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Relationships between tree-ring width index and NDVI of grassland in Delingha

Chinese Science Bulletin 2006年第9期51卷 1106-1114页

作者： HE Jicheng1,3.& SHAO Xuemei1,21. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china 2. Institute of Tibetan Plateau Research, Chinese Academy of Sciences, beijing 100085, china 3. Graduate School of Chinese Academy of Sciences, beijing 10003., china Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate School of Chinese Academy of Sciences Beijing China Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

Using five well-replicated Qilian juniper (Sabina przewalskii Kom.) tree-ring width index se- ries, monthly normalized difference vegetation index (NDVI) of grassland, and climatic data from 1982 to 2001, the relationships between tree-ring width index, NDVI of grassland, and climatic data were analyzed firstly. Then, the relationship between tree-ring width index and NDVI of grassland was explored. The re- sults showed that: (1) Temperature and precipitation in June influenced tree-ring width index and NDVI of grassland deeply in Delingha. (2) There were sig- nificant relationships between five tree-ring width index series (DLH1-DLH5) and monthly NDVI of grassland from June to September, with the most significant relationship being between tree-ring width index series and NDVI of grassland in August. (3. The PC1 (the first principal component derived from DLH1-DLH5 series) exhibited good agreement with monthly NDVI of grassland in the grass growth sea- son (from June to September) and the averaged NDVI in the growth season, which was attributed to their common responses to water-supply limit in Delingha. This study may allow an increase in studying the past dynamics of grassland in Delingha in that the variation of grassland NDVI during the last millennium has been reconstructed from PC1.

关键词：圆柏祁连山 NDVI 草原年轮宽度指数

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Geographical Agglomeration of Chinese Manufacturing Industries

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中国人口·资源与环境：英文版 2007年第2期5卷 3-11页

作者： Zhang Hua 1, 2, Zheng Wei3.1. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china 2. Graduate School of the Chinese Academy of Sciences, beijing 10003., china 3. School of Geography, beijing Normal University, beijing 100875, china Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China School of Geography Beijing Normal University Beijing 100875 China

Based on the plant level data from the First National Census of Basic Units, the Second National Census of Basic Units, and the First National Economic Census of china, this paper ex- amines the geographical agglomeration of Chinese manufacturing industries at a more disaggregated level both by industrial classi-fication and spatial unit analysis. Applying the agglomeration index proposed by Maurel and Sedillot, studies show that the most agglomerated industries are resource-intensive, and capital and technology intensive while industries demanding localized inputs or serving localized markets or favored by local governments are fairly dispersed. The more disaggregated industries are more spa- tially agglomerated. At the finer spatial scale, industries are more dispersed. Results indicate that within-county spillovers are stronger than nearby-county spillovers, and within-prefecture spillovers are stronger than nearby prefecture spillovers. Local- ized spillovers are still quite substantial at a range beyond that of counties. Comparing the agglomeration index of Chinese manu- facturing industries in 1996, 2001 and 2004, agglomeration seems to be a general tendency. Results also indicate that some industries have experienced remarkable changes in their levels of agglom- eration in the period 1996–2004.

关键词： industrial agglomeration manufacturing industries the MS index

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Quantitative exploration of the mechanisms behind the urban thermal environment in beijing

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Progress in Natural Science:Materials International 2009年第12期19卷 1757-1763页

作者： Dan Meng,Xiaojuan Li~*,Wenji Zhao,Huili Gong Key Laboratory of 3. Information Acquisition and Application,Ministry of Education,Key Laboratory of Resource,Environment and GIS in beijing,College of Resources Environment and Tourism,Capital Normal University,beijing 100048,china [a]Key Laboratory of 3. Information Acquisition and Application Ministry of Education Key Laboratory of Resource Environment and GIS in Beijing College of Resources Environment and Tourism Capital Normal University Beijing 100048 China

