| 释义 |
hot spot
Also hot-spot.
I.
1. Physiol. One of numerous small areas on the skin that are specially sensitive to heat.
1888W. Stirling tr. Landois's Text-bk. Human Physiol. (ed. 3) xiv. 836 The chain of the ‘cold-spots’ usually does not coincide with those of the ‘hot-spots’. 1911Encycl. Brit. XXVII. 97/1 There are points [on the skin], stimulated by addition of heat, hot spots, while others are stimulated by withdrawal of heat, cold spots. 1926S. Wright Applied Physiol. i. 21 If all the ‘hot’ and ‘cold’ spots are marked out, the areas of skin between them are found to be insensitive to punctate thermal stimuli.
II. A spot that is hot (lit. and fig.).
2. [spot n.110.] A small area in a surface or body that is at a higher temperature than its surroundings.
1919G. Kapp Princ. Electr. Engin. II. vi. 143 The average internal temperature of a winding can be more accurately deduced from a resistance test, whilst for the discovery of so called ‘hot spots’ thermo-couples must be used. 1936D. M. Robinson Dielectric Phenomena in High Voltage Cables ii. 16 A cable subjected to excess voltage may develop local hot spots, and..frequently fails at or near the hottest of these points. 1947Sci. News IV. 150 With a metal sliding on glass with a load of a few pounds, visible hot spots (temp. 520–570° C.) can be seen when the sliding speed is as low as one or two feet per second. 1958H. Etherington Nuclear Engin. Handbk. xii. 17 Hot-spot effects usually require a correction in the calculation of maximum temperature. 1959H. F. Taylor et al. Foundry Engin. x. 277 Under normal conditions of cooling, metal at the center of the d region is a hot spot, the last to solidify. 1970Times 30 Oct. 23/2 A small..infra-red television camera..for detecting the ‘hot spots’ in overhead power lines and substations which can lead to serious breakdowns. 1972Physics Bull. May 284/2 This effect has been used to detect hot spots and hence structural flaws in systems as diverse as integrated circuits and the human body.
3. [hot a. 7 b, spot n.1 8.]
a. A night-club or other place of lively public entertainment.
1931D. Runyon Guys & Dolls (1932) iii. 53 There are very seldom any customers in Good Time Charley's until along about five o'clock in the morning..and then it is sometimes a very hot spot indeed. 1937J. Weidman I can get it for you Wholesale xxv. 227 The line in Winchell's column: Martha Mills..is doing the hot spots with what prominent young manufacturer of feminine haberdashery? 1940Time 15 Apr. 98/2 Eschewing Hollywood hotspots, they prefer at-homes with the quieter younger set. 1954G. Smith Flaw in Crystal iv. 39 The Wind in the Willows [a roadhouse] had been a noted hot-spot when I was a schoolboy. 1954Manch. Guardian Weekly 26 Aug. 7/1 Intellectuals..went on a kind of jazz-slumming in the Harlem hot spots.
b. A place of danger; spec. a place where war is being actively engaged in or experienced.
1941Illustr. Lond. News CXCIX. 200 (caption) Miss Cowles, an American journalist, whose pre-war assignments took her to most of the ‘hot-spots’ of Europe [sc. Prague, Berlin, Warsaw, etc.]. 1966Economist 19 Feb. 711/2 The Administration wanted to distinguish financially between men who had been in ‘hot spots’ and those who had only served in non-combat zones. 1973G. Beare Snake on Grave xii. 62 You're putting yourself on the hot⁓spot, Sammy.
4. Specific technical applications in the literal sense.
a. In an internal combustion engine, a portion of the manifold or combustion chamber that is heated in order to facilitate vaporization of the liquid fuel; also, a region of overheating that tends to cause pre-ignition. b. Astr. A region in the sun's corona (generally associated with a solar flare) that is temporarily at a higher temperature than normal and is emitting a characteristic spectrum of radiation. c. Electronics. In a mercury-arc rectifier with a pool cathode, that part of the pool of mercury with which the arc is in contact and from which electrons are emitted.
a.1924Motor Manual (ed. 25) ii. 32 As an additional means towards obtaining efficient carburation a ‘hot spot’ arrangement is provided on a number of cars. 1929Times 2 Nov. 4/7 The inlet manifold is jointed to the exhaust centrally, and thus a hot-spot is provided. 1934Jrnl. R. Aeronaut. Soc. XXXVIII. 960 Thus making absolutely sure of high compression without hot spots acting as sparks in the combustion chamber. 1959Chambers's Encycl. VII. 639/1 [In the petrol engine] pre-ignition is usually caused by an unsuitable plug or some local hot-spot, e.g. the exhaust valve head. 1968Practical Motorist Dec. 459/1 Some hot spots are fitted with a thermostatically controlled flap which diverts the mixture away from the hot spot once the engine is running at normal temperature.
b.1936Harvard Coll. Observatory Circ. No. 410. 22 This region [of the chromosphere] appears to be one of abnormal excitation, possibly caused by a ‘hot spot’ near the limb of the sun at the time of the eclipse. 1958Sci. Amer. Aug. 41/2 When the sun is observed with a radio telescope tuned to 10 centimeters, the hot spots in its atmosphere stand out brilliantly. 1966McGraw-Hill Encycl. Sci. & Technol. XIII. 282/2 Coronal hot spots, indicated by emission of the yellow line of Ca XV at 5694 A above the photosphere by some 30,000 km, have been found in all spectrographic observations of the corona over a limb flare.
c.1937W. G. Dow Fund. Engin. Electronics xix. 426 The cathode ‘hot spots’ of mercury-pool-type mercury vapor rectifiers dodge about erratically on the mercury surface. 1971B. Scharf Engin. & its Lang. xx. 277 Where the arc terminates on the surface of the mercury a ‘hot spot’ occurs which forms the source of electronic emission.
