Homogeneous Second System of Center-focus Type to System Concluding Parameters;

Designed principle of the rotational stand uses for measuring a camber with double focuses;

A kind of directness arithmetic about conic′s focus;

The focal points of their arguments such as advance informed agreement (AIA), risk assessment and risk management, information exchange and other related issues have been expounded and analyzed.

Based on the Lyapunov stability theory,through improving related theorem,obtain simple and effective methods of judging center or the focal point of nonlinear system and estimating the attraction territory of non-autonomous system.

By the definitions of the conjugate point and the focal point in a geodesic,the paper proves that for any geodesic γ:［0,+∞)→M,in a complete Gauss surface M with positive curvature,there exists t＞0 such that γ(t) is a focal point of γ(0).

Study on the twin-focus technique in laser welding;

The most popular detection methods both at home and aboard are introduced,and a method on the position control system for beam focus is presented during laser beam cutting process based on CCD,which can accurate detect and control the laser focus position during laser beam cutting process by using the laser triangulation and CCD imaging system coordination digital image proce.

According to the interaction and degree of interaction between electron beam and metal, the EB focal spot is classified to the static focal spot, the quasi-dynamic focal spot and the dynamic foca.