单词 | fluorescence |
释义 | fluorescencen. The distinctive luminosity shown by some substances when illuminated with light, esp. ultraviolet light; the emission of light by a substance as it absorbs light or other electromagnetic radiation of a different (usually shorter) wavelength. Also: the property of a substance of possessing this property. Also figurative.Fluorescence is widely used for lighting and in many analytical procedures.Fluorescence is distinguished from phosphorescence by ceasing when the incident illumination ceases (in technical use a duration of 10−8 second is sometimes used as the arbitrary maximum duration of fluorescence after the cessation of illumination; if it lasts longer than this the phenomenon is classed as phosphorescence). Fluorescence occurs when orbital electrons that have been raised to an excited state by incident light pass to a lower energy state by an allowed transition (in phosphorescence the transition is a forbidden one, which occurs over a longer timescale).resonance, X-ray fluorescence: see the first element. ΘΚΠ the world > matter > light > light emitted under particular conditions > [noun] > fluorescence fluorescence1852 Day-Glo1944 the world > matter > physics > electromagnetic radiation > light > intensity of light, luminosity > [noun] > fluorescence epipolic dispersion1845 fluorescence1852 X-ray fluorescence1896 XRF1954 the world > matter > physics > electromagnetic radiation > light > intensity of light, luminosity > [noun] > fluorescence > coloured fluorescence1852 1852 G. G. Stokes in Philos. Trans. (Royal Soc.) 142 479 I am almost inclined to coin a word and call the appearance fluorescence, from fluor-spar, as the analogous term opalescence is derived from the name of a mineral. 1855 Philos. Trans. (Royal Soc.) 145 211 The beautiful fluorescence exhibited by a solution of the inner bark of the horse-chestnut. 1867 R. Hunt Ure's Dict. Arts (ed. 6) III. 405 Pennsylvanian petroleum is dark-coloured, with a peculiar greenish lustre or fluorescence. 1897 Electr. World 20 Feb. 267/1 He noticed that enamels, glass and porcelain exhibit fluorescence under the influence of X-Rays. 1907 T. A. Edison U.S. Patent 865,367 1/1 The object I have in mind is to produce light by fluorescence. 1940 Proc. Royal Soc. A. 174 353 We have reinvestigated also the quenching of the fluorescence of uranium salts by iodide ions. 1950 Sci. News 15 95 Porphyrin is easily detected because it shows an intense red fluorescence when held before an ultra-violet lamp. 1990 C. Paglia Sexual Personae v. 167 The pornographic fluorescence of the Dying Slave comes from its will-lessness, its sensually engorged surrender. 2002 R. J. Richards Romantic Conception Life iii. 140 What a fluorescence of ideas these conversations have produced for me, you can well imagine. 2010 Church Times 10 Sept. 30/1 He..used electro-optic scattering, birefringence, dichroism and fluorescence to study minerals, colloids, and macromolecules. Compounds C1. General attributive, as fluorescence band, fluorescence emission, fluorescence intensity, fluorescence lifetime, etc. ΚΠ 1872 Chem. News 13 Sept. 133/2 Hence may be understood..how the bright fluorescence bands correspond to the dark absorption-bands. 1907 Physical Rev. 24 374 This opening was set at different distances from the end of the cell and the fluorescence intensity was measured for three or four different positions. 1915 Astrophysical Jrnl. 42 22 The light absorbed by the aromatic phenol ethers..extends over the same range of wave-lengths as does the fluorescence emission of their alcoholic solution. 1953 M. Kasha in J. L. Magee et al. Basic Mechanisms Radiobiol. II. iv. 91 The singlet-singlet fluorescence lifetime is comparable. 1977 J. March Adv. Org. Chem. (ed. 2) vii. 216 For compounds which do fluoresce, the fluorescence emission spectra are usually the approximate mirror images of the absorption spectra. 1999 Rev. Sci. Instruments 70 4685/2 The two-phase ratio detector circuit..for making..fluorescence lifetime measurements is shown. 