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Simulating the transfer and fate of hexachlorocyclohexane in recent 50 years in beijing, china

Science china Earth sciences 2005年第12期48卷 2203-2213页

作者： CAO Hongying1, LIANG Tao1 & TAO Shu2.1. institute of Geographical sciences and Natural Resources Research,{2., beijing 100101, china 2. laboratory for Earth Surface Processes, Peking University, beijing 100871, china institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences Beijing China laboratory for Earth Surface Processes Peking University Beijing China

Taking beijing as a study area, a dynamic fugacity model was used to simulate the transfer and fate of technical HCHs according to the physic-chemical properties of the studying environment and HCH isomers. Dynamic changes of the transfer fluxes and concentrations of HCH isomers during 1952.2.03 were simulated and the model results suggest good agreement between the calculated and measured concentrations of HCH isomers. During 1952.1983, the average input and output amount of HCHs through agricultural application and degradation are 130 t and 150 t respectively. The dominant transfer processes of HCHs in the study area are air-soil deposition, soil erosion and soil-air diffusion, transfer fluxes of these processes are 80 t?a?1, 16 t?a?1 and 11 t?a?1, which account for 92. of total transfer fluxes of HCHs isomers. There were approximately 2.3t HCHs in all environmental compartments of the study area during this period and 97% of which existed in soil compartment. Air and water advection became the dominant input sources of HCHs after 1984 when the application of technical HCHs was prohib-ited, concentration of HCHs quickly descended to a quite low level in several years. Total amount of HCHs isomers remaining in the study area environment now is less than 5% that before 1983, and this percentage may descend to 0.5% after 2. years by prediction.

关键词： fugacity model, hexachlorocyclohexane, compartment, transfer flux, fate.

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SHRIMP ages of detrital zircons from the Changcheng System in the Ming Tombs area,beijing:Constraints on the protolith nature and maximum depositional age of the Mesoproterozoic cover of the North china Craton

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chinese Science Bulletin 2003年第22期48卷 2500-2506页

作者： WAN Yusheng1,2. ZHANG Qiaoda1 & SONG Tianrui1 1. institute of Geology, chinese {2. of Geological sciences, beijing 100037, china 2. beijing SHRIMP laboratory, beijing 100037, china Correspondence should be addressed to Wan Yusheng (e-mail: wanyusheng@***) institute of Geology Chinese Academy of Geological Sciences Beijing China beijing SHRIMP laboratory Beijing China

The Mesoproterozoic Changcheng System is widely distributed in the North china Craton. Determining its time of deposition and sources is important to understand the Precambrian crustal evolution of the North china Craton. This paper suggests age distribution patterns for detrital zircons from clastic sediments of the Changcheng System in the Ming Tombs area, {2.. Samples of feldspar-bearing sandstone (CHc-2. and pure sandstone (CHc-9) were collected from the Changzhougou Formation, which constitutes the basal part of the Changcheng System. Detrital zircons show an age range from 2.35 to 2.60 Ga. However, sample CHc-9 in the upper Changzhougou Formation also contains some zircons with ages of 1.9-1.8 Ga and 2.3-2.1 Ga. The age patterns lead to the following conclusions: (1) Most of the detrital material came from a source area composed predominantly of ~2.5 Ga continental crust of the North china Craton; (2. 1.9-1.8 Ga reflects the age record of Palaeoproterozoic continent-continent collisional event in the North china Craton; and (3) the oldest age for deposition of the Changcheng System is 1.8 Ga.

