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THE SOLVABILITY CONDITIONS FOR THE INVERSE PROBLEM OF MATRICES POSITIVE SEMIDEFINITE ON A SUBSPACE

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Journal of computational Mathematics 1994年第1期12卷 78-87页

作者： HU, XY ZHANG, L DU, WZ hunan UNIV CHANGSHAPEOPLES R CHINA hunan comp ctr CHANGSHAPEOPLES R CHINA

This paper studies the following two problems: Problem I. Given X, B is-an-element-of R(n x m), find A is-an-element-of P(s,n), such that AX = B, where Ps, n = {A is-an-element-of SR(n x n)\x(T) Ax greater-than-or-equal-to 0, for-all S(T) x = 0, for given S is-an-element-of R(p)n x p}. Problem II. Given A* is-an-element-of R(n x n), find A is-an-element-of S(E), such that \\A*-A\\ = inf(A is-an-element-of S(E) \\A*-A\\ where S(E) denotes the solution set of Problem I. The necessary and sufficient conditions for the solvability of Problem I, the expression of the general solution of Problem I and the solution of Problem II are given for two cases. For the general case, the equivalent form of conditions for the solvability of Problem I is given.

关键词： eigenvalue symmetric holds nonnegative solvability matrices inverse convex satisfying hunan

The Irregular Weighted Wavelet Frame Conjugate Gradient Algorithm

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China Communications 2007年第4期4卷 48-54页

作者： Jiang Li Yi Aichun Zhang Changfan Zhu Shanhua hunan Univ Technol Dept Informat & Computat Sci Zhuzhou 412008 Peoples R China hunan Univ Technol Sch Comp & Commun Zhuzhou 412008 Peoples R China hunan Univ Technol Sch Elect Engn Zhuzhou 412008 Peoples R China

The dropping off of data during information transmission and the storage device’s damage *** leads the sampled data to be *** paper, based on the stability theory of irregular wavelet frame and the irregular weighted wavelet frame operator,proposed an irregular weighted wavelet fame conjugate gradient iterative algorithm for the reconstruction of non-uniformly sampling signal. compared the experiment results with the iterative algorithm of the Ref.[5],the new algorithm has remarkable advantages in approximation error,running time and so on.

关键词： Non-uniform sampling frame algorithm irregular wavelet frame conjugate gradient algorithm

Specific Mass Spectrometric Fragmentations from the Dissociation of Intermediate Ion-Neutral complexes

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Chinese Chemical Letters 1998年第1期9卷 93-97页

作者： She, YM Wei, JH Tu, YP Liu, SY hunan Normal Univ Anal & Testing Ctr Changsha 410006 Hunan Peoples R China Chinese Acad Sci Changchun Inst Appl Chem Changchun 1300222 Jilin Peoples R China

It is reported that two kinds of specific mass spectrometric fragmentations are generated from dissociations of the intermediates of both the ion-neutral complex and the proton-bound complex. Collision-induced dissociation, isotopic labelling, and semi-empirical AM1 calculations were used to investigate the formation mechanism of the ion of m/z 139 from ionized tetrahydroimidazole-substituted methylene beta-diketones and the unimolecular fragmentations pathway of 3-phenyl-1-butyn-3-ol upon electron impact.

关键词： mass spectrometric fragmentation ion-neutral complex proton bound complex dissociation

Superconvergence for triangular cubic elements

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Chinese Science Bulletin 1999年第1期44卷 47-49页

作者： Chuanmiao Chen Jicheng Jin Shi Shu hunan Normal Univ Inst Comp Changsha 410081 Peoples R China Xiangtan Univ Dept Math Xiangtan 411105 Peoples R China

A new structure of superconvergence for the cubic triangular finite element approximation u/2 to a second-order elliptic problem Au=f is studied based on some orthogonal expansions in an interval. Suppose that Ω is a convex polygonal domain with boundary L, its triangulation is uniform and Th is a set of vertexes and side midpoints of all elements. Then uh itself has no superconvergence points in Ω, while in any interior subdomain Ω0 the average gradient Duh has superconvergence D（dh-u）=O(hm+1lnh) at z∈Th∩Ω0（no other superconvergence points）. Furthermore, prescribe u=0 on L1.Then the superconvergence near L1 will surely disappear; if αavu+bu=0 on L3, where v is the conormal direction, the numercal experiments show superconvergence up to L3（the case of A=-Δ and b=0 has already been proved）.

