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SOME RESULTS ON INFINITE DIMENSIONAL NOVIKOV ALGEBRAS

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Chinese Annals of Mathematics,Series B 2003年第3期24卷 309-314页

作者： ZHAO YUFENG MENG DAOJI department of Mathematics, Nankai university,{2., china. department of Mathematics, Nankai university,{2., china. Nankai Univ Dept Math Tianjin 300071 Peoples R China

This paper gives some sufficient conditions for determining the simplicity of infinite di-mensional Novikov algebras of characteristic 0, and also constructs a class of simple Novikovalgebras by extending the base fie... 详细信息

关键词： Novikov algebra Novikov-Poisson Algebra Algebraic deformation

Tunneling Through Black Rings

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Communications in Theoretical Physics 2007年第5期47卷 835-842页

作者： ZHAO Liu department of Physics,Nankai university,{2. 300071,china department of Physics Nankai University

Hawking radiation of black ring solutions to 5-dimensional Einstein-Maxwell-dilaton theory is analyzedby use of the Parikh-Wilczek tunneling *** get the correct tunneling amplitude and emission rate,we adoptand develop the Angheben-Nadalini-Vanzo-Zerbini covariant approach to cover the effects of rotation and electronicdischarge all at once,and the effect of back reaction is also taken into *** constitutes a unified approach tothe tunneling *** the first law of thermodynamics for black rings holds,the emission rate is proportionalto the exponential of the change of Bekenstein-Hawking *** calculation for black ring temperatures agreesexactly with the results obtained via the classical surface gravity method and the quasi-local formalism.

关键词： black ring radiation tunneling method

Principle of limitation of physical quantities and cyclic universe

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Science china(Physics,Mechanics & Astronomy) 2008年第5期51卷 451-458页

作者： HE GuoZhu department of Physics,Nankai university,{2. 300071,china 1. department of Physics Nankai University Tianjin 300071 China

A close study of Heisenberg uncertainty principles reveals many significant facts,and all four major physical quantities,energy,time,momentum and length,have both lower and upper ***,many questions come *** are these limits?Some answers may lead to the understanding of the development of our *** is the shortest limit of time?At the beginning of big bang,there exists a tre-mendously short time,the Planck *** may be just the shortest time limit in our *** longest time limit might be the lifetime of our *** longest length might be the final diameter of our expanding *** these lead to a finite *** more coupling formulae are formed for the other two pairs of physical quantities,mass and speed,thermal energy and *** four physical quantities must also have *** already knew that speed has upper limit and temperature has lower *** these two formulae,Planck and Einstein equations are derived *** most other physical quantities are somewhat related to these major physical quantities,it seems that there exists a principle of limitation of physical quantities.A quantitative sketch of big bang is *** also shows that our universe will contract back to another big *** principle of limitation opens up some fields of *** may bring nature back to the harmony and determined world described by classical physics.

关键词： principle of limitation of physical quantities limits coupling formulae cyclic universe extension of conven-tional quantum mechanics no uncertainty for physical quantities quantitative evaluation of big bang

THE FULL DISCRETE DISCONTINUOUS FINITE ELEMENT ANALYSIS FOR FIRST-ORDER LINEAR HYPERBOLICEQUATION

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Journal of Computational Mathematics 1999年第1期17卷 97-112页

作者： Che Sun Shu-jie Qin(department of Mathematics, Nankai university,{2., china) Nankai Univ Dept Math Tianjin 300071 Peoples R China

In this paper, the full discrete discontinuous Galerkin finite element method to solove 2.dimensional first-order linear hyperbolic problem is considered. Two practical schemes, Euler scheme and Crank-Nicolson scheme, are constructed. For each of them, the stability and error estimation with optimal order approximation is established in the norm stronger than L-2.norm.

关键词： hyperbolic equation discontinuous FEM Euler scheme

On homotopy regular monomorphisms

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Chinese Science Bulletin 1998年第1期43卷 27-30页

作者： CHEN Jixiang department of Mathematics, Nankai university,{2., china department of Mathematics Nankai University Tianjin China

A concept of homotopy regular monomorphism is introduced which is strictly between homotopy monomorphism and homotopy equivalence. And it characterizes homotopy equivalence in some sense.

