Funding for this research was provided by:
The National Social Science Foundation of China (No.16BGL145)
Article History
Received: 22 February 2018
Accepted: 26 April 2018
First Online: 16 May 2018
Compliance with ethical standards
:
: We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled.