Liang,
some clean cutting and a nice design, you are really coming along. It look like I will not be coming to China this fall after all. I really hate that! For sure I will be in Beijing in spring of next year and will try to get down your way before or after Beijing.
Michael,
looks like hot glue to me, do a search on the forum here, there are a number of threads about holding work, and releasing it. FYI , normally hot glue is released by putting the object in the freezer, or by alcohol.