Funding for this research was provided by:
National Natural Science Foundation of China (51379170)
Research and Innovation Team of WTCC (CX2018A04)
Text and Data Mining valid from 2018-06-15
Received: 12 February 2018
Accepted: 30 May 2018
First Online: 15 June 2018
: The authors declare that they have no competing interests.
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