Li, Jiansheng
Zhao, Ayun
Liu, Yanci
Li, Xueyun
Xie, Jiarong
Zhu, Yawen
Funding for this research was provided by:
Foundation for Young Teacher of Northwest Normal University (NWNU-LKQ N-11-34)
Natural Science Foundation of Gansu Province (CN) (1506RJYA120)
Scientific research project of Gansu Province (2015A-004)