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Evidence from carbon isotope measurements for biological origins of individual long-chain n-alkanes in sediments from the Nansha Sea,china

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chinese Science Bulletin 2002年第7期47卷 578-581页

作者： DUAN Yi & wang ZhipingState key laboratory of gas geochemistry, lanzhou institute of geology, chinese academy of sciences, lanzhou 730000, china institute of Environmental Science, Beijing Normal University, Beijing 100875, china State key laboratory of gas geochemistry Lanzhou Institute of Geology Chinese Academy of Sciences Lanzhou China institute of Environmental Science Beijing Normal University Beijing China

Carbon isotopes are measured for individual long-chain n-alkanes in sediments from the Nansha Sea. The features of carbon isotopic compositions of individual n-alkanes and their origins are studied. The results show that the long-chain n-alkanes have a light carbon isotopic composition and a genetic feature of mixing sources, and low-latitude higher plants and microbes are considered to be their main end member sources. Based on the abundances and carbon isotopic compositions of individual n-alkanes, the fractional contributions of the two end member sources to individual n-alkanes are quantitatively calculated by using a mixing model. The obtained data indicate that the fractional contributions of the two biological sources are different in the three samples. A trend is that the contribution of microbes increases with the depth. These results provide the theory basis and quantitatively studied method for carbon isotopic applied research of individual n-alkanes.

关键词： modern marine sediment individual n-alkane carbon isotopic composition biological source.

Advances in geochemical research on nanometer materials

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Progress in Natural Science:Materials International 2006年第4期16卷 331-337页

作者： ZHU Xiaoqing and wang Zhonggang key laboratory of Ore Deposit geochemistry, institute of geochemistry, chinese academy of sciences, Guiyang 550002, china key laboratory of Ore Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Important advances have been made in the field of geochemistry since nanometer science and technology were introduced into the field of geoscience. The nanometer particulates have been discovered in naturally-occurring ore deposits, volcano-eruptive materials and geo-gases, and a more detailed exploration of the metallogenic mechanism of endogenic metallic ore deposits has been conducted. It is considered that some ore-forming metals may transport in the form of native particulates. Because they have very strong capabilities of adsorption, adsorption is always regarded as an important mechanism of metallogenesis under supergenic and low temperature conditions. Therefore, a new technology of ore exploration has also been developed. This paper attempts to review the new advances in geochemical research on nanometer materials, as well as its perspectivess.

关键词： nanometer geochemistry adsorption metallogenic theory prospecting method.

The solid lubricating material experiment device for Shenzhou-7 Spaceship

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Science china(Technological sciences) 2010年第9期53卷 2521-2527页

作者： wang Ke1,2,REN WeiJia1,wang ShiDa1 & WENG LiJun3 1 academy of Opto-Electronics,chinese academy of sciences,Beijing 100190,china 2 Graduate University of chinese academy of sciences,Beijing 100049,china 3 lanzhou institute of Chemical Physics,chinese academy of sciences,lanzhou 730000,china academy of Opto-Electronics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China lanzhou institute of Chemical Physics Chinese Academy of Sciences Lanzhou China

A solid lubricating material exposure experiment in space is one of the missions during the seventh manned spaceflight of china,and the key is to develop a device which can be fixed reliably outside of the orbital module and can be fetched conveniently by an astronaut during space *** solid lubricating material experiment device needs to be locked reliably in a vibrating and impacting environment during the launch phase,and should meet the requirement that it can be unlocked and fetched reliably by the astronaut wearing an extravehicular spacesuit via simple operations in orbit in an environment of high and low *** for the device we developed,the environmental characteristic of the mission was analyzed,the mechanical analysis and thermal analysis were carried out,and then a mechanism with functions of mechanical locking,structural self-locking and manual unlocking was *** device was verified by a sequence of experiments and was fetched by the astronaut during the flight of the Shenzhou-7 Spaceship.

关键词： manned spaceflight exposure experiment mechanism unlock

Decrease trend of dust event frequency over the past 200 years recorded in the Malan ice core from the northern Tibetan Plateau

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chinese Science Bulletin 2005年第24期50卷 2866-2871页

作者： wang Ninglian key laboratory of Cryosphere and Environment, Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, lanzhou 73000, china institute of Tibetan Plateau Research, chinese academy of sciences, Beijing 100085, china key laboratory of Cryosphere and Environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

By analyses of the dust layers in the Malan ice core from the northern Tibetan Plateau, it was found that dirty ratio in this core might be a good proxy for dust event frequency. The variations in the dirty ratio displayed a de- crease trend over the past 200 years, which implies that dust events became less frequent during the study period. The decrease trend in the variations in dust event frequency might be caused mostly by the natural processes, including increasing precipitation and weakening westerly which might be related with global warming. Furthermore, significant negative correlation was found between the dirty ratio and δ 18O in the Malan ice core. This is highly important for studying the effect of atmospheric dust on climate change.