The driving mechanism behind the formation of urban thermal environments is the result of a combination of *** was chosen as the study area,and the technique of principal component analysis(PCA) was used.A spatial regression method was also applied for quantitative explanation of the thermal *** Landsat thematic mapper images were used to quantify potential causing *** the eigenvalues of each factor and its relationship with land surface temperature,the first three principal components(PCs) are regarded as the main causative factors explaining the mechanism as independent *** first three PCs mainly reflect urban construction,road density and the normalized difference vegetation index(NDVI),*** least squares,spatial lag and spatial error regression models were established separately for the relationships between the first three PCs and land surface temperature(LST).In the two spatial regression models,z-statistics for both the spatial lag parameter(ρ) and spatial residual parameter(λ) are significant,indicating the necessity of using spatial regression to replace the OLS regression model,as well as indicating that the spatial error regression model is superior to the spatial lag regression ***,the normalized difference built-up index(NDBI) and road density are the most significant positive contributions to LST.

关键词： Urban thermal environment Drive mechanism Spatial regression beijing

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B_c Meson Studies

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高能物理与核物理 2002年第Z1期26卷 1-10页

作者： CHANG Chao-Hsi (Institute of Theoretical Physics, Chinese Academy of Sciences, beijing 100080, china) Inst. of Theor. Phys. Chinese Acad. of Sci. Beijing 100080 China

Our studies on the meson Bc arc briefly *** decays of the meson Bc to a P-wave charmonium Xc or hc are reported comparatively precisely because they are fresh

关键词：高能物理核物理增刊张肇西 B_c Meson Studies Rev

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SHRIMP zircon U-Pb geochronology of early Mesozoic felsic igneous rocks from the southern Lancangjiang and its tectonic implications

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Science china Earth Sciences 2006年第10期49卷 1032-1042页

作者： PENG Touping1,2, WANG Yuejun1, FAN Weiming1, LIU Dunyi3. SHI Yuruo3.& MIAO Laicheng4 1. Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, china 2. Graduate University of Chinese Academy of Sciences, beijing 10003., china 3. SHRIMP isotope Laboratory, Chinese Academy of Geological Sciences, beijing 10003., china 4. Institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 100029, china Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Graduate University of Chinese Academy of Sciences Beijing China SHRIMP isotope Laboratory Chinese Academy of Geological Sciences Beijing China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

The SHRIMP zircon U-Pb geochronology of three typical samples, including two monzo nitic granites from the Lincang batholith and a rhyolite from the Manghuai Formation are presented in the southern Lancangjiang, western Yunnan Province. The analyses of zircons for the biotite monzonitic granites from the northern (02DX-13.) and southern (20JH-10) Lincang batholith show the single and tight clusters on the concordia, and yield the weighted mean 206Pb/23.U ages of 229.4 ± 3.0 Ma and 23..4 ± 3.6 Ma, respectively, representing the crystallized ages of these granites. The zircons for the rhyolitic sample (02DX-95) from the Manghuai Formation give a weighted mean 206Pb/23.U age of 23..0 ± 5.0 Ma. These data suggest that the igneous rocks from the Lincang granitic batholith and Manghuai Formation have a similar crystallized age. In combination with other data, it is inferred that both were generated at a narrow age span (~23. Ma) and were originated from the postcollisional tectonic regime. An early Proterozoic 206Pb/23.U apparent age of 1977±44 Ma is additionally obtained from one zircon from the biotite monzonitic granite (southern Lincang batholith), indicative of devel- opment of the early Proterozoic Yangtze basement in the region. These precisely geochronological data provide important constraints on better understanding the Paleozoic tectonic evolution of the Tethys, western Yunnan Province.

关键词： SHRIMP zircon U-Pb dating, Middle Triassic, Lincang granitic batholith, Manghuai Formation rhyolite, southern Lancangjiang.

