Funding for this research was provided by:
National Natural Science Foundation of China (11472009)
Construction Plan for Innovative Research Team of North China University of Technology (XN018010)
Scientific Research for Undergraduate of North China University of Technology
Article History
Received: 20 December 2017
Accepted: 4 July 2018
First Online: 16 July 2018
Compliance with ethical standards
:
: The authors declare that there are no competing interests regarding the publication of this paper.