微扰的耦合非线性薛定谔方程的近似求解

将直接微扰方法应用于可积的含修正项的非线性薛定谔方程，通过近似解与精确解的比较确定了直接微扰方法的可靠性.继而，将该方法应用于微扰的耦合非线性薛定谔方程，并获得了该微扰方程的可靠的近似解. 关键词： 直接微扰方法 微扰 耦合非线性薛定谔方程 近似解     

扰动mKdV耦合系统的孤子解

采用了一个简单而有效的技巧,研究了一类扰动mKdV耦合系统.首先利用同伦映射方法求解一个相应的复值函数微分方程孤子的近似解.然后得到了原扰动mKdV耦合系统孤子的近似解. 关键词： 孤子 扰动mKdV方程 同伦映射     

一个广义扰动mKdV耦合系统2极孤子的近似解

采用了一个简单而有效的技巧,研究了一类扰动mKdV耦合系统.首先利用变分迭代方法求解一个相应的复值函数微分方程2-极孤子的近似解.然后得到了原扰动mKdV耦合系统2-极孤子的近似解.     

一类非线性扰动Nizhnik-Novikov-Veselov系统的孤立波近似解析解

采用了一个简单而有效的技巧,研究了一类非线性扰动Nizhnik-Novikov-Veselov系统.首先引入一个相应典型系统的孤立波解.然后利用同伦映射方法得到了原非线性扰动Nizhnik-Novikov-Veselov系统的近似解析解.     

非线性扰动时滞长波系统孤波近似解

本文是讨论一类时滞非线性扰动长波系统的孤波解.首先,引入非扰动的典型长波方程的精确解.然后,用同伦映射和改进的技巧构造了非线性扰动时滞长波系统孤波行波解的近似展开式.     

一类非线性扰动发展方程的广义迭代解

利用广义变分迭代方法研究了一类非线性发展扰动方程.首先引入一个泛函.然后求其变分,最后构造方程解的迭代关系式.得到了问题的近似解和精确解析解. 关键词： 发展方程 扰动 变分迭代     

(3+1)维Burgers扰动系统孤波的解法

研究了在物理模型中的一类扰动高维非线性Burgers系统. 利用经过改进的广义变分迭代方法, 构造了相应迭代关系式. 得到了扰动系统的孤波近似解.     

非线性耦合微分方程组的精确解析解

提出了利用耦合的Riccati方程组的某些特解构造非线性微分方程组精确解析解的一种方法.应用这种方法研究了两个耦合的常微分方程组,系统地获得了它们的一些精确解.给出了非线性浅水波近似方程组和非线性Schr?dinger-KdV方程组若干新的孤波解. 关键词： 非线性耦合方程组 Riccati方程组 符号计算 孤波     

海-气耦合动力系统的改进变分迭代解法

研究了一个描述厄尔尼诺和南方涛动振荡物理机理的海-气耦合动力系统.利用改进变分迭代方法 (MVIM)简捷地得到了该非线性模型近似解的展开式.通过与特殊情形下模型精确解的比较,说明获得的MVIM 近似解具有非常好的准确度.     

一类扰动非线性发展方程的类孤子同伦近似解析解

采用一个简单而有效的技巧,研究了一类扰动非线性发展方程.首先,引入一个相应典型方程的孤子近似解.然后,利用同伦映射方法得到了原扰动非线性发展方程的近似解. 关键词： 孤子 扰动发展方程 同伦映射     

Static solitary wave solution in 1D quantum quenched systems

We use Morita's formulation to describe quenched systems. Through the Holstein-Primakoff (HP) representation we quantize the system in 1D and it gives coupled non-linear Schrödinger equations. We show that a static solitary wave is a solution of these equations.     

Coupled nonlinear Schrödinger equations including growth and damping

We give an analytical and numerical analysis of a system of coupled nonlinear Schrödinger equations with complex coefficients describing wave-wave interaction in the presence of a linear and non-linear damping (growth). An exact solitary solution is found for arbitrary damping rate for one of the waves when the linear damping of the second wave is zero. In general, the wave envelopes are composed of dispersive shock waves which are explosively unstable.     

