| 单词 | dark well |
| 释义 | > as lemmasdark well dark well n. Microscopy (now historical) a black, typically cylindrical fitting placed in an optical microscope in order to form a dark background for a transparent object when illuminated from above. ΚΠ 1848 J. Quekett Pract. Treat. Use Microscope iii. ix. 294 This plan will be found highly advantageous for most objects; they may be well seen with the Lieberkuhn; the black cement acts as a stop or dark well. 1920 Trans. Amer. Microsc. Soc. 39 99 The simplest way to produce a dark-well is to turn the condenser aside and place a piece of black velvet over the foot of the microscope. 2004 D. Stoner tr. H. Moe Story of Microscope ix. 167/2 The condenser is achromatic and centrable and is positioned in a cylinder (dark well) with rackwork. < as lemmas |
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