From July 25 to 30, 2016, Mengkun Liu from American State University was invited to visit the National Center for Nanoscience and Technology. During this period, Mr. Liu made an academic report on characterizing the phase transition of two-dimensional materials using near-field optical technology, and we also had an in-depth exchange with Mr. Liu on the latest research progress of the research group. After the meeting, Mr. Liu gave technical guidance to the use of near-field optical instruments in our center and tested the samples they carried, put forward specific opinions on the upgrading and transformation scheme of near-field instruments in our center and expressed the intention to cooperate with us in instrument development.