Bifurcations and solutions for the generalized nonlinear Schrödinger equation

The theory of bifurcations for dynamical system is employed to construct new exact solutions of the generalized nonlinear Schrödinger equation. Firstly, the generalized nonlinear Schrödinger equation was converted into ordinary differential equation system by using traveling wave transform. Then, the system's Hamiltonian, orbits phases diagrams are found. Finally, six families of solutions are constructed by integrating along difference orbits, which consist of Jacobi elliptic function solutions, hyperbolic function solutions, trigonometric function solutions, solitary wave solutions, breaking wave solutions, and kink wave solutions.     

1-Soliton Solution of 1+2 Dimensional Nonlinear Schrödinger’s Equation in Kerr Law Media

This paper integrates the nonlinear Schrödinger’s equation in 1+2 dimensions with Kerr law nonlinearity. An exact 1-soliton solution is obtained in closed form using the solitary wave ansatz. Finally, the consertved quantities are calculated using this soliton solution.     

Towards an exact factorization of the molecular wave function

An exact single-product factorisation of the molecular wave function for the timedependent Schrödinger equation is investigated by using an ansatz involving a phase factor. By using the Frenkel variational method, we obtain the Schrödinger equations for the electronic and nuclear wave functions. The concept of a potential energy surface (PES) is retained by introducing a modified Hamiltonian as suggested earlier by Cederbaum. The parameter ω in the phase factor is chosen such that the equations of motion retain the physically appealing Born– Oppenheimer-like form, and is therefore unique.     

New optical soliton solutions for nonlinear complex fractional Schrödinger equation via new auxiliary equation method and novel $$({G'}/{G})$$-expansion method

In this research, we apply two different techniques on nonlinear complex fractional nonlinear Schrödinger equation which is a very important model in fractional quantum mechanics. Nonlinear Schrödinger equation is one of the basic models in fibre optics and many other branches of science. We use the conformable fractional derivative to transfer the nonlinear real integer-order nonlinear Schrödinger equation to nonlinear complex fractional nonlinear Schrödinger equation. We apply new auxiliary equation method and novel \(\left( {G'}/{G}\right) \)-expansion method on nonlinear complex fractional Schrödinger equation to obtain new optical forms of solitary travelling wave solutions. We find many new optical solitary travelling wave solutions for this model. These solutions are obtained precisely and efficiency of the method can be demonstrated.     

Exact solutions of some nonlinear partial differential equations using functional variable method

The functional variable method is a powerful solution method for obtaining exact solutions of some nonlinear partial differential equations. In this paper, the functional variable method is used to establish exact solutions of the generalized forms of Klein–Gordon equation, the (2?+?1)-dimensional Camassa–Holm Kadomtsev–Petviashvili equation and the higher-order nonlinear Schrödinger equation. By using this useful method, we found some exact solutions of the above-mentioned equations. The obtained solutions include solitary wave solutions, periodic wave solutions and combined formal solutions. It is shown that the proposed method is effective and general.     

(2+1)维扰动时滞破裂孤波方程行波解的摄动方法

研究了一类(2+1)维扰动时滞破裂孤波方程. 首先讨论了对应的无时滞情形下的破裂方程,利用待定系数投射方法得到了孤波精确解. 再利用同伦、摄动近似方法得到了扰动破裂孤波方程的行波渐近解. 关键词： 孤波 行波解 近似解     

Exact hole-bound states for semiconductor quantum wells with arbitrary potential profiles

An efficient numerical-analytical method for finding confined and continuum states in quantum-well systems with arbitrary potential profiles, described by coupled Schrödinger equations, is presented. The method is based on the analytical properties of the wave functions, in particular, the power series representation of solutions of the corresponding coupled differential equations. Using only the general properties of the coefficients of a system of an arbitrary number of coupled Schrödinger equations, and imposing for definiteness the simplest boundary conditions, we derive exact expressions for the wave functions and present methods for accurate calculations of the energies and wave functions of confined states and of the wave functions of continuum states in quantum wells. The method is applied to the calculation of the dispersion of hole bound states in a single GaAs quantum well with truncated parabolic confining potentials of different strengths. The results are compared with data available from previous calculations.     

Darboux transformations for a system of coupled discrete Schrödinger equations

Darboux transformations and a factorization procedure are presented for a system of coupled finite-difference Schrödinger equations. The conformity between generalized Darboux transformations and the factorization method is established. Factorization chains and consequences of Darboux transformations are obtained for a system of coupled discrete Schrödinger equations. The proposed approach permits constructing a new series of potential matrices with known spectral characteristics for which coupled-channel discrete Schrödinger equations have exact solutions.