I can't get the Alien Abductor through the spot by the fan. I stopped the fan but every time i try to move forward, I get kicked out of the tunnel. I can't get past the bars. What do I do?

Not sure, Melia, but does this thread possibly pertain to your problem?

You know what I found out? I found another player who'd had the same problem and it turns out that he was already in the duct facing the exit. That's the problem I had. I thought I was facing the fan and trying to get in when in reality I was facing the fan from inside the duct!
Geesh!

I do have another problem though. I'm trying to find the linguistics lab and followed the walkthrough to where it said it was. There's supposed to be a red access card on the table to the right. I've been looking for the last hour and haven't found it.

For locating the red access card, a video walkthrough might be your best bet - either that, or checking out a different walkthrough. That might help also.