[1] Cent China Normal Univ, Sch Math & Stat, Hubei Key Lab Math Phys, Wuhan 430079, Peoples R China
[2] Shanxi Datong Univ, Sch Math & Stat, Datong 037009, Peoples R China
[3] Shanghai Jiao Tong Univ, Sch Math Sci, Inst Nat Sci, Ctr Appl Math,MOE,LSC, Shanghai 200240, Peoples R China
[4] Shanghai Jiao Tong Univ, SHL, MAC, Shanghai 200240, Peoples R China