1. 研究生
    A post-graduate or a postgraduate student is a student with a first degree from a university who is studying or doing research at a more advanced level.

postgraduate的解释

2. 研究生的
    Postgraduate study or research is done by a student who has a first degree and is studying or doing research at a more advanced level.

    e.g. ...postgraduate courses...
           研究生课程
    e.g. Dr Hoffman did his postgraduate work at Leicester University.
           霍夫曼博士是在莱斯特大学读的研究生。