| 释义 |
radiant, a. and n.|ˈreɪdɪənt|
Also 5–6 radyant, 6 -aunt(e, -iaunt; 6 radyent, 7–9 -ient.
[ad. L. radiānt-em, pres. pple. of radiāre to emit rays: see radius n. Cf. mod.F. radiant.]
A. adj.
1. a. Sending out rays of light; shining brightly.
c1450Cov. Myst. xli. (Shaks. Soc.) 387 Heyl! radyant sterre, the sunne is not so bryth. c1510Gesta Rom. Add. Stories ii. 433 [Christ's] body yt was..more radyent than ony syluer. 1590Shakes. Mids. N. iii. i. 95 Most radiant Piramus, most Lilly white of hue. 1604Drayton Owl (R.) The great eagle..Which from the mountain (with a radiant eye) Brav'd the bright cressit of the glorious sky. 1667Milton P.L. iii. 63 On his right The radiant image of his Glory sat, His onely Son. 1742Young Nt. Th. iv. 373 This gloom of night,..with all her radiant worlds. 1812J. Wilson Isle of Palms ii. 493 Her little sail beneath the sun Gleams radiant as the snow. 1872Blackie Lays Highl. 75 The height which bears The sailor's radiant mark.
fig.1838Emerson Literary Ethics Wks. (Bohn) II. 208 The humblest.. in view of these radiant facts, may now theorize and hope. 1874H. R. Reynolds John Bapt. iv. §6. 262 The author..treats the Old Testament as radiant with the features and fragrant with the Spirit of the Christ.
b. Represented as sending out rays of light, or having radial projections resembling this. In Her. = rayonné.
1614Selden Titles Hon. 138 Which the learned Paschalius interprets for a Crown radiant. 1661Morgan Sph. Gentry iv. vi. 83 A kind of radiant or pointed Coronet. 1780Edmondson Compl. Body Heraldry II. Gloss., Radiant, Rayonned..terms used to express any ordinary edged with glittering rays, or shining beams. 1799G. Smith Laboratory II. 16 The radiant crown, on ancient coin, signifies that the prince was..Deified.
c. Of the eyes or looks: Bright, expressive of lively joy, hope, or the like; beaming.
1794Burns Charming Month of May 5 The glorious sun..Out-rival'd by the radiant eyes Of..charming Chloe. 1859Hawthorne Fr. & It. Jrnls. II. 287 The most radiant eye that the dull earth ever opened to see heaven withal. 1878Browning Poets Croisic clix, Let, through the tumult, break the poet's face Radiant.
d. Designed to send out radiant heat.
1936Faber & Kells Heating & Air-Conditioning iv. 81 The warming effect of convectors is slower than with the radiant type of heater. 1936Economist 28 Mar. 738/1 Our High Beam fires have proved to be the most efficient radiant gas fires in the world. 1951Good Housek. Home Encycl. 35/2 More recently the use of ‘radiant radiators’..has become more common. 1957Heating, Ventilating, Air Conditioning Guide XXXV. 399 Radiant heaters..have a refractory directly above the burners which is heated to incandescence. 1962Listener 13 Sept. 411/3 It [sc. an electric cooker] has two radiant plates. 1964J. J. Barton Heating & Ventilating xii. 318 The principal heat requirements are provided by convection, with a small radiant unit providing sufficient beamed heat for topping-up. 1977Direct Electric Heating (Electricity Council) v. 21/1 Direct electric heating appliances and equipment... They may be divided into four basic groups, namely—(i) Low intensity radiant systems incorporated in the building fabric. (ii) Individual radiant-convector units. (iii) Forced warm air systems. (iv) Hot water radiator systems.
2. a. Issuing or appearing in the form of rays (of light); hence, bright, shining, splendid. Also transf. of qualities, as beauty.
1509Hawes Past. Pleas. iii. (Percy Soc.) 15 The radiant bryghtnes of golden Phebus. Ibid. xxxv. 112 The mone..is fayre replendysshaunte In the longe nyght with rayes radyaunte. 1548Udall Erasm. Par. N.T. Pref. C ij b, The clere radiaunt sunnebeames of his holy woorde. 1601Shakes. Twel. N. i. v. 181 Most radiant, exquisite, and vnmatchable beautie. 1646Sir T. Browne Pseud. Ep. v. ix. (1686) 202 With scintillations, or radiant Halo's about their heads. c1750Shenstone Elegy ix. 28 All that bears the radiant stamp of Kings. 1781Cowper Truth 61 Meridian sunbeams tempt him to unfold His radiant glories. 1810Crabbe Borough i, Velvet leaf with radiant beauty drest. 1878M. A. Brown Nadeschda 66 A radiant glow o'erspread Her rigid face.
†b. Of heat: Strong, fierce. Obs. rare—1.
1508Fisher 7 Penit. Ps. cxxx. Wks. (1876) 231 Ionas..made hym a shadowynge place for his defence agaynst the radyaunt heet of the sonne.
3. a. Moving or operating in a radial manner; esp. radiant heat: see heat n. 2 b. Also radiant heating; radiant-heated adj.
