Funding for this research was provided by:
National Nature Science Foundation of China (11361039)
Natural Science Foundation of Inner Mongolia (2017MS0124)
Inner Mongolia Autonomous Region University Scientific Research Project (NJZY17045)
Article History
Received: 9 November 2018
Accepted: 16 January 2019
First Online: 23 January 2019
Competing interests
: The authors declare that there are no competing interests.