Yu, Jiyuan
Article History
Received: 10 July 2018
Revised: 12 September 2020
Accepted: 28 January 2021
First Online: 4 June 2021
Conflict of Interest
: The editors declare that there is no conflict of interest in the publication of this article.
: The editors declare that this manuscript is the result of Jiyuan Yu's independent creation. Except for quoted contents, this manuscript does not contain any research achievements that have been published or written by other individuals or groups. Though the late Jiyuan Yu has not overseen the process of editing, a surviving member of Yu's family gave editors full discretion in preparing the manuscript for publication. The editors carefully preserved Yu's voice and did not include any additional materials.
: Not applicable.
: Not applicable.
: Jiyuan Yu is the only author.