echelon

• 名词，指组织、职业或社会中的等级或阶层；也指军队或飞机以平行线排列的梯次编队。

A noun referring to a level or rank in an organization, profession, or society, or a formation of troops or aircraft arranged in parallel lines.

1. Military formationC1formal

   A body of troops, ships, or aircraft arranged in a line or in parallel lines with a regular offset.

   梯队

   • The bombers flew in an echelon formation.
   • The troops advanced in echelons to provide mutual support.
   • The naval fleet was arranged in a staggered echelon.

2. Optical deviceC2formalscientific

   A diffraction grating consisting of a pile of plates of equal thickness arranged stepwise with a constant offset, used to analyze light spectra.

   阶梯光栅

   • The scientist used an echelon grating to study the spectral lines.
   • The echelon's stepwise arrangement allows for high-resolution diffraction.
   • This type of echelon is essential in advanced spectroscopy.