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The boundary of palaearctic and oriental realms in western china

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Progress in Natural Science:Materials International 2008年第7期18卷 833-841页

作者： Ling Chen a,b,c, Yanling Songd,*, Shufang Xu e a Northwest Institute of Plateau Biology, chinese academy of sciences, Xining 810001, china b Graduate University of the chinese academy of sciences, beijing 100039, china c National Science Foundation of china, beijing 100085, china d Institute of Zoology, chinese academy of sciences, beijing 100101, china e beijing academy of Agriculture and Forestry sciences, beijing 100097, china Northwest Institute of Plateau Biology Chinese Academy of Sciences Xining 810001 China Graduate University of the chinese academy of sciences Beijing 100039 China National Science Foundation of china Beijing 100085 China Institute of Zoology Chinese Academy of Sciences Beijing 100101 China beijing academy of Agriculture and Forestry sciences Beijing 100097 China

In the world-wide zoogeographic division, there has been no consentaneous understanding about the delimitation between palaearctic and oriental realms in western china. In this study, we will discuss the division based on amphibian distribution in Shaanxi, Gansu, Sichuan, Yunnan, and Tibet according to species coefficient similarity between each zoogeographic province. The results show that the northern border lies from Qinling Mountains–Feng Xian (Shaanxi)–Debu (Gansu)–Aba (Sichuan)–Batang–Bomi (Tibet), to Linzhi districts, and the southern border is from Taibai–Feng Xian in Shaanxi–Wen Xian (Gansu)–Songpan–Kangding–Daocheng (Sichuan), to Zhongdian–Gongshan in Yunnan, and westward to Motuo and Bomi district in Tibet.

关键词： Amphibian Zoogeography Palaearctic Oriental Hengduan Mt.

The Constrained Solutions of Two Matrix Equations

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Acta Mathematica Sinica,English Series 2002年第4期18卷 671-678页

作者： An Ping LIAO Zhong Zhi BAI Department of mathematics. Hunan University. Changshu, 410082. P. R. china Department of mathematics and Information Science, Changsha University, Changsha 410003. P. R. china academy of mathematics and system. sciences. chinese academy of sciences. beijing 100080. P. R. china State Key Laboratory of Scientific/Engineering Computing. chinese academy of sciences. Institute of Computational mathematics and Scientific/Engineering Computing. academy of mathematics and system sciences. chinese academy of sciences. P. O. Box 2719. beijing 100080. P. R. china Department of mathematics Hunan University Changsha 410082 P. R. China Department of mathematics and Information sciences Changsha University Changsha 410003 P. R. China academy of mathematics and system sciences Chinese Academy of Sciences Beijing 100080 P. R. China State Key Laboratory of Scientific/Engineering Computing Chinese Academy of Sciences Institue of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and System Sciences Chinese Academy of Sciences 2719 Beijing 100080 P. R. China

We study the symmetric positive semidefinite solution of the matrix equation AX_1A^T + BX_2B^T=C. where A is a given real m×n matrix. B is a given real m×p matrix, and C is a given real m×m matrix, with m, n, p positive integers: and the bisymmetric positive semidefinite solution of the matrix equation D^T XD=C, where D is a given real n×m matrix. C is a given real m×m matrix, with m. n positive integers. By making use of the generalized singular value decomposition, we derive general analytic formulae, and present necessary and sufficient conditions for guaranteeing the existence of these solutions.

关键词： Matrix equation Symmetric positive semidefinite matrix Bisymmetric positive semidefinite matrix

The gravity wave instability induced by photochemistry in summer polar mesopause region

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chinese Science Bulletin 2000年第3期45卷 267-272页

作者： Center for Space Science and Applied Research, chinese academy of sciences, beijing 100080, china Laboratory of Numeric Study of Heliospheric Physics, chinese academy of sciences, beijing 100080, china Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric Physics Chinese Academy of Sciences Beijing China

The effect of diabatic process due to the photochemical heating and cooling on the gravity wave propagation in middle atmosphere is studied. A linear gravity wave model which considers the diabatic process is established. The unstable region and the growth rate of the gravity wave caused by photochemistry are calculated. And the comparison between the model and the adiabatic gravity wave theory of pure dynamics is made. The results indicate that the photochemical heating process can induce the instability of gravity wave at mesopause. The intensity of the instability becomes stronger as the temperature decreases. The temperature feature and the altitude characteristics of the instability are consistent with the observation. Therefore, the instability of the gravity wave induced by photochemistry may be an important mechanism in polar mesopause region in summer.

关键词： photochemistry instability gravity wave growth rate.

ERGODICITY OF LINEAR SPDE DRIVEN BY LVY NOISE

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Journal of systems Science & Complexity 2010年第1期23卷 137-152页

作者： Zhao DONG Yingchao XIE Institute of Applied mathematics Academy of Mathematics and Systems Sciences Chinese Academy of Sciences Beijing 100190 China Department of mathematics Xuzhou Normal University Xuzhou 221116 China.

