Funding for this research was provided by:
National Natural Science Foundation of China (11571207)
Natural Science Foundation of Shandong Province (ZR2018MA011)
Taishan Scholar Foundation of Shandong Province
Article History
Received: 19 January 2019
Accepted: 18 March 2019
First Online: 21 March 2019
Ethics approval and consent to participate
: Not applicable.
: The authors declare that they have no competing interests.
: All authors agree to publication of this paper in JIAP.