Based on mathematic and physical meanings of the curves, the first flame time of sustaining grain was deduced as zero time of rise stage for pressure-rise velocity and the end time of flame propagation as the limit time from rise to drop.

• 根据两条曲线的数学与物理意义推断主装药首次火焰时刻为升压速率上升阶段过零时刻,火焰传播结束时刻为升压速率由上升转下降的极值时刻;