中文摘要：

为了获得变系数非线性发展方程的无穷序列复合型新解，研究了G＇（ξ）/G（ξ）展开法．通过引入一种函数变换，把常系数二阶齐次线性常微分方程的求解问题转化为一元二次方程和Riccati方程的求解问题．在此基础上，利用Riccati方程解的非线性叠加公式，获得了常系数二阶齐次线性常微分方程的无穷序列复合型新解．借助这些复合型新解与符号计算系统Mathematica，构造了带强迫项变系数组合KdV方程的无穷序列复合型类孤子新精确解．

英文摘要：

The G＇（ξ）/G（ξ） expansion method is extensively studied to search for new infinite sequence of complex solutions to nonlinear evolution equations with variable coefficients. According to a function transformation, the solving of homo- geneous linear ordinary differential equation with constant coefficients of second order can be changed into the solving of a one-unknown quadratic equation and the Riccati equation. Based on this, new infinite sequence complex solutions of homogeneous linear ordinary differential equation with constant coefficients of second order are obtained by the non- linear superposition formula of the solutions to Riccati equation. By means of the new complex solutions, new infinite sequence complex soliton-like exact solutions to the combined KdV equation with variable coefficients and forced term are constructed with the help of symbolic computation system Mathematica.