Funding for this research was provided by:
Higher Education Discipline Innovation Project (B13042)
the National Key Research and Development Plan (2016YFA0300801)
the Sichuan Science and Technology Support Project (2016GZ0250)
the International Cooperation Project (2013HH0003)
Text and Data Mining valid from 2019-05-10
Received: 7 January 2019
Accepted: 29 April 2019
First Online: 10 May 2019
: The authors declare that they have no competing interests.
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