I am an international student who are applying for admission to
Department of IEOR at CU.(Fall 2003 Graduate School)
Now I want to write Emails to 2 professors.
(p.s.  their home pages==http://www.columbia.edu/~ks20/ &
http://www.columbia.edu/~ps147/)
Because their research topics are interested by me. I need to have a
short discuss with him/her to let them have a good impression for me.
Even trying to catch the prof.'s taste and letting them feel interestd
to me!
But I don't know how to make an impressfully academic discuss with
ph.D.?
Afterall I am not a excellent and diligent one!!

The most impressive way to present yourself is to show that you have a
good knowledge of the subject, and, most importantly, that it fills
you with enthusiasm.

These professors are likely to be busy people. Whatever you write
needs to be short and snappy, so that they don't feel you are imposing
on their time with your message.