An air gun with sucking function comprises a gun body, an air intake control set and an airflow switching and controlling element. The drum door is provided with an automatic latch system that can be automatically latched and unlatched on command. 0 such as to cause precipitation under vigorous stirring conditions of the chitosan matrix in the form of microparticles. A body portion is connected to a second end of the first region, the body portion extending away from the flat panel. The coupling intensifying region is provided at, at least one of a boundary between the ferromagnetic layer and the nonmagnetic coupling layer and a boundary between the nonmagnetic coupling layer and the magnetic layer. 5 mm to 1 mm, and a minimum distance between the pair of electrodes is 0.