laser physics
6.In this paper, the physics meckanism of theinitiation and growth of ionization in the process of laser-indu-ced-air breakdown is stated, and the calculating formula of bre-akdown threshold is given.
7.Math.and Physics Department,Yanshan University,Qinhuangdao 066004)[/align][align=left][b]Abstract[/b]:Through the pictures taken by means of laser speckle on the metal material weldment,we can obtain double-exposed displacement patterns at a temperature range.By point-to-point analysis heat displacement field at the welding points can be measured,and the distribution of thermal strain and thermal stress can be obtained.As a result,the flaws at welding points can be measured through experiments.
