Funding for this research was provided by:
the National Natural Science Foundation of China (61602519)
Ministry of Education of China (MOE) Project of Humanities and Social Sciences (16YJC860026)
China Postdoctoral Science Foundation (2013M542021)
China Postdoctoral Science Foundation (2014M562026)
the Natural Science Foundation of Hubei Province, China (2013CFC090)
the Fundamental Research Funds for the Central Universities, Zhongnan University of Economics and Law (2012096)
Article History
Received: 5 May 2017
Revised: 7 June 2017
Accepted: 5 July 2017
First Online: 11 August 2017