Funding for this research was provided by:
National Natural Science Foundation of China (61772513, 61772047)
Open Funds of CETC Big Data Research Institute Co.,Ltd., (W-2018022)
The Science and Technology Project of the State Archives Administrator (2015-B-10)
The Fundamental Research Funds for the Central Universities (328201803)
Text and Data Mining valid from 2019-02-20
First Online: 20 February 2019
Compliance with ethical standards
: None of the authors declare that he/she has conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.