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Kinematics and dynamics of the Mesozoic orogeny and late-orogenic extensional collapse in the Sino-Mongolian border areas

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Science china Earth Sciences 2005年第7期48卷 849-862页

作者： ZHENG Yadong 1 & WANG Tao2.1. key laboratory of Orogenic Belts and Crustal Evolution (Peking University), Ministry of Education, {2. 100871, china 2. institute of Geology, Chinese Academy of Geological Sciences, {2. 100037, china key laboratory of Orogenic Belts and Crustal Evolution (Peking University) Ministry of Education Beijing 100871 China institute of Geology Chinese Academy of Geological Sciences Beijinq 100037 China

The Sino-Mongolian border areas underwent two important tectonic events during Mesozoic time after late Paleozoic orogeny: a late Triassic to earlier Jurassic contractional event that resulted in a large-scale south-vergent thrust during the orogeny and a late Jurassic-earlier Cretaceous extensional event in a north-south direction that formed a metamorphic core complex. The kinematic and dynamic analyses show that the thrust sheet moved southwards with a kinematic vorticity number of ca. -0.10 and sub-horizontal maximum compressive stress axis that belongs to a contraction-thickening shear. The upper plate of the late-orogenic detachment relatively moved in a 165°direction. The average kinematic vorticity in its earlier stage was 0.74 that belongs to simple shear dominated shearing and related to the maximum compressive stress axes dipping at ～66°, while the later average kinematic vorticity was ～0.55°that belongs to pure shear dominated shearing with sub-vertical maximum compressive stress axes. This suggests that the thrusting led to the crust thickened and the lower plate rocks that were originally located in the upper crust depressed through a brittle-ductile transition zone into the lower crust and became warmer. The heated rocks trended to uplift since their increasing volume and decreasing density while the loading of the upper-plate rocks increased due to the structural thickening. Under the combined effect of the loading and the thermal-uplifting, the ductile shear zone in between increased in its component of vertical pure shear. Once its pure-shear component exceeded its simple-shear one the ductile shear zone became an extension-thinned shear zone. This progressive transitional process reflects internal and essential temporal and spatial relationships: the extensional factor nucleated during the crust thickening by thrusting and increase of the extensional factor finally led to late-orogenic collapse.

关键词： Mesozoic thrusting,late-orogenic collapse,kinematic vorticity number,stress state.

BUD2.encoding an S-adenosylmethionine decarboxylase,is required for Arabidopsis growth and development

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Cell Research 2006年第5期16卷 446-456页

作者： Chunmin Ge~(1,2.*) Xia Cui~(1,2.*) Yonghong Wang~1 Yuxin Hu~3 Zhiming Fu~1 Dongfen Zhang~(1,2. Zhukuan Cheng~1 Jiayang Li~1 ~1state key {2. of Plant Genomics and National Center for Plant Gene Research,institute of Genetics and Developmental Biology,Chinese Academy of Sciences,beijing 100101,china ~2.raduate School,Chinese Academy of Sciences,beijing 100101,china ~3institute of Botany,Chinese Academy of Sciences,beijing 100093,china state key {2. of Plant Genomics and National Center for Plant Gene Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China institute of Botany Chinese Academy of Sciences Beijing China

Polyamines are implicated in regulating various developmental processes in plants,but their exact roles and how theygovern these processes still remain *** report here an Arabidopsis bushy and dwarf mutant,bud2.which resultsfrom the complete deletion of one member of the small gene family that encodes S-adenosylmethionine decarboxylases(SAMDCs) necessary for the formation of the indispensable intermediate in the polyamine biosynthetic ***2.plant has enlarged vascular systems in inflorescences,roots,and petioles,and an altered homeostasis *** double mutant of bud2.and samdcl,a knockdown mutant of another SAMDC member,is embryo lethal,demonstrat-ing that SAMDCs are essential for plant *** results suggest that polyamines are required for the normalgrowth and development of higher plants.

关键词： BUD2 polyamines embryogenesis plant architecture Arabidopsis

The refined theory of transversely isotropic piezoelectric rectangular beams

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 473-486页

作者： GAO Yang1 & WANG Minzhong2.1. College of Science, china Agricultural University, beijing 100083, china 2. state key laboratory for Turbulence and Complex Systems and Department of Mechanics and Engi- neering Science, Peking University, beijing 100871, china College of Science China Agricultural University Beijing China state key {2. for Turbulence and Complex Systems and Department of Mechanics and Engineering Science Peking University Beijing China

The problem of deducing one-dimensional theory from two-dimensional theory for a transversely isotropic piezoelectric rectangular beam is investigated. Based on the piezoelasticity theory, the refined theory of piezoelectric beams is derived by using the general solution of transversely isotropic piezoelasticity and Lur'e method without ad hoc assumptions. Based on the refined theory of piezoelectric beams, the exact equations for the beams without transverse surface loadings are derived, which consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beams under transverse loadings are derived directly from the refined beam theory. As a special case, the governing differential equations for transversely isotropic elastic beams are obtained from the corresponding equations of piezoelectric beams. To illustrate the application of the beam theory developed, a uniformly loaded and simply supported piezoelectric beam is examined.

关键词： rectangular beams, the refined theory, piezoelectric, transversely isotropic.

