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ON THE CLASSIC NONHOLONOMIC DYNAMICS

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Acta Mechanica Sinica 1989年第3期5卷 253-259页

作者： Guo Zhongheng Gao Puyun~(2))(department of mathematics,Peking university) 2)At present,Dept.of mathematics,Xiantan Normal School. 1. department of mathematics Peking University Peking China

For first-order nonlinear nonholonomic systems,the present paper proves that the d-δ operations are commutative and derives the equation of motion without making use of the addition al Appell-Chetaev *** equation of ... 详细信息

关键词： nonholonomic dynamics commutativity of d-δ operations Appell-Chetaev condition Vacco dynamics

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 department of mathematics, Shantou university, Shantou 515063, China 2 College of mathematics and Information Sciences, Guangxi university, Nanning 530004, China 1. department of mathematics 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 NONLINEAR GALERKIN METHOD WITH VARIABLEMODES FOR KURAMOTO-SIVASHINSKY EQUATION

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Journal of Computational mathematics 1999年第3期17卷 243-256页

作者： Yu-jiang wu(Depadrtment of mathematics, Shanghai university, Jiadiap Shanghai 201800, China department of mathematics, Lanzhou university, Lanzhou 750000, China) 上海大学数学系上海

This article proposes a kind of nonlinear Galerkin methods with variable modes for the long-term integration of Kuramoto-Sivashinsky equation. It consists of finding an appropriate or best number of modes in the correction of the method. Convergence results and error estimates are derived for this method. Numerical examples show also the efficiency and advantage of our method over the usual nonlinear Galerkin method and the classical Galerkin method.

关键词： Kuramoto-Sivaskinsky equation nonlinear Galerkin method approximation convergence

Effects of Ta Addition on Microstructure and Transformation Behavior of Ni-Ti Alloys

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Journal of Materials Science & Technology 2001年第1期17卷 5-6页

作者： K.H.Wu and JL.Ma department of Mechanical Engineering, florida International university, Miami, fl 33174, U.S.A. florida Int Univ Dept Mech Engn Miami FL 33174 USA

The effect of adding Ta on the changes of microstructure and Ms temperature of a dualphase shape memory alloy with compositions of (Ni51 Ti49)1 -***. and Ni50-Ti50 -***.g were systematically studied. An optical microscope, SEM, X-ray diffraction and DSC were utilized in this work. The evolution of the microstructure as a function of Ta content was characterized. The variation of the Ni/Ti ratio in the NiTi phase plays an important role in the change of the Ms temperatures due to the addition of Ta. A pseudobinary NiTi-Ta phase diagram was proposed based on these results.

关键词： Ti Ta Effects of Ta Addition on Microstructure and Transformation Behavior of Ni-Ti Alloys

Fuzzy controllers based on some fuzzy implication operators and their response functions

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Progress in Natural Science:Materials International 2004年第1期14卷 16-21页

作者： LI Hongxing 1*, YOU Fei 1 and PENG Jiayin 2(1. department of mathematics, Beijing Normal university, Beijing 100875, China 2. department of mathematics, Neijiang Teacher's College, Neijiang 641112, China) Beijing Normal Univ Dept Math Beijing 100875 Peoples R China

The fuzzy controllers constructed by 23 fuzzy implication operators based on CRI algorithm and their response functions are discussed. The conclusions show that the fuzzy controllers constructed by 9 fuzzy implication operators are universal approximators to continuous functions and can be used in practical fuzzy control systems. And these 9 fuzzy implication operators except for Einstein operator intersection are all the adjoint pairs of some fuzzy implication operators. Besides, there are 3 other fuzzy controllers formed by fuzzy implication operators being regarded approximately as fitted functions.

