Yang, Yunyun
Xie, Gang http://orcid.org/0000-0002-3382-3615
Funding for this research was provided by:
Innovation Foundations of Education for Graduate Students of Shanxi Province (2016BY061)
National Natural Science Foundation of China (61402319, 61503271)
Article History
Received: 9 September 2016
Accepted: 17 June 2017
First Online: 30 June 2017
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.