| 释义 |
proportional, a. and n.|prəʊˈpɔəʃənəl|
[ad. L. prōportiōnāl-is: see proportion n. and -al1. So F. proportionnel.]
A. adj.
1. Of or pertaining to proportion; relative; also, Used in obtaining proportions.
proportional compasses, compasses having two opposite pairs of legs turning on a common pivot, which is adjustable in a slide, so as to vary the distance apart of the points at each end in any desired ratio. proportional counter, an ionization chamber in which the voltage between the electrodes is great enough to produce gas amplification but not so great that the output pulse ceases to be proportional to the initial ionization; so proportional counting. proportional limit (Mech.), the maximum stress to which a body or material can be subjected without a departure from the proportionality of stress and strain. proportional scales: see quot. 1710; also called logarithmical scales.
1561T. Norton Calvin's Inst. i. 6 b, To wey..the knitting together, the proportional agreement, the beautie, and vse in the frame of mannes body. Ibid. iii. ii. (1634) 263 In these formes of speech standeth a proportionall relation. 1570Dee Math. Pref. d iv b, The Proportionall, and Paradoxall Compasses (of me Inuented). 1690Locke Hum. Und. ii. xxviii. §1 These Relations depending on the Equality and Excess of the same simple Idea, in several Subjects, may be called..Proportional. 1690[see logarithmetical]. 1710J. Harris Lex. Techn. II, Proportional Scales, sometimes also called Logarithmetical; are only the Artificial Numbers or Logarithms placed on Lines, for the ease and advantage of Multiplying, Dividing, Extracting Roots, &c. by means of Compasses or by Sliding-Rules. 1807T. Young Lect. Nat. Philos. I. x. 103 Proportional compasses are..of great use in reducing lines and figures to a different scale. 1906Proc. R. Soc. XII. 427 Bars tested in torsion to some stress below the elastic limit (proportional limit of bar) and the direction of torsion reversed immediately. 1937Rev. Sci. Instruments VIII. 254 (heading) Properties of the proportional (Geiger-Klemperer) counter. Ibid. 255/1 The proportional or Geiger-Klemperer counter which is operated in a range of potential below discharge but above the region of ionization by collision has been used in several series of experiments, notably where the detection of protons in the presence of gamma-radiation is required. 1939Rev. Mod. Physics XI. 213/2 With the gases mentioned, stable proportional counting and freedom from extremely critical voltage control can only be achieved with the aid of high gain amplifiers. 1950D. H. Wilkinson Ionization Chambers vi. 157 With simple precautions as to the allowed region of initial ionization the proportional counter becomes a precision instrument, and may be used as an accurate measure of particle energy. 1950E. E. Wahlstrom Introd. Theoret. Igneous Petrol. v. 115 Both the elastic limit and the proportional limit vary with the time through which the stress is applied. 1958Faires & Parks Radioisotope Lab. Techniques xi. 111 In order to obtain the high electric fields required to produce gas amplification, the proportional counter usually takes the form of a metal cylinder, having a fine wire, insulated at its ends, stretched along its length. 1961G. R. Choppin Exper. Nuclear Chem. xi. 186 This fact and the sensitivity to impurities make Geiger-Müller counting less attractive than proportional counting. 1971Nature 16 Apr. 448/1 Several investigators have measured the diffuse cosmic X-ray intensity in the 1/4 keV band by means of rocket-borne gas proportional counters. 1972Mallows & Pickering Stress Anal. Probl. S.I. Units ii. 37 It is common..to use the proportional limit, elastic limit, and yield stress as alternatives for one another in design calculations: since they are usually close to one another, this is quite acceptable.
2. a. That is in proportion, or in due proportion; having (suitable) comparative relation; corresponding, esp. in degree or amount.
[1396: implied in proportionally 1.] 1570Dee Math. Pref. b iij, With some proportionall consideration for our time, and being. a1631Donne Serm. xxvii. (1640) 270 We must hold them so as may be analogall, proportional, agreeable to the Articles of our Faith. 1669Staynred Fortif. 6 To draw the Proportional Dimension of a Regular Fort of 6 Sides. 1769Robertson Chas. V, III. viii. 74 Animated with a zeal in defence of their religion proportional to the fierceness with which it had been attacked. 1831Brewster Optics vii. 70 Taking as much of each as seem to be proportional to the rays in each coloured space.
b. proportional representation, a system of parliamentary representation based on numerical (rather than regional) divisions of the electorate, spec. one by which each party is represented in proportion to the numerical strength of the vote it receives, usually by means of a method of transferable vote (see transferable a.).
