“2-yr mean citedness” is the OpenAlex field summary_stats.2yr_mean_citedness (CC0): mean citations per paper over a two-year window. It is a raw bibliometric field, not a journal rating, and is not used for default ranking.
Engineering50Materials Science29Chemistry17Physics and Astronomy11Technology: Chemical technology: Biotechnology1Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials1