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Distribution characteristics of iodine in humic acid-high underground water in Inner Mongolia and their relations to IDD disease

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chinese Science Bulletin 1999年第S2期44卷 85-86页

作者： YU Xiaoying state key {2. of environmental g.ochemistry, institute of g.ochemistry, chinese academy of sciences, g.iyang.550002, china state key {2. of environmental g.ochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE concentrations of iodine in humic acid-high underground water are not low, but the IDD disease isprevailing in some areas and no such disease is reported in some other areas. In order to explore the causes of disease and the factors affecting the concentrations of I in underground water, the author collected51 water samples from the Amengbayingmaodao Farm, Langshan Town, Linghe City of Bameng, ShibaTown of Wuyuan County, Qingshan Town of Wulatiehou Prefecture, and Zhijiliang Village in the suburbsof Hohhot City in the central and western part of Inner Mongolia for investigation. The analytical resultsshow that the water samples were relatively alkaline （pH=7.91 on average）. The average concentrationsof cations vary in the order of Na+>Ca2.> Mg2.>K+ while those of anions follow the decreasing

关键词： iodine humic acid distribution characteristics.

ANNUAL LAMINATIONS IN THE SEDIMENTS OF HONgFENg LAKE, china

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chinese geographical Science 1996年第4期6卷 375-382页

作者： Wu Fengchang Wan guojiang(state key {2. of environmental g.ochemistry, institute of g.ochemistry, the chinese academy of sciences, g.iyang.550002, PRC) state key {2. of environmental g.ochemistry Institute of Geochemistry the Chinese Academy of Sciences Guiyang PRC

Hongfeng Lake is an eutrophic freshwater atificial *** began to restore water in 1960. Three sediment cores were taken from both about 2.m of water in the center of Hongfeng bake in May 1991. The stratigraphy of the three cores was easily matched .by using prominent marking horizons and characteristic aqnences of laminations. In three layer Samples studied, diatom and other algae taxa appear in repeating apuences. The presence of laminations may reflect either the regular changes of physical-chemical conditions within the lake or the variation in the intensity of erosion and transport of material from the catchment, pat iculaly where instability in the lake-water system has occult as a result of human activities. The larninations were mainly cantal by seasonal variation of envionmental conditions,particularly *** t of the previous examples, they have ben fo￣ at most recent Sediments, in a small freshwater lake in the eastern slOPe of the QinghaiXiZang Plateau, china in a subtropical climate, which is adenly controlled by ￣theastern and southwestern mon￣n. It is believed that it's the first reported instanceOf laminated lake sediments from china.

关键词： annual laminations Hongfeng Lake carbonate g.ochemistry

Structural and microstructural transformations in Bi_2.r_2.a_(1-x)Y_xCu_2._(8+y) system

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chinese Science Bulletin 1997年第3期42卷 192-196页

作者： SONg Chengyu, WEN Shulin and CHE guangcan1. Shanghai institute of Ceramics, chinese academy of sciences, Shanghai 2.0050,{2. 2. state key laboratory of Supercon-ductivity, institute of Physics, chinese academy of sciences, Beijing 100080,{2. Shanghai institute of Ceramics Chinese Academy of Sciences Shanghai China state key {2. of Superconductivity Institute of Physics Chinese Academy of Sciences Beijing China

SINCE the discovery of high-Tc superconductors, experiments have revealed that the phase diagrams of La2.xSrxCuO4 and YBa2.u3O6+x resemble each other. The antiferromagnetic phase is commonly situated in the vicinity o... 详细信息

SINCE the discovery of high-Tc superconductors, experiments have revealed that the phase diagrams of La2.xSrxCuO4 and YBa2./sub>Cu3O6+x resemble each other. The antiferromagnetic phase is commonly situated in the vicinity of the superconductive phase. In Bi-2.12.sys-

关键词： Bi2.r2.a1-xYxCu2.y substitution structural transformation.

Plastic deformation of nanocrystalline nickel

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Science china(Technological sciences) 2009年第8期52卷 2216-2221页

作者： WU XiaoLei state key {2. of Nonlinear Mechanics, institute of Mechanics, chinese academy of sciences, Beijing 100190, china state key {2. of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing China

A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline (NC) Ni subject to cold rolling at liquid nitrogen temperature. The activation of grain-boundary-mediated-plasticity is evidenced in NC-Ni, including twinning and formation of stacking fault via partial dislocation slips from the grain boundary. The formation and storage of 60? full dislocations are observed inside NC-grains. The grain/twin boundaries act as the barriers of dislocation slips, leading to dislocation pile-up, severe lattice distortion, and formation of sub-grain boundary. The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation. The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

关键词： nanocrystalline metal plastic deformation deformation twinning dislocation microstructure

SILICA-SUPPORTED NICKEL AND ZIRCONIUM CATALYSTS FOR BRANCHED POLYETHYLENE

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chinese Journal of Polymer Science 2003年第4期21卷 453-458页

作者：孙文华 state key {2. of Engineering Plastics The Center for Molecular sciences institute of Chemistry chinese academy of sciences Beijing 100080 china Stt. key Lab. of Eng. Plastics Center for Molecular Sciences Chinese Academy of Sciences Beijing 100080 China

8-Aminoquinoline nickel dichloride and bis(cyclopentadienyl)zirconium dichloride (Cp_2.rCl_2. were supportedsimultaneously on silica to produce branched polyethylene successfully by combined polymerization. The supportedpolymerization results showed that the molecular weight of polyethylene increased while the molecular weight distributionbecame wider and the molecular chains of oligomers remaning in the final solution became shorter as compared to theoligomers obtained in polymerization processes with pure 8-aminoquinoline nickel dichloride catalysis, as well as theCp_2.rCl_2.and nickel combination system. With decreasing amount of Ni catalyst in the supported catalyst, the molecular chains of oligomers in the resulting solution became shorter, while α-olefin selectivity increased.