1870Putnam's Mag. June 720/1 When once the theory of proportional representation is reduced to practice..it will assert its superiority. 1873Mill Autobiogr. vii. 302 The two greatest improvements which remain to be made in Representative Government... One of them was Personal, or, as it is called with equal propriety, Proportional Representation. 1884Pall Mall G. 19 Dec. 3/1 Proportional Representation finds little favour with the caucuses. 1909[see transferable a.]. 1917H. G. Wells in Times 30 Mar. 7/5 The essential point to grasp is that Proportional Representation is not a novel scheme, but a carefully worked-out remedy for universally recognized ills. 1940F. A. Hermens Democracy & Proportional Representation 1 There are few devices of democratic government on which opinions differ so sharply as on proportional representation. 1952[see Gaullist a. and n.]. 1963J. Grimond Liberal Challenge xi. 314, I believe..that the best solution might be to keep the present system for the Commons but introduce proportional representation for a second chamber. 1976Scotsman 24 Dec. 4/3 A series of amendments to provide for the Scottish and Welsh assemblies to be elected by proportional representation were tabled yesterday.
3. Math.
a. That is in proportion (sense 9); having the same or a constant ratio.
1570Billingsley Euclid v. def. 7. 131 Magnitudes which are in one and the selfe same proportion, are called Proportionall. 1594Blundevil Exerc. i. xxiii. (1636) 51 Multiply the two numbers..the one by the other,..the square Root of the Product shall be the meane Proportionall number betwixt them. 1706W. Jones Syn. Palmar. Matheseos 66 The Powers of Proportionals are also Proportional. 1798Hutton Course Math. (1810) I. 309 Three quantities are said to be Proportional, when the ratio of the first to the second is equal to the ratio of the second to the third. Ibid. 319 Triangles which have their Sides Proportional, are Equiangular. 1851Richardson Geol. v. (1855) 87 The planes of a crystal are said to be similar when their corresponding edges are proportional. 1871Tyndall Fragm. Sci. (1879) I. i. 15 The heat is proportional to the square of the velocity.
b. proportional circles, proportional radii, proportional spirals: see quots.
1704J. Harris Lex. Techn. I, Proportional Spirals, are such Spiral Lines as the Rhumb Lines on the Terrestrial Globe, which because they make equal Angles with every Meridian, must also..make equal Angles with the Meridians in the Stereographick Projection on the Plane of the Equator. 1825J. Nicholson Operat. Mechanic 21 When these two circles [representing wheel and pinion] are so placed that their outer rims shall touch each other, a line drawn from the centre of the one to the centre of the other is termed the line of centres; and the radii of the two circles the proportional radii. These circles are sometimes called proportional circles, but by mill-wrights in general pitch lines.
B. n.
†1. That which is proportional; a proportionate part; a relative quantity. Obs.
c1386Chaucer Frankl. T. 550 And hise proporcioneles conuenientz For hise equacions in euery thyng. 1856Jrnl. R. Agric. Soc. XVII. i. 177 We get blighted leaves and straw, with too small a proportional of corn.
2. Math. One of the terms of a proportion.
1570Dee Math. Pref. c iij b, Betwene two lines giuen, finde two middle proportionals, in Continuall proportion. 1656tr. Hobbes' Elem. Philos. (1839) 168 If there be never so many continual proportionals..their differences will be proportional to them. 1743Emerson Fluxions 131 Let the Number of geometrical Proportionals be increas'd..and let the arithmetic Proportionals be in like Manner increased. 1798Hutton Course Math. (1810) I. 110 The four proportionals, 4, 2, 6, 3 are set thus, 4:2::6:3, which means, that 4 is to 2 as 6 is to 3; or thus, 4:2 = 6:3, or thus, 4/2 = 6/3, both which mean, that the ratio of 4 to 2, is equal to the ratio of 6 to 3. 1827Ibid. 119 The mean proportional between two numbers is the square root of their product.
†3. Chem. The smallest combining proportion of a chemical element or compound; a combining equivalent; the proportional weight of an atom or molecule. Obs.
1825Brande Man. Pharm. 204 In its dry state it [Nitric Acid] consists of—5 proportionals of Oxygen..1 [of] Nitrogen. 1832G. R. Porter Porcelain & Gl. 164 Silica, boracic acid, and oxide of lead, brought together in single proportionals. 1836–41Brande Chem. (ed. 5) 435 The decomposition..furnishes a good illustration of the theory of definite proportionals, both in volumes and weights. 1855Grove Corr. Phys. Forces (ed. 3) 181 No compound is known in which twenty-seven grains of iron will combine with two proportionals or sixteen grains of oxygen. |