[1] Anhui Polytech Univ, Sch Math Phys & Finance, Wuhu 241000, Peoples R China
[2] East China Normal Univ, Sch Math Sci, Key Lab Pure Math & Math Practice, Shanghai 200241, Peoples R China
[3] Univ New South Wales, Sch Engn & Informat Technol, Canberra, ACT 2600, Australia