake linear/petrol evaporation）, -17% locally resuspended road dust, -17% marine aerosols, -12% secondary aerosols/field burning, and -11% vehicle emissions.

关键词： PM2.5 PM10-2.5 Roadside Chemical composition Source apportionment Hong Kong

Comparative Analysis of the Volatile Components in the Fresh Roots and Rhizomes of Curcuma wenyujin by Static Headspace Gas Chromatography Mass Spectrometry

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chinese Journal of Chemistry 2006年第10期24卷 1346-1351页

作者：方芳程志红郭寅龙蔡延奔 Shanghai Mass Spectrometry center Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China Wenzhou Institute oflndustry and Science research Wenzhou Zhejiang 325028 China

Static headspace GC-MS method coupled with H/D exchange was firstly developed to determine and identify the volatile components in the fresh root and rhizome of Curcuma wenyujin. The TIC chromatograms of 3 batches of fresh roots harvested at different time showed significant difference in the volatile components： the constitution was the same but the content of them was different. More than 60 volatile components in fresh roots （Root of C. wenyujin） and rhizomes （Rhizome of C. wenyujin） of C. wenyujin were detected, of which 51 and 48 volatile components were identified respectively. The fresh roots and rhizomes of C. wenyujin were found to have the similar volatile components. The contents of these components were calibrated by the response of β-elemene. In addition, the principal active component, β-elemene, was further confirmed and relatively quantified by its standard. γ-terpinene showed obvious allylic hydrogen/deuterium exchange using deuterium oxide which gave a new method to identify some compounds containing allylic hydrogen. At the same time, the active hydrogen compounds were also further confirmed. The results show that HS-GC-MS of volatile components from medical plants. method is a fast, simple and efficient way for the analysis

关键词： Curcuma wenyujin static headspace GC-MS H/D exchange volatile component

Flow field control for 2-meter high-speed free-jet wind tunnel

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chinese Journal of Aeronautics 2023年第10期36卷 77-89页

作者： Jiayi TIAN Zhongwei LING Weijie LIU Jianhua Qin Neng XIONG China Aerodynamics research and Development center Mianyang 621000China

The 2-meter High-speed Free-jet Wind Tunnel(2 m HFWT)is China’s first large-scale open-jet trisonic wind *** to traditional closed high-speed wind tunnels,this wind tunnel is endowed with remarkable advantages of ample test chamber space,less interference from the tunnel wall,flexible model support mode,and adjustable continuous variation of the Mach ***,its unique structure makes traditional wind tunnel control methods difficult to apply and brings significant challenges to wind tunnel flow field *** this paper,a flow field control system is designed for the 2 m HFWT by comprehensively using advanced control technologies such as neural network,gain scheduling,feedforward control,and adaptive *** practical application tests,it is proved that the proposed control system successfully solves the problem of high-precision flow field control under continual depletion of storage tank pressure,and realizes distinctive functions of adaptive static pressure matching and continuously varying Mach number at supersonic *** addition,due to the application of workflow technology,the flow field control system can flexibly adapt to the implementation of tests of different types and operation conditions,thus fully satisfying the needs of conducting various conventional and special tests in the 2 m HFWT.

关键词： Continuously varying Mach number Wind tunnel Flow field control Neural network Static pressure matching Feedforward control

Anisotropy of the Wear Behavior for Carbon Nanotube-Reinforced 6061Al Composites

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Acta Metallurgica Sinica(English Letters) 2023年第5期36卷 814-826页

作者： X.N.Li J.F.Zhang W.H.Xue K.Ma P.Y.Li Z.Y.Liu B.L.Xiao D.R.Ni Q.Z.Wang D.Wang Z.Y.Ma School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Shi-Changxu Innovation center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