关键词： superconvergence triangular cubic element finite element approxination.

Analytical Study of Moving Excitations for One-dimensional Homogeneous Lattice with Quartic Anharmonicity

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Journal of Materials Science & Technology 1999年第4期15卷 345-347页

作者： Zhou, GH Yan, JR hunan Normal Univ Dept Phys Changsha 410081 Peoples R China hunan Normal Univ Inst Nonlinear Sci Changsha 410081 Peoples R China Chinese Acad Sci Int Ctr Mat Phys Shenyang 110015 Peoples R China

The moving nonlinear excitations (intrinsic localized vibrational modes) for one-dimensional homogeneous monoatomic lattice with quartic anharmonicity are obtained analytically by means of the semidiscrete approximation, with which the carrier wave is treated explicitly while the envelope function is described in the continuum approximation. Besides the moving pulse-like type of excitations which was found previously in both analytical and numerical works, we find that the moving kink-like type of excitations can also exist. And the kink-like excitations appeared previously only in the stationary form for such a lattice system.

关键词： Crystalline materials

REGULARITY OF BIRKHOFF INTERPOLATION

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Journal of computational Mathematics 1994年第4期12卷 357-365页

作者： Shi Ying-guang(computing Centen Academia Sinica, Beijing, China) CHINESE ACAD SCI CTR COMPBEIJINGPEOPLES R CHINA

A comparison theorem concerning the regularity of Brikhoff interpolation is given. As an application of this theorem the regularity of (0,1,...,p - 1, p + 1,...,M - 1, q) interpolation (0 < p < M less-than-or-equal-to... 详细信息

关键词： interpolation Reading Massachusetts matrices London

A PRECONDITIONER DETERMINED BY A SUBDOMAIN COVERING THE INTERFACE

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Journal of computational Mathematics 1994年第1期12卷 71-77页

作者： Zhang Sheng(computing Center, Academia Sinica, Beijing, China) CHINESE ACAD SCI CTR COMPBEIJINGPEOPLES R CHINA

A method for construction of a preconditioner for the capacitance matrix on the interface is described. The preconditioner is determined by a subdomain covering the interface, and the condition number of the preconditioned matrix is dependent on the width of the covering subdomain and independent of the discrete mesh size and discontinuity of the coefficients of the differential operator. Some applications of our theory are presented at last.

关键词： Math PDE

THE MULTIGRID METHOD OF NONCONFORMING FINITE ELEMENTS FOR SOLVING THE BIHARMONIC EQUATION

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Journal of computational Mathematics 1994年第1期12卷 61-70页

作者： Yu Xi-jun(computing Center, Academia Sinica, Beijing, China) CHINESE ACAD SCI CTR COMPBEIJINGPEOPLES R CHINA

An optimal order of the multigrid method is given in energy-norm for the nonconforming finite element for solving the biharmonic equation, by using the nodal interpolation operator as the transfer operator between grids.

关键词： Math THE MULTIGRID METHOD OF NONCONFORMING FINITE ELEMENTS FOR SOLVING THE BIHARMONIC EQUATION

(0,1, …, m - 2, m) INTERPOLATION FOR THE LAGUERREABSCISSAS

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Journal of computational Mathematics 1994年第3期12卷 123-131页

作者： Shi Ying-guang (computing Center, Academia Sinica, Beijing, China) CHINESE ACAD SCI CTR COMPBEIJINGPEOPLES R CHINA

A necessary and sufficient condition of regularity of (0,1,…, m - 2, m) interpo-lation on the zeros of the Laguerre polynomials Ln(α) (x) (α≥ -1) in a manageable form is established. Meanwhile, the explicit representation of the fundamental polynomials, when they exist, is given. Moreover, it is shown that, if the problem of (0,1,…, m - 2, TO) interpolation has an infinity of solutions, then the general form of the solutions is f0(x) + Cf1(x) with an arbitrary constant C.

关键词： INTERPOLATION FOR THE LAGUERREABSCISSAS

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