Institution: | 1. Center for Nonlinear Studies, Northwest University, Xi'an 710069, China
;2. Department of Mathematics, Northwest University, Xi'an 710069, China
;3. Department of Mathematics, South-Central University of
Nationalities, Wuhan 430074, China
;4. Wuhan Institute of Physics and Mathematics, the Chinese
Academy of Sciences, Wuhan 430071, China |