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New adaptive quasi-sliding mode control for nonlinear discrete-time systems

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Journal of Systems Engineering and Electronics 2008年第1期19卷 154-160页

作者： Wang Weihong1,2 & Hou Zhongsheng3.1. School of Tra?c and Transportation, beijing Jiaotong Univ., beijing 100044, P. R. china 2. Dept. of Automation, Taiyuan Univ. of Science & Technology, Taiyuan 03.024, P. R. china 3. Advanced Control Systems Lab, School of Electronics and Information Engineering, beijing Jiaotong Univ., beijing 100044, P. R. china [a]School of Traffic and Transportation Beijing Jiaotong Univ. Beijing 100044 P. R. China [b]Dept. of Automation Taiyuan Univ. of Science & Technology Taiyuan 030024 P. R. China [c]Advanced Control Systems Lab School of Electronics and Information Engineering Beijing Jiaotong Univ. Beijing 100044 P. R. China

A new adaptive quasi-sliding mode control algorithm is developed for a class of nonlinear discrete-time systems, which is especially useful for nonlinear systems with vaguely known dynamics. This design is model-free, and is based directly on pseudo-partial-derivatives derived on-line from the input and output information of the system using an improved recursive projection type of identification algorithm. The theoretical analysis and simulation results show that the adaptive quasi-sliding mode control system is stable and convergent.

关键词： quasi-sliding mode control adaptive control model-free control pseudo-partial-derivative

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From quantum spectra to classical orbits: Varying rectangular billiards

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Progress in Natural Science:Materials International 2008年第8期18卷 927-930页

作者： Jun Lu * Department of Foundational Science, beijing Union University, beijing 100101, china Institute of Theoretical Physics, Chinese Academy of Sciences,{3., china Department of Foundational Science Beijing Union University Beijing 100101 China Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100080 China

The quantum-spectrum function is introduced by means of the eigenvalues and the eigenfunctions in the system of varying rectangular billiards. It is found that the Fourier transform of the quantum-spectrum function corresponds with the classical orbits in the system. These results give new evidence about the classical-quantum correspondence.

关键词： Quantum spectrum Classical-quantum correspondence Semiclassical physics

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The precipitation and effect of nano nitrides in HSLC steel

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Science china(Technological Sciences) 2008年第7期51卷 989-998页

作者： FU Jie1, LIU YangChun1,2 & WU HuaJie1,3.1 School of Metallurgical and Ecological Engineering, University of Science and Technology beijing, beijing 100083. china 2 Shougang Technology Research Institute, Shougang (Group) Corporation, beijing 100041, china 3.Metallurgical Engineering Research Institute, University of Science and Technology beijing, beijing 100083. china 1. School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China 2. Shougang Technology Research Institute Shougang (Group) Corporation Beijing 100041 China 3. Metallurgical Engineering Research Institute University of Science and Technology Beijing Beijing 100083 China

The existing forms of N and Al in HSLC (high strength low carbon) steel produced by TSCR (thin slab casting and rolling process), the precipitation thermodynamics and kinetics of AlN, and its effects on structure and mechanical property are studied. The experimental results show that only a small quantity of nitrogen is com- bined into AlN in HSLC steel produced by TSCR and most of the nitrogen in steel is still free nitrogen. Aluminum-nitride is mainly precipitated during the period of slow air cooling after coiling, but not during rolling and water cooling. The acid-soluble aluminum has no obvious effect on the grain size and mechanical property of HSLC steel produced by TSCR whose acid-soluble aluminum content is 0.005%―0.043.. The precipitation of AlN is not the main cause of grain refinement of HSLC steel produced by TSCR, nor is AlN the dominating precipitate that has precipitation strengthening effect. The nano nitrides are not pure AlN, but have complex compositions.

