| 释义 |
filament|ˈfɪləmənt|
[ad. mod.L. fīlāment-um, f. late L. fīlāre to spin, f. fīlum thread. Cf. F. filament.]
1. a. A tenuous thread-like body, resembling a fibre of tow; a minute fibre. Often in scientific use, as applied to animal or vegetable structure.
1594T. B. La Primaud. Fr. Acad. ii. 31 The..filaments..are litle long threeds, slender & white, solide & strong. 1664Power Exp. Philos. i. 66 Those long filaments of which the substance of Brain..consists. 1671Grew Anat. Plants i. vi. §9 (1682) 43 Every one having a Seed appendent to it, whose Coats it entreth by a double Filament. 1774J. Bryant Mythol. I. 364 The rivers conveyed down their streams fine filaments of brass. 1791Hamilton Berthollet's Dyeing I. i. ii. i. 123 Differences in wool consist in the length and fineness of its filaments. 1841H. Miller O.R. Sandst. i. 12 The stone..was of..filamentary texture, the filaments radiating in straight lines from the centre to the circumference. 1854J. Scoffern in Orr's Circ. Sc. Chem. 6 The suspending filament should be..unspun silk. 1855Bain Senses & Int. i. ii. §14 The part where the filaments of the nerve are distributed. 1876Rock Text. Fabr. i. 1 The filaments drawn out of the leaves of plants.
fig. = ‘Scrap’, ‘shred’.
1870Lowell Among my Bks. Ser. i. (1873) 356 Is there the least filament of truth in it? 1875Emerson Lett. & Soc. Aims, Quot. & Orig. Wks. (Bohn) III. 214 From the slenderest filament of fact a good fable is constructed.
b. spec. The infusible conductor (orig. some form of carbon; now commonly tungsten), placed in the glass bulb of an incandescent electric lamp and raised to incandescence by the passage of the current; a similar conductor in a thermionic valve that serves as a heater or as a directly heated cathode.
1881S. P. Thompson Elem. Less. Electr. §374 In these lamps the carbon filament is mounted upon conducting wires..which pass into a glass bulb, into which they are sealed, the bulbs being afterwards exhausted of air. 1885Proc. R. Soc. XXXVIII. 219 If a galvanometer G be connected between a, the positive electrode, and e, a derived current will be observed to pass..through the rarefied space ec when the main current is increased to a certain strength, and the filament reaches a certain degree of incandescence. 1904Fleming Brit. Pat. 24,850 1 An appliance which..constitutes..an electrical valve. I construct it as follows:—In a glass bulb, I seal two or more carbon filaments... These filaments each have their own separate terminals. 1930Engineering 28 Nov. 671/3 The filaments of all the five valves are connected in parallel. 1950P. Parker Electronics xviii. 900 Hum may be introduced into the output of a valve by the magnetic and electric fields of its filament or heater. 1965M. Mandl Fund. Electronics (ed. 2) xi. 200 The heater filament is placed sufficiently close to the cathode so that the heater will raise the temperature of the cathode to the point where it will emit electrons.
c. Zool. The shaft of a down feather.
1869[see barbule 2]. 1959Van Tyne & Berger Fund. Ornith. iii. 71 It is probable that in their evolutionary history birds began with a covering of scales and a few feather filaments (cryptoptiles) scattered between them.
d. Textiles. A thread of man-made fibre.
1927T. Woodhouse Artificial Silk 34 The introduction of small pumps near the filament-forming tubes. 1955Times 10 May 18/3 More inquiry continues to come forward for filament rayon and staple yarns. 1957R. W. Moncrieff Man-Made Fibres xxii. 342 The fibre is spun from the molten polymer..through a spinneret with circular holes; the individual filaments solidify almost immediately.
2. a. transf., e.g. in filament of air, light, etc.; also in Hydromechanics (see quot. 1850).
