In this article,“celestial coordinate system”, the difficult point in the teaching of the Conspectus of the Earth, is analysed and studied and three key points are proposed: finding the joint point, establishing an coordinate system mode that can be accepted easily and giving out the basic dots & great circle system very distinctly.

In this paper,a method of large arc grinding using multi-bar linkage in commercial plan-grinding machine was introduced,in which the straight movement of the machine table was transformed to small rotating of the worked parts.

Three-Dimensional Thermal-Mechanical-Coupled Elastoplastic Finite Element Analysis on Large Section Round Bar Continuous Rolling with Oval-Round Passes;