Visiting Beijing during a 14 hour layover from USA to India on Indian Passport.

I am traveling to India from USA (current valid US visa) and have 14 hrs layover in Beijing. I am planning to visit the city for a few hours and come back to the airport to continue my flight to India. Is it possible to obtain Chinese visa for a day upon Arrival at the airport to go out and visit the places nearby during the layover? or will I have to apply for it in advance? Also will that be a G or L visa?