5. Technical senses representing transferred senses either of hot or of the phr. as a whole.
a. In an ingot or casting (see quot. 1908). b. A particularly active part of a forest fire; so hot-spotting vbl. n. (see quot. 1953). c. Theatr., Photogr., etc. An area that is markedly brighter than its surroundings. d. Nuclear Sci. An area where the radiation level is much higher than in the surroundings; a local concentration of radioactivity. e. Genetics. A part of a gene especially liable to undergo mutation.
a.1908B. Stoughton Metall. Iron & Steel xii. 349 These localities, where the segregation is high, and which are known, when very bad, as ‘hot spots’, are sometimes porous or surrounded by porous parts of the casting. 1938Rosenholtz & Oesterle Elem. Ferrous Metal. ii, Hot spots are irregularities occasioned by the uneven distribution of the coarse and fine parts of the charge in such a way that the coarse parts are concentrated near the furnace walls.
b.1938Fire Control Notes Oct. 26 This work includes such jobs as..burning out material between the line and the fire edge, and reduction of hot spots. 1940Ibid. July 141 It is well for the scout to carry a pulaski or light ax for blazing or hot-spotting. 1953Brit. Commonw. Forest Terminol. i. 77 Hot-spotting, checking the spread of fire on hot spots alone or at salient points, as an emergency measure employed in advance of control-line construction.
c.1952Granville Dict. Theatr. Terms 99 Hot spot, a bright spot in an area of uneven lighting. 1958New Scientist 25 Dec. 1569/3 Some areas on the document will be reproduced as dark grey.., while on others, known colloquially as ‘hot spots’, there will be such a powerful reflection of light that any markings on such areas may be completely blotted out. 1971L. B. Happé Basic Motion Pict. Technol. vii. 218 A brighter central area, or hot spot, is particularly obvious when a short focal length lens is used on a camera and a long focal length on the projector.
d.1955Bull. Atomic Sci. Feb. 46/2 One would expect ‘hot spots’ even far downwind but since the history of the bomb cloud would already be several hours ‘old’ by then, there would be a corresponding drop in intensity. 1955Sci. Amer. Aug. 37/1 A particularly malignant feature of some of the radioisotopes is their tendency to concentrate in ‘hot spots’ instead of distributing themselves evenly through the bone or other tissue they invade. 1962Listener 19 July 104/2 The concentration of radio⁓active substances into ‘hot spots’ may well be exaggerated in the rapidly dividing cells of the foetus.
e.1958Benzer & Freese in Proc. Nat. Acad. Sci. XLIV. 115 A striking feature of the map is the existence of certain ‘hot spots’, where mutations recur with high probability. 1964W. Hayes Genetics of Bacteria & their Viruses viii. 171 Out of 1,612 spontaneous mutations..more than 500 occur at a single site or ‘hot spot’ in the B cistron. 1967E. Steiner tr. Esser & Kuenen's Genetics of Fungi v. 300 A hot spot probably consists of a single base pair, at least one member of which is particularly sensitive to a specific mutagen.
▸ Computing. An area on a computer screen which can be clicked on to activate a function; spec. an image or piece of text acting as a hyperlink. Also: the active point on a cursor, such as the tip of an arrow.
1988Courier-Mail (Queensland) 19 Apr. 33 Felix uses the same movement as a pen and has a unique feature called ‘Hot Spots’ selected by cursor, which when clicked-on, activate pre-set command macros. 1992InfoWorld (Nexis) 19 Oct. 22 The ‘hot spot’ of the pointers—where your mouse actually ‘clicks’—is indicated by an ‘X’ in the upper-left corner. 1997‘Q’ Deadmeat 379 ‘This is where you can help us,’ said Scotto, clicking on a hot spot on the web site. 2004Church Times 18 June 19/4 Image maps provide areas that link to other URLs (known as hotspots).
▸ Computing. A public place where a wireless Internet signal is available and the Internet can be accessed.
1999Business Wire (Nexis) 11 May The solution..enables in-building public wireless hotspots such as airport lounges, providing wireless portable computer connectivity. 2003Wall St. Jrnl. 5 Nov. d4/1, I tested two methods of finding Wi-Fi hot spots: Web sites that let you search for locations and a device that ‘sniffs’ for Wi-Fi and notifies you when a signal is near. 2006Daily Tel. 7 Mar. b9/1 The UK has about 12,500 hotspots and, as wi-fi's range steadily increases, these will multiply. |