Zheng, Shijian
Shao, Shuai
Zhang, Jian
Wang, Yongqiang
Demkowicz, Michael J.
Beyerlein, Irene J.
Mara, Nathan A.
Article History
Received: 24 April 2015
Accepted: 26 August 2015
First Online: 21 October 2015
Competing interests
: The authors declare no competing financial interests.