Funding for this research was provided by:
the Natural Science Foundation of Fujian Province (2015J01019)
the Science Research Projection of the Education Department of Fujian Province (JAT160182)
NSFC (11021101, 11290142, 91130003 and 11701086)
Article History
Received: 17 July 2018
Accepted: 2 December 2018
First Online: 11 December 2018
Competing interests
: The authors declare that they have no competing interests.