Funding for this research was provided by:
National Natural Science Foundation of China (11704058)
Fundamental Research Funds for the Central Universities (DUT16RC (3)111, 106112017CDJXFLX0014)
Text and Data Mining valid from 2018-07-05
Received: 22 March 2018
Accepted: 12 June 2018
First Online: 5 July 2018
: The authors declare that they have no competing interests.
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