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Anisotropic effect on the vibronic reduction factors

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Chinese Science Bulletin 2006年第21期51卷 2553-2558页

作者： QIU Qing-chun1.2.& QIAO Fen1.2.1. department of Physics and IT, Medical College,{1.,{2. 51.041. China 2. department of Physics,{1., {2. 51.063, China department of Physics and IT Medical College Shantou University Shantou 515041 China department of Physics Shantou University Shantou 515063 China

The reduction factors p and q defined by Ham in the Ee JT system and their relation 2.-p=1.have been well accepted and the concept of reduction factors is widely used in the studies of vibronic coupling. However, when the system is under the anisotropic conditions, the reduction factors and their relation will change accordingly. The first-order reduction factors p and q of Ee system were further studied using the method of unitary transformation here. The relation between p and q proposed by Ham was investigated under both conditions of the linear coupling and the anisotropic effects. The result demonstrated that the relation of 2.-p=1.was only correct for the linear vibronic coupling, but not correct when the anisotropic effect was considered. This result suggested that the anisotropic effect influence considerably the reduction factors, and hence the physical properties of materials. Our method could be also applied to other JT systems, especially the highly symmetric JT systems involving C60 molecules.

关键词：电子振动耦合声子交迭 Jahn-Teller效应各向异性

Necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property

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Chinese Science Bulletin 1997年第3期42卷 259-260页

作者： MAI Jiehua and GU Rongbao1.Institute of mathematics,{1., {2. 51.063, China 2. department of mathematics, Anhui university, Hefei 2.0039, China Institute of mathematics Shantou University Shantou China department of {1. Anhui University Hefei China

IN this letter we discuss the necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property. According to ref. [1., on a closed surface, every minimal set of a C^r(r≥2. flow is trivial, but it is possible for a C^0 flow to contain non-trivial minimal sets. Thus C^0 flows on closed surfaces are more complicated than C^r(r≥2. flows.

关键词： Necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property

Multiwavelet sampling theorem in Sobolev spaces

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Science China mathematics 2010年第12期53卷 3197-3214页

作者： LI YouFa 1.2.& YANG ShouZhi 1. 1.{1. of {1.,{2., shantou 51.063, China 2.College of {1. and Information Sciences, Guangxi university, Nanning 530004, China 1. department of {1. Shantou University Shantou 515063 China2. College of Mathematics and Information Sciences Guangxi University Nanning 530004 China

This paper is to establish the multiwavelet sampling theorem in Sobolev spaces. Sampling theorem plays a very important role in digital signal communication. The most classical sampling theorem is Shannon sampling theorem, which works for bandlimited signals. Recently, sampling theorems in wavelets or multiwavelets subspaces are extensively studied in the literature. In this paper, we firstly propose the concept of dual multiwavelet frames in dual Sobolev spaces (H s (R) , H-s (R)). Then we construct a special class of dual multiwavelet frames, from which the multiwavelet sampling theorem in Sobolev spaces is obtained. That is, for any f ∈ H s (R) with s > 1.2. it can be exactly recovered by its samples. Especially, the sampling theorem works for continuous signals in L 2.(R), whose Sobolev exponents are greater than 1./2.

关键词： Sobolev spaces refinable function vectors dual multiwavelet frames delta function sampling theorem

A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science China(Physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1., LONG Yuqiu 2.& LIU {1. 1.1. College of Civil Engineering, Hunan {1., Changsha 41.082. China 2. {2. of Civil Engineering, Tsinghua {1., Beijing 1.0084, China 1. College of Civil Engineering Hunan University 410082 Changsha China 2. {1. of Civil Engineering Tsinghua University 100084 Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

Global smooth solution of multi-dimensional non-homogeneous conservation laws

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Progress in Natural Science:Materials International 2004年第10期14卷 15-22页

作者： YANG Xiaozhou 1.and ZHANG Tong 2. (1.{1. of {1.,{2. university,{2.51.063,China 2.Institute of {1.,Chinese Academy of Sci-ences,Beijing1.0080,China) shantou Univ Dept Math Shantou 515063 Peoples R China Chinese Acad Sci Inst Math Beijing 100080 Peoples R China

The initial value problem of multi-dimensional non-homogeneous conservation laws is studied and a sufficient condition of the existence of its global smooth solution is ***,three equivalent propositions of the existence of global smooth solution for multi-dimensional homogeneous scalar conservation laws are also *** global smooth solution is uniquely expressed by the global implicit function that is determined by a scalar equation,not by a system as usual methods do.

