China, academy stay high on list of research yield

Quality-focused index shows country's gap to US, though still huge, is narrowing

The Chinese Academy of Sciences remains the world's top academic institution, and China held onto the second spot for the quality of research output in the latest Nature Index tables, which have been published annually since 2014.

The tables - released on Thursday and compiled by one of the world's leading research publishers, Springer Nature - are influential in the evaluation of high-quality research output, and are based on the percentage of authors from the country or institution and the number of affiliated institutions per scientific article.