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Decay of geometry for unimodal maps:The C^2 case

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Chinese Science Bulletin 2009年第11期54卷 1859-1862页

作者： SHEN WeiXiao1,2 1 department of mathematics, university of Science and {3. of china, hefei 23.026, china 2 department of mathematics, National university of Singapore, Singapore 117543. Singapore department of mathematics University of Science and Technology of China Hefei China department of mathematics National University of Singapore Singapore Singapore

We prove that a C2 unimodal interval map with critical order not greater than 2 has the decay of geometry property, by showing that all the cross-ratio estimates needed in the previous proof for the C3.case remain true.

关键词：衰变几何图案件几何性质比率估计证明

A Series of Soliton-like and Double-like Periodic Solutions of a (2+1)-Dimensional Asymmetric Nizhnik-Novikov-Vesselov Equation

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Communications in Theoretical Physics 2004年第11期42卷 655-660页

作者： CHEN Yong,~(1,3.4, WANG Qi~(2,4) LI Biao~(2,4) ~1department of mathematics,Ningbo university,Ningbo 3.5211,{3. ~2department of Applied mathematics,Dalian university of technology,Dalian 116024,{3. ~3.0} of Physics,Shanghai Jiao Tong university,Shanghai 20003.,{3. ~4Key Laboratory of mathematics Mechanization~ the Chinese Academy of Sciences,Beijing 100080,{3. department of mathematics Ningbo University Ningbo 315211 China department of Physics Shanghai Jiao Tong University Shanghai 200030 China Key Laboratory of mathematics Mechanization the Chinese Academy of Sciences Beijing 100080 China department of Applied mathematics Dalian University of Technology Dalian 116024 China

We generalize the algebraic method presented by Fan [***.A:***.3. (2003. 7009)] to uniformlyconstruct a series of soliton-like solutions and double-llke periodic solutions for nonlinear partial differential equations(NPDE),As an application of the method,we choose a (2+1)-dimensional asymmetric Nizhnik-Novikov-Vesselov equa-tion and successfully construct new and more general solutions including a series of nontraveling wave and coefficientfunctions’ soliton-like solutions,double-like periodic and trigonometric-like function solutions.

关键词： symbolic computation soliton-like solution Weierstrass and Jacobi elliptic functions periodic solution

Convergence analysis for general linear methods applied to stiff delay differential equations

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Progress in Natural Science:Materials International 2002年第6期12卷 16-22页

作者： ZHANG Chengjian(department of mathematics, Huazhong university of Science and {3., Wuhan 43.074, china) Huazhong Univ Sci & Technol Dept Math Wuhan 430074 Peoples R China

For Runge-Kutta methods applied to stiff delay differential equations (DDEs), the concept of D-convergence was proposed, which is an extension to that of B-convergence in ordinary differential equations (ODEs) . In this paper, D-convergence of general linear methods is discussed and the previous related results are improved. Some order results to determine D-convergence of the methods are obtained.

关键词： D-convergence general linear methods stiff delay differential equations.

Direct CP violation in hadronic B decays

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Science china(Physics,Mechanics & Astronomy) 2006年第3期49卷 357-366页

作者： HONG Bihai1,2 & Lü Caidian3.1. department of Physics, Lishui university, Lishui 3.3.00,china 2. department of Physics, Shanghai Jiaotong university, Shanghai 20003., china 3. Institute of High Energy Physics, Beijing 100049,china department of Physics Lishui University Lishui China department of Physics Shanghai Jiaotong University Shanghai China Institute of High Energy Physics Beijing China

There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely factorization, QCD factorization and the perturbative QCD approach based on kT factorization, using new parameters and full wave functions. Although they get similar results for many of the branching ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements of B factories.

关键词： CP violation hadronic B decay factorization.

An algebraic invariant for Jordan automorphisms on B(H):The set of idempotents

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Science china mathematics 2005年第12期48卷 1585-1596页

作者： CUI Jianlian & HOU Jinchuan department of Mathematical Science, Tsinghua university, Beijing 100084, china department of Applied mathematics, Taiyuan university of technology, Taiyuan 03.024, china department of mathematics, Shanxi Teachers university, Linfen 041004, china department of Mathematical Science Tsinghua University Beijing 100084 China department of Applied mathematics Taiyuan University of Technology Taiyuan 030024 China department of mathematics Shanxi Teachers University Linfen 041004 China

Let H be an infinite dimensional complex Hilbert space. Denote by B(H) the algebra of all bounded linear operators on H, and by I(H) the set of all idempo-tents in B(H). Suppose that Φ is a surjective map from B(H) onto itself. If for every λ ∈ {-1,1,2,3.1/2,1/3. and A, B ∈ B(H), A - λB ∈ I(H) (?) Φ(A) - λΦ(B) ∈ I(H), then Φ is a Jordan ring automorphism, i.e. there exists a continuous invertible linear or conjugate linear operator T on H such that Φ(A) = TAT-1 for all A ∈ B(H), or Φ(A) = TA*T-1 for all A ∈ B(H); if, in addition, A-iB ∈ I(H) (?) Φ(A) -ιΦ(B) ∈ I(H), here ι is the imaginary unit, then Φ is either an automorphism or an anti-automorphism.

