Funding for this research was provided by:
NSFC (21563002)
the Research Program of Sciences at Universities of Inner Mongolia Autonomous Region (NJZZ235)
the Natural Science Foundation of Inner Mongolia Autonomous Region (2015MS0201)
Article History
Received: 18 March 2018
Accepted: 12 October 2018
First Online: 22 October 2018
Compliance with ethical standards
:
: The authors declare that they have no competing interests.