声束轴线 beam axis
举一反三
- 声束有效截面 effective cross—section of beam
- 声程beam path；path length
- The cross section of a straight beam remains plane when the beam deforms due to bending. This causes ( ) on one side of the beam and ( ) on the other side. The neutral axis is subjected to ( ) .? normal stress; shear stress; zero stress|tensile stress; compressive stress; zero stress|compressive stress; tensile stress; maximum normal stress|shear stress; normal stress; zero stress
- 何谓主声束？什么是声束的指向性？
- 平行水闸轴线剖切得到的剖视图是什么?What is the ... axis of the sluice?