This paper discusses the ergodicity of a linear stochastic partial differential equation driven by Levy noise.

关键词： Ergodicity invariant measure L^vy noise linear SPDE.

Reducibility of hyperplane arrangements

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Science china mathematics 2007年第5期50卷 689-697页

作者： Guang-feng JIANG & Jian-ming YU Department of mathematics, beijing University of Chemical Technology, beijing 100029, china academy of mathematics and systems Science, chinese academy of sciences, beijing 100080, china 1. Department of mathematics Beijing University of Chemical Technology Beijing 100029 China 2. academy of mathematics and systems Science Chinese Academy of Sciences Beijing 100080 China

Certain problems on reducibility of central hyperplane arrangements are settled. Firstly, a necessary and sufficient condition on reducibility is obtained. More precisely, it is proved that the number of irreducible components of a central hyperplane arrangement equals the dimension of the space consisting of the logarithmic derivations of the arrangement with degree zero or one. Secondly, it is proved that the decomposition of an arrangement into a direct sum of its irreducible components is unique up to an isomorphism of the ambient space. Thirdly, an effective algorithm for determining the number of irreducible components and decomposing an arrangement into a direct sum of its irreducible components is offered. This algorithm can decide whether an arrangement is reducible, and if it is the case, what the defining equations of irreducible components are.

关键词： hyperplane arrangement irreducible component logarithmic derivation 32S22 14N20

Influence of curved interfaces of phase change on the radial segregation of crystal growth

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chinese Science Bulletin 1997年第7期42卷 601-605页

作者： HU WenruiInstitute of Mechanics, chinese academy of sciences, beijing 100080, china WASEDA UNIV DEPT APPL CHEMTOKYO 169JAPAN

THE radial uniformity of components is an important parameter for crystal growth of a semiconductor of binary alloy. Radial segregation may be influenced by many factors, such as the convection, curved solidification ... 详细信息

关键词： microgravity science crystal growth diffusion process.

ORDER RESULTS FOR ALGEBRAICALLY STABLEMONO-IMPLICIT RUNGE-KUTTA METHODS

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Journal of Computational mathematics 1999年第6期17卷 639-644页

作者： Ai-guo Xiao(1. Department of mathematics, Xiangtan University, Xiangtan 411105, china2. ICMSEC, chinese academy of sciences, beijing 10080, china) Xiangtan Univ Dept Math Poona 411005 Maharashtra India chinese Acad Sci ICMSEC Beijing 100080 Peoples R China

It is well known that mono-implicit Runge-Kutta methods have been applied in the efficient numerical solution of initial or boundary value problems of ordinary differential equations. Burrage (1994) has shown that the order of an s-stage monoimplicit Runge-Kutta method is at most s+1 and the stage order is at most 3. In this paper, it is shown that the order of an s-stage mono-implicit Runge-Kutta method being algebraically stable is at most min((s) over tilde, 4), and the stage order together with the optimal B-convergence order is at most min(s, 2), where [GRAPHICS]

关键词： ordinary differential equations mono-implicit Runge-Kutta methods order algebraical stability

Applications of URANS on predicting unsteady turbulent separated flows

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Acta Mechanica Sinica 2009年第3期25卷 319-324页

作者： Jinglei Xu Huiyang Ma Department of Physics, Graduate University of the chinese academy of sciences, 100049 beijing, china Department of Physics Graduate University of the Chinese Academy of Sciences 100049 Beijing China

Accurate prediction of unsteady separated turbulent flows remains one of the toughest tasks and a practi cal challenge for turbulence modeling. In this paper, a 2D flow past a circular cylinder at Reynolds number 3,900 is numerically investigated by using the technique of unsteady RANS （URANS）. Some typical linear and nonlinear eddy viscosity turbulence models （LEVM and NLEVM） and a quadratic explicit algebraic stress model （EASM） are evaluated. Numerical results have shown that a high-performance cubic NLEVM, such as CLS, are superior to the others in simulating turbulent separated flows with unsteady vortex shedding.

关键词： URANS Nonlinear eddy viscosity turbulencemodel ,Separated flows Circular cylinder

Recent beijing Spectroscopy (BES) results

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Science china(Physics,Mechanics & Astronomy) 2008年第6期51卷 567-576页

作者： LI WeiGuo Institute of High Energy Physics, chinese academy of sciences, beijing 100049, china 1. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

Recent experimental results from beijing Spectroscopy (BES) are reviewed, including the hadron spectroscopy from J/ψ decays, and a number of new states are found or confirmed, including σ, κ, X(1835), ωφ threshold enhancement in J/ψ→γωφ, a broad resonance in J/ψ→K + K ? π 0, decay studies of ψ(2S) and χ CJ , as well as the results of ψ(3770) non-D $ \bar D $ decays. The current status of BEPCII/BESIII, the major upgrade of BEPC/BESII, is also reported.

关键词： beijing Spectroscopy hadron spectroscopy charm physics BEPCII