Institution: | 1. Department of Mathematics, Capital Normal University,
Beijing 100037, China
;2. College of Mathematics and Information Science,
Hebei Normal University, Shijiazhuang 050016, China
;3. Department of Physics, Hebei Normal University, Shijiazhuang
050016, China
;4. CCAST (World Laboratory), P.O. Box 8730, Beijing 100080, China |