Xu, Xian-Feng
Duan, Chen-Dong
Liu, Lai-Jun
Yang, Xiao-Jun
Funding for this research was provided by:
the National Natural Science Foundation of China (61201407, 61473047)
China Postdoctoral Science Foundation (2013M542309)
the Special Fund for Basic Scientific Research of Central Colleges, Chang'an University (0009-2014G1321038)