Can I use 72 hour transit visa when entering Shanghai on second visit to China within 14 days?

My wife and I are travelling to China as part of a tour party for a 15 day tour. When the tour finishes we are flying to Japan for 10 day visit. We then fly from Osaka (Japan) to Shanghai before flying on to Australia the next day. Do we need a double entry one or will a single entry for the tour part of our trip and 72 hour free transit for the second visit of approximately 30 hours satisfy the requirements