Annihilation Solitons and Chaotic Solitons for the （2＋1）-Dimensional Breaking Soliton System

By means of an improved mapping method and a variable separation method, a series of variable separation solutions including solitary wave solutions, periodic wave solutions and rational function solutions） to the （2＋1）-dimensional breaking soliton system is derived. Based on the derived solitary wave excitation, we obtain some special annihilation solitons and chaotic solitons in this short note.     

大学物理教学中引入非线性科学的认识与实践

本文论述了非线性科学引入物理教学的必要性及用普通物理风格讲述这一内容的可行教学方案。     

大学物理教学中引入非线性科学的认识与实践

本文论述了非线性科学引入物理教学的必要性及用普通物理风格讲述这一内容的可行教学方案．     

反应扩散系统中螺旋波的失稳

文章以反应扩散系统为例,介绍了在可激发系统与振荡系统中螺旋波产生、发展、演化的一些基本性质及规律,并讨论了作者近年来对螺旋波的各种失稳途径、时空混沌的产生机理及螺旋波控制方面所做的实验与理论工作,重点讨论了两类螺旋波失稳现象：爱克豪斯失稳与多普勒失稳,两类失稳都使系统从有规律的螺旋波态变为时空混沌（缺陷湍流）态。     

噪声在外加周期信号控制强湍中的作用研究

研究了噪声在控制中的作用.研究发现,较小强度的偏噪声信号能够使系统失去层流态,重新进入无序态,此时模式之间的广义相同步也失去了;而噪声强度较大时,系统则能够维持准周期的层流态,模式相位之间依然能够达到广义相同步. 关键词： 相同步 时空混沌 湍流 非线性漂移波     

非线性电路通向混沌的演化过程

给出了四阶非线性电路通向复杂性的两种演化模式,指出这两种模式与三个共存的平衡点有关.在第一种模式中,不稳定的平衡点由Hopf分岔导致了稳定的周期运动,经过倍周期分岔通向混沌,其所有的吸引子都保持对称结构;而在第二种模式中,另两个平衡点由Hopf分岔产生相互对称的极限环,并分别导致了两个混沌吸引子,其分岔过程步调一致,而且所有的吸引子都相互对称.随着参数的变化,这两个混沌吸引子相互作用形成一个扩大的混沌吸引子,导致与第一种分岔模式中定性一致的混沌运动.     

离子声孤立子的实验研究

本文在稳态等离子体装置中,对离子声孤立子的激发、空间传播和马赫数等进行了研究。实验结果表明,在目前情况下有必要考虑等离子体扩散对孤立子行为的影响。     

我们的"非线性物理"课

提出了对理工科大学开设“非线性物理”课的课程体系的设计思路，介绍了该课程教学内容的具体安排。     

一类由饱和引起的非线性现象

以一个功率因数校正boost变换器为例，描述了当系统在饱和与非饱和状态间不断切换时出现的一类非线性现象，分析了这些现象的特点和产生原因.推导了考虑饱和的分段微分方程，并据此进行了仿真，结果表明,系统一方面会出现倍周期分岔和混沌等传统的非线性现象，另一方面由于整流输入电流碰到饱和边界，系统的定性行为发生突变，会出现边界碰撞分岔，还能从混沌直接变为周期1.这类由饱和引起的非线性现象及相关分析得到了实验验证.     

Some Aspects of Quantum Entanglement for CAR Systems

We show some distinct features of quantum entanglement for bipartite CAR systems such as the failure of triangle inequality of von Neumann entropy and the possible change of our entanglement degree under local operations. Those are due to the nonindependence of CAR systems and never occur in any algebraic independent systems. We introduce a new notion half-sided entanglement.     

Nonlinear Dynamical Symmetries of Some Two-Dimensional Quantum Systems

In this paper nonlinear dynamical symmetries of three quantum systems are studied in detail, such as theKepler-Coulomb system and the isotropic harmonic oscillator in a two-dimensional curved space, and the generalizedpseudo-oscillators in the two-dimensional flat space. Their nonlinear spectrum generating algebras are shown to berelevant to polynomial angular momentum algebras.     

