| 释义 |
perturbation|pɜːtɜːˈbeɪʃən|
[a. OF. perturbacion (14th c. in Littré), ad. L. perturbātiōn-em, n. of action f. perturbāre to perturb.]
1. The action of perturbing; the fact or condition of being perturbed; disturbance, disorder, commotion; mental agitation or disquietude; trouble.
c1374Chaucer Boeth. i. pr. v. 16 (Camb. MS.), Thilke passyuns þat ben woxen hard in swellynge by perturbasyouns fflowyng in to thi thowht. c1380Wyclif Sel. Wks. III. 401 Freris ben cause..of perturbacioun in Cristendom. 1460Rolls of Parlt. V. 382/2 Outrageous and ymmesurable perturbation and violence of the peas. 1555Sc. Acts Mary (1814) II. 500/1 Gif ony wemen or vthers..singand makis perturbatioun to the Quenis liegis in the passage throw Burrowis and vthers landwart townis. 1594Shakes. Rich. III, v. iii. 161 Richard, thy Wife,..Now filles thy sleepe with perturbations. 1667Milton P.L. x. 113 Love was not in thir looks,..but apparent guilt, And shame, and perturbation, and despaire. 1719De Foe Crusoe i. xiii, The Perturbation of my Mind was very great. 1870J. H. Newman Gram. Assent i