This paper studies the influence of both punch shape and constructivetechnological factors as well as the compressive and tensile stresses on the endurance of cold extrusion punches.

研究了凸模形状、结构- 工艺因素、压应力和拉应力对冷挤压凸模耐用度的影响。

youdao

The cloud's round shape is likely what is known as a hole-punch cloud.

云的圆形很可能就是人们所称的穿洞云。

youdao

Punch press: machine tool that changes the size or shape of a piece of material usually sheet metal by applying pressure to a die in which the workpiece is held.

冲床：将压力加到装有工件的模具上，以改变一片材料，通常是金属片的大小和形状的机床。

youdao

Bend your knees and duck down, rolling your head in a 'U'shape under the punch from 'inside' to 'out.

BBC: DEFENCE