Funding for this research was provided by:
Natural Science Foundation of Jilin Engineering Normal University (XYB201814)
Partially supported by the Fundamental Research Funds for Central Universities (2017B19714)
Natural Science Foundation of Jiangsu Province (BK20180500)
Article History
Received: 21 August 2018
Accepted: 26 November 2018
First Online: 4 December 2018
Competing interests
: The authors declare that they have no competing interests.