The relationship of flame velocity,channel gap and quenching length at different temperatures of flame arrester cell was obtained: the quenching length is larger for the higher temperature of flame arrester cell at the same flame velocity and channel gap;the larger the flame velocity and channel gap,the more.

This paper discuss obstruct explode shell in bottleneck obstruct explode organ reply flammable gas tramp material explode combustion products across bottleneck gap process degradation affect, and point out remainder energy pass on factor about bottleneck gap.

The Research for the Crack Spacing of the Reinforced Concrete Beam;

Cracking positions are the weakest part of Continuously Reinforced Concrete Pavement,and crack spacing and crack width are the two control indexes.

Taking the Lei yi highway as the main body,This article carries on the long-term observation,makes the research on the law of development of Crack Spacing and Crack width,and then evaluates the crack Spacing and the width fit and unfit quality,Finally it provides the reference to the research on the CRCP long-term performance.

5 a,and the test results of crack space and crack width were analyzed by using statistical method.

Based on the elastic foundation beam,the control differential equation of tunnel lining is worked out,according to the theory of Saint-Venant,the predominance equation about the center angle to the crack space is established, then the crack space of tunnel lining under the loads can be worked out and according to the crack space,the crack width can be calculated.

Based on the theoretical analysis about cracking distribution of the beams under normal limiting condition,the formula about calculating cracking space were presented.