A brilliant new Chinese train innovation – get on & off the bullet train without the train stopping. No time is wasted.  The high speed train is moving all the time. If there are 30 stations between Qingdao, Beijing and Guangzhou, just stopping and accelerating again at each station will waste both energy and time.  A mere 5 minute stop per station (elderly passengers cannot be hurried) will result in a total loss of 5 minutes x 30 stations or 2.5 hours of train journey time!
Useful Links:
Qingdao Railway-Train Stations
Qingdao Railway-Train Schedule