Effect of outside force on working accuracy of thin-wall long cylindric part machined with double-tool;

By analysing the relation of every particle,centre of mass,internal force and outside force,this paper explains that the quiescent rubforce is the ultimate reason of moving ahead,where the Newton s secend dynamic law is used.

The outside force which is the necessary condition and one of the basic forms of dialectical negation plays a decisive role in the direction and nature of the development of things.

The discussion of the external force and the distribution of the resulting charge and the electric field while taking out a copper plate from a capacitor;

The earths internal force generates the embryos of gigantic geomorphological waves; The external force, on the other hand, carves it into different scales of waves by erosion, transportation and deposition, and finally into the calm waves of peneplains.

The developing level of the technology of producing in-situ gradient composites in outside force field (centrifugal method and electromagnetic separation method)has been reported.