[1] Capital Normal Univ, Sch Math Sci, Beijing 100048, Peoples R China
[2] Henan Univ, Coll Math & Informat Sci, Kaifeng 475001, Peoples R China
[3] Chinese Acad Sci, Acad Math & Syst Sci, Inst Appl Math, Beijing 100190, Peoples R China
[4] Qilu Univ Technol, Sch Sci, Jinan 250353, Peoples R China
[5] Beijing Ctr Math & Informat Interdisciplinary Sci, Beijing 100048, Peoples R China
[6] Capital Normal Univ, Inst Math & Interdisciplinary Sci, Beijing 100048, Peoples R China