Husimi Function of Excited Squeezed Vacuum State

The q-p phase-space distribution function is a popular tool to study semiclassical physics and to describe the quantum aspects of a system. In this paper by using the pure state density operator formula of the Husimi operator Δ_h(q,p;κ)=|p,q〉_κκ〈p,q| we deduce the Husimi function of the excited squeezed vacuum state. Then we study the behavior of Husimi distribution graphically.     

Existing Regions of Either Rarefactive or Compressive Solitary Waves for Particular Dusty Plasma

By deriving a Korteweg-de Vries (KdV) equation for particular dusty plasma, we find the existing regions of solitary waves. The regions of both rarefactive and compressive solitary waves have also been given in this paper for a two-temperature ions and a hot adiabatic dusty fluid, where the dust charges can vary.     

On gl（2｜2）（2）k Current Superalgebra and Twisted Conformal Field Theory

Motivated by the recently discovered hidden symmetry of the type IIB Green-Schwarz superstring on certain background, the non-semisimple Kac-Moody twisted superalgebra gl（2｜2）（2）k is investigated by means of the vector coherent state method and boson-fermion realization. The free field realization of the twisted current superalgebra at general level k is constructed. The corresponding Conformai Field Theory （CFT） has zero central charge. According to the classification theory, this CFT is a nonunitary field theory. After projecting out a U（1） factor and an outer automorphism operator, we get the free field representation of psl（2｜2）（2）k, which is the a/gebra of gl（2｜2）（2）k modulo the Z4-outer automorphism, the CFT has central charge -2.     

Variable-Coefficient Hyperbola Function Method and Its Application to （2＋1）-Dimensional Variable-Coefficient Broer-Kaup System

Based on a new intermediate transformation, a variable-coeFficient hyperbola function method is proposed.Being concise and straightforward, it is applied to the (2 1)-dimensional variable-coeFficient Broer-Kaup system. As a result, several new families of exact soliton-like solutions are obtained, besides the travelling wave. When imposing some conditions on them, the new exact solitary wave solutions of the (2 1)-dimensional Broer Kaup system are given. The method can be applied to other variable-coeFficient nonlinear evolution equations in mathematical physics.     

Elliptic Equation and New Solutions to Nonlinear Wave Equations

The new solutions to elliptic equation are shown, and then the elliptic: equation is taken as a transformation and is applied to solve nonlinear wave equations. It is shown that more kinds of solutions are derived, such as periodic solutions of rational form, solitary wave solutions of rational form, and so on.     

A hierarchy of lattice soliton equations and its Darboux transformation

A new discrete spectral problem is introduced and the corresponding hierarchy of the lattice soliton equations are derived by means of the trace identity. We find a new Darboux transformation of the lattice soliton equation, through which the explicit solutions are shown.     

The dynamical feature of transition of a Hamiltonian system to a dissipative system

The mechanism of generation and annihilation of attractors during transition from a Hamiltonian system to a dissipative system is studied numerically using the dissipative standard map. The transient process related to the formation of attracting basins of periodic attractors is studied by discussing the evolution of the KAM tori of the standard map. The result shows that as damping increases, attractors are mainly generated from elliptic orbits of the Hamiltonian system and annihilated by colliding with unstable periodic orbits originating from the corresponding hyperbolic orbits of the Hamiltonian system. The transient process also exhibits the general feature of bifurcation.     

基于数学物理方程预制密肋模板等效刚度拟板的分析法

预制密肋模板是装配整体式叠合楼盖永不拆除的结构构件,是由平板和密肋交叉梁组成.通过对其平板和密肋梁之间耦合作用的研究,建立了预制密肋模板.等效平板刚度的计算数学物理方程,并基于刚度最小的原则,确定了密肋模板等效平板的弯曲中心平面,将预制密肋板等效成平板,建立了简化的预制密肋模板竖向承载的理论计算方法.研究结果表明模板的跨度、肋梁间距、肋梁高度和模板的厚度对其力学响应具有明显的影响.     

球面平均值函数及其微分方程的推导

三维波动方程初值问题是数学物理方法课程的重要教学内容.本文讨论球面平均法求解该问题时,球面平均值的定义及其满足的偏微分方程的建立过程.在教材常见推导的基础上,本文提出了球面平均值方程一种更简洁的推导方法.本文的讨论有利于澄清球面平均值函数的含义,为球面平均法以及球坐标系下数学物理方程的教学提供参考.     

Exact Solutions of （2＋1）-Dimensional Euler Equation Found by Weak Darboux Transformation

The weak Darboux transformation of the （2＋1） dimensional Euler equation is used to find its exact solutions. Starting from a constant velocity field solution, a set of quite general periodic wave solutions such as the Rossby waves can be simply obtained from the weak Darboux transformation with zero spectral parameters. The constant vorticity seed solution is utilized to generate Bessel waves.