Center for Nonlinear Studies, Department of Mathematics, Northwest University, Xi'an 710069;
Institute of Modern Physics, Northwest University, Xi'an 710069;
Center of Nonlinear Science, Ningbo University, Ningbo 315211;
Center for Nonlinear Studies, Department of Mathematics, Northwest University, Xi'an 710069;
Center for Nonlinear Studies, Department of Mathematics, Northwest University, Xi'an 710069;
