Zhao, Pingzhi
Sokolov, Lubomir N.
Ye, Jian
Tang, Cheng-Yi
Shi, Jisen
Zhen, Yan
Lan, Wenzhi
Hong, Zhi
Qi, Jinliang
Lu, Gui-Hua
Pandey, Girdhar K.
Yang, Yong-Hua
Article History
Received: 9 February 2016
Accepted: 8 June 2016
First Online: 28 June 2016
Competing interests
: The authors declare no competing financial interests.