Xue, Gang
Liu, Shifeng
Ma, Yicao
Funding for this research was provided by:
Beijing Social Science Foundation Grant (19JDGLA002)
Article History
Received: 1 July 2020
Accepted: 18 August 2020
First Online: 12 October 2020
Compliance with ethical standards
:
: On behalf of all authors, the corresponding author states that there is no conflict of interest.