Is visa required departing from Beijing

Iam an Australian travelling from Sydney / Being onwards to Mongolia for a 10 day tour. Our flight arrives in Beijing at 5am and flight to Mongolia doesn't leave till 9am the following day. We plan on booking a hotel in Beijing overnight. Do we need to get a visa for less than 30 hours stay? Coming back from Mongolia we travel back to Beijing and then need to catch a separate flight to Moscow. As we will be arriving Beijing airport, collect our luggage and go thru immigration, do we need to have entry permit?