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N DIMENSIONAL FINITE WAVELET FILTERS

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Journal of Computational mathematics 2003年第5期21卷 595-602页

作者： Si-long Peng (NADEC, institute of Automation, chinese academy of sciences,{2., china) NADEC Institute of Automation Chinese Academy of Sciences 北京 100080

In this paper, a large class of n dimensional orthogonal and biorthognal wavelet filters (lowpass and highpass) are presented in explicit expression. We also characterize orthogonal filters with linear phase in this c... 详细信息

关键词： n Dimension Linear phase Wavelet filters.

Formation of Ultrafine Metal Particles and Metal Oxide Precursor on Anodized Al by Electrolysis Deposition

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Journal of Materials Science & Technology 2000年第1期16卷 50-54页

作者： Lingchuan LI (institute of Chemical Metallurgy, chinese academy of sciences,{2., china) institute of Chemical Metallurgy Chinese Academy of Sciences Beijing 100080 China

Nickel was deposited by ac electrolysis deposition in the pores of the porous oxide film of Al produced by anodizing in phosphoric acid. Ultrafine rod-shaped Ni particles were formed in the pores. At the same time a film of Ni oxide precursor was developed on the surface of the porous oxide film. The Ni particles and the Ni oxide precursor were examined by SEM, TEM and X-ray diffraction. The thickness of the barrier layer of the porous oxide film was thin and it attributed to the formation of the metal particles, while the formation of the oxide precursor was associated with the surface pits which were developed in the pretreatment of Al.

关键词： Al Formation of Ultrafine Metal Particles and Metal Oxide Precursor on Anodized Al by Electrolysis Deposition

LEAST-SQUARES MIXED FINITE ELEMENT METHOD FOR SADDLE-POINT PROBLEM

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Journal of Computational mathematics 2000年第4期18卷 353-364页

作者： Lie-heng Wang Huo-yuan Duan (LSEC, institute of Computational mathematics and Scientific/Engineering Computing, {2. of mathematics and System sciences, chinese academy of sciences, beijing, 100080, china) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京 100080

In this paper, a least-squares mixed finite element method for the solution of the primal saddle-point problem is developed. It is proved that the approximate problem is consistent ellipticity in the conforming finite element spaces with only the discrete BB-condition needed for a smaller auxiliary problem. The abstract error estimate is derived. [ABSTRACT FROM AUTHOR]

关键词： least-squares method mixed finite element approximation saddle-point problem

Wandering domains in the transcendental dynamics

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chinese Science Bulletin 2001年第1期46卷 34-35页

作者： WANG Yuefeiinstitute of mathematics,{2., beijing 100080, china institute of mathematics Chinese Academy of Sciences Beijing China

It is shown that new classes of non-critically finite entire functions do not have wandering domains.

关键词： iteration Fatou set Julia set wandering domains.

Some key technics of drop tower experiment device of National Microgravity Laboratory (china) (NMLC)

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Science china(Technological sciences) 2005年第3期48卷 305-316页

作者： ZHANG Xiaoqian 1 , YUAN Longgen 1 , WU Wendong 1 , TIAN Lanqiao 2.& YAO Kangzhuang 2.1. institute of Engineering Thermophysics, chinese academy of sciences,{2., china 2. institute of Mechanics, chinese academy of sciences,{2., china institute of Engineering Thermophysics Chinese Academy of Sciences

Drop tower is an important ground based facility for microgravity science experiment. The technical performances of the drop tower NMLC are advanced compared with similar facilities in the US, Germany and Japan. The main components such as drop capsule, deceleration devices, release mechanism present its advantages and creativities.

关键词： drop tower facility,drop capsule,deceleration devices,release mechanism.

A note on noncommutative moment problems

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Science china mathematics 2005年第8期48卷 1144-1151页

作者： MA Xiujuan School of sciences, Hebei University of Technology, Tianjin 300130, china {2. institute, academy of {2. and Systems Science, chinese academy of sciences, beijing 100080, china School of sciences Hebei University of Technology Tianjin China mathematics institute Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China

Noncommutative moment problems for C*-algebras are studied. We generalize a result of Hadwin on tracial states to nontracial case. Our results are applied to obtain simple solutions to moment problems on the square and the circle as well as extend the positive unital functionals from a (discrete) complex group algebra to states on the group C*-algebra.

关键词： moment, free product, state, group C*-algebra.

NUMERICAL SOLUTION OF THE UNSTEADYINCOMPRESSIBLE NAVIER-STOKES EQUATIONS ON THECURVILINEAR HALF-STAGGERED MESHNUMERICAL SOLUTION OF THE UNSTEADYINCOMPRESSIBLE NAVIER-STOKES EQUATIONS ON THECURVILINEAR HALF-STAGGERED MESH

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Journal of Computational mathematics 2000年第5期18卷 521-540页

作者： Lan-chieh Huang (institute of Computational mathematics and Scientific/Engineering Computing,{2., beijing 100080, china) 中科院计算数学与科学工程计算所北京 100080

In this paper, the Crank-Nicholson + component-consistent pressure correction method for the numerical solution of the unsteady incompressible Navier-Stokes equation of [1] on the rectangular half-Staggered mesh has been extended to the curvilinear half-Staggered mesh. The discrete projection, both for the projection step in the solution procedure and for the related differential-algebraic equations, has been carefully studied and verified. It is proved that the proposed method is also unconditionally (in t) nonlinearly stable on the curvilinear mesh, provided the mesh is not too skewed. It is seen that for problems with an outflow boundary, the half-Staggered mesh is especially advantageous. Results of preliminary numerical experiments support these claims.

关键词： Unsteady incompressible Navier-Stokes equations Curvilinear half- staggered mesh Discrete projection.

Quasirational dynamic system

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chinese Science Bulletin 2000年第14期45卷 1277-1279页

作者： SUN Daochun & YANG Lo1. Department of mathematics, South china Normal University, Guangzhou 510631, china 2. institute of mathematics, academy of mathematics and System sciences, chinese academy of sciences, beijing 100080, china Department of mathematics South China Normal University Guangzhou China institute of mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China

Using the iterations of quasirational mappings, the theorems on dynamic system are generalized to the quasirational dynamic system. Some different results are also obtained.

关键词： quasirational mapping dynamic system covering surface.

STABILITY ANALYSIS OF FINITE ELEMENT METHODS FORTHE ACOUSTIC WAVE EQUATION WITH ABSORBINGBOUNDARY CONDITIONS (PART I)

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Journal of Computational mathematics 1999年第3期17卷 293-306页

作者： Xiu-min Shao Zhi-ling Lan(institute of mathematics, {2. of sciences, beijing 100080, china) 中科院数学所北京

In Part I and Part II of this paper initial-boundary value problems of the acoustic wave equation with absorbing boundary conditions are considered. Their finite element-finite difference computational schemes are proposed. The stability of the schemes is discussed and the corresponding stability conditions are given. Part I and Part II concern the first- and the second-order absorbing boundary conditions, respectively. Finally, numerical results are presented in Part II to show the correctness of theoretical analysis. (Author abstract) 7 Refs.

关键词： stability finite element methods wave equation absorbing boundary conditions