关键词：锆石原岩中国北部地区地壳演变

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Distribution and health risk assessment of organochlorine pesticides(OCPs) in industrial site soils:A case study of urban renewal in beijing,china

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Journal of Environmental sciences 2009年第3期21卷 366-372页

作者： YANG Wenrui,WANG Rusong,ZHOU Chuanbin,LI FengState key laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental sciences,{2. academy of sciences,beijing 100085,china. State key laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

A field survey was conducted in a contaminated industrial site of southern beijing, china to investigate the contents and distribution of the organochlorine pesticides （α-, β-, y-, δ-HCH, p,p＇-DDT, p,p＇-DDE, p,p＇-DDD and o,p＇-DDT） in the profiles of soil, and a health risk assessment was carded out with CalTOX multimedia exposure model. Results showed that mean concentrations of total hexachlorocyclohexane isomers （HCHs） and total dichlorodiphenyltrichloroethane isomers （DDXs） in soils were in the range of 13.2.- 148.71 mg/kg, and 3.02.67.43 mg/kg, respectively. Organochlorine pesticides （OCPs） content peaked in the surface and declined in soil profile with depth. The amounts of HCHs in three profiles of soil were larger than DDXs. Composition analysis indicated that there was a trend of degradation of OCPs in the site, but the mean of HCHs and DDXs concentration were over the state warning standard limit （HCHs, 0.50 mg/kg; DDXs, 0.50 mg/kg）. According to current land use development, health risk assessment with CalTOX and Monte Carlo analysis showed that health risks mainly came from two exposure pathways： dermal uptake and inhalation, and the total risk values all exceeded the general acceptable health risk value （10-6）. The sensitivity analysis indicated that five parameters significantly contributed to total risk.

关键词： pollution hexachlorocyclohexane isomers (HCHs) dichlorodiphenyltrichloroethane isomers (DDXs) soil profiles Monte Carlo sensitivity

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Trophic transfer of mercury and methylmercury in an aquatic ecosystem impacted by municipal sewage effluents in beijing, china

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Journal of Environmental sciences 2010年第8期22卷 1189-1194页

作者： Jianjie Fu, Yawei Wang, Qunfang Zhou, Guibin Jiang State Key laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental sciences,{2., beijing 100085, china. State Key laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Gaobeidian Lake, located in beijing, china, serves as a recipient lake for efluents from a large municipal sewage treatment plant （MSTP）. In order to evaluate the effects of discharging MSTP efluent on the mercury contamination of the local aquatic ecosystem, sediment cores, water, plankton, fish, and turtle samples were collected from Gaobeidian Lake for mercury speciation analysis. High concentrations of total mercury （T-Hg） were detected in sediment cores （5.2.–17.0 μg/g dry weight （dw）, average： 10.1 μg/g）. The ratio of methylmercury （MeHg） to T-Hg was less than 0.3% in sediments and ranged from 35% to 76% in biota samples. The highest level of T-Hg and MeHg were found in aquatic bryophyte and crucian carp （3673 and 437 ng/g dw, respectively）. The relative contents of MeHg were significantly correlated with trophic levels （R2.= 0.5506, p 0.001）, which confirmed that MeHg can be bio-transferred and biomagnified via food chain in this aquatic ecosystem.

关键词： methylmercury total mercury trophic levels aquatic ecosystem municipal sewage treatment plants

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Characteristics of air particulate matter and their sources in urban and rural area of beijing, china

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Journal of Environmental sciences 2000年第4期12卷 402-409页

作者： YANG Shao jin, DONG Jin quan, CHENG Bing ru (institute of High Energy Physics, chinese academy of sciences, {2. 100080, china) institute of High Energy Physics Chinese Academy of Sciences Beijing 100080 China

During October 1993 and March 1996, the samples of fine and coarse air particulate matter have been collected at representative urban and rural site of beijing with the Gent Stacked Filter Unit Sampler. Instrumental neutron activation analysis (INAA) and proton induced X ray emission (PIXE) method were used to determine the elemental composition of the particulate matter. Average elemental concentrations and enrichment factors were calculated for the fine and coarse size fractions. Based on the particulate matter data obtained at urban and rural site together with the chemical constituents of the aerosol from the different sources are discussed. The results show that the relative particulate mass and elemental concentrations of crustal and pollutant elements in the air particulate matter collected over the urban are higher than rural and winter heating period are higher than in ordinary season. beijing atmosphere is polluted by aerosols from regional and faraway sources. It was noticed that the toxic or harmful elements such as As, Sb, Pb, Cu, Ni, S and Zn were mainly enriched in fine particles with diameter less than 2.μm. A receptor model was used to assess the relative contribution of major air pollution sources at receptor sites in beijing. Trace elements were used as the markers for the above assessment. Factor analysis method was used to identify possible emission sources of air particles. The major sources of dust soil, coal burning, motor vehicle emission, industry emission and refuse incineration were identified.

