Funding for this research was provided by:
Fundamental Research Funds for the Central Universities (ZK1044)
Xiamen University Prospering Philosophy and Social Science Project
Text and Data Mining valid from 2018-08-18
Received: 26 March 2018
Accepted: 16 July 2018
First Online: 18 August 2018
: The author declares that there are no competing interests.
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