SUN Enxi Dalian Railway College,Dalian,ChinaYANG Dazhi Dalian University of Technology,Dalian,ChinaXU Zuyao (T.Y.Hsu) Shanghai Jiaotong University,Shanghai,ChinaYANG Fuming ZHAO Ruwen Institute of Physics,Academia Sinica,Beijing,China YANG Dazhi,Professor,Dalian University of Technology,Dalian 116024,China