Nonlinear Dynamical Symmetries of Some Two-Dimensional Quantum Systems

In this paper nonlinear dynamical symmetries of three quantum systems are studied in detail, such as the Kepler-Coulomb system and the isotropic harmonic oscillator in a two-dimensional curved space, and the generalized pseudo-oscillators in the two-dimensional fiat space. Their nonlinear spectrum generating algebras are shown to be relevant to polynomial angular momentum algebras.     

Some Problems of Nonlinear Dynamics of Turbulent Thermals

Radiophysics and Quantum Electronics - A well-known simplified model of turbulent convection from local sources of buoyancy and/or momentum acting for a short time has been developed and...     

Noether-Type Symmetries and Associated Conservation Laws of Some Systems of Nonlinear PDEs

The algorithm for constructing conservation laws of Euler Lagvange type equations via Noether-type symmetry operators associated with partial Lagrangian has been presented. As applications, many new conservation laws of some important systems of nonlinear partial differential equations have been obtained.     

Nonlinear Plasma Dynanics in the Plasma Wakefield Accelerator

Excitation of nonlinear plasma oscillations by an ultrarelativistic electron beam is considered in this paper. It is shown, by analytical solutions of the fully relativistic nonlinear fluid equations in one dimension, that under certain conditions on the relative densities of the electron beam and the plasma, extremely large longitudinal electric fields can be generated in the wake of the beam. This scheme can be considered as a nonlinear regime of the plasma wakefield accelerator (PWFA), and is seen to have the advantage that the transformer ratio, the ratio of the maximum amplitude of the accelerating field behind the driving beam over the maximum amplitude of the decelerating field inside of the beam, can be made arbitrarily large, dependent only on the length of the driving beam. The effects of beam loading on the efficiency of this scheme are considered, and are shown to be equivalent to those predicted in the linear regime.     

Aspects of Entanglement in Quantum Many-Body Systems

Knowledge of the entanglement properties of the wave functions commonly used to describe quantum many-particle systems can enhance our understanding of their correlation structure and provide new insights into quantum phase transitions that are observed experimentally or predicted theoretically. To illustrate this theme, we first examine the bipartite entanglement contained in the wave functions generated by microscopic many-body theory for the transverse Ising model, a system of Pauli spins on a lattice that exhibits an order-disorder magnetic quantum phase transition under variation of the coupling parameter. Results for the single-site entanglement and measures of two-site bipartite entanglement are obtained for optimal wave functions of Jastrow-Hartree type. Second, we address the nature of bipartite and tripartite entanglement of spins in the ground state of the noninteracting Fermi gas, through analysis of its two- and three-fermion reduced density matrices. The presence of genuine tripartite entanglement is established and characterized by implementation of suitable entanglement witnesses and stabilizer operators. We close with a broader discussion of the relationships between the entanglement properties of strongly interacting systems of identical quantum particles and the dynamical and statistical correlations entering their wave functions.     

Some Aspects of Photoacoustic Tomography

A solution of the inverse problem of optoacoustic tomography is given in the present work within the framework of chronotomography under conditions of complex two-component absorption. The results of numerical experiments conducted with different model controllable and stochastic experimental errors are discussed.     

Some Aspects of Time-Reversal in Chemical Kinetics

Chemical kinetics govern the dynamics of chemical systems leading towards chemical equilibrium. There are several general properties of the dynamics of chemical reactions such as the existence of disparate time scales and the fact that most time scales are dissipative. This causes a transient relaxation to lower dimensional attracting manifolds in composition space. In this work, we discuss this behavior and investigate how a time reversal effects this behavior. For this, both macroscopic chemical systems as well as microscopic chemical systems (elementary reactions) are considered.