Hao, Shijie
Cui, Lishan
Guo, Fangmin
Liu, Yinong
Shi, Xiaobin
Jiang, Daqiang
Brown, Dennis E.
Ren, Yang
Article History
Received: 9 September 2014
Accepted: 10 February 2015
First Online: 9 March 2015
Competing interests
: The authors declare no competing financial interests.