Funding for this research was provided by:
National Natural Science Foundation of China (71273166, 71273165, 71573163)
National Office for Philosophy and Social Sciences (18CJL030)
NG Teng Fong/Sino Outstanding Youth Fund of HUEL
Text and Data Mining valid from 2019-02-08
Received: 21 November 2018
Accepted: 24 January 2019
First Online: 8 February 2019
: The authors declare that they have no competing interests.
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