Funding for this research was provided by:
Natural Science Foundation of Hebei Province (C2019208188)
the Doctoral Research Foundation Project of Hebei University of Science and Technology (81/1181288, 81/1181289)
the PT Foundation of Hebei University of Science and Technology (82/1182218)
Article History
Received: 10 October 2019
Accepted: 4 February 2020
First Online: 13 February 2020
Compliance with Ethical Standards
:
: Gaoshuang Hu declares that she has no conflict of interest. Shan Gao declares that he has no conflict of interest. Xue Han declares that she has no conflict of interest. Lixin Yang declares that he has no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: A statement regarding informed consent is not applicable for this study.