| 释义 |
Fraunhofer|ˈfraʊnhəʊfə(r)|
The name of Joseph von Fraunhofer (1787–1826), Bavarian optician and physicist, used attrib. or in the possessive to designate certain phenomena investigated by him, as Fraunhofer('s) diffraction, diffraction in which the diffraction pattern is a linear function of the variation in phase across the diffracting aperture or object; Fraunhofer('s) lines, the dark lines in the spectra of the sun and other stars; Fraunhofer spectrum, a solar or stellar spectrum containing Fraunhofer lines.
1837Fraunhofer's lines [see line n.2 8 c]. 1840J. F. W. Herschel in Phil. Trans. R. Soc. CXXX. 17 The orange-red rays, or the less refrangible half of the portion from C to D in Fraunhofer's spectrum. 1843Phil. Mag. 3rd Ser. XXII. 361 The spectrum which results is given in great purity, and Fraunhofer's lines are quite apparent. 1888Encycl. Brit. XXIV. 430/1 (heading) Fraunhofer's diffraction phenomena. 1905R. W. Wood Physical Optics vii. 161 (heading) Mathematical treatment of Fraunhofer diffraction phenomena. 1937Discovery Apr. 109/2 The Fraunhofer spectrum line, C, of hydrogen in the red at wavelength 6563 Ångström units (also known as Hα). 1963R. W. Ditchburn Light (ed. 2) viii. 291 A Fraunhofer diffraction pattern is formed in the focal plane of the lens. 1966McGraw-Hill Encycl. Sci. & Technol. XIII. 267 Of the 92 natural elements, 64 are represented in the Fraunhofer spectrum. 1968R. A. Lyttleton Myst. Solar Syst. iv. 141 When a comet is quiescent,..the detectable light consists of a continuum crossed by the familiar solar Fraunhöfer [sic] lines. |