Wu, S. Y.
Tong, X.
Nie, C. D.
Peng, D. Q.
Gong, S. G.
Wang, Z. Q.
Funding for this research was provided by:
the Hunan Provincial Natural Science Foundation of China (13JJ6040)
the China Postdoctoral Science Foundation (2013M542125)
the National Nature Science Foundation of China (51206071)