| 释义 |
▪ I. tracer1|ˈtreɪsə(r)|
[f. trace v.1 + -er1.]
One who or that which traces.
1. One who follows the footprints or track of anything; one who tracks, investigates, or searches out; spec. one whose business is the tracing of missing persons, property, parcels, letters, etc.
1552Huloet, Tracer, uestigiator. 1611Florio, Rintracciatore, a tracer. Also a sifter out of secrets, a narrow searcher. 1627Hakewill Apol. iii. i. §5. 152 Plyny..a diligent and curious tracer of the prints of Natures footsteps. 1629H. Burton Truth's Triumph 210 The timorous..hare..to deceiue her pursuers or tracers, makes many doubles. 1724Moffet Hesperi-neso-gr. (1755) 4 To be performed by Some tracer of antiquity. 1866Intell. Observ. No. 56. 99 Some deep-thinking tracer of structural relations. 1888Sci. Amer. 6 Oct. 217/1 Nearly all the great [rail] roads employ a corps of what are known as ‘lost car searchers’ or ‘tracers’. 1902Daily Chron. 18 June 10/7 Furniture (Hire).—Wanted immediately smart man as collector and tracer; must have good knowledge of the hire trade. 1904Ibid. 22 Aug. 4/5 The various postal organisations of sorters, telegraphists, postmen, linemen, tracers, &c.
2. A thing used in tracing; spec.
a. Anat. A slender probe used in tracing the course of a nerve or vessel.
b. In U.S. Railway or Postal usage, An inquiry form forwarded from point to point on which the successive movements of a missing car, parcel, or article have to be recorded.
c. A substance (as a radioactive isotope or a dye) with distinctive properties that is introduced into a system so that its subsequent distribution may be readily followed. Freq. attrib.
1882Wilder & Gage Anat. Technol. 72 The tracer is apparently similar to the ‘seeker’ of the English anatomists. 1899Syd. Soc. Lex., Tracer, an instrument used in dissection for isolating nerves or vessels by teasing. 1899Westm. Gaz. 17 June 7/2 The ‘tracer’ had chased the ore into the master-mechanic's possession. 1938Encycl. Brit. Bk. of Year 320/2 The use of deuterium as a tracer in biochemical studies has been important. 1946Nature 12 Oct. 527/1 The attempt..to correlate by radioactive-tracer techniques the localization of heavy metals in the body and their chemotherapeutic activity. 1952New Biol. XIII. 63 One method..involves injecting into such mammals as sheep and rats a very minute dose (called a ‘tracer dose’) of the isotope. 1960P. Daudel tr. Eisner's Radioactive Tracers in Chem. & Industry v. 164 The Russian workers..have investigated the action of modifying agents in the extraction..of metals..using radioactive tracers. 1962O. Hockwin in A. Pirie Lens Metabolism Rel. Cataract 423 We investigated the metabolism of nucleotides and carbohydrates by ion exchange using labelled inorganic phosphate as a tracer. 1963G. L. Pickard Descr. Physical Oceanogr. vi. 81 Radioactive materials seem attractive as tracers of water movement... A very convenient artificial tracer is the red dye rhodamine-B. 1971Physics Bull. Jan. 22/2 Satellites also have their use in the determination of wind. A tracer moving with the wind and identifiable from the satellite is required; there are two suitable tracers, cloud elements and balloons. 1979Sci. Amer. Apr. 130/1 (Advt.), Using beryllium-7 as a tracer of stratospheric ozone, our scientists found that such ozone is distributed throughout high pressure weather systems. 1979Nature 26 July 299/2 Sunspots have long been used as tracers to determine the rotation rate of the Sun.
3. gen. One who or that which traces lines or makes tracings; spec.
a. Mil. At a siege, one who traces parallels; a member of a tracing party.
b. One whose work it is to trace copies of drawings or plans.
c. One whose business is the tracing of patterns for embroidery.
d. A tool for marking out designs or patterns; also, a chasing or engraving tool.
e. A stylus for tracing on copying paper; also, the writing instrument of a pantograph or of a self-recording machine.
f. A mechanical contrivance for making tracings on a larger or smaller scale.
g. Ice-cutting: see quot. 1884.
