The structure of an injection mould with three-step parting mechanism was designed after an analysis on the requirements for use and the forming process for the cap of a bottle for shampoo.

During the production in tertiary infill wells,the surface gathering process is simplified at a large scale.

Meanwhile,several examples were given,which put forward some suggestions on three-stage drying design and renovation of old spry trying tower.

3 superharmonic resonance of wire subjected to harmonic excitation in temperature field is studied.

Estimation of the 3-harmonic from Distortion Electromotive Forces in Auto Alternators;