Exact Solutions For Some Nonlinear Evolution Equations

In this paper, we mainly study some nonlinear evolution equationswith physical background by using the improved tanh method and sine-cosinemethod,based on the soliton theory and modern computer techology.With thesymbolic computation system Matlab,we obtain their new soliton solutions andnew exact solutions.First,we deal with a (3+1)-dimensional Schr(o|¨)dinger equation:By using the sine-cosine method,we obtain some soliton solutions and rationalsolutions of the (3+1)-dimensional Schr(o|¨)dinger equation.Totally there are sixsolutions which we founded .Secondly,by using an improved tanh Function method and using the equa-tion F(ξ) = A + BF(ξ) + CF(ξ)2 as the disturbance equation,we study a(2+1)-dimensional breaking soliton equation: we found some exact solutions of the (2+1)-dimensional breaking soliton equa-tion through varying the parameters in the disturbance equation ,.The solutionsnot only include soliton solutions,rational solutions, but also include soliton-likeand triangle periodic solutions.Totally there are ten solutions which are of sixdifferent type of function.