释义 |
Crookes|krʊks| The name of Sir William Crookes (1832–1919), English scientist, used attrib. or in the possessive to designate phenomena observed and apparatus invented by him. Crookes or Crookes's (dark) space, the dark space between the negative glow and the cathode of a vacuum tube, observed when the pressure is very low; also called cathode dark space, cathodic dark space. Crookes or Crookes's glass, a type of glass which protects the eyes from intense radiation, bright sunlight, etc. Crookes or Crookes's layer, (a) the layer of vapour underlying any mass or liquid in the spheroidal state, insulating it from the surface on which it rests; (b) = Crookes (dark) space. Crookes or Crookes's radiometer: see radiometer 2. Crookes rays, = cathode rays. Crookes's tube, a highly evacuated tube in which stratified electric discharges can be observed.
1884A. Daniell Princ. Physics 325 Let us now suppose that the particles recoiling from the heated surface do not meet other molecules, but impinge on the walls of the vessel. A layer of particles in such a condition is called a Crookes' layer. 1885Encycl. Brit. XIX. 249/1 In Crookes's radiometer the free path is very long. 1889Cent. Dict., Crookes's tubes. 1892G. F. Barker Physics 329 The layer of vapor which has to support the drop is called a Crookes layer. 1893J. J. Thomson Recent Res. Electr. & Magn. 108 Next to this [sc. the negative electrode] there is a comparatively dark region..called sometimes ‘Crookes' space’ and sometimes the ‘first dark space’. 1896Daily News 29 May 5/2 The rays which produce the fluorescence are certainly the Crookes rays. 1902Encycl. Brit. XXVIII. 47/2 The Crookes dark space. 1906Amer. Jrnl. Sci. 4th Ser. XXII. 312 The extremely tenuous condition of the residual elementary gas or gases in a Crookes tube. 1910Hawkins's Electr. Dict., Crookes' Effect, the radiant effect produced in a vacuum glass tube in which the exhaustion has been carried to a high degree, when electricity is discharged through it between suitable electrodes. 1918J. H. Parsons Dis. Eye (ed. 3) x. 184 Smoked or orange tinted (not blue) glasses..are most efficacious when made with Crookes's glass. 1927L. B. Loeb Kinetic Theory of Gases vii. 241 The Crookes radiometer, so often seen in opticians' windows, consisting of a set of mica vanes blackened on one face and mounted on an axis so that they are free to rotate inside a partially evacuated glass vessel and which rotate when radiation falls on them. 1931Glass Dec. 509/1 Several Crookes glasses were shown. 1958C. G. Wilson Electr. & Magn. xii. 365 At a pressure of 10-2 mm. Hg. or less, the Faraday Dark Space and Negative Glow disappear and the Crooke's [sic] Dark Space almost fills the tube. Hence Crookesian |ˈkrʊksɪən| a., pertaining to Crookes or to instruments invented by him (rare).
1899Science Siftings XVI. 117/2 The Crookesian scale⁓pan. Ibid., Crookesian radiometer. |