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Linear relationship between the interdecadal and interannual variabilities of North china rainfall in rainy season

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chinese Science Bulletin 2003年第10期48卷 1040-1044页

作者： LU Riyu Institute of Atmospheric Physics, chinese academy of Sciences, beijing {3., china Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100080 China

Interdecadal and interannual timescales are dominant in the North china rainfall in rainy season (July and August). On the interdecadal timescale, the North china rainfall exhibited an abrupt decrease at the end of 1970s. In this study, we examined the effect of this abrupt rainfall decrease on the association between rainfall and circulation on the interannual timescale, and found that the interdecadal variation does not change the physical mechanism responsible for the interannual variation of North china rainfall. There is a linear relationship between the interdecadal and interannual variabilities of North china rainfall in rainy season.

关键词：线性关系中国北部降雨量大气环流

Numerical Calculation of a Standing Soliton

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Communications in Nonlinear Science and Numerical Simulation 1999年第3期4卷 3-5页

作者： Xianchu ZHOU and Yi RUI(LNM Institute of Mechanics, chinese academy of Sciences, beijing {3., china) LNM Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

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关键词： standing soliton cubic Schrodinger equation numerical simulation

SYNTHESIS OF POLY(ETHYLENE TEREPHTHALATE)-POLYCAPROLACTONE BLOCK COPOLYMER BY DIRECT COPOLYMERIZATION

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chinese Journal of Polymer Science 1999年第3期17卷 231-235页

作者： Shen-guo Wang Kai Tang Institute of Chemistry, chinese academy of Sciences, beijing {3., china chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

Po ly(ethylene terephthalate)-polycaprolactone block copolymer (PCL-b-PET) is a polyester with improved biodegradability. In the present paper, a new direct copolymerization method of epsilon-caprolactone (epsilon-CL) and bishydroxyethylene terephthalate (BHET) in the presence of Ti(OBu)(4) was proposed for the synthesis of PCL-b-PET. The PCL-b-PET copolymer was characterized by IR, GPC and H-1-NMR techniques, and the effects of synthesis conditions, such as temperature, reaction time and concentration of catalyst on the copolymerization were discussed.

关键词： poly(ethylene terephthalate)-polycaprolactone block copolymer direct copolymerization biodegradable polymer

Asymptotic behavior of the divergence on loop spaces over a compact Riemannian manifold

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chinese Science Bulletin 1998年第4期43卷 272-274页

作者： LI Xiangdong Probability Laboratory, Institute of Applied Mathematics, chinese academy of Sciences, beijing {3., china Probability Laboratory Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

The asymptotic behavior of the divergence on loop space is studied over a compact Riemannian manifold via quasi_sure analysis. A Sobolev estimate plays a crucial role.

关键词： divergence exponential integrability Sobolev estimate.

Application of asymptotic waveform approximation technique to hybrid FE/BI method for 3. scattering

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Science in china(Series F) 2007年第1期50卷 124-134页

作者： PENG Zhen1,2,3.& SHENG XinQing2 1 Institute of Electronics, chinese academy of Sciences, beijing {3., china 2 Department of Electronic Engineering, beijing Institute of Technology, beijing 100081, china 3.Graduated University of chinese academy of Sciences, beijing 10003., china 1. Institute of Electronics Chinese Academy of Sciences Beijing 100080 China 2. Department of Electronic Engineering Beijing Institute of Technology Beijing 100081 China 3. Graduated University of chinese academy of Sciences Beijing 100039 China

The asymptotic waveform evaluation （AWE） technique is a rational function approximation method in computational mathemetics, which is used in many appllcations in computational electromagnetlca. In this paper, the performance of the AWE technique in conjunction with hybrid finite element/boundary integral （FE/BI） method is firstly Inveetlgeted. The formuletlon of the AWE applied in hybrid FE/BI method is given in detail. The characteristic implementation of the application of the AWE to the hybrid FE/BI method is discussed. Numarlcel results demonstrate that the AWE technique can greatly speed up the hybrid FE/BI method to acquire wide-band and wide-angle backecatter radar-cross-section （RCS） by complex targets.

关键词： hybrid FE/BI AWE electromagnetic scattering RCS

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.

Quasi-Homeomorphisms and Measures of Finite Energy Integrals of Generalized Dirichlet Forms

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Acta Mathematica Sinica,English Series 2000年第2期16卷 325-336页

作者： Wei Sun Institute of Applied Mathematics,chinese academy of Sciences,beijing,{3.,P.R.china Institute of Applied Mathematics Chinese Academy of Sciences Beijing 100080 P. R. China

We introduce the quasi-homeomorphisms of generalized Dirichlet forms and prove that any quasi-regular generalized Dirichlet form is quasi-homeomorphic to a semi-regular generalized Dirichlet form. Moreover. we apply this quasi-homeomorphism method to study the measures of finite energy integrals of generalized Dirichlet forms. We show that any 1-coexcessive function which is dominated by a function in is associated with a measure of finite energy integral. Consequently, we prove that a Borel set B is-exceptional if and only if μ(B)=0 for any measure μ of finite energy integral.

关键词： Generalized Dirichlet form Quasi-homeomorphism Measure of finite energy integral

Hyperbolic geometry with geometric algebra

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chinese Science Bulletin 1997年第3期42卷 262-263页

作者： LI Hong boInstitute of Systems Science, chinese academy of Sciences, beijing {3., china Institute of Systems Science Chinese Academy of Sciences Beijing China

WE use the geometric algebra in refs. [1, 2] to study hyperbolic geometry. The n-dimensional hyperbolic space Hn is taken to be the unit sphere of G1 (I-n,1) with antipodal points identified. We study typically H2: the dualities between generalized point and generalized line, between generalized triangle and imaginary triangle; convex generalized triangles; Lorentz transformations; generalized circles and double-cycles, etc. Below we list some of the results.

关键词： line Hyperbolic geometry with geometric algebra

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(r,k)-catching code

chinese Science Bulletin 1998年第10期43卷 812-815页

作者： LI Anping Institute of Applied Mathematics, chinese academy of Sciences, beijing {3., china Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

A collection of r_words on an alphabet of n letters is called (r,k)_catching code if for every r_word w there is one selected member v such that v coincides with w in at least k places. How large is the smallest size of the (r,k)_catching code and how to find the minimal (r,k)_\%catching code? Some methods are advanced to construct such codes.

关键词： catching code.