Meanwhile,it puts forward the causes for the different brightness at bright fringe center in Thomas Young dual-slit interference.

The effect of [Mn]/[S],[S],[P],casting speed, secondary cooling on centerline cracking in the web of CC beam blank is analyzed, and the suggestions are brought forward.

Causes and preventions of center crack in slab;

According to the examined result and production record of continuous caster, the reasons causing the center crack of continuous casting slab in Taigang Group Linfen Iron & steel Co.

Based on the analytical solution of stress field around the center crack in an infinite sheet,the normal stress distribution model was established on the cracked cross section for tensile thin-walled member.

In connection with the actual conditions of JISCO slab caster,the factors affecting the formation of the center cracks in continuous cast steel slabs were investigated and the corresponding countermeasures were put forward.

Analysis and study on central crack in continuously rolled billets of low alloy steel;

It is further found that most of the centerline cracks and triangle-zone cracks occur inside the slab also at five places very well corresponding to the five lower temperature regions on slab surface.

Based on the underground of high efficient CC in Ma steel,the longitudinal surface crack and centerline crack,the uppermost defects of beam blank CC production are studied.

Based on the underground of high efficient CC in Ma\'steel,the longitudinal surface crack and centerline crack,the uppermost defects of beam blank CC production are studied.