For my exit at USU, I've had great success with blocking access to journals and publications by configuring the machine's firewall and Tor's exit policy to reject outbound to the university's IP block, except for our DNS servers. I pulled up a journal in my laptop using Chrome and got access, but when I used Tor (with torrc configured to use my exit) the same page timed out because the machine couldn't contact the library's resources. I don't know if there's a session key, Kerberos, or some kind of other access-granting mechanism that the library's site uses to grant journal access to machines on USU, but when I block outbound it doesn't go through, whatever it is. Your mileage may vary depending on how your network is configured. For me, experimentation worked just fine, and I would recommend blocking campus machines anyway. If it doesn't work, try something different, or talk to your sysadmins and get advice.
Jesse V.