Do I need visa to transit through Beijing (two independent flights)?

Next month I will transit through PEK airport.
I will come from Tokyo to Beijing (PEK), and then leave to Algeria after 10 hours.
The problem is that the two flights are not connected.
Do I need to get off the transit area in order to collect my luggage and then check-in again with for the next flight.
In this case Do I need a transit visa?

My 3-month old baby is registered on my passport.
Next month, we will transit through Beijing (PEK) to Algeria.
Do I need a visa also for my baby is I need to get off the transit area?
Thanks