Chinese English

The process by which the direction of a WAVE moving in SHALLOW WATER at an angle to the contours is changed. That part of the WAVE advancing in shallower water moves more slowly than the other part still advancing in deeper water, causing the WAVE CREST to bend toward alignment with the underwater contours. Also called wave refraction. The bending of WAVE CRESTS by CURRENTS.

在浅水区，与等深线成一定角度运动的波浪方向改变的过程。这是因为在浅水区前进的那部分波浪，比在深水区同时前进的波浪速度要慢，引起前者波峰折向，变为与等深线一致的方向。亦称 wave refraction（水波折射）。 由于潮流引起的波弯曲。

Correct positioning of one component of a composite map image in relation to the other compo­nents. Achieved, for example, by punching sets of holes, having a fixed horizontal relationship to each other, in each component sheet and then attaching the components together using specially designed fasten­ers. See also PUNCH REGISTER SYSTEM.

编绘地图图形中一个要素相对于其他要素的正确定位。例如，在每一块分版上打一组套合孔，使之相互间有固定的水平关系，然后用专门设计的线夹将这些要素版固定在仪器。参见punch register system（打孔定位装置）。

Within the IALA Maritime Buoyage System there are two international buoyage regions, designa­ted as Region A and Region B, where lateral marks differ only in the colours of port and starboard hand marks.

国际航标协会（IALA）海上浮标系统中有两个国际浮标制度区，指定为A区和B区，其侧面标志仅以左右舷侧面标的颜色区分。

Precessional motion of a set of NODES. The expression is used principally with respect to the MOON, the NODES of which make a comple­te westerly REVOLUTION in approximately 18.6 years.

对摄像机或望远镜的透镜来说，等效焦距与入射光瞳直径之比，可表示为f:4.5；亦称 f-number（f数），f-stop（光圈级数）或speed of lens（透镜速率）。

Motion of one object or body relative to another. The expression is usually used in connection with problems involving motion of one craft, torpedo, or missile relative to another, the direction of such motion being called direction of relative movement, and the SPEED of such motion being called speed of relative movement or relative speed. Usually called apparent motion when applied to the change of position of a CELESTIAL BODY as observed from the EARTH. Also called relative movement.

一物体相对于另一物体的运动。常用于船只、鱼雷、导弹相对于另一物体的运动这一类问题。这种运动的方向称相对运动方向，速度称相对运动速度或相对速度。在用于自地球观测天体位置变化时，常称视运动。也称relative movement（相对运动）。

A device for holding or releasing a mecha­nism, particularly the device by which the TANGENT SCREW of a SEXTANT or surveying instrument is held in place or disengaged from the LIMB, or CIRCLE respec­tively. In oceanography acoustic releases are used to sever deployed instruments from their anchoring.

固定或释放机械的装置。特别是六分仪或测量仪器上的微动螺旋，分别用于固定或松动测角器或度盘。 在海洋学中，声学释放器用于切断配置仪器与其系固装置的联系。

The ELEVATIONS or the inequalities, collecti­ve­ly, of a land surface; represented on a MAP or CHART by CONTOURS, HYPSOMETRIC TINTS, SHADING, SPOT ELEVA­TIONS, HACHURES, etc.