Affiliation: | NIE ChangXiong 1,2,LI TongZhu 3,HE YiJun 4 & WU ChuanXi 5 1 Faculty of Mathematics , Computer Sciences,Hubei University,Wuhan 430062,China,2 School of Mathematical Sciences,Peking University,Beijing 100871,3 Faculty of Sciences,Beijing Institute of Technology,Beijing 100081,4 School of Mathematical Sciences,Shanxi University,Taiyuan 030006,5 Institute of Mathematics |