The Construction of Numerical Scheme forHyperbolic Equation and Exact Considerationof Numerical Diffusion and Dispersion

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 156-162页

作者： Qingdong CAI(state key {2. for Turbulence Research, Peking University, {2. 100871, china) state key {2. for Turbulence Research Peking University Beijing 100871 China

A new technique in the formulation of numerical scheme for hyperbolicequation is developed. It is different from the classical FD and FE methods. We begin withthe algebraic equations with some undefined parameters, and get the difference equationthrough Taylor-series expansion. When the parameters in the partial difference equationare defined, the equation is what the scheme will simulate. The numerical example ofthe viscous Burgers equation shows the validity of the scheme. This method deals withthe numerical viscosity and dispersion exactly, giving a preliminary explanation to someproblems that the CFD face now.

关键词： modified equation Taylor expansion consistency truncation error

Progress in interspecies cloning of mammals

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Progress in Natural Science:Materials International 2004年第1期14卷 2-9页

作者： WEN Duancheng, BI Chunming and CHEN Dayuan(state key {2. of Reproductive Biology, institute of zoology, Chinese Academy of Sciences, beijing 100080, china) Chinese Acad Sci Inst Zool State Key Lab Reprod Biol Beijing 100080 Peoples R China

Interspecies mammalian cloning can be achieved by application of two key techniques, i.e. the technique of interspecies nuclear transfer and the technique of interspecies pregnancy. The general principles, problems and possible solutions, as well as the recent advances of interspecies mammalian cloning have been summarized in this review.

关键词： interspecies cloning interspecies nuclear transfer interspecies pregnancy mammals

Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

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Science china Earth Sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2. ZHAO Zhidan1,2. ZHANG Hongfei3, ZHANG Benren3 & CHEN Yuelong2.1. state key {2. of Geological Processes and Mineral Resources, china University of Geosciences, beijing 100083, china 2. School of Earth Science and Mineral Resources, china University of Geosciences, beijing 100083, china 3. Faculty of Earth Sciences, china University of Geosciences, Wuhan 430074, china state key {2. of Geological Processes and Mineral Resources China University of Geosciences Beijing China School of Earth Science and Mineral Resources China University of Geosciences Beijing China Faculty of Earth Sciences China University of Geosciences Wuhan China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.2.). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2.b-Zr/4-Y and Ti/100-Zr-YX3 tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143)Nd/^(144)Nd (0.512.55-0.512.78). Pb isotopes are in the rangeof ^(2.6)Pb/^(2.4)Pb (18.054-2..562., ^(2.7)Pb/^(2.4)Pb (15.537-15.743) and ^(2.8)Pb/^(2.4)Pb(38.068-38.530). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.

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 {2. 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

Post-earthquake assessment of building damage degree using LiDAR data and imagery

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Science china(Technological Sciences) 2008年第S2期51卷 133-143页

作者： LI ManChun1,CHENG Liang1,2.GONG JianYa2.LIU YongXue1,CHEN ZhenJie1,LI FeiXue1,CHEN Gang1,CHEN Dong1 & SONG XiaoGang3 1 Department of Geographic Information Science,Nanjing University,Nanjing 2.0093,china 2.state {2. {2. of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 430079,china 3 state {2. {2. of Earthquake Dynamics,institute of Geology,china Earthquake Administration,beijing 10002.,china Department of Geographic Information Science Nanjing University Nanjing China state key {2. of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan China state key {2. of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing China

Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed *** the launch of the high resolution sensors such as IKONOS and QuickBird,it becomes realistic to identify damages on the scale of individual *** the low accuracy of the results has often led to the use of visual interpretation ***,it is very difficult to estimate the degree of building damage(*** damage,moderate damage,or severe damage) in detail using the existing ***,a novel approach integrating LiDAR data and high resolution optical imagery is proposed for evaluating building damage degree *** approach consists of two steps:3D building model reconstruction and rooftop patch-oriented 3D change ***,a method is proposed for automatically reconstructing 3D building models with precise geometric position and fine details,using pre-earthquake LiDAR data and high resolution ***,focusing on each rooftop patch of the 3D building models,the pre- and post-earthquake LiDAR points belonging to the patch are collected and compared to detect whether it was destroyed or not,and then the degree of building damage can be identified based on the ratio of the destroyed rooftop patches to all rooftop *** novelty of the proposed approach is to detect damages on the scale of building's rooftop patch and realize quantitative estimation of building damage degree.

关键词： post-earthquake assessment building damage degree rooftop patch LiDAR imagery

Principle of small target detection for hyperspectral imagery

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Science china Earth Sciences 2007年第8期50卷 1225-1231页

作者： GENG XiuRui1,2.3 & ZHAO YongChao2.3,4 1 Research Center for Remote Sensing and GIS, Department of Geography, beijing Normal University, beijing 100875,{2. 2.state key laboratory of Remote Sensing Science, Chinese Academy of Sciences, beijing 100101,{2. 3 institute of Erectronics, Chinese Academy of Sciences, beijing 100080,{2. 4 Center for for Assessment and Monitoring of Forest and Environmental Resources and Division of Ecosystem Sciences University of California Berkeley, CA 9472.-3114, USA Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing China state key {2. of Remote Sensing Science Chinese Academy of Sciences Beijing China institute of Erectronics Chinese Academy of Sciences Beijing China Center for for Assessment and Monitoring of Forest and Environmental Resources and Division of Ecosystem Sciences University of California Berkeley USA

This paper generalizes the progress of algorithms in small target detection for hyperspectral imaging, and finds that whitening the image is the key point of many methods in small target detection. An al-gorithm is presented to detect desired targets by converting large targets into small ones based on the weighted sample autocorrelation matrix.

关键词： hyperspectral whiten target detection