Funding for this research was provided by:
National Natural Science Foundation of China (U1404701)
Scholarship Programm of China Scholarship Council (201509895007)
Scientific Research Foundation of the Henan University of Technology (2017RCJH11)
Key Research Institute of Humanities and Social Sciences at Universities of Henan (2015-JD-04)
Article History
First Online: 27 November 2018
Compliance with ethical standard
:
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.