Professor Li, I've long admired your academic achievements.
Tips
usage
久仰 is a set polite phrase used when meeting someone for the first time. 久仰大名 (I've long admired your great name) is the most common form. It can sound overly formal in casual settings.
register
This is a formal/classical greeting. In casual speech, people just say 你好 or 幸会. Using 久仰 in everyday conversation can sound humorous or ironic.
