Funding for this research was provided by:
National Natural Science Foundation of China (61370210)
New Century Excellent Talents in Fujian Province (SX2015-01)
Text and Data Mining valid from 2018-03-15
Received: 2 January 2018
Accepted: 28 February 2018
First Online: 15 March 2018
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.