| 释义 |
achromatic, a.|ˌækrəʊˈmætɪk|
[f. Gr. ἀχρώµατ-ος colourless (f. ἀ priv. + χρῶµατ- colour) + -ic.]
1. Optics. Free from colour; not showing colour from the decomposition of light in passing through a refracting medium; as an achromatic lens or telescope. (Sometimes used substantively by ellipsis of ‘lens,’ as ‘a four-inch achromatic.’)
1766Maty (tr. from Fr.) in Phil. Trans. LVI. 57, I likewise made use of a very good achromatic telescope. 1784Herschel in Phil. Trans. LXXV. 44 One of Mr. Dollond's best 3½ feet achromatics. 1805Edin. Rev. Apr. 34 The fact, that the eye is achromatic, cannot be doubted. 1831Brewster Optics ix. §67. 83 They..will refract white light to a single focus free of colour. Such a lens is called achromatic. 1848Quekett Microscope (1855) 37 In 1747..Euler suggested the construction of achromatic object-glasses. 1859Parkinson Optics ix. 154 A combination of prisms or lenses is said to be achromatic when the dispersion of the pencils of light refracted through them is reduced within the narrowest possible limits. 1869Tyndall Lect. on Light 42 The human eye is not achromatic. It suffers from chromatic aberration. 1878Newcomb Pop. Astron. ii. i. 125 An achromatic of four inches aperture was then considered of extraordinary size.
2. Biol. Of tissue: Uncoloured, not absorbing colour from a fluid. See achromatin.
1882J. T. Cunningham in Jrnl. Microsc. Sc. Jan. 41, Figs. 30 and 31, from the cranial cartilage of a toad, show the achromatic striæ more clearly. |