关键词： thin slab casting and rolling high strength low carbon steel AlN nano nitride precipitation strengthening

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Corrosion and electrochemical behavior of as-cast Mg-5Y-7Gd-1Nd-0.5Zr magnesium alloys in 5%NaCl aqueous solution

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Progress in Natural Science:Materials International 2011年第4期21卷 314-321页

作者： Xin ZHANG~(1,2,3.,Kui ZHANG~1,Xing-gang LI~1,Cong WANG~4,Hong-wei LI~(2,3.,Chang-shun WANG~(2,3.,Xia DENG~1 1.State Key Laboratory for Fabrication and Processing of Nonferrous Metals, beijing General Research Institute for Nonferrous Metals,beijing 100088,china 2.beijing Engineering Research Center for Advanced Manufacturing and Evaluation of Special Vehicle Parts,beijing 100072,china 3.Institute of Technology,beijing North Vehicle Group Corporation,beijing 100072,china 4.Fengtai Military Representative Office,beijing Military Representative Office,PLA,beijing 100072,china [a] State Key Laboratory for Fabrication and Processing of Nonferrous Metals Beijing General Research Institute for Nonferrous Metals Beijing 100088 China [b] beijing Engineering Research Center for Advanced Manufacturing and Evaluation of Special Vehicle Parts Beijing 100072 China [c] Institute of Technology Beijing North Vehicle Group Corporation Beijing 100072 China [d] Fengtai Military Representative Office Beijing Military Representative Office PLA Beijing 100072 China

The corrosion mechanism of the as-cast Mg-5Y-7Gd-1Nd-0.5Zr magnesium alloy immersed in 5%NaCl aqueous solution was investigated by electrochemical test and *** electrochemical results indicate that the corrosion resistance of Mg-5Y-7Gd-1Nd-0.5Zr alloy in 5%NaCl aqueous solution gradually deteriorates with immersion time increasing from 2 h,24 h,60 h,to 108 h,which is consistent with the SEM observation of corrosion *** Cl-anion leads to the initiation and development of the corrosion pits,and Mg-5Y-7Gd-1Nd-0.5Zr alloy exhibits filiform type of attack under significant anodic control of magnesium solution *** corrosion potential becomes noble with increasing immersion time.

关键词： magnesium alloys Mg-5Y-7Gd-1Nd-0.5Zr corrosion electrochemical behavior

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Distribution,formation and evolution of sand ridges on the East china Sea shelf

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Science china(Technological Sciences) 2010年第3期53卷 822-828页

作者： ZHAO RenBao 1,2,SUN HaiTao 3.WU YaSheng 3.&ZHAO ChuanFeng 1,2 1MOE Key Laboratory of Petroleum Engineering,china University of Petroleum,beijing 102249,china 2 Enhanced Oil Recovering Research Center,china University of Petroleum,beijing 102249,china 3.aculty of Natural Resource&Information Technology,china University of Petroleum,beijing 102249,china 1. MOE Key Laboratory of Petroleum Engineering China University of Petroleum Beijing 102249 China2. Enhanced Oil Recovering Research Center China University of Petroleum Beijing 102249 China3. Faculty of Natural Resource & Information Technology China University of Petroleum Beijing 102249 China

Influence of CO2 corrosion on reservoir mineralogical composition,pore structure and their mechanical characteristics was studied using XRD,SEM,rock tri-axial machine and core flow experimental *** was found that the corrosion effect was mainly attributed to rock texture and structure,fluid composition and external dynamical conditions in the experimental *** cores with bedding structures,their bedding surfaces were the preferential corrosion regions,because micro-cracks would evolve at these surfaces in the pressure-releasing ***,for cores with massive structures controlled by stable water environment,the CO2 corrosion would result in pore enlargement and secondary pore *** gas velocity from outlet showed sharp increase in the injection process of CO2-H2O *** could be explained by two changes caused by *** was the opening and closure of *** other was particle *** the corrosion time increased,both tensile strength and compressive strength decreased,which confirmed decrease of cementation *** should also be noted that permeability increase and micro-cracks generation would pose damage to the capacity of CO2 geological storage.

关键词： carbon dioxide geological storage mineralization enhanced oil recovery corrosion

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