Over 50 years after WWII was a significant period in American socialism development, during which American socialist movement was plunged into great straits because of rampant attack from monopolist capitalists, tortuous development in international communist movement and CPUSA immaturity.

The steel pipe industry in China is at present situated in a new turning point, as well as in a balanced point of development.

In this paper the rolling rules of symmetrical rigid body on a convex curved surface arbitrarily are studied,general calculating formulae are given for turning point(transition from pure rolling to slip rolling) and slip falling point(when rigid body leaves from curved surface)as well as correspondent mass centre velocity.

The theory and experiment of optical feed back self-mixing interference signal turning points are researched.

According to these values and the user-defined distance threshold, this method records important turning points reflecting the sequence’s feature.