variable cross-section 基本例句 变截面 In order to meet the requirement of EBW of the large complex profile parts and parts of variable_cross section in aircraft production, a large vacuum EBW machine has been designed.为满足飞机生产中大型复杂型面和变截面零件电子束焊接的需要设计了一套大型真空电子束焊机。