Using the improved exp(-Φ(ξ)) expansion method to find the soliton solutions of the nonlinear evolution equation

With the help of the symbolic calculation software Mathematica, the nonlinear coupled Schrodinger system, (2 + 1)-dimensional dispersive long-wave system and (2 + 1)-dimensional Nizhnik-Novikov-Veselov system are solved by using the improved exp(- Phi(xi)) expansion method. Diverse new soliton solutions are obtained, and the structure and properties of soliton solutions are studied. We derive seven sets of exact solutions under different conditions for the nonlinear coupled Schrodinger system and the (2 + 1)-dimensional dispersive long wave equation, respectively, and for the (2 + 1)-dimensional Nizhnik-Novikov-Veselov system, we find the inelastic interaction solitary waves and fussion soliton.