https://techcrunch.com/2018/05/30/chinese-visas-state-department-trump-june-11/

In a policy change set for next month, the Trump administration is moving to shorten visas for Chinese students in fields like tech and engineering. While most visas are issued for the longest possible length of time under law, the new policy will allow U.S. officials to put a one-year cap on visas for Chinese graduate students who are “studying in fields like robotics, aviation and high-tech manufacturing,” according to the Associated Press.

A State Department official told The Hill that “Although the large majority of visas issued to Chinese nationals are issued for the maximum validity, consular officers may limit the validity of visas on a case-by-case basis” under the new rules.