助推阶段 meaning in Chinese

boost phase

And the effect of the work order of the two propellant units to the performance of the trajectory and the matching conditions to obtain the theoretical optimum trajectory is discussed too . according to the ballistic speciality of a hybrid base - bleed - rocket extended - range projectile during base - bleed and rocket work , its physical parameter is non - constant , such as its mass position of mass centre polar and equatorial moment of inertia . after a mulriple ballistic model of constant physical parameter is established , a mulriple ballistic model of continuous and non - continuous physical parameter is educed and the program is compiled , the theoretical tool is constructed to study othe other pivotal technology of a hybrid base - bleed - rocket extended - range projectile
本文根据底排?火箭复合增程弹其底排燃减阻和火箭助推阶段的质量、质心位置、转动惯量等结构特征参量变化的弹道特征，在建立底排?火箭复合增程弹结构特征参量为不变常量的多元弹道计算模型基础上，导出了结构特征参量为连续变化量和非连续变化量的底排?火箭复合增程弹多元弹道计算模型，编制了相应的计算机数值分析程序，构建了研究底排?火箭复合增程弹其它关键技术的理论工具。