关键词： fuzzy implication operators CRI algorithm fuzzy controllers response functions universal approximators

Analytical study of stationary soliton excitations in diamond-structure chain with quartic anharmonicity

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原子与分子物理学报 2001年第2期18卷 143-149页

作者： XIA Qing lin 1, ZHOU Guang hui 2, YAN Jia ren 2 (1.department of Applied Physics and Heat Engineering, central South university, Hunan Changsha 410083 2.department of Physics, Hunan Normal university, Hunan Changsha 410081) 中南大学湖南长沙 410083 湖南师范大学湖南长沙 410081

This work analytically study soliton excitations in an one dimensional chain with the same mass but two alternating force constants between the nearest neighbors by means of multiple scales method plus quasi discrete approximation. This model simulates a row of atoms in the 〈111〉 direction of a diamond structure type of crystals. The explicit expressions of the stationary soliton solutions are obtained at some special wave vectors of the carrier wave ( q =±π/ a for acoustic mode and q=0 , ±π/ a for optical mode). The configuration of the atomic displacements of this model is different from that of diatomic chain with quartic anharmonicity.

关键词： Stationary soliton excitation Diamond structure Multiple scales method Quasi discrete approximation

Complex role of matrix metalloproteinases in angiogenesis

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Cell Research 1998年第3期8卷 171-177页

作者： SANG QING XIANG AMY(Biochemistry Division, department of Chemistry, florida State university, Tallahassee, florida 32306-4390, usa) Biochemistry Division Department of Chemistry Florida State University Tallahassee USA

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) play a significant role in regulating angiogenesis, the process of new blood vessel formation. Interstitial collagenase (MMP-1), 72 kDa gelatinase A/type IV collagenase (MMP-2), and 92 kDa gelatinase B/type IV collagenase (MMP-9) dissolve extracellular matrix (ECM) and may initiate and Promote angiogenesis. TIMP-1, TIMP-2, TIMP-3, and possibly,TIMP-4 inhibit neovascularisation. A new paradigm is emerging that matrilysin (MMP-7), MMP-9, and metalloelastase (MMP-12) may block angiogehesis by converting plasndnogen to angiostatin, which is one of the most potent angiogenesis antagonists. MMPs and TIMPs play a complex role in regulating angiogenesis. An understanding of the biochemical and cellular pathways and mechanisms of angiogenesis will provide importal information to allow the control of angiogenesis, e.g. the stimulation of angiogenesis for coronary collateral circulation formation; while the inhibition for treating arthritis and cancer.

关键词： Collagenases tissue inhibitors of metalloproteinases neovascularization plasminogen angiostatin converting enzymes extracellular matrix

A POSTERIORI ERROR ESTIMATES IN ADINI FINITE ELEMENT FOR EIGENVALUE PROBLEMS

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Journal of Computational mathematics 2000年第4期18卷 413-418页

作者： Yi-du Yang (department of mathematics, Guizhou Normal university, Guiyang, 550001) 贵州师范大学贵州贵阳 550001

In this paper, we discuss a posteriori error estimates of the eigenvalue λ[sub h] given by Adini nonconforming finite element. We give an assymptotically exact error estimator of the λ[sub h]. We prove that the order of convergence of the λ[sub h] is just 2 and the converge from below for sufficiently small h. [ABSTRACT FROM AUTHOR]

关键词： eigenvalue nonconforming finite element error estimate

A GOLDSTEIN'S TYPE PROJECTION METHOD FOR A CLASSOF VARIANT VARIATIONAL INEQUALITIES

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Journal of Computational mathematics 1999年第4期17卷 425-434页

作者： Bing-sheng He(department of mathematics, Nanjing university, Nanjing 210008, China) department of mathematics Nanjing University Nanjing 210008 China

Some optimization problems in mathematical programming can be translated to a variant variational inequality of the following form: Find a vectoru*, such that This paper presents a simple iterative method for solving this class of variational inequalities. The method can be viewed as an extension of theGoldstein's projection method. Some results of preliminary numerical experiments are given to indicate its applications.

关键词： Variational inequality Goldstein projection method.