[1541Aberdeen Regr. (1844) I. 176 Item, ane traschor, ane stuffin sclyise.] c1790J. Imison Sch. Art ii. 29 With a little pointed tracer or burnisher go over your strokes which you drew upon the oiled paper, and you shall have the same very neatly and exactly drawn upon the white paper. 1799G. Smith Laboratory II. 37 Trace the out-line with a brass bodkin, or a tracer, made on purpose, of a piece of wire, of iron or brass. 1812Shelley in Hogg Life (1858) II. 150 The tracers of a circle. 1825J. Nicholson Operat. Mechanic 317 The frame carrying the dividing-point or tracer, is made to slide on the frame which carries the endless-screw to any distance. 1844Civil Eng. & Arch. Jrnl. VII. 187/1 A solid cone revolving on its axis, during the perpendicular descent of a tracer. 1852Trans. Soc. Arts LVI. 134 The cutters and tracers used together should be of the same size. 1859F. A. Griffiths Artill. Man. (1862) 250 Tracers [of a siege-battery]—1 non-commissioned officer, and 2 privates. 1878G. B. Prescott Sp. Telephone (1879) 297 The lower diagram is what the tracer wrote when the stanza was repeated. 1884Cassell's Fam. Mag. Feb. 188/1 There are..tracers, or hand-ploughs, to mark out the areas to be cut by grooves [in ice]. 1890W. J. Gordon Foundry 174 At last the film of putty with which the flat plate was spread to show the tracer's progress is scored along every line. The roller is finished. 1908Daily Chron. 12 June 9/6 Tracer for embroidery, female; also cutters wanted. 1911Webster, Tracer,..any of several chasing tools for ornamenting in metal, esp. for making and finishing corners, borders, and the like.
4. a. Bullets or shells whose course is made visible by the trail that they emit during flight; occas. in sing. sense. Orig., the trail produced by these.
1910Blackw. Mag. July 6/2 The projectiles of airship guns may possibly give out a jet of flame and a smoke ‘tracer’ on discharge. 1922Encycl. Brit. XXX. 120/2 For night use, the tracer shows a luminous spark, for day use the tracer gives a smoky trail. 1937Times 16 Apr. 8/6 This was a most spectacular demonstration, the machine-guns using tracer and the new smoke observation projectiles. 1957P. Kemp Mine were of Trouble ix. 173 A minute later bursts of tracer flew over us from high ground on our right. 1967Boston Sunday Globe 23 Apr. 16/4 Helicopter gunships tried to protect the other busy helicopters by circling in pairs, one with a light on to draw a stream of enemy tracers. 1970L. Deighton Bomber xxiii. 335 He was in the nose watching ropes of red and yellow tracer curve towards them and fall away. 1983‘W. Haggard’ Heirloom xv. 169 He'd seen..appeals for death..that airman with tracer burning his lungs out.
b. attrib. and Comb.
1916‘Taffrail’ Pincher Martin xv. 278 A thin trail of dim light climbed skywards in a curve as a tracer shell hurtled its way through the air. 1918‘Boyd Cable’ Air Men o' War 22 Tracer bullets emit smoke and flame to allow the shooter to follow their flight. 1928C. F. S. Gamble Story of North Sea Air Station xii. 179 When about 1,500 feet below the airship, he fired two trays of explosive and tracer ammunition from his Lewis gun into her. 1943Sun (Baltimore) 3 Aug. 4/6 During this exchange of fire, a Japanese plane had managed to get on the tail of Captain Walter's Warhawk. Tracer bullets were flying past him, but none hit. 1944Return to Attack (Army Board, N.Z.) 18/1 The flash and crack of the high-velocity tank guns, the low parabola of the tracer shell. 1969G. Macbeth War Quartet 40 Tracer-filled In open air-space. 1973M. Woodhouse Blue Bone xii. 135 A machine-gun stammered and tracer bullets began to draw graceful curves in space. 1976A. White Long Silence vii. 58, I saw a lone fighter come in from the west... Sudden streams of tracer fire came from him.
Add:[2.] d. A device which is designed to transmit a signal and which can therefore be traced when attached to a moving vehicle, etc.
1972K. Bonfiglioli Don't point that Thing at Me xii. 95 The tiny transistorised tracer-beacon..was magnetised fiercely to the underside of my right-hand front mudguard. 1984J. Savarin Wolfrun xiii. 168, I was asked to plant a tracer on the car. 1989Judge Dredd No. 2. 30/2 He did this by carrying a tracer, but its signal was blocked by the rock walls of the Judda base within Ayers Rock.
▪ II. tracer2|ˈtreɪsə(r)|
[f. trace n.2 + -er1.]
A trace-horse; also, a trace-horse boy.
1839Black Hist. Brechin ix. 212 He loosed the tracer, leaped on its back..and..went off. 1843A. Bethune Sc. Fireside Stor. 134 The sudden jerk..brought the shaft horse, who was a powerful animal, still nearer to that side of the road, while it made both him and the tracer lower their heads. 1899J. Lumsden Edin. Poems & Songs 110 Boot-blackers, news-boys—the smartest we ken! An' their billies, the tracers—Dickie an' Ben. |