Zhang, Kun
Li, Huan-huan
Grünberg, Peter
Li, Qiang
Ye, Sheng-tao
Tian, Yu-feng
Yan, Shi-shen
Lin, Zhao-jun
Kang, Shi-shou
Chen, Yan-xue
Liu, Guo-lei
Mei, Liang-mo
Article History
Received: 26 June 2015
Accepted: 20 August 2015
First Online: 21 September 2015
Competing interests
: The authors declare no competing financial interests.