Figure 1. The co-occurrence map of the top 50 authors with the greatest number of articles in the first (A, 2009-2013) and second (B, 2014-2018) halves of the decade from 2009 to 2018.

The larger the circle in the figure, the larger the number of articles published by the author. The thicker the lines, more cooperation among the authors. The connection will be displayed only when the number of the author's cooperative publication is no less than 12.