简述冲击式汽轮机级的工作原理和级内能量转换过程及特点。
Cast iron pistons used in large propulsion diesel engines are constructed with () not taper what so ever。 the skirt being tapered and smaller than the crown。 the skirt being tapered and larger than the crown。 the crown being tapered and smaller than the skirt。
舷侧纵桁与强肋骨、主肋骨及横舱壁的连接形式是什么?
什么许多航运企业优先建立质量安全管理体系、实施双标认证?
主肋骨及其安装有何规定?
产品的生命周期理论合理地解释了()。