Li, W. B.
Liu, Z.
Meng, Z. F.
Ren, S.
Xu, S. E.
Zhang, Y.
Wang, M. Y.
Funding for this research was provided by:
National Natural Science Foundation of China (41271244)
Social Development Project in Shaanxi (2013K0105)
Science and Technology Project in Shaanxi (2012K0215)