Hou, Zhibo
Zhu, Huangjun
Xiang, Guo-Yong
Li, Chuan-Feng
Guo, Guang-Can
Article History
Received: 1 April 2015
Revised: 1 November 2015
Accepted: 17 December 2015
First Online: 23 February 2016
Competing interests
: The authors declare no conflict of interest.