1800Henry Epit. Chem. (1808) 29 Radiant Caloric exhibits several interesting properties. 1835Kirby Hab. & Inst. Anim. I. Introd. 40 Both in the vegetable and animal it [Life] is a radiant principle. 1887Crookes in Proc. Royal Soc. XLII. 111 (title) On Radiant Matter Spectroscopy. 1912Cassier's Mag. XLI. 569/1 (heading) Radiant heating. Ibid. 570/1 The demonstrations were continued..at the experimental works of the Radiant Heating Syndicate. 1962Punch 24 Jan. 178/2 The ‘tropical radiant-heated indoor pool’. 1966McGraw-Hill Encycl. Sci. & Technol. XI. 213/1 Any radiant-heating system using a fluid heat conveyor may be employed as a cooling system by substituting cold water or other cold fluid.
b. radiant efficiency, the ratio of the radiant flux emitted to the power consumed; radiant energy, energy in the form of (usu. electromagnetic) radiation; radiant flux, the rate of flow of radiant energy; radiant power = radiant flux above.
1914Rep. Brit. Assoc. Adv. Sci. 1913 435 The true remedy must be sought for in increasing the ‘radiant efficiency’ of the [gas] fire. Ibid. 436 Part of the radiant energy is directly determined..by using a radiation calorimeter. 1917Astrophysical Jrnl. XLV. 44 Through this space radiant energy is passing at a certain rate. This rate constitutes the radiant flux through the space. 1923Sci. Papers U.S. Bureau of Standards No. 475. 132 The ratio of luminosity to radiant power—the luminous efficiency. 1932Hardy & Perrin Princ. Optics i. 19 If the human eye were uniformly sensitive to radiation of all wave lengths, the radiant power expressed in watts would provide an adequate method of evaluating the flux. 1936Faber & Kell Heating & Air-Conditioning of Buildings iv. 74 Their [sc. gas fires'] radiant efficiency is about 50 per cent. (with an additional 10 per cent. convection). 1944Jrnl. Optical Soc. Amer. XXXIV. 252/2 When radiant flux is evaluated with respect to its capacity to evoke the brightness attribute of visual sensation it is called luminous flux. 1970M. V. Klein Optics iv. 121 The radiant energy density..is the radiant energy contained in a unit volume of space. Radiant power or radiant flux..is the time rate of change, or rate of transfer, of radiant energy.
4. (Chiefly Bot.) Extending in a radial manner; having parts so extending.
1830Lindley Nat. Syst. Bot. 153 The radiant stigma of Papaver. 1845― Sch. Bot. vi. (1858) 84 Flowers either flosculous or radiant. 1847W. E. Steele Field Bot. 34 Pet[als] obcordate, the outer ones radiant and deeply bifid.
5. Characterized by radiation.
1825J. Nicholson Operat. Mechanic 406 Cut into grooves,..in a radiant direction from the centre. 1851Ruskin Stones Ven. (1874) I. xx. 223 The scallop also is a pretty radiant form. 1881Nature XXIII. 462 A means..for carrying energy in a ‘radiant’ manner.
6. radiant point:
a. Any point forming a centre from which rays or radii proceed.
1726E. Stone New Math. Dict. 1727–41Chambers Cycl. s.v., Every radiant point diffuses innumerable rays all round. 1831Brewster Optics i. 10 The point of divergence..or the radiant point, as it is called. 1833N. Arnott Physics (ed. 5) II. 209 If the distance of the radiant point be very great, they [the rays] really are..nearly parallel.
b. Astron. The apparent focal point of a meteoric shower. So radiant region.
1864A. S. Herschel in Monthly Notices R. Astron. Soc. (1865) 33 Two radiant-points of shooting stars..presented themselves in Auriga and in Cetus. 1864Brit. Assoc. Rep. Meteors (1865) 101 Allowing a radiant-region of 10° to 15° in diameter for each. 1867–77G. F. Chambers Astron. ix. iii. 799 Herrick regarded the position of the radiant-point as being near the cluster..in the sword-hand of Perseus.
B. n.
1. a. Physics. A point or object from which light or heat radiates.
1727–41Chambers Cycl. s.v., All the rays proceeding from the same radiant continually diverge..Every ray is supposed to carry with it the species, or image, of the radiant. 1800Herschel in Phil. Trans. XC. 295 Our next division comprehends the heat of coloured radiants. 1869Tyndall Notes Lect. Light §291 All bodies, whether luminous or non-luminous, are radiants; if they do not radiate light they radiate heat. 1880Le Conte Sight 29 The central rays from all radiants cross each other in the lens.
b. Each of the units in a radiant fire that are designed to radiate heat.
1914Rep. Brit. Assoc. Adv. Sci. 1913 436 A little later a more marked step in the evolution of the new radiating fire consisted in joining the two or three fireclay pieces into one, and thus making the firefront consist of a series of hollow fireclay columns (now known as radiants). 1936Economist 28 Mar. 738/1 Our ‘Thermo-XX Beam’ radiant..was the first radiant designed to emit an increased proportion of short infra-red rays, and its introduction marked a new stage in the development of the gas fire. 1953‘N. Shute’ In Wet 173 They sat down in arm chairs before the radiants of the electric fire. 1958Woman's Journal Mar. 20/2, I..sat down by my hissing gas fire. One of the radiants was missing.
2. Geom. ‘A straight line proceeding from a given point or fixed pole about which it is conceived to revolve’ (Brande Dict. Sci. 1842).
1842Brande Dict. Sci., etc. 1012 The theory of the description of lines of the second order by the intersection of radiants is given by Newton in the Principia. 1846Clerk Maxwell in Campbell Life (1882) 77, r and r′ being the radients to any point of the curve from the two foci.
3. Astron. A radiant point (see 6 b above).
1864British Assoc. Rep. Meteors (1865) 101 Professor Heis..has..divided his meteor-showers and radiants into bi-monthly divisions. 1884Athenæum 20 Dec. 809/3 The meteors from some radiants leave a streak; those from others are swift. |