According to the process programs and constraints of hot rolling strip production in a steel plant,a prize collecting traveling salesman problem(PCTSP) based model for hot strip rolling unit planning is presented,an ant colony optimization(ACO) algorithm is designed to solve it.

Application of unit combination method on the variant Geneva mechanism;

Analysis to an type of cable-strut unit;

Teaching unit project of moral and social studies;

Upper bound limit analysis of slope stability by element integration method;

Single Fracture-based Equivalent Hydraulic Conductivity Tensor for Element;

The accurate equation of element stiffness matrix for variable cross section bars;

CNC machine structure units identified based on model experimentation;

The development of priority design theory of municipal sewage treatment plant in different stages is reflected,some units of its priority design and from PLC parts are also analyed,finally several further research problems having yet to be solved for the theoretical research of priority design municipital sewage treatment plant are presentanted.

The main characteristics of tapered roller bearing units are analyzed in this paper and compared with that of other kinds of bearing.