关键词： conservation laws global smooth solution global implicit function diffeomorphism

Lipschitz spaces and Q_K type spaces

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Science China mathematics 2010年第3期53卷 771-778页

作者： LI Hao 1., WULAN Hasi 1. & ZHOU JiZhen 1.2.1.{1. of {1.,{2., shantou 51.063, China 2.School of Sciences, Anhui university of Science and Technology, Huainan 2.2.01. China 1. department of {1. Shantou University Shantou 515063 China2. School of Sciences Anhui University of Science and Technology Huainan 232001 China

If f(z) =Σ∞ n=0 anzn and g(z) =Σ∞n=0bnzn for functions f, g are analytic in the unit disc, the Hadamard products of f and g is defined by f * g = ∞ n=0 a n b n z n . In this paper, the Lipschitz spaces Λ(s, α) ... 详细信息

关键词： Q K type spaces Lipschitz spaces Hadamard products

A class of compactly supported symmetric/antisymmetric B-spline wavelets

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Progress in Natural Science:Materials International 2005年第2期15卷 31-36页

作者： YANG Shouzhi* and LOU Zengjian(department of {1.,{2., shantou 51.063, China) department of {1. Shantou University Shantou 515063 China

An algorithm for constructing a class of compactly supported symmetric/antisymmetric B-spline wavelets is presented. For any mth order and kth order cardinal B-spline Nm(x), Nk(x), if m+k is an even integer, the corresponding mth order B-spline wavelets ψkm(x) can be constructed, which are compactly supported symmetric/antisymmetric. In addition, if ψkm(x), m>1.is mth B-spline wavelet associated with two spline functions Nm(x) and Nk(x), then (ψkm(x))′(x) is m-1.h B-spline wavelet associated with N m-1.x) and N k+1.x), i.e. (ψkm(x))′(x)=2.ψ k+1.m-1.x). Similarly, ∫x0ψkm(t)dt, k>1.is m+1.h B-spline wavelet associated with N m+1.x) and N k-1.x). Using this method, we recovered Chui and Wang’s spline wavelets. Since a class of B-spline wavelets are symmetric/antisymmetric, their linear phase property is assured. Several examples are also presented.

关键词： compactly supported B-spline function B-spline wavelet symmetric antisymmetric

Commuting double Ockham algebras

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Science China mathematics 2008年第2期51卷 185-194页

作者： FANG Jie department of {1.,{2. university,{2. 51.063,China department of {1. Shantou University Shantou 515063 China

In this paper,we study a certain class of double Ockham algebras (L;∧,∨,f,k,0,1., namely the bounded distributive lattices (L;∧,∨,0,1. endowed with a commuting pair of unary op- erations f and k,both of which are dual *** characterize the subdirectly irreducible members,and also consider the special case when both (L;f) and (L;k) are de Morgan *** show via Priestley duality that there are precisely nine non-isomorphic subdirectly irreducible members, all of which are simple.

关键词： subdirectly irreducible double Ockham algebra Priestley duality 06D1. 06D30

Two-dimensional water-filling power allocation algorithm for MIMO-OFDM systems

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Science China(Information Sciences) 2010年第6期53卷 1242-1250页

作者： JIANG YongQuan 1., SHEN MinFen 1.& ZHOU YuanPing 2.1.{1. of Electronic Engineering,{1., {2. 51.063, China 2.{1. of Electronic Engineering, Sichuan university, Chengdu 61.064, China 1. department of Electronic Engineering Shantou University Shantou 515063 China2. Department of Electronic Engineering Sichuan University Chengdu 610064 China

Departing from the narrowband channel model, more and more researchers have recently considered the application of multiple-input multiple-output(MIMO) systems over frequency-selective fading channels in combination with the orthogonal frequency-division multiplexing(OFDM) *** this paper, we focus on the capacity of MIMO-OFDM systems and how to increase the *** has been proved that the capacity of a MIMO system with space-dimensional water-filling power allocation is greater than that of the system with uniform power *** MIMO-OFDM systems, there is an additional degree of freedom to allocate power with respect to MIMO systems:the OFDM sub-channels in *** the singular value decomposition(SVD) applied to the channel frequency response matrix, the two-dimensional water-filling power allocation algorithm for MIMO-OFDM systems is proposed based on the Lagrange method, and the corresponding capacity analysis formula is *** results show that the capacity of a MIMO-OFDM system with the proposed two-dimensional water-filling power allocation is greater than that of the system with uniform power allocation and also greater than that of the system with the one-dimensional water-filling power allocation.

关键词： MIMO-OFDM two-dimensional water-filling power allocation capacity analysis singular value decomposition(SVD)