关键词： atmospheric particulate matter urban rural source aerosol

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Characteristics of InGaN multiple quantum well blue-violet laser diodes

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Science china(Technological sciences) 2006年第6期49卷 727-732页

作者： LI Deyao1, ZHANG Shuming1, WANG Jianfeng1, CHEN Jun1, CHEN Lianghui2. CHONG Ming2. ZHU Jianjun1, ZHAO Degang1, LIU Zongshun1, YANG Hui1 & LIANG Junwu1 1. State Key laboratory of Integrated optoelectronics,{2., chinese academy of sciences, beijing 1.0083. china 2. nano-optoelectronics laboratory,{2., chinese academy of sciences, beijing 1.0083. china State Key laboratory of Integrated optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing China nano-optoelectronics {2. Institute of Semiconductors Chinese Academy of Sciences Beijing China

Studies on InGaN multiple quantum well blue-violet laser diodes have been reported. Laser structures with long-period multiple quantum wells were grown by metal-organic chemical vapor deposition. Triple-axis X-ray diffraction (TAXRD) measurements show that the multiple quantum wells were high quality. Ridge waveguide laser diodes were fabricated with cleaved facet mirrors. The laser diodes lase at room temperature under a pulsed current. A threshold current density of 3.3 kA/cm[2.; a characteristic temperature T 0 of 145 K were observed for the laser diode.

关键词： metalorganic chemical vapor deposition (MOCVD), GaN-based laser diodes, multiple quantum well, ridge waveguide, threshold current.

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Paleotemperature changes over the past 3000 years in eastern beijing, china: A reconstraction based on Mg/Sr records in a stalagmite

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chinese Science Bulletin 2003年第4期48卷 395-400页

作者： MA Zhibang1, LI Hongchun2. XIA Ming1, KU Tehlung2. PENG Zicheng3, CHEN Yushu4 & ZHANG Zhaofeng3 1. institute of Geology and Geophysics, chinese academy of sciences, {2. 10002., china 2. Department of Earth sciences, University of Southern California, Los Angeles, CA90089-0740, USA 3. Department of Earth and Space Science, University of Science and Technology of china, Hefei 2.002., china 4. {2. Foshan Tourist Service Centre, {2. 1012.1, china institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Department of Earth sciences University of Southern California Los Angeles CA 90089-0740 United States Department of Earth and Space Science University of Science and Technology of China Hefei 230026 China beijing Foshan Tourist Service Centre Beijing 101201 China

The Mg/Sr ratio in a stalagmite, which is di-rectly proportional to DMg/Ca, the solid-liquid distribution coefficient of Mg, is proposed as a geochemical thermometer to estimate paleotemperature changes. The paleotempera-ture change in eastern beijing over the past 3000 years has been reconstructed by using this thermometer in the stalag-mite ZFFS-1 from Jingdong Cave. The records can be di-vided into two periods: 3000—2.00 aBP, cool and wet, the air temperature averaging 9.8℃; and 2.00 aBP—present, hot and dry, the air temperature being 1℃ higher than the mean value (11.7℃) of the past 3000 years. During 500—2.0 aBP, the air temperature was about 1.2. lower than that of the present, corresponding to the Little Ice Age in Europe. Like d 18O and d 13C, Mg/Sr (or DMg/Ca) reflects an obviously warming trend of the past 2.0 years. These results are sup-ported by historic records.

