1. Deflagration is combustion wave propagating at a velocity less than the speed of sound.

2. The lead delay element after deflagration was split with a knife, and observed by a microscope, the residue in layer form was found somewhere in the longitudinal direction.

3. The situation about studies deflagration to detonation transition in gaseous mixture, propellants and explosives is reviewed.

4. Deflagration of combustible cloud formed by hydrocarbon fuels dispersed in air can easily transfered to detonation.

5. It prevented backfire of natural gas that brings deflagration and guaranteed burner safety.

6. DDT tube, photoelectric cell, strain gauge and witness board are used to study the transition characteristics of the deflagration to detonation of NEPE propellant slurry in the mixing process.

7. The explosives can be detected for the impact force of their deflagration with the modified cantilever.

8. The study ways, characterization parameters and influence factors of deflagration to detonation transition are introduced.

9. The present experimental investigation attempts to understand the suppressing effect of metal mesh construction on deflagration waves of premixed ethyne air mixture in unconfined space.