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Terrestrial mollusc records from Xifeng and Luochuan L9 loess strata and their implications for paleoclimatic evolution in the chinese Loess Plateau during marine Oxygen Isotope Stages 2.-2.

Terrestrial mollusc records from Xifeng and Luochuan L9 loes...

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中国科学院地质与地球物理研究所第11届（2.11年度）学术年会

作者： B.Wu~(1,2. and N.Q.Wu~1 1 Key Laboratory of Cenozoic Geology and Environment,institute of Geology and Geophysics,{2. academy of Sciences,P.O.Box 982.,beijing,10002.,china 2.Graduate University of the {2. academy of Sciences,beijing,100049,china

Marine Isotope Stages 2.-2. is a key period of the Mid-Pleistocene Transition,however,its climate variability is still *** coarse-grained loess unit L9,one of the most prominent units in the chinese loess stratigraphy,yields a high potential terrestrial record of paleoclimatic and paleoenvironmental changes during this *** this study, two high-resolution terrestrial mollusc records of L9 loess strata from the Xifeng and Luochuan sequences in the chinese Loess Plateau were *** mollusc results show that the MIS 2.,the early and late parts of MIS 2. were dominated by cold and dry *** mild-humid climate occurred in MIS 2. and the middle part of MIS *** climatic conditions at Xifeng region were cooler and more unstable compared to Luochuan region.A comparison of mollusc species composition and other proxies of L9 strata (MIS 2.-2.) with those of LI loess units(MIS 4-2. indicates that the L9 loess was not deposited under the most severe glacial conditions in Quaternary climate history as suggested in previous *** study shows that climatic conditions in the Loess Plateau during the L9 loess forming period were similar to that of gentle glacials(MIS 2. and MIS 2.) and interglacial(MIS 2.),as suggested by the marineδO *** cooling fluctuations occurred at 30 ka, 900 ka and 880 ka,which might hint to the global "900 ka cooling event".The "900-ka event" in the Loess Plateau does not seem to be a simple long glaciation,but rather several complex climatic fluctuations superposed on a general cooling *** uplift of the Tibetan Plateau and the general cooling experienced by the Earth during this period may have resulted in abundant dust sources and increased dust transport capability,as indicated by increased grain size and the mass accumulation rate of L9 loess.

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Antenna Temperature Calibration Algorithm and Design of the Calibration Experiment for Spaceborne Microwave Radiometers

Antenna Temperature Calibration Algorithm and Design of the ...

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2.09 3rd IEEE International Symposium on Microwave,Antenna,Propagation and EMC Technologies for Wireless Communications

作者： Zhao Jin 1 2.Dong Xiaolong 1 Zhang Dehai 1 1 Center for Space Science and Applied Research chinese academy of Sciences 2.Graduate University of chinese academy of Sciences beijing china

Calibration of microwave radiometer is the procedure and processing to setup a quantitive relationship between the output of the instrument, which usually is the digital sampling of the receiver output voltage, and microwave emission incident on the receiving antenna. Design of the calibration subsystem of a spaceborne microwave radiometer with fixed pointing antennas is described in this paper. The calibration equation is derived based on this design, by modeling the radiative transfer of microwave emissions, from input of the receiving antennas to the output of the calibration switches inside the receivers. Then a calibration experiment is designed to test the calibration model and acquire the calibration coefficients.

关键词： component calibration spaceborne microwave radiometer

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Nutrient cycling characteristics of Quercus acutissima and Pinus massoniana mixed forest in the Three Gorge Reservoir area, china

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Journal of Environmental Sciences 1998年第3期10卷 123-129页

作者： Wu GangDepartment of System Ecology, Research Center for Eco Environmental Sciences, chinese academy of Sciences, {2. 100085, china

The cycling characteristics of nitrogen(N), phosphorus(P) and potassium(K) of the Quercus acutissima and Pinus massoniana mixed forest which is the most common forest type in the Three Gorge Reservoir areas in china, were systematically analyzed. The results showed that N, P and K accumulated in the plant pool and in the litter pool, while total N, P, and K were deficient in the soil pool and in the forest systems. Contents of N in the soil of depth 2.—40 cm were the key factor limiting growth of trees. The biological outside cycling coefficients were 878, 72.5 and 117 times of inside cycling coefficients of N, P and K, respectively. 3392. 102. and 1588 kg of N, P and K return to the litter pool from branches, leaves and throughfall per year, but, 1431, 132.and 1048 kg of N, P and K return to the soil from litter pool per year respectively. It is clear that 58% of N, 87% of P, and 34% of K are lost by surface runoff per year. 549%, 130%, and 834% of N, P and K withdraw from leaves to branches, 499%, 199% and 730% of N, P and K withdraw from branches to trunks per year, respectively.

关键词： nutrient cycling Q. acutissima and P. massoniana mixed forest Three Gorge Reservoir.

