Funding for this research was provided by:
Program for New Century Excellent Talents in University (NCET-13-0037)
Humanities and Social Sciences Foundation of Ministry of Education of China (14YJA630019)
Article History
First Online: 9 February 2018
Compliance with ethical standards
:
: 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.