关键词：青藏高原马伦冰核气候变化扬尘事件发生频率

Metallogenic mechanisms of super-large Cu and Au deposits in the Dexing region and simulating experiments

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chinese Journal Of geochemistry 2010年第1期29卷 1-14页

作者： WU Xueyi and wang Zijiang The State key laboratory of Ore Deposit geochemistry,institute of geochemistry,chinese academy of sciences,Guiyang 55002,china The State key laboratory of Ore Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang China

Based on the results of previous studies and under the direction of the theory of "ore deposit genesis",the authors made use of high temperature and high pressure experimental facilities and conditions at the Tectono-geochemistry Research Room under the State key laboratory of Ore Deposit geochemistry,institute of geochemistry,chinese academy of sciences,and put the focus on the multi-source of tectonically controlling ore-forming materials,the characteristics of multi-stage and multi-episode hydrothermal activities and mineralization and the characteristics of multi-genesis and multi-ore deposition so as to shed light on the metallogenic mechanisms of super-large Cu and Au *** addition simulating experiments were made on multi-stage and multi-episode tectonic activities and rock and ore deformation,multi-stage and multi-episode tectonic activities and mobilization and migration of ore-forming materials,and multi-stage and multi-episode tectonic activities and superimposition and enrichment of ore-forming *** experimental results showed that under the action of multi-stage and multi-episode tectonic stress the deformation and fragmentation of not only rocks and ores have been intensified,and but also the ore-forming materials originally disbursed in the rocks and ores have been mobilized and migrated and superimposed and *** experimental results also provided the scientific experimental data and grounds for deep-going research on the rules of metallogenesis and geneses of super-large ore deposits in the Dexing region,Jiangxi Province.

关键词：成矿机制模拟实验德兴地区金矿床超大型构造地球化学成矿物质来源国家重点实验室

Water transfer characteristics during methane hydrate formation and dissociation processes inside saturated sand

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Journal of Natural gas Chemistry 2010年第1期19卷 71-76页

作者： Peng Zhang, Qingbai Wu, Yibin Pu, Guanli Jiang, Jing Zhan, Yingmei wang State key laboratory, Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, lanzhou 730000, Gansu, china State key laboratory Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 Gansu China

gas hydrates formation and dissociation processes inside porous media are always accompanied by water transfer behavior, which is similar to the water behavior of ice freezing and thawing processes. These processes have been studied by many researchers, but all the studies are so far on the water transfer characteristics outside porous media and the water transfer characteristics inside porous media have been little known. In this study, in order to study the water transfer characteristics inside porous media during methane hydrate formation and dissociation processes, a novel apparatus with three pF-meter sensors which can detect water content changes inside porous media was applied. It was experimentally observed that methane hydrate formation processes were accompanied by water transfer from bottom to top inside porous media, however, the water behavior during hydrate dissociation processes was abnormal, for which more studies are needed to find out the real reason in our future work.

关键词： methane hydrate formation and dissociation processes: water transfer inside porous media saturated

Nitric Oxide Emission Following Wetting of Dry Soils in Subtropical Humid Forests

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Pedosphere 2009年第6期19卷 692-699页

作者： LI De-Jun and wang Xin-Ming 2 State key laboratory of Organic geochemistry, Guangzhou institute of geochemistry, chinese academy of sciences, Guangzhou 510640 (china) State key laboratory of Organic geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 (China)

Information about soil nitric oxide （NO） emissions from subtropical forests is quite limited, and even less is known about the pulse emission of NO when wetting soils after a long period of dryness. In this study, we measured NO fluxes following wetting of dry soft in a broadleaf forest and a pine forest in subtropical china. Large pulses of NO fluxes were observed after soil wetting in both forests. NO fluxes increased significantly within 0.5 h following wetting in both forests and reached peak 1 and 4 h after soil wetting in the pine forest and the broadleaf forest, respectively. In the broadleaf forest, averaged peak flux of NO pulses was 157 ng N m^-2 s^-1, which was 8 times the flux value before wetting, and in the pine forest, the averaged peak flux was 135 ng N m-2 s 1, which was 15.5 times the flux value before wetting. The total pulses-induced NO emissions during the dry season were roughly estimated to be 29.4 mg N m^-2 in the broadleaf forest and 22.2 mg N m^-2 in the pine forest or made up a proportion of 4.6% of the annual NO emission in the broadleaf forest and 5.3% in the pine forest.

关键词： dry season flux. NO. pulse subtropical china

Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

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Science china Earth sciences 2006年第11期49卷 1156-1169页

作者： wang Genxu1,3 , LI Yuanshou2 , WU Qingbai2 & wang Yibo3 1. institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, lanzhou 730000, china 3. Resource and Environment School, lanzhou University, lanzhou 730000, china institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Resource and Environment School Lanzhou University Lanzhou China Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

A neotype for Colpodexylon gracilentum Dou (Lycopsida) from the Middle Devonian of North Xinjiang,china

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Journal of Systematics and Evolution 2011年第4期49卷 372-378页

作者： Hong-He XU Yi wang (State key laboratory of Palaeobiology and Stratigraphy,Nanjing institute of geology and Palaeontology,chinese academy of sciences,Nanjing 210008,china) (State key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China)

According to newly collected and well preserved specimens,herbaceous lycopsids Colpodexylon gracilentum Dou and Colpodexylon laminatum Dou from the late Middle Devonian of Xinjiang,NW china are reduced to ***,for which a neotype is designated and emended diagnosis is *** gracilentum has leaves with three nearly equal segments,an elliptical sporangium adaxially attached by a pad on the isomorphic sporophyll.

关键词： Colpodexylon Devonian lycopsid neotype Xinjiang.