Xiong, Jing
Zhou, Ming-feng
Wang, Ya-dong
Chen, Li-ping
Xu, Wan-fu
Wang, Yao-dong
Deng, Fan
Liu, Si-de
Article History
Received: 10 May 2016
Accepted: 7 September 2016
First Online: 23 September 2016
Competing interests
: The authors declare no competing financial interests.