Who is the little brother playing in Xisha Underwater in Grave Notes?

Play a bald man. According to the original text, he should be a famous professor. On a bed sat a middle-aged man, a little fat and bald, with a shiny face. When he saw me come in, he stood up and shook hands with me and said, "Nice to meet you, nice to meet you. My surname is Zhang. " The bald man waved his hand exaggeratedly and said, "Experts don't deserve it. Everyone is just studying. It's just that I was lucky enough to publish several papers, so I don't want to mention my small achievements. " I have never seen anyone talk like this, and I don't know how to answer him, so I have to say, "You are too modest."