Chen, Wei http://orcid.org/0000-0002-5825-1422
Chai, Huichan
Zhao, Zhou
Wang, Qiqing
Hong, Haoyuan http://orcid.org/0000-0001-6224-069X
Funding for this research was provided by:
National Science Foundation of China (41302276)
Natural Science Foundation of Shaanxi Province (2012JM5008)