全球科研城市榜单出炉
Global science cities 2020
近日发布的“自然指数-科研城市2020”将北京列为全球科研城市首位，纽约、波士顿、旧金山-圣何塞地区和上海紧随其后。
Beijing ranked as the top science city globally, followed by New York, Boston, San Francisco/San Jose and Shanghai, in the Nature Index global science city 2020 rankings.
除北京之外，还有四座中国城市——南京、武汉、广州、合肥跻身全球科研城市排行前20位。
Four other Chinese cities - Nanjing, Wuhan, Guangzhou and Hefei - ranked among the top 20 global science cities.
自然指数创始人戴维·斯文班克斯表示，人才、资金、研究机构和其它资源的集中，是全球五大科研城市保持领先地位的重要因素。
David Swinbanks, founder of the Nature Index, said a concentration of talent, funding, research institutions and other resources is crucial for the top five global science cities to maintain their leading positions.
该指数使用的一个关键指标是“份额”，即一个城市对本国科学出版物的贡献。
A key metric used by the index is "share" - a city's contribution to science publication in its own country.
数据显示，北京对中国的科学文章贡献份额为21%，是排名前五的其他城市的两倍多。
Data shows Beijing's contribution to China was 21%, more than double that of any other city in the top five.
北京还是中国科学院所在地，中国科学院的贡献份额位居机构首位，同时它也是中国科研合作的枢纽。
Beijing is also home to the Chinese Academy of Sciences, which, at the institutional level, leads the index in share and acts as a central hub of Chinese scientific collaboration.