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Science china(Physics,Mechanics & Astronomy) 2008年第4期51卷 356-364页

作者： WEN Ping,ZHAO ZuoFeng & WANG WeiHua institute of Physics,chinese {2. of sciences,beijing 100080,china institute of Physics Chinese Academy of Sciences Beijing China

Enthalpy recovery is not only an important characteristic of physical aging of glass,but also a good tool to investigate the physical aging. Using differential scanning calorimeter (DSC),the enthalpy recovery of Zr46.75Ti8.2.Cu7.5Ni10Be2..5 bulk metallic glass (BMG) was studied. The typical characteristics of enthalpy recovery of glass including the sub-Tg peak and ‘overshot’ were found in BMG. The evolution of the sub-Tg peak and ‘overshot’ were described by the free volume theory and Hodge’s model,respectively. It was found that the former failed to describe the enthalpy recovery in the BMG,while the latter could give a qualitative explanation. In com-bination with the dynamics in the BMG,the origin of the enthalpy recovery in the BMG was discussed. The results show that BMGs are an ideal material to investi-gate the physical aging. The further understanding of physical aging of BMGs is useful to clarify the nature of glass and improve the application and device of new types of BMGs.

关键词： bulk metallic glass enthalpy recovery physical aging

Multi-dimensional versions of a formula of Popoviciu

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Science china Mathematics 2007年第2期50卷 285-291页

作者： Zhi-qiang XU institute of Computational Math and Sci/Eng computing, {2. of Mathematics and Systems Science, chinese academy of sciences, beijing 100080, china institute of Computational Math and Sci/Eng computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China

In this paper, an explicit formulation for multivariate truncated power functions of degree one is given firstly. Based on multivariate truncated power functions of degree one, a formulation is presented which counts the number of non-negative integer solutions of s×(s + 1) linear Diophantine equations and it can be considered as a multi-dimensional versions of the formula counting the number of non-negative integer solutions of ax + by = n which is given by Popoviciu in 1953.

关键词： multivariate splines discrete truncated power linear Diophantine equations 41A15 05A15

GAUSS-SEIDEL-TYPE MULTIGRID METHODS

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Journal of Computational Mathematics 2003年第4期21卷 421-434页

作者： Zhao-hui Huang Qian-shun Chang (academy of Mathematics and System sciences,{2., beijing 100080, china) academy of Mathematics and System sciences Chinese Academy of Sciences 北京 100080

By making use of the Gauss-Seidel-type solution method, the procedure for computing the interpolation operator of multigrid methods is simplified. This leads to a saving of computational time. Three new kinds of interpolation formulae are obtained by adopting different approximate methods, to try to enhance the accuracy of the interpolatory operator. A theoretical study proves the two-level convergence of these Gauss-Seidel-type MG methods. A series of numerical experiments is presented to evaluate the relative performance of the methods with respect to the convergence factor, CPU-time(for one V-cycle and the setup phase) and computational complexity.

关键词： Multigrid methods Gauss-Seidel solution Interpolation formula Convergence.

Geochemical characteristics of rare earth elements in Wuhan section of the Yangtze River

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Journal of Environmental sciences 1995年第1期7卷 44-51页

作者： Wang Lijun Zhang Shen Zhang Chaosheng(institute of Geography,chinese {2. of sciences,beijing 100101,china)Li Xiuxia(institute of High Energy Physics,chinese {2. of sciences,beijing 100080,china) Inst of Geog Chinese Academy of Sciences Beijing China China

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关键词： geochemical characteristics rare earth elements Yangtze River

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,{2., china 中科院化学所北京 100080 中科院化学所北京

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,{2., 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.

Plus cupping degrees do not form an ideal

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Science in china(Series F) 2004年第5期47卷 635-654页

作者： LI Angsheng1,2.& ZHAO Yicheng1 1. institute of Software,chinese {2. of sciences,beijing 100080,china 2. School of Information sciences,beijing Normal University,beijing 100871,china institute of Software Chinese Academy of Sciences Beijing China School of Information sciences Beijing Normal University Beijing China

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0 详细信息

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0

关键词： computably enumerable set Turing degree definability.

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,{2., 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,{2., 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

A shortest path algorithm for moving objects in spatial network databases

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Progress in Natural Science:Materials International 2008年第7期18卷 893-899页

作者： Xiaolan Yin a,b,*, Zhiming Ding c, Jing Li a a technology Center of Software Engineering, institute of Software, {2. academy of Science, P.O. Box 8718, beijing 100080, china b Graduate University, chinese academy of sciences, beijing 100049, china c technology Center of Basic Software, institute of Software, chinese academy of sciences, beijing 100080, china technology Center of Software Engineering Institute of Software Chinese Academy of Science P.O. Box 8718 Beijing 100080 China Graduate University Chinese Academy of Sciences Beijing 100049 China technology Center of Basic Software Institute of Software Chinese Academy of Sciences Beijing 100080 China

One of the most important kinds of queries in Spatial Network Databases (SNDB) to support location-based services (LBS) is the shortest path query. Given an object in a network, e.g. a location of a car on a road network, and a set of objects of interests, e.g. hotels, gas station, and car, the shortest path query returns the shortest path from the query object to interested objects. The studies of shortest path query have two kinds of ways, online processing and preprocessing. The studies of preprocessing suppose that the interest objects are static. This paper proposes a shortest path algorithm with a set of index structures to support the situation of moving objects. This algorithm can transform a dynamic problem to a static problem. In this paper we focus on road networks. However, our algorithms do not use any domain specific information, and therefore can be applied to any network. This algorithm’s complexity is O(klog2.), and traditional Dijkstra’s complexity is O((i + k)2..

关键词： Moving object Spatial network databases Shortest path index Shortest path