Xu, Cheng
Qu, Hongzhu
Wang, Guangyu
Xie, Bingbing
Shi, Yi
Yang, Yaran
Zhao, Zhao
Hu, Lan
Fang, Xiangdong
Yan, Jiangwei
Feng, Lei
Article History
Received: 18 March 2015
Accepted: 5 November 2015
First Online: 4 December 2015
Change Date: 8 January 2016
Change Type: Update
Change Details: The version of this Article previously published omitted Jiangwei Yan as a corresponding author. Correspondence and request for materials should also be addressed to yanjw@big.ac.cn. This has now been corrected in the HTML and PDF versions of the Article.
Competing interests
: The authors declare no competing financial interests.