[5] Zhang wrote his thesis on the orientation of the orbital plane of double stars under the mentorship of George Van Biesbroeck.

[5][6] While pursuing his Ph.D. at the University of Chicago, in 1928, Zhang discovered an asteroid which was given the provisional designation 1928 UF and later the number 1125.

With his agreement the new object 1957 UN1 was reassigned the official designation 1125 China in place of the lost 1928 UF.

However, in 1986, the newly discovered object 1986 QK1 was confirmed to be a rediscovery of the original 1928 UF, and this object was named 3789 Zhongguo ("中国" (Zhōngguó) is the Mandarin Chinese word for "China", in pinyin transliteration, whereas Zhōnghuá is a slightly older word for "China").

Tsuchinshan is the Wade-Giles transliteration corresponding to the pinyin Zĭjīn Shān, which is Mandarin Chinese for "Purple Mountain", named after the observatory he oversaw.