关键词： 8-Aminoquinoline nickel dichloride, Cp_2.rCl_2 Silica supported catalysts Branched polyethylene

Applications of synchrotron-based X-ray techniques in environmental science

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Science china Chemistry 2010年第12期53卷 2529-2538页

作者： LUO Lei & ZHANg ShuZhen state key {2. of environmental Chemistry and Ecotoxicology Research Center for Eco-environmental sciences,chinese academy of sciences,Beijing 100085,china state key {2. of environmental Chemistry and Ecotoxicology Research Center for Eco-environmental sciences Chinese Academy of Sciences Beijing China

Synchrotron-based X-ray techniques have been widely applied to the fields of environmental science due to their element-specific and nondestructive properties and unique spectral and spatial resolution *** techniques are capable of in situ investigating chemical speciation,microstructure and mapping of elements in question at the molecular or nanometer scale,and thus provide direct evidence for reaction mechanisms for various environmental *** this contribution,the applications of three types of the techniques commonly used in the fields of environmental research are reviewed,namely X-ray absorption spectroscopy (XAS),X-ray fluorescence (XRF) spectroscopy and scanning transmission X-ray microscopy (STXM).In particular,the recent advances of the techniques in china are elaborated,and a selection of the applied examples are provided in the field of environmental ***,the perspectives of synchrotron-based X-ray techniques are *** their great progress and wide application,the techniques have revolutionized our understanding of significant geo-and bio-chemical *** is anticipatable that synchrotron-based X-ray techniques will continue to play a significant role in the fields and significant advances will be obtained in decades ahead.

关键词： synchrotron spectroscopy spectromicroscopy environmental science

In situ DRIFTS study of hygroscopic behavior of mineral aerosol

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Journal of environmental sciences 2010年第4期22卷 555-560页

作者： Qingxin Ma,Hong He,Yongchun Liu state key {2. of environmental Chemistry and Ecotoxicology,Research Center for Eco-environmental sciences,chinese academy of sciences,Beijing 100085,china. state key {2. of environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

In situ diffusion reflectance infrared Fourier transform spectroscopy was used to study the water adsorption on mineral oxides （SiO2. a-Al2.3, MgO, Fe2.3, TiO2.. The results showed that all the water adsorption isotherms were well fitted with the Brunauer-Emmett-Teller （BET）-Ⅲ type equation, with the calculated monolayers occurring at 2.%-30% relative humidity. It showed that about 1-5 layers of water adsorbed on oxides surfaces in ambient relative humidity （2.%-90%）. The measured deliquescence relative humidity of NaCl was （74 ± 1）%, which demonstrated that DRIFTS is a useful method for the study the hygroscopic behavior of mineral dust. In addition, the limits of DRIPTS were also discussed.

关键词： DRIFTS mineral oxides water adsorption hygroscopicity

Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in china

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Journal of Systematics and Evolution 2011年第2期49卷 95-107页

作者： 1,2.3 Sheng-Bin CHEN § 1 gao-Ming JIANg 3 Zhi-Yun OUYANg 3 Wei-Hua XU 3 Yi XIAO 1 (state key {2. of Vegetation and environmental Change, institute of Botany, chinese academy of sciences, Beijing 100093, china) 2.(graduate University of the chinese academy of sciences, Beijing 100049, china) 3 (state key {2. of Urban and Regional Ecology, Research Center for Eco-environmental sciences, chinese academy of sciences, Beijing 100085, china) (state key {2. of Vegetation and environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (graduate University of the chinese academy of sciences Beijing 100049 China) (state key {2. of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China)

environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from{2., we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.

关键词： habitat heterogeneity pteridophytes seed plants species richness water-energy hypothesis.

Effect of temperature on the sorption and desorption of perfluorooctane sulfonate on humic acid

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Journal of environmental sciences 2010年第3期22卷 355-361页

作者： Chengxia Jia, Chun You, gang Pan state key {2. of environmental Aquatic Chemistry, Research Center for Eco-environmental sciences, chinese academy of sciences, Beijing 100085, china. state key {2. of environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Sorption and desorption of perfluorooctane sulfonate （PFOS） on humic acid at different temperatures were studied. It was found that the sorption process could be modeled with power kinetic equation very well, suggesting that diflusion predominated the sorption of PFOS on the humic acid. The sorption capacity was doubled when the temperature increased from 5 to 35°C, and thermodynamics parameters △g0 was calculated to be –7.11 to –5.04 kJ/mol, △H0 was 14.2.kJ/mol, and △S 0 was 69.5 J/（mol·K）, indicating that the sorption was a spontaneous, endothermic, and entropy driven process. Desorption hysteresis occurred at all studied temperatures which suggested that humic acid may be an important sink of PFOS in the environment.

关键词： perfluorooctane sulfonate sorption desorption temperature humic acid