If the valve body material can be welded, but very different thermal expansion coefficient, or changes in operating temperature range of a larger thread junction closure weld must be honey.
During stereo matching, the feature points whose correlation coefficients are within certain range less than the maximal coefficient can be taken as an original matching feature point set.
A new kind of strength design method of gun barrel and corresponding safety coefficient choice range were presented, and the strength failure process of gun barrels was analyzed.