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复杂产品虚拟样机工程

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计算机集成制造系统-CIMS 2002年第9期8卷 678-683页

作者：李伯虎柴旭东航天科工集团二院北京100854 清华大学国家CIMS工程技术研究中心北京100084

复杂产品虚拟样机技术是当前CIMS技术研究与应用的热点 ,其样机的开发工作已成为一项复杂的系统工程。复杂产品虚拟样机开发技术是融合与产品有关的专业领域技术与建模仿真技术、信息技术、多媒体虚拟现实技术、人工智能技术、系统... 详细信息

复杂产品虚拟样机技术是当前CIMS技术研究与应用的热点 ,其样机的开发工作已成为一项复杂的系统工程。复杂产品虚拟样机开发技术是融合与产品有关的专业领域技术与建模仿真技术、信息技术、多媒体虚拟现实技术、人工智能技术、系统技术和管理技术等多学科的一门综合性技术。基于笔者的研究与初步实践 ,本文提出了复杂产品虚拟样机工程的概念 ,并对其技术内涵、组成、运行模式、体系结构及其相关关键技术进行了探讨 ,以期促进复杂产品虚拟样机技术在我国企业的研究、实施与应用。

关键词：现代集成制造系统 CIMS 复杂产品虚拟样机虚拟样机工程

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稀土离子(Gd^(3+),Eu^(3+))加载于纳米介孔ZrO_2.的发光

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中国稀土学报 2002年第6期20卷 531-534页

作者：杨秀健陈永虎施朝淑陈航榕李福利中国科技大学物理系安徽合肥230026 中国科学院上海硅酸盐所上海200050 首都师范大学物理系北京100037

水热合成法制备的高度有序多孔ZrO2.有规则六角排列、均匀纳米孔洞(约1.8nm),丰富的表面、界面态及比表面积和强的蓝 (近)紫外光发射,使其较常规体材料有更优异的性质。以稀土离子为探针,研究了Gd3+,Eu3+在这些纳米微孔中的发光行为。... 详细信息

水热合成法制备的高度有序多孔ZrO2.有规则六角排列、均匀纳米孔洞(约1.8nm),丰富的表面、界面态及比表面积和强的蓝 (近)紫外光发射,使其较常规体材料有更优异的性质。以稀土离子为探针,研究了Gd3+,Eu3+在这些纳米微孔中的发光行为。结果表明,500℃下,介孔ZrO2.稀土离子相作用并有效地将能量传递给稀土离子,增进稀土离子发光。而在ZrO2.Gd Eu体系中,Gd3+在ZrO2.Eu3+间起桥梁作用,使基质ZrO2.Eu3+的能量传递更为有效。

关键词：稀土离子纳米介孔ZrO2 稀土加载光致发光二氧化锆纳米材料

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Stomatal movement in response to long distance-communicated signals initiated by heat shock in partial roots of Commelina communis L.

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Science china(Life Sciences) 2006年第1期49卷 18-25页

作者： YANG Songjie1, HUANG Conglin2. WU Zhongyi2. HU Jianfang3, LI Tianzhong3, LIU Shigui1 & JIA Wensuo3 1. School of Life Science, Sichuan University, Chengdu 610064, china 2. beijing Agriculture and Forestry {2., beijing Agriculture and Biotechnology Center, beijing 10089, china . 3. State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, china Agricultural University, beijing 100094, china School of Life Science Sichuan University Chengdu 610064 China beijing Agriculture and Forestry academy Beijing Agriculture and Biotechnology Center Beijing 10089 China State Key Laboratory of Plant Physiology and Biochemistry College of Agronomy and Biotechnology China Agricultural University Beijing 100094 China

The systematic or long-distance signal transmission plays crucial roles inanimal lives. Compared with animals, however, much less is known about the roles of long-distancesignal communication in plant lives. Using the model plant Commelina communisL, we have probed theroot to shoot communication mediated by heat-shock signals. The results showed that a heat shock of5 min at 40°C in partial roots, i.e. half or even 1/4 root system, could lead to a significantdecrease in stomatal conductance. The regulation capability depends on both heat shock temperatureand the amount of root system, i.e. with higher temperature and more roots stressed, the leafconductance would decrease more significantly. Interestingly, the stomatal regulation by heat shocksignal is in a manner of oscillation: when stomata conductance decreased to the lowest level withinabout 30 min, it would increase rapidly and sometimes even exceed the initial level, and afterseveral cycles the stomata conductance would be finallystabilized at a lower level. Feeding xylemsap collected from heat-shocked plants could lead to a decrease in stomata conductance, suggestingthat the heat shock-initiated signal is basically a positive signal. Further studies showed thatheat shock wasnot able to affect ABA content in xylem sap, and also, not able to lead to a decreasein leaf water status, which suggested that the stomatal regulation was neither mediated by ABA norby a hydraulic signal. Heat shock could lead to an increase in xylemsap H_2._2.content, andmoreover, the removal of H_2._2.by catalase could partially recover the stomatal inhibition by xylemsap collected from heat-shocked plants, suggesting that H_2._2.might be able to act as one of theroot signals to control the stomatal movement. Due to the fact that heat-shock and drought areusually two concomitant stresses, the stomatal regulation by heat-shock signal should be ofsignificance for plant response to stresses. The observation for the stomatal regulation in an

关键词： root signal, leaf conductance, heat shock, long-distance, signal transmission, abscisic acid.

