On the afternoon of February 1, Dr. Lv Zejie returned to the laboratory to visit the teachers and students. Dr. Lv is a PhD student of Prof. Xi and Prof. Zhang in the class of 2016, focusing on nitrogen fixation research and rare-earth chemistry, and he has done a lot of outstanding work during his PhD. After completing his PhD in 21 years, he went to the Sven Schneider's group of the University of Gottingen, Germany for postdoctoral research. During this visit, he shared his valuable scientific research experience and experimental skills with his teachers and classmates, which benefited us a lot. In addition, they also visited the laboratory with him and reviewed the equipment used during the laboratory. Finally, everyone took a group photo, leaving an unforgettable memory!