关键词：北京京东溶洞石笋 Mg/Sr记录古气温测年 3000年

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Dry electrode for the measurement of biopotential signals

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Science china(Information sciences) 2011年第11期54卷 2435-2442页

作者： WANG Yu 1,2.PEI WeiHua 2.GUO Kai 2.GUI Qiang 2.LI XiaoQian 2.CHEN HongDa 2.& YANG JianHong 11 institute of Microelectronics,School of Physical Science and Technology,Lanzhou University Lanzhou 730000,china 2.State Key {2. on Integrated optoelectronics,institute of semiconductors,chinese academy of sciences,beijing 1.0083.china institute of Microelectronics School of Physical Science and Technology Lanzhou University Lanzhou China State Key laboratory on Integrated optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing China

This paper introduces a kind of silicon-based dry electrode for measuring biological *** uses microneedle arrays to penetrate into the stratum corneum to reduce skin *** dry electrode requires neither skin preparation nor the electrolytic gel,is easy to use and causes no skin *** different technologies are chosen to manufacture microneedle arrays of dry *** is deep dry etching combined with isotropic wet *** other is mechanical dicing combined with chemical wet etching (including isotropic wet etching and anisotropic wet etching).Microneedle arrays are coated with metal and divided into 2. mm 2.as dry electrode *** testing shows that the impedance value of dry electrode can be comparable with that of commercial electrode in the 2. Hz-10 kHz frequency *** steady-state visual evoked potential recording and analysis prove that the dry electrode can be used to detect electroencephalography.

关键词： dry electrode microneedle array dry etching wet etching EEG

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Discovery of immune related factors in Fenneropenaeus chinensis by annotation of ESTs

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Progress in Natural Science:Materials International 2004年第1期14卷 48-55页

作者： SHEN Yaoqing 1,2. , XIANG Jianhai 1*, WANG Bing 1,2. , LI Fuhua 1 and TONG Wei 3(1. Experimental Marine Biology laboratory, institute of Oceanology,{2., Qingdao 2.6071,china 2. Graduate School of the{2., beijing 100039, china 3. Genomics & Bioinformatics institute,{2., beijing 101300, china) chinese Acad Sci Inst Oceanol Expt Marine Biol Lab Qingdao 266071 Peoples R China chinese Acad Sci Grad Sch Beijing 100039 Peoples R China chinese Acad Sci Geonom & Bioinformat Inst Beijing 101300 Peoples R China

A total of 10446 expressed sequence tags (ESTs) are obtained by a large scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis . An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

关键词： Fenneropenaeus chinensis bioinformatics ESTs immune factors

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Effect of As Interstitial Diffusionon on the Properties of Undoped Semi-insulating LECGaAs

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Rare Metals 2001年第3期20卷 187-191页

作者： Ruixia Yang, Fuqiang Zhang, Nuofu Chen 1) Hebei University of Technology, Tianjin 300130, china 2. institute of semiconductors,{2., beijing 1.0083. china 河北工业大学天津 300130 中科院半导体所北京 100083

Annealing was carried out at 950 and 112. degreesC under various As pressure for undoped (ND) semi-insulating (SI) LECGaAs. The effects of annealing on native defects and electrical properties were investigated. Experimental results indicate that, after an annealing at 950 degreesC for 14 h under low As pressure, the Hall mobility decreases and the resistivity increases dramatically for the samples. These changes in electrical properties are due to the generation of intrinsic acceptor defects, and the generation of the intrinsic acceptor defects originates from the outdiffusion of As interstitial at high temperature. The generation of the intrinsic defects and these changes in electrical properties can be suppressed by increasing the applied As pressure during annealing. The concentration of the main donor defect E12.(AsGaVGa) can be decreased by about one order of magnitude by an evacuated annealing at 112. degreesC for 2.8 h followed by a fast cooling. The decrease in E12.concentration can also be suppressed by increasing the As pressure during annealing.

关键词： semi-insulating GaAs intrinsic acceptor defects As interstitial indiffusion As pressure annealing

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