关键词： Hilbert space operators,Jordan automorphisms,idempotents.

A multicast routing algorithm with multiple trees

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Journal of Systems Engineering and Electronics 2005年第2期16卷 426-432页

作者： Cui Xunxue 1,2 , Gao Wei3.& Fang Hongyu41. New Star Research Institute of Applied technology, hefei 23.03., P. R. china 2. Jiangsu Key Laboratory of Computer Information Processing technology,Soochow university, Suzhou 215006, P. R. china 3. department of Electronic Engineering and Information Science,university of Science and technology of china, hefei 23.027, P. R. china 4. School of Electronic Science and technology, Anhui university, hefei 23.03., P. R. china New Star Research Institute of Applied technology Hefei 230031 P. R. China 2. Jiangsu Key Laboratory of Computer Information Processing technology Soochow University Suzhou 215006 P. R. China department of Electronic Engineering and Information Science University of Science and Technology of China Hefei 230027 P. R. China School of Electronic Science and technology Anhui University Hefei 230039 P. R. China

Quality of service (QoS) multicast routing has continued to be a very important research topic in the Internet. A method of multicast routing is proposed to simultaneously optimize several parameters based on multiobjective genetic algorithm, after the related work is reviewed. The contribution lies on that the selection process of such routing is treated with multiobjective optimization. Different quality criterions in IP network are taken into account for multicast communications. A set of routing trees is generated to approximate the Pareto front of multicast problem. Multiple trees can be selected from the final set of nondominated solutions, and applied to obtain a good overall link cost and balance traffic distribution according to some simulation results.

关键词： multicast routing quality of service multiobjective optimization genetic algorithms.

Langevin Treatment of Atomic Coherence Effect on Hybrid Erbium doped Fiber Amplification

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Chinese Journal of Lasers 1999年第6期8卷 3-5页

作者： LIU Fangxin 1,3.GUO Yang 2 MING Hai 2 ( 1 Structure Research Laboratory, 2 department of Physics, 3.department of Astronomy and Applied Physics, university of Science and {3. of china, hefei 23.026, china) 中国科学技术大学结构研究实验室结构分析开放实验室安徽合肥 230026 中国科学技术大学物理系安徽合肥

The effects of atomic coherence on hybrid erbium doped fiber amplifier (HEDFA) pumped simultaneously by two diode lasers with different frequencies are studied by using Langevin quantum theory. The expressions of coherence and incoherence gain are derived. The theoretical results show that HEDFA has a near flat bandwidth response from 153. to 1568 nm and large coherence gain under the conditions of low temperature and small detuning.

关键词： atomic coherence hybrid erbium doped fiber amplifier LD pump

GENERALIZED KP EQUATION AND MIURA TRANSFORMATION

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Chinese Science Bulletin 1989年第1期34卷 1-6页

作者：田畴 department of mathematics University of Science and Technology of China Hefei

Suppose u is independent of y, we obtain the KdV equation ul+uxxx+6uux=0.

关键词： Bieklund transformation Miura transformation Sauze transformation.

Superconductivity of small metal grains

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Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 431-441页

作者： ZHENG Renrong1 CHEN Zhiqian2 & ZHU Shunquan1,3.1. department of Physics, Shanghai Normal university, Shanghai 20023., china 2. department of Physics, Southwest Normal university, Chongqing 400715, china 3. department of Computer and Electric technology, Shanghai Business School, Shanghai 201400, china department of Physics Shanghai Normal University Shanghai China department of Physics Southwest Normal University Chongqing China department of Computer and Electric technology Shanghai Business School Shanghai China

The formulas of the energy gap and superconducting critical temperature appropriate for systems with both odd and even number of electrons are derived; the bases of the derivations are BCS theory and energy level statistics. Numerical results qualitatively agree with the experimental phenomena. i.e., the superconductivity of small metallic grains will first enhance then decrease to zero when the grain are getting smaller and smaller. The calculations indicate that the above phenomena happen in the metallic grains belonging to Gaussian Orthogonal Ensemble (GOE) and Gaussian Unitary ensemble (GUE) with zero spin; The superconductivity of small metallic grains in Gaussian Symplectic Ensemble (GSE) will monotonically decrease to zero with the decreasing of the grain size. The analyses suggest that the superconductivity enhancements come from pairing and the balance of the strengths between spin-orbital coupling and external magnetic field. In order to take the latter into account, it is necessary to include the level statistics given by Random Matrix Theory (RMT) in describing small metallic grains.

关键词： size effect, superconductivity enhancements, small metallic grains.