Sun, Zhe
Hu, Zheng-ping
Wang, Meng
Zhao, Shu-huan
Funding for this research was provided by:
National Natural Science Foundation of China (61071199)
Natural Science Foundation of Hebei Province (F2016203422)
Article History
First Online: 28 April 2017
Compliance with ethical standards
:
: We declare that there is no conflict of interest regarding the publication of this paper.