Figures & data
Only research articles were included, while other publication types such as reviews, proceeding papers and meeting abstracts were excluded. Subject to the retrieval time (March 4, 2022), data for 2022 is incomplete.
The size of node indicates the amount of articles in each category, and categories with more than 130 articles were labeled. The thickness of the purple ring reflects the degree of betweenness centrality. Nodes in red indicate a sharp increase of citations detected.
Clusters are labeled in black text based on the top terms extracted by CiteSpace and based on in-depth reading of the main citing articles and cited references. Important references with the highest citations are labeled in purple text. The thickness of the purple ring reflects the degree of betweenness centrality.
Supplemental material