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Dating sediments on several lakes inferred from radionuclide profiles

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Journal of Environmental Sciences 1998年第1期10卷 58-65页

作者： Xiang Liang Lake Sediment and Environment Laboratory,Nanjing institute of Geography & Limnology, chinese {2. of Sciences,Nanjing 2.0008,china

In this paper, several sediment cores from three lakes (Gucheng Lake, Dianchi Lake and Dabusopao Lake) in the different regions of china were dated radiometrically by 2.0 Pb, 137 Cs and in Dianchi also by 2.1 Am. The study shows that the profiles of 137 Cs in lake sediment of china generally have 2.4 distinct chronological markers, i.e. the onset of fallout in 1954 and peak fallout in 1963, 1974 and 1986. As many places of the northern hemisphere, the peak fallout in 1963 was the result of the {2. atomic weapons test. But in some areas of china, there may be have one or two other peaks of 137 Cs fallout, one can derive from Chernobyl fallout in 1986 and the other is caused by the nuclear testing fallout in early 1970s. So in these areas, the profiles of 137 Cs can have 2.or 3 peaks as the time markers. 2.1 Am, which is another fallout product from nuclear weapons testing, also provides a useful dating marker in Dianchi. These time markers are of considerable value to confirm 2.0 Pb dates in the three lakes. Despite there are some questions remain concerning the interpretation of these radionuclide records in lake sediments, coupling with 2.0 Pb and 137 Cs (and/or 2.1 Am) is suggested to be a valuable limnological tool for establishing sediment chronologies for the lake sediments in china.

关键词： lake sediment radionuclide dating method.

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CONSISTENCY OF LS ESTIMATOR IN SIMPLE LINEAR EV REGRESSION MODELS

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Acta Mathematica Scientia 2005年第1期25卷 50-58页

作者：刘继学陈希孺 Department of Statistics and Finance University of Science and Technology of china Hefei 230026 China Department of Mathematics Graduate School of chinese academy of Sciences Beijing 100039 China

Consistency of LS estimate of simple linear EV model is studied. It is shown that under some common assumptions of the model, both weak and strong consistency of the estimate are equivalent but it is not so for quadra... 详细信息

关键词： EV model consistency

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Characteristics of nitrogen forms in the southern Huanghai Sea surface sediments

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Acta Oceanologica Sinica 2004年第3期23卷 473-482页

作者： LüXiaoxia SONGJinming LIXuegang YUANHuamao ZHANTianrong LINing GAOXuelu instituteofOceanology ChineseAcademyofSciencesQingdao266071China GraduateSchoolofchineseacademyofSciences Beijing100039China

The distributions of different forms of nitrogen in the surface sediments of the southern Huanghai Sea are different and affected by various factors. The contents of IEF-N, SOEF-N and TN gradually decrease eastward, and those of SAEF-N northward, while those of WAEF-N westward. Around the seaport of the old Huanghe (Yellow) River, the contents of both SOEF-N and TN are the highest. Among all the factors, the content of fine sediment is the predominant factor to affect the distributions of different forms of nitrogen. The contents of IEF-N, SOEF-N, and TN have visibly positive correlation with the content of fine sediments, and the correlative coefficient is 0.68, 0.58 and 0.71 respectively, showing that the contents of the three forms of nitrogen increase with those of fine sediments. The content of WAEF-N is related to that of fine sediments to a certain extent, with a correlative coefficient of 0.35; while the content of SAEF-N is not related to that of fine sediments, showing that the content of SAEF-N is not controlled by fine grain-size fractions of sediments. In addition, the distributions of different forms of nitrogen are also interacted one another, and the contents of IEF-N and SOEF-N are obviously affected by TN, while those of inorganic nitrogen (WAEF-N, SAEF-N and IEF-N) are not affected by SOEF-N and TN obviously, although they are interacted each other.

关键词： nitrogen form characteristics controlling factors southern Huanghai Sea surface sediment

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A Sterically Hindered Zirconocene Complex (1,2.Ph_2._5H_3)_2.rCl_2.Synthesis,Structure and Properties as Olefin Polymerization Catalyst

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chinese Chemical Letters 2000年第7期11卷 641-644页

作者： Fan ZHANG Ying MU Yue Tao ZHANG Cong Xi CHEN Hui Min ZHAI Han HONG(Department of Chemistry, Jilin University, Changchun 13002.institute of Chemistry, chinese {2. of Sciences, beijing 100080) Jilin Univ Dept Chem Changchun 130023 Peoples R China chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

An unbridged zirconocene complex bis(1,2.diphenylcyclopentadienyl)zirconium dichloride [(1,2.Ph2.C5H3)2.rCl2. 1 has been synthesized and structurally characterized. When activated by MAO, 1 produces ultra-high molecular weight polyethylene with high melting transition temperature, as well as atactic oligopropylene with average molecular weight of ~1150 g mol-1.

关键词： Zirconium complex metallocene catalyst olefin polymerization

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