Funding for this research was provided by:
National Natural Science Foundation of China (81171886; 81372587)
Beijing Municipal Natural Science Foundation (7132018)
Beijing City Board of Education Development Project (KZ201310025021)
the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality (IDHT20140514)
Text and Data Mining valid from 2019-05-09
First Online: 9 May 2019
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