火山口中间是火山灰锥，投下了三角形的暗影。
An ash cone rises from the center of the crater, casting a dark triangular shadow.
文章结合编程实例介绍了球弧数控车削三种常用的工艺方法，即车圆法、移圆法、车锥法。
This paper introduces three kinds of CNC turning method combined with practical example, concentric circle turning, center shifting turning and taper profile composition turning.
对某锥柱形装药固体火箭发动机(SRM)燃烧室和喷管的内流场进行了三维两相一体化计算。
This paper makes a 3-d two-phase flow united calculation of the inner flow field of chamber and nozzle in certain SRM.
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