Chen, Ruipeng http://orcid.org/0000-0002-9262-3701
Li, Xiaoya
Funding for this research was provided by:
Scientific Research Funds of North Minzu University (No.2018XYZSX03)
National Natural Science Foundation of China (No.11761004; No.61761002)
First-Class Disciplines Foundation of Ningxia (Grant No.NXYLXK2017B09)
Article History
Received: 12 July 2018
Accepted: 13 November 2018
First Online: 16 November 2018
Competing interests
: The authors declare that they have no competing interests.