开放的序曲：竺可桢与1971年之后的中外科学文化交流

Group 1 - The article discusses the improvement of China's relations with Western countries following Nixon's visit to China and the establishment of diplomatic ties with the UK, highlighting informal diplomatic activities in various fields such as science, culture, and arts to broaden foreign exchanges [1] - The thawing of Sino-American relations is exemplified by the exchanges between scientists, particularly through the visits of prominent figures like Yang Zhenning and Li Zhengdao [2][4] - The article notes that Yang Zhenning's first visit to China in July 1971 was met with mixed reactions, as some domestic scholars felt resentment towards the preferential treatment he received compared to those who remained in China [5][6] Group 2 - Following the warming of Sino-American relations, Yang Zhenning's second visit in June-July 1972 further emphasized the importance of scientific theoretical research and academic exchanges [7][8] - The article highlights a letter from 18 physicists to Premier Zhou Enlai advocating for the advancement of high-energy accelerator and detector technology, which Zhou supported [8] - The increasing frequency of cultural exchanges is illustrated by the visits of various Western scholars and artists to China, including the London Philharmonic Orchestra's performance in 1973, marking a significant moment in cultural diplomacy [25][28]