talk with professors about prospective graduate study Following some tips about graduate study, I have contacted the professors before the admission cycle, and managed to secure some appointments with them. I have read through their publications that match my research interests, and prepared some brief write up about my research experiences (though I had sent them my CV beforehand).

I am just confused about what I should expect from such meetings. To be frank, do you think to impress them to the point that they agree to accept me is a feasible thing? Or I should aim for something simpler, like maintaining relationships with them through this semester?
As a rule, I think such meetings are a bad idea.  At a minimum you should go in with no admissions agenda.  If you are interested in research and only research I think the meeting will go well.  But if your real agenda is to help the admissions process, they will read through the facade and probably be annoyed.