In the paper,based on the study of the chain possibility of matrix,the author puts forward some properties of combination and its application in combination mathematics.

Influence of adding salt on the salt tolerance of Mesona Blumes gum and its molecular chain stiffness;

Computer aided designing system for single axial symmetric flexible hinge;

Analysis on magnification ability and loading capacity of displacement magnification mechanism of flexible hinge;

Design and performance analysis on flexible hinged magnifying mechanism applied to piezoelectric piling-up pump;

Preparation of polyimide with flexible chains in the main chain and the groping application in fabric;

Through analysis of structures,thermodynamic and rheology behaviors of PBTA copolyesters before and after chain extension,effect of chain extender dosage on their structures and properties wer.

And the polyesters were modified through co-polymerization with low molecular weight hydroxyl-terminated poly L-lactide,poly(caprolactone)diol,TDI through chain extension to improve their properties of degradation and mechanics.

Adopting PZT as the micro-displacement driver and a kind of flexible joint as the guiding device,it compensates moving position of ball feed machine tools automatically and realizes the second precise orientation.

Adopting the actuator as the micro-displacement driver and a flexible joint as the guiding device, this mechanism compensates the moving position of the traditional lead-screw driven of working table machine tools automatically and realizes the secondary precise (positioning).

A kind of micro-positioning stage driven by piezoelectric actuator and guided by flexible joint is researched and designed for improving the precision of machining tools.