Title: New multi-order exact solutions to a kind of nonlinear evolution equations
Abstract: Based on the Lamé equation and new Lamé functions, the perturbation method and Jacobi elliptic function expansion method are applied to get the multi-order ex act solutions of a kind of nonlinear evolution equations (such as mKdV equation, nonlinear Klein-Gordon equation Ⅱ etc.), where some more new multi-order exact solutions are found among different nonlinear evolution equations. These multi- order exact solutions correspond to different periodic solutions, which can dege nerate into different solitary wave solutions, such as band-soliton, bell-shaped solitary wave, etc.