Wu, Helin
Ren, Yong
Hu, Feng
Funding for this research was provided by:
the Scientific and Technological Research Program of Chongqing Municipal Education Commission (KJ1400922)
the National Natural Science Foundation of China (11871076, 11801307)
the Natural Science Foundation of Shandong Province (ZR2016JL002 and ZR2017MA012)
Article History
Received: 5 June 2018
Accepted: 4 December 2018
First Online: 12 December 2018
Competing interests
: The authors declare that they have no competing interests.