| 释义 |
displacement|dɪsˈpleɪsmənt|
[f. displace v. + -ment: cf. OF. desplacement, mod.F. déplacement, perh. the immediate source of sense 1.]
The act of displacing or fact of being displaced.
1. Removal from an office or dignity; deposition. (The earliest sense, but somewhat rare.)
1611Speed Hist. Gt. Brit. ix. xvi. §44 His displacement from the Regency of France. 1797W. Taylor in Monthly Rev. XXIII. 570 Without the least intention of carrying their schemes farther than the displacement of their adversaries. 1857Toulm. Smith Parish 91 Election, displacement, and fresh election depend on the Parish only.
2. a. Removal of a thing from its place; putting out of place; shifting, dislocation.
1803W. Taylor in Ann. Rev. I. 320 Change of air, removal, displacement, seem to be efficient remedies. 1840A. Tweedie Pract. Med. III. 380 When the displacement is very considerable, the functions of the heart may be much embarrassed. 1863Kinglake Crimea (1876) I. xv. 354 Occasioned by some accidental displacement of words. 1880Haughton Phys. Geog. ii. 46 note, A vertical displacement of the strata.
b. Physics. The amount by which anything is displaced; the difference or geometrical relation between the initial position of a body and its position at some subsequent instant.
1837Whewell Hist. Induct. Sc. (1857) I. 150 The displacement of the sun by parallax is so small that [etc.]. 1879Thomson & Tait Nat. Phil. I. i. §90 We may consider the whole motion as made up of successive elementary displacements.
c. Thermometry. (See quot.)
1871B. Stewart Heat §22 It is found that thermometers are liable to an alteration of their zero points, especially when the bulb has been filled not long before graduation..This displacement may in the course of years amount to about 1° C.
d. Electr. (See quots.)
1873J. C. Maxwell Electr. & Magn. I. i. 60 The electric polarization of an elementary portion of a dielectric is a forced state into which the medium is thrown by the action of electromotive force, and which disappears when that force is removed. We may conceive it to consist in what we may call an electrical displacement, produced by the electromotive force. 1885Watson & Burbury Electr. & Magn. I. §258. 1895 Silvanus Thompson Electr. & Magn. §57 Displacement. Whenever electric forces act on a dielectric, tending to drive electricity in at one side and out at the other..the quantity of electricity which has apparently been transferred..was called by Maxwell ‘the displacement’. Ibid. §516 Experiment proves that displacement-currents, while they last, set up magnetic fields around them; just as connexion-currents and conduction-currents do.
e. displacement law, any of three laws in Physics: (a) that the wavelength at which a black body radiates most energy is inversely proportional to its absolute temperature; (b) (see quot. 1922); (c) that when an atom emits an alpha particle its atomic number decreases by two, and when it emits a beta particle its atomic number increases by one.
1904T. Preston Theory of Heat (ed. 2) vi. 600 This important equation expresses the fact that if radiation of a particular wave-length corresponding to a definite temperature is adiabatically altered to another wave-length, then the temperature changes in the inverse ratio. This is known as Wien's displacement law. 1922Encycl. Brit. XXXII. 561/1 Perhaps the most comprehensive connexion of spectra with the periodic table is established by the ‘displacement law’ of Kossel and Sommerfeld... The displacement law states that, when an element is ionized, the enhanced series take on the same type of complexity as the arc series produced by the element to the left (i.e. in the preceding group) in the periodic table. 1926R. W. Lawson tr. Hevesy & Paneth's Man. Radioactivity xiii. 114 In this way we obtain the following ‘displacement law’: The emission of α particles by an element results in the production of an element situated two places lower down in the natural sequence of the elements, whereas when the disintegrating element emits β-rays, an element is produced which is situated one place higher in the system. 1927Rutherford in Proc. Physical Soc. XXXIX. 360 This generalisation, known as the Displacement Law, first put forward in general form by Russell, Fajans and Soddy, gives us at once the nuclear charge and mass of each element in the radioactive series, and thus fixes the ordinary physical and chemical properties of each radioactive element, as well as its atomic weight. 1968M. S. Livingston Particle Physics ii. 16 Soddy and others established the displacement law.
f. Psychol. The substitution of one idea or impulse for another, as in dreams, obsessions, etc.; the unconscious transfer of intense feelings or emotions to something of greater or less consequence; also = sublimation 5 c.
