Funding for this research was provided by:
National Natural Science Foundation of China (21505050, 51672109, 61504048, 21707043)
Natural Science Foundation of Shandong Province for Excellent Young Scholars (ZR2016JL015, ZR2017BEE005)
Technological Development Program in Shandong Province Education Department (J15LJ06)
Text and Data Mining valid from 2018-08-30
Received: 28 February 2018
Accepted: 21 August 2018
First Online: 30 August 2018
: The authors declare that they have no competing interests.
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