Funding for this research was provided by:
National Science Foundation (16CZX015)
China Postdoctoral Science Foundation (2014T70578)
Major Projects about Key Research Institute on Humanities and Social Sciences by Ministry of Education (13JZD004)
China Scholarship Council – Leiden University Joint Scholarship Program
Received: 2 February 2017
Accepted: 2 August 2017
First Online: 23 August 2017
: The authors declare that they have no competing interests.
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