Yang, Yihao
Jing, Liqiao
Shen, Lian
Wang, Zuojia
Zheng, Bin
Wang, Huaping
Li, Erping
Shen, Nian-Hai
Koschny, Thomas
Soukoulis, Costas M
Chen, Hongsheng
Article History
Received: 29 March 2017
Revised: 17 June 2017
Accepted: 27 June 2017
First Online: 25 August 2017
Competing interests
: The authors declare no conflict of interest.