Wu, Xiang-feng
Zhao, Ze-hua
Sun, Yang
Li, Hui
Wang, Yi-jin
Zhang, Chen-xu
Gong, Xiao-dong
Wang, Yu-duan
Yang, Xin-yue
Liu, Yu
Funding for this research was provided by:
Youth Science and Technology Foundation of Higher Education Institutions of Hebei Province, China (No.Q2012111)
Natural Science Foundation of Hebei Province, China (No.E2013210011)