1913A. A. Brill tr. Freud's Interpr. Dreams vi. 286 The result of this displacement is that the dream content no longer resembles the core of the dream thoughts at all. Ibid. vi. 402 The dream activity makes use of the displacement of psychic intensities up to the transvaluation of all psychic values. 1955H. C. Abraham tr. K. Abraham's Clin. Papers iii. vii. 189 We should be straining the facts if we attempted to make an artificial separation between displacement and secondary elaboration. 1962Henderson & Gillespie Text-bk. Psychiatry (ed. 9) vii. 128 Displacement consists in the transfer of the emotional setting of one idea to some other apparently insignificant idea. 1964Gould & Kolb Dict. Social Sci. 204/1 ‘Fiddling’ with objects such as pencils is a masturbation substitute or displacement. Ibid. 204/2 In social psychology the concept displacement has been used with respect to the hostility expressed toward minority groups.
g. Applied attrib. to an activity or behaviour pattern occurring outside its normal context and arising from a conflict of impulses (see quots.).
1947E. A. Armstrong Bird Display & Behaviour ii. 36 Toying with odds and ends may be regarded as..providing emotional outlets. They are ‘displacement’ or substitute activities, common enough in human life. Ibid. viii. 106 ‘Displacement’ activities will be regarded as a special type within the larger class of false activities. 1951N. Tinbergen Stud. Instinct v. 114 It is a striking fact that displacement activities often occur in a situation in which the fighting drive and the drive to escape are both activated. Ibid. 116 Herring gulls and many other birds..feed their mates during courtship; it is not at all improbable that this..is displacement feeding. Ibid. 117 If male sticklebacks are forced to nest very closely together, they will show nearly continuous displacement digging. Ibid. viii. 210 In man learned patterns, like lighting a cigarette, handling keys or handkerchief, &c., often act as displacement activities. 1957New Scientist 26 Sept. 42 Displacement activities usually result from a conflict between two strongly activated but antagonistic drives, or from strong motivation, usually sexual, in the absence of the necessary stimulus required for the release of the consummatory act. 1962Listener 2 Aug. 169/1 Many such irrelevant actions are known in animals. Dr Tinbergen has called them ‘displacement activities’. They are seen in conflict situations, where an animal's automatic behaviour mechanisms cannot work smoothly in its current environment. Ibid. 169/2 Human displacement activities are not easily catalogued.
3. a. Removal of a thing by substitution of something else in its place; ‘replacement’.
1868Gladstone Juv. Mundi iii. (1869) 100 There must have been a great displacement of the Pelasgic vocabulary. 1880Libr. Univ. Knowl. IX. 297 The displacement of human labor through..machinery.
b. Hydrostatics. The displacing of a liquid by a body immersed in or floating on it; the amount or weight of fluid so displaced by a floating body, e.g. a ship. centre of displacement: see centre n. 16.
1802–19Rees Cycl. s.v. Shipbuilding (L.), To ascertain the centre of displacement, or centre of gravity, of the immersed part of a ship's bottom. 1833Marryat P. Simple xiii, He was always talking about centres of gravity, displacement of fluid, and Lord knows what. 1869E. J. Reed Our Iron-Clad Ships iv. 71 The dimensions and outside form of a ship determine her displacement. 1876W. H. G. Kingston Brit. Navy 535 Her total length is 320 feet..with a displacement of 11,407 tons. 1935C. G. Burge Complete Bk. Aviation 263/1 Displacement, the mass of air displaced by the gas in an aerostat.
c. Pharm. The process of obtaining an extract of a substance by pouring over it successive quantities of a menstruum until all the soluble matters are extracted: = percolation.
1883Syd. Soc. Lex., Displacement..In Pharmacy, the term is used in the same sense as Percolation..D. apparatus, a means of obtaining extracts, whether aqueous or alcoholic. The body is pulverised, and then partially exhausted with a liquid, which is replaced by an additional quantity of the same, or of another liquid.
d. Bot. Abnormality in the position or form of a leaf or organ.
1869M. T. Masters Veget. Teratol. 89 Instances of displacement of leaves arising from suppression.
Add:[2.] [b.] (ii) Mech. The volume swept by a reciprocating piston, as in a pump or engine.
1897K. P. Dahlstrom tr. Weisbach & Herrmann's Mech. Pumping Machinery ii. 48 The volume below the piston then simply flows through it to the space above, and the amount delivered merely equals the displacement of the piston rod. 1922Glazebrook Dict. Appl. Physics I. 509/2 On the out stroke the delivery is equal to the difference between the volumes of the piston and plunger displacements. 1971B. Scharf Engin. & its Lang. xi. 193 Displacement may be measured in cubic inches (cubic centimetres) per stroke or per minute, or in gallons (litres) per minute.
4. Special Comb.: displacement pump, any pump in which liquid is moved out of the pump chamber by a moving surface or by the introduction of compressed air or gas.
1924N. Swindin Mod. Theory & Pract. of Pumping ix. 277 (heading) *Displacement pumps for inflammable liquids. 1976I. J. Karassik et al. Pump Handbk. i. 4 Displacement pumps are essentially divided into reciprocating and rotary types. |