The slide must be in a vacuum to make sure that the electron beamused to scan its surface does not come into contact with anyobstructions.
载片必需放在真空内，是为了确保扫描其表面的电子束不会受到任何妨碍。
2
When angular contact thrust ball bearings operate at high speeds, the centrifugal forces and gyratory moments acting on the balls may cause them to slide on the raceways.
角接触推力球轴承在高速运转时，作用在球上的离心力和旋转力矩可能会导致钢球在滚道内滑动。
3
When the incidence wave is strong enough, the contact interface will separate or slide on local area, which is harmful to the safety of the structure.