2006 Jrnl. Photochem. & Photobiol. A. 183 13/2 The fluorescence intensity decreases as the high concentration of Zn2+ cations quenches the fluorescence. C2. fluorescence spectrum n. [after German Fluorescenzspectrum (1858 or earlier; now Fluoreszenzspektrum)] the spectrum of the light emitted by a substance when it is excited to fluorescence.The spectrum is distinctive of the substance concerned, and does not vary with the wavelength of the incident light. ΘΚΠ the world > matter > physics > electromagnetic radiation > light > chromatism > [noun] > spectrum > types of Fraunhofer spectrum1837 gas spectrum1859 interference spectrum1860 flame spectrum1862 absorption spectrum1864 fluorescence spectrum1867 band spectrum1869 comparison spectrum1877 infra-red1881 emission spectrum1888 X-ray spectrum1910 1867 Index Foreign Sci. Periodicals 19 Apr. 47/2 J. Müller.—On the fluorescence spectrum of the electric light. 1885 J. Lassell & C. Lassell tr. H. Schellen Spectrum Anal. (ed. 2) lxi. 242 The visible part of the spectrum is then removed from sight, and the fluorescence spectrum alone occupies the field. 1953 A. G. E. Pearse Histochem. iv. 61 No reactions are known by which tryptochrome could be demonstrated histochemically, although it has a characteristic fluorescence spectrum. 2007 R. Menzel Photonics (ed. 2) vii. 547 The aggregation in the sample can usually be observed via the ground state absorption and the fluorescence spectrum. fluorescence microscope n. [after German Fluoreszenzmikroskop (1911 or earlier)] an optical microscope in which an image is generated by the fluorescence of the examined object when illuminated with light of an appropriate wavelength. ΚΠ 1912 Trans. Amer. Microsc. Soc. 31 (caption) 217 Reichert Fluorescence-Microscope. 1967 L. L. Iverson Uptake & Storage Noradrenaline in Sympathetic Nerves 17 By illuminating the tissue sections with ultraviolet light and observing the green or green-yellow fluorescence of these derivatives in a fluorescence microscope it is possible to visualize the catecholamines. 2010 M. J. Day Vet. Immunol. iv. 43/1 When the slide is examined at a particular wavelength of light under a fluorescence microscope, the fluorochrome becomes excited and the antibody-labelled organism becomes visible. fluorescence microscopy n. the use of fluorescence microscopes in scientific investigation; the science or technology concerned with this. ΘΚΠ the world > physical sensation > sight and vision > optical skills and techniques > [noun] > use of instruments microscopy1665 telescopy1802 photometry1807 stereoscopy1861 polariscopy1872 ultramicroscopy1906 pseudoscopy1910 fluorescence microscopy1932 stroboscopy1932 electron microscopy1934 phase microscopy1946 X-ray microscopy1948 strioscopy1967 stereoviewing1968 transmission electron microscopy1968 photopolarimetry1974 STM1982 1932 Jrnl. Sci. Instr. 9 365 An outfit for ‘fluorescence microscopy’ is described in List. No. 6065e of the optical works of C. Reichert of 24/26 Bennogasse, Vienna. 1993 Brit. Jrnl. Surg. 80 181/2 Acridine orange, a fluorescent dye used for labelling white blood cells, was used to study leucocyte behaviour..by intravital fluorescence microscopy. 2003 Nature 16 Oct. 672/1 The resolution of fluorescence microscopy limits protein localization to large organellar structures. fluorescence spectroscopy n. = fluorometry n. ΘΚΠ the world > matter > physics > electromagnetic radiation > light > intensity of light, luminosity > [noun] > fluorescence > measurement of fluorometry1913 fluorimetry1921 fluorescence spectroscopy1929 fluorophotometry1943 1929 Brit. Chem Abstr. B 217/2 The examination of cacao butter and its adulterants by absorption and fluorescence spectroscopy. 1987 Marine Pollution Bull. 18 528 Significant correlations were found between aromatic hydrocarbon concentrations obtained by fluorescence spectroscopy and both aliphatic and aromatic hydrocarbon concentrations obtained by gas chromatographic analysis. 2005 Agric. Res. Jan. 15/1 One method.., fluorescence spectroscopy, involves recording optical spectra from molecules absorbing and emitting light. This entry has been updated (OED Third Edition, March 2012; most recently modified version published online March 2022). < n.1852 |
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