非线性系统的精确解

Based on the computerized symbolic, a new generalized tanh functions method is used for constructing exact travelling wave solutions of nonlinear partial differential equations （PDES） in a unified way. The main idea of our method is to take full advantage of an auxiliary ordinary differential equation which has more new solutions. At the same time, we present a more general transformation, which is a generalized method for finding more types of travelling wave solutions of nonlinear evolution equations （NLEEs）. More new exact travelling wave solutions to two nonlinear systems are explicitly obtained.     

Construction of doubly-periodic solutions to nonlinear partial differential equations using improved Jacobi elliptic function expansion method and symbolic computation

Some doubly-periodic solutions of the Zakharov--Kuznetsov equation are presented. Our approach is to introduce an auxiliary ordinary differential equation and use its Jacobi elliptic function solutions to construct doubly-periodic solutions of the Zakharov--Kuznetsov equation, which has been derived by Gottwald as a two-dimensional model for nonlinear Rossby waves. When the modulus k \rightarrow 1, these solutions reduce to the solitary wave solutions of the equation.     

新的双曲函数有理展开法和符号计算构造差分mkdv的孤波解

本文通过利用一个广泛的题设提出一种推广的双曲函数展开法, 并利用此方法求解了 离散的 mKdV 方程, 获得了丰富的显式精确解. 此方法可以用于求其他非线性系统的精确解.     

从动量流的角度谈重力的定义

重力是一个非常重要的物理概念, 围绕重力概念存在分歧. 力是牛顿时代建立的抽象概念, 重力是体现 万有引力作用效果的一种效果力, 这种抽象的虚拟力概念不利于学生掌握. 力也可以看成是动量流强度, 文献[ 1 1] 从动量流视觉定义了重力, 这是应该肯定的. 但该定义也存在一些问题, 对此进行辨析, 并用动量流概念重新定义重 力, 通过对相关问题的解释说明重力新定义的合理性和有效性