From the angle of aesthetical psychology, the reason was analyzed why three-segment in design is so popular among the public,especially among master art-designers,and the methodology and technique in applying the idea in plane and product-plastic design was also discussed.

To confront with the opportunities and challenges of "Lewis interval",higher vocational education should construct new "three-segment" model of combination of working with learning,every segment operates independently as well as link organically to form harmonious symbiosis.

If the negati on of negation is sieved as a baseline and moderated and symbolized,the model of"syllogism"in the process of the negation of negation will be expressed as a periodic link.

More importantly, its thinking mode of word-image-meaning is quite different from Greek syllogism.

Analysing the non-equilibrium of charging for series-connected lead acid batteries,adopting two-level main circuit combined with three-step charging,the design of an improved charger was proposed,the design solves the problem of non-equilibrium.