trainsit visa in Beijing airport and the luggage claim

I am a Canadain citizen and will be flying from Phuket, Thailand to Beijing, China on May 22, 2011 on Asia Air. I then have a 14 hour layover where I change airlines to Aeroflot, and depart Beijing, China to London, England at 2:00am on May 23, 2011.

1. Do I require a transit visa if I choose not to leave Beijing airport? Is this true for up to a 24 hour transit?

2. How do I claim my luggage, and then check my luggage in to my next flight without clearing customs upon arrival? Will Asia Air transfer my luggage to Aeroflot for me?

3. Does Beijing internation airport issue transit visa's upon arrival if I do require one?

Thank you for you time.