Funding for this research was provided by:
National Natural Science Foundation of China (61773120)
National Natural Science Foundation of China (61873328)
National Natural Science Fund for Distinguished Young Scholars of China (61525304)
National Excellent Doctoral Dissertation of China (2014-92)
MOE (Ministry of Education in China) Liberal Arts and Social Sciences Foundation (17YJCZH157)
Article History
First Online: 13 November 2019
Compliance with ethical standards
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: The authors declare that there is no conflict of interest regarding the publication of this paper.