关键词： homotopy monomorphism homotopy equalizer homotopy regular monomorphism homotopy pull back.

THE STABILITY OF THE PERIODIC SOLUTIONS OF SECOND ORDER HAMILTONIAN SYSTEMS

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Chinese Annals of Mathematics,Series B 2000年第2期21卷 225-232页

作者： LIU CHUNGEN(department of Mathematics, Nankai university,{2., china.) department of Mathematics Nankai University Tianjin 300071 China

This paper studies the stability of the periodic solutions of the second order Hamiltonian systems with even superquadratic or subquadratic potentials. The author proves that in the subquadratic case, there exist infinite geometrically distinct elliptic periodic solutions, and in the superquadratic case, there exist infinite geometrically distinct periodic solutions with at most one instability direction if they are half period non-degenerate, otherwise they are elliptic.

关键词： Krein type Stability Periodic elliptic solution Hamitonian systems

The mechanism of breakdown in laminar-turbulent transition of a supersonic boundary layer on a flat plate-temporal mode

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Science china(Physics,Mechanics & Astronomy) 2005年第5期48卷 614-625页

作者： HUANG Zhangfeng 1, CAO Wei 1,2.& ZHOU Heng 1,2.1. department of Mechanics, tianjin {2., tianjin 300072. china 2. Liu-Hui Center of Applied Mathematics, Nankai {2. and tianjin {2., tianjin 300072. china 1. department of Mechanics Tianjin University 300072 Tianjin China 2. Liu-Hui Center of Applied Mathematics Nankai University and Tianjin University 300072 Tianjin China

Temporal mode direction numerical simulation has been done for the transition of a supersonic boundary layer on a flat plate with Mach number 4.5. Analysis of the result showed that during the breakdown process in laminar-turbulent transition, the mechanism causing the mean flow profile to evolve swiftly from laminar to turbulent was that the modification of mean flow profile by the disturbances,when they became larger,led to a remarkable change of its stability characteristics. Though the most unstable T-S wave was of second mode for laminar flow, the first mode waves played the key role in the breakdown process in laminar-turbulent transition.

关键词： supersonic boundary layer, transition, breakdown.

Automorphisms with order three of affine Lie algebras

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Chinese Science Bulletin 1998年第21期43卷 1793-1798页

作者： JIN Quanqin 1,2.and HOU Zixin 2.1. department of Mathematics, Hebei university, Baoding 071002.{2. 2. department of Mathematics, Nankai university, tianjin 300071,{2. department of Mathematics Hebei University Baoding China department of Mathematics Nankai University Tianjin China

Some properties of automorphisms of affine Lie algebras are presented. Automorphisms with order three are classified up to conjugacy, and their fixed point sets are also computed. As a corollary, it is proved that two... 详细信息

关键词： affine Lie algebra automorphism of order three first (second) kind of automorphism.

From discrete [Mn_4] cluster to 1D complex: Two new mixed-valence manganese complexes with slow magnetization relaxation

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Science china Chemistry 2009年第9期52卷 1463-1469页

作者： YANG PeiPei & LI LiCun department of Chemistry, Nankai university,{2., china department of Chemistry Nankai University Tianjin 300071 China

A tetranuclear manganese complex [Mn4(HL)4(MeOH)4(SCN)2.·3MeOH (1) and a one-dimensional assembly of [Mn4] units, [Mn4(HL)4(MeOH)4(N(CN)2.2.·2.5MeOH (2. (H3L = 2.6-bis(hydroxymethyl)-4-methyl-phenol), have been synthesized and studied. Complexes 1 and 2.crystallize in the triclinic space group P 1and monoclinic space group P2./n, respectively. Complex 1 possesses a mixed-valence tetranuclear dicubane unit, which comprises two MnⅡ and two MnⅢ ions. Complex 2.is built from the similar tetranuclear [Mn4] units connected through two N(CN)2.anions into a 1-D chain. The temperature dependence of the magnetic susceptibilities of 1 and 2.indicates ferromagnetic interactions between the manganese ions. Frequency-dependent out-of-phase signals of alternating current magnetic susceptibilities are observed in the low temperature range for both complexes, indicating a slow magnetic relaxation.

关键词： tetranuclear manganese complex 1D complex magnetic properties slow magnetic relaxation