Kang, Ting
Zhang, Qimin
Funding for this research was provided by:
the Natural Science Foundation of Ningxia University (ZR16002)
National Natural Science Foundation of China (11661064)
Ningxia College Scientific Research Project (NGY2017217)
Article History
Received: 8 May 2018
Accepted: 1 October 2018
First Online: 11 October 2018
Competing interests
: The authors declare that they have no competing interests.