1646Sir T. Browne Pseud. Ep. ii. iv. 80 Effluvium passing out in a smaller thred and more enlengthened filament..stirreth not the bodies interposed. 1712Blackmore Creation ii. (1718) 51 The ever-rolling Orb's impulsive Ray On the next Threads and Filaments does bear. 1810Vince Elem. Astron. xxi. 229 Part of that exceedingly fine filament of light was intercepted. 1822–56De Quincey Confess. (1862) 73 Slender as a filament of air. 1828J. M. Spearman Brit. Gunner (ed. 2) 200 The lateral pressure of a filament of fluid is equal to its vertical pressure. c1850Rudim. Navig. (Weale) 154 A Filament is an imaginary portion of a stream, of very small breadth, consisting of a row of corpuscles, or of an indefinite number of particles, following each other in the same direction. 1860Tyndall Glac. i. xxi. 146 The fog was drawn away in long filaments by the wind. 1879G. B. Prescott Sp. Telephone 128 The action of the helix..upon filings, consists in grouping them under the forms of filaments parallel to the axis.
b. Astr. A narrow thread-like streamer from the sun's chromosphere or in its corona.
a1869J. Nasmyth in E. Dunkin Midnight Sky (1869) 224 The filaments in question are seen..at the edges of the luminous surface. 1871English Mechanic 24 Nov. 243/1 The chromosphere is surmounted by filaments like brilliant hairs. 1902Encycl. Brit. XXVII. 630/2 The drawings in the volume quoted show its polar rays, wings, interlacing filaments, and rifts as they are now known to be, as well as the forms and details of the prominences. 1955Sci. Amer. Feb. 44/3 Certain hydrogen clouds in the sun's atmosphere known as ‘filaments’. 1968P. Moore Sun ix. 81 The prominences..can..be examined when full on the disk, when the Sun is observed or photographed in hydrogen light, but they then look rather like dark snakes, and are called filaments.
3. Bot. That part of the stamen which supports the anther; also (see quot. 1884).
1756P. Browne Jamaica 123 Vegetables that have three distinct Filaments or male generative parts in every flower. 1759B. Stillingfleet Misc. Tracts Nat. Hist. Introd. (1762) 30 Six long thready substances called the filaments each terminated by an oblong body..called the anthera. 1776Withering Brit. Plants (1796) I. 22, 10 Stamens in each, and the Filaments not united. 1858Carpenter Veg. Phys. §9 The filaments of the Berberry stamen. 1884Syd. Soc. Lex., Sexual Filament, the one-celled stalk of the oogonium of some Algæ when it also bears an antheridium.
4. nonce-uses.
a. A thread-like band.
b. (with etymological reference) A spun thread.
1715tr. Pancirollus' Rerum Mem. I. iv. ii. 157 The Pagan Priests had a Cap upon their Heads, which..they bound..with a woollen Filament. 1791Cowper Odyss. viii. 345 Hung them numerous from the roof diffused Like spider's filaments.
5. attrib. and Comb., as filament bulb, filament-cathode, filament current; filament battery, a battery that provides the current for the filament of a valve; filament lamp, an electric light bulb in which the light is produced by an incandescent filament.
1919Radio Rev. Oct. 47 The filament battery is used to supply the anode circuit voltage, as well as for lighting the filament. 1949A. V. Eastman Fund. Vacuum Tubes (ed. 3) iii. 45 A 45-volt battery is used to supply the plate voltage, its negative terminal being connected to the negative terminal of the filament battery.
1904Fleming Brit. Pat. 24,850 2 The above described multiple carbon filament bulb..may be used as a receiving instrument in wireless telegraphy. 1966R. G. Kloeffler Electron Tubes i. 6 Directly heated filament-cathodes require comparatively little heating power and are used in tubes designed for use with dry batteries.
1885Proc. R. Soc. XXXVIII. 227 Returned to 90 volts and repeated the experiments. Filament current readings the same as before. 1921W. H. Eccles Contin. Wave Wireless Telegr. i. 266 The filament current and the length of the filament which could be used directly on a 10-volt battery at a temperature of 2,300°K.
1885Proc. R. Soc. XXXVIII. 220 The lamp..was a short (75 mm.) filament lamp, with a platinum plate. 1908Chem. Abstr. II. 1929 The hourly expense of the metallic filament lamp is 60% less than that of the carbon. 1952H. Hewitt Mod. Lighting Techn. 33 This rapid development in electric lamps has derived from the employment of several different principles, the incandescence of the filament lamp being followed by the luminescence of the discharge tube. |