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Dynamical Behavior of Core ^3He Nuclear Reaction-Diffusion Systems and Sun＇s Gravitational Field

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Transactions of tianjin university 2005年第1期11卷 30-34页

作者：杜九林申洪 School of Sciences Tianjin University Tianjin 300072 China department of physics Gannan Teachers College Ganzhou 330047 China

The coupling of the sun's gravitational field with processes of diffusion and convection exerts a significant influence on the dynamical behavior of the core 3He nuclear reaction-diffusion system. Stability analyses of the system are made in this paper by using the theory of nonequilibrium dynamics. It is showed that, in the nuclear reaction regions extending from the center to about 0.38 times of the radius of the sun, the gravitational field enables the core 3He nuclear reaction-diffusion system to become unstable and, after the instability, new states to appear in the system have characteristic of time oscillation. This may change the production rates of both 7Be and 8B neutrinos.

关键词： stellar nuclear reaction solar neutrino problem astrophysical hydrodynamics

Discussion of Some Problems About Nonlinear Time Series Prediction Using v-Support Vector Machine

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Communications in Theoretical physics 2007年第7期48卷 117-124页

作者： GAO Cheng-Feng CHEN Tian-Lun NAN Tian-Shi department of physics,Nankai {2.,tianjin 300071,china department of physics Nankai University Tianjin 300071 China

Some problems in using v-support vector machine(v-SVM)for the prediction of nonlinear time series *** problems include selection of various net parameters,which affect the performance of prediction,mixtureof kernels,and decomposition cooperation linear programming v-SVM regression,which result in improvements of *** simulations in the prediction of nonlinear time series produced by Mackey-Glass equation andLorenz equation provide some improved results.

关键词： v-SVM nonlinear time series prediction

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. 300071, 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 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. 300071, 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

Nonlinear Dynamical Behavior in BS Evolution Model Based on Small-World Network Added with Nonlinear Preference

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Communications in Theoretical physics 2007年第7期48卷 137-142页

作者： ZHANG Ying-Yue YANG Qiu-Ying CHEN Tian-Lun department of physics,Nankai {2.,tianjin 300071,china department of physics Nankai University Tianjin 300071 China

We introduce a modified small-world network adding new links with nonlinearly preferential connectioninstead of adding randomly,then we apply Bak-Sneppen(BS)evolution model on this *** study severalimportant structural properties of our network such as the distribution of link-degree,the maximum link-degree,and thegth of the shortest *** further argue several dynamical characteristics of the model such as the important criticalvalue f_c,the f_0 avalanche,and the mutating condition,and find that those characteristics show panticular behaviors.

关键词： power-law behavior small-world network evolution model nonlinear preference

Investigation on mechanism of reducing diffusible hydrogen in weld using microelements

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china Welding 1996年第2期5卷 125-131页

作者： DU Zeyu DING Ping and ZHANG Wenyue(Materials Science and Engineering department,tianjin {2.,tianjin,300072,P.R.china.) Materials Science and Engineering department Tianjin University Tianjin 300072 P.R. China su.edu

In this paper,the influence of microelements yttrium(Y)and tellurium(Te)on the diffusible hydrogen in weld bead has been investigated in a systemic way by means of alloying addition in the molten pool(AAMP).The results indicate that AAMP can notably reduce the diffusible hydrogen,economize the precious microelements microelements and improve the technological *** the microelements will play an important role in further developing the welding *** paper lays emphasis on the discussion of the mechanism of reducing hydrogen by microelements Y and *** is considered from the results that both Y and Te belong to surface active elements and can reduce the diffusible hydrogen in weld bead because they can change the surface properlies of molten pool metal and reduce the absorption of hydrogen atom in arc space of liquid metal *** research has a great significance in the development and utilization of microelements in welding.

关键词： microelements diffusible hydrogen surface active elements weld bead

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. 300071, 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

A CHARACTERIZATION OF REALCOMPACT STONIAN SPACES X AND EXTENDED RIESZ HOMOMORPHISMS ON C~∞(X)

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Systems Science and Mathematical Sciences 2000年第2期13卷 159-163页

作者： XIONG Hongyun ZHANG Xinjun (department of Mathematics, tianjin university,{2., china) 天津大学数学系天津 300072 天津大学数学系天津

Let X be a Stonian space and C∞(X) the Riesz space of all extended realvalued continuous functions from X into R-(=[-∞, +∞]). By Ω∞ we denote the collectionof all extended Riesz homomorphisms φ from C∞(X) into R with φ(Ix) = 1. In thispaper, we obtain that the Stonian space X is realcompact if and only if for every φ ∈Ω∞there exists a unique x ∈ X such that φ(f) = f(x) for any f ∈ C∞(X). When the Stonian space X is realcompact and Ω∞ is equipped with the topology induced by C∞(X), it is proved that Ω∞ is homeomorphic to X.

关键词： Stonian space realcompact extended realvalued continuous function extended Riesz homomorphism Gelfand mapping.

Nonlinear effect on inertia component of wave forces on a cylinder

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Acta Oceanologica Sinica 1995年第3期14卷 429-437页

作者： Li Yanbao and Song Reng(department of Hydraulic Engineering, tianjin university,{2., china)

A series of experiments on wave forces on a cylinder have been carried out when inertia component isdominant for a small she cylinder. The influence of nonlinear effect on the inertia component of wave forces on a cylinder is analyzed. The applicable range of nonlinear wave theories, such as Stokes and cnoidal wave theories, in calculating wave forces on a cylinder is discussed. A correction method is suggested for linear wave theory in calculated waveforces on a cylinder under the nonlinear condition.

关键词： Wave forces on cylinder inertia component Stokes wave cnoidal wave