Optimization of flash extraction of burnet saponins by Box-Behnken design Optimization of flash-type extraction technology of alisol B 23-acetate from Alismatis Rhizoma by response surface methodology Analysis of the Conditions for Lightning Fire Occurrence in Daxing‘ anling Region Optimization of flash-type extraction of burnet saponins by Box-Behnken design Progress of smashing tissue extraction in research of Chinese materia medica Studies on flash extraction methods of Arnebia euchroma