[1] Acad Armored Forces Engn Peoples Liberat Army, Dept Phys, Beijing 100072, Peoples R China
[2] Shijiazhuang Railway Inst, Phys Grad Sch, Shijiazhuang 050043, Peoples R China
[3] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China