Carbon nanotube(CNT)-reinforced 6061Al(CNT/6061Al)composites with directionally aligned CNT were fabricated,and their wear behavior was *** results indicate that the wear properties of CNT/6061Al composites exhibited a significant anisotropy.A certain CNT concentrations(1 wt%and 2 wt%)could effectively improve the wear resistance of CNT/6061Al composites along the CNT circumferential and CNT radial directions for the load transfer,grain refinement and self-lubrication effect of *** Brass{011}and{112}textures inhibited the load transfer effect of CNT along the CNT radial direction,resulting in a better wear resistance along CNT circumferential direction than CNT radial *** the CNT axial direction,the weak deformability of composites caused by the intensifyingfiber texture was the main reasons for the poor wear resistance of CNT/6061Al composites with increasing CNT concentration.

关键词： Carbon nanotube Metal matrix composite Wear Anisotropy

Analysis of Environmental Endocrine Disrupting Activities in Wastewater Treatment Plant Effluents Using Recombinant Yeast Assays Incorporated with Exogenous Metabolic Activation System

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Biomedical and Environmental Sciences 2011年第2期24卷 132-139页

作者： LI Jian CHEN Ming WANG ZiJian MA Mei PENG XianZhi Engineering research center of Groundwater Pollution Control and Remediation Ministry of Education College of Water Sciences Beijing Normal University Beijing 100875 China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 Guangdong China

Objective To measure the endocrine disrupting chemicals （EDCs） in wastewater and evaluate the EDCs removal efficiencies in the municipal wastewater treatment plants （WWTP）. Methods A battery of in vitro recombinant yeast bioassays incorporated with exogenous metabolic activation system （rat liver preparation, S9 mix） was conducted to assess the estrogen receptor （ER）, androgen receptor （AR）, progesterone receptor （PR）, and thyroid receptor （TR） ant/agonistic activities of effluents collected from Datansha WWTP. Results The indirect estrogenic, anti‐androgenic, anti‐progesteronic, and anti‐thyroidic activities were observed in the influent. The removal efficiencies of EDCs were above 74%, suggesting that the present wastewater treatment processes were good enough to remove most of these indirect endocrine disrupting chemicals. Conclusion The incorporation of exogenous metabolic capacity into the test system was valid for the study of indirect effects on ER, AR, PR, and TR.

关键词： Recombinant yeast assay Endocrine disrupting chemicals Wastewater sample Metabolic activation

Michelson laser interferometer-based vibration noise contribution measurement method for cold atom interferometry gravimeter

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chinese Physics B 2020年第7期29卷 85-91页

作者： Ning Zhang Qingqing Hu Qian Wang Qingchen Ji Weijing Zhao Rong Wei Yuzhu Wang Key Laboratory for Quantum Optics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Advanced Interdisciplinary Technology research center National Innovation Institute of Defense TechnologyBeijing 100010China Department of Physics Shanghai UniversityShanghai 201800China

The measurement performance of the atom interferometry absolute gravimeter is strongly affected by the ground vibration *** propose a vibration noise evaluation scheme using a Michelson laser interferometer constructed by the intrinsic Raman laser of the atomic *** analysis shows that the vibration phase measurement accuracy is better than 4 mrad,which corresponds to about 10-^10 g accuracy for a single shot gravity *** with the commercial seismometer or accelerometer,this method is a simple,low cost,direct,and fully synchronized measurement of the vibration phase which should benefit the development of the atomic *** the other side,limited by equivalence principle,the result of the laser interferometer is not absolute but relative vibration *** cap method could be used to evaluation the noise contribution of vibration,which is a different method from others and should benefit the development of the atomic gravimeter.

关键词： atomic gravimeter Raman laser vibration monitoring

Wear behavior of the raw and pre-smashed carbon nanotubes reinforced 6061Al composites fabricated by powder metallurgy

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Science China(Technological Sciences) 2022年第5期65卷 1149-1159页

作者： LI XiaoNan LIU ZhenYu ZAN YuNing XIAO BoLü NI DingRui WANG QuanZhao WANG Dong MA ZongYi Shi-changxu Innovation center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China

The raw and pre-smashed(PS)carbon nanotube(CNT)reinforced 6061Al composites(CNT/6061Al)with different CNT contents were respectively fabricated by powder metallurgy *** was found that reducing the CNT cluster size by presmashing processing could sharply reduce the friction coefficient,and significantly improve the density,hardness,and wear resistance of the CNT/6061Al *** the raw-CNT/6061Al composites,the wear rate increased approximately linear trend while the CNT content was over 1 wt.%.The plastic deformation,deep grooves,and serious delamination were presented on the wear *** wear process was gradually transformed from Al-copper base counterpart wear into Al-Al wear for the higher adhesion-binding energy between aluminum and copper base *** for the PS-CNT/6061Al composites,the wear rate gradually decreased as the CNT content increased from 0 to 2 wt.%.This was mainly because the generation of the thinner mechanically mixed layer(MML)and the PS-CNT prevented the direct contact between specimen and copper base counterpart,which effectively inhibited the adhesive *** excessive PS-CNTaddition(~3 wt.%)would weaken the bonding between CNT and 6061Al,and thus the wear resistance of the composite was reduced apparently.

关键词： wear carbon nanotube aluminum matrix composites clustering

A Comparative Analysis of Primary and Extreme Characteristics of Dry or Wet Status between Asia and North America

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Advances in Atmospheric Sciences 2011年第2期28卷 352-362页

作者：华丽娟马柱国钟霖浩 College of Earth Science Graduate University of Chinese Academy of Sciences Regional center for Temperate East Asia Key Laboratory of Regional Climate-Environment Research for the Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric Physics Chinese Academy of Sciences

In this study, the Palmer Drought Severity Index （PDSI） was used to analyze the average and extreme dry/wet states of Asia and North America from 1953 to 2003. The results indicate that the two continents underwent drying trends during this period. Compared with North America, Asia showed more severe drought trends. However, more significant and regular seasonal variation for drought was found in North America. The driest regions in Asia were located in the northern region of China, Mongolia, and eastern mid-Siberian plateau. Most regions in central North America were relatively wetter than other regions. The northern and southwestern regions of North America, as well as the Atlantic and Pacific coastal areas, experienced the most drought during this period. A sharp increase of the drought area and the number of extreme drought events took place from 1997 to 2003 in both Asia and North America. Severe drought events were more likely to occur during the summer on both continents. Asia had the most extreme drought events during July, but North America reached its highest drought frequency from June to September. In Asia, a persistent increasing trend of extreme drought emerged throughout the studied period. However, a more complex evolution of drought emerged in North America： a decreasing trend appeared before the mid-1960s and an increasing trend appeared after the late 1970s. A relatively steady dry/wet status was observed between the mid-1960s and the late 1970s. The role of exceptional, extreme drought events with respect to the La Nin？a event was considered during 1997–2003.

关键词： mean dry/wet status extreme drought event Asia North America comparative analysis Palmer Drought Severity Index (PDSI)

Optical design of adjustable light emitting diode for different lighting requirements

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chinese Physics B 2012年第12期21卷 436-439页

作者：芦佳宁余杰童玉珍张国义 research center for Wide Gap Semiconductor Peking University

Light emitting diode （LED） sources have been widely used for illumination. Optical design, especially freedom compact lens design is necessary to make LED sources applied in lighting industry, such as large-range interior lighting and small-range condensed lighting. For different lighting requirements, the size of target planes should be variable. In our paper we provide a method to design freedom lens according to the energy conservation law and Snell law through establishing energy mapping between the luminous flux emitted by a Lambertian LED source and a certain area of the target plane. The algorithm of our design can easily change the radius of each circular target plane, which makes the size of the target plane adjustable. Ray-tracing software Tracepro is used to validate the illuminance maps and polar-distribution maps. We design lenses for different sizes of target planes to meet specific lighting requirements.

关键词： LED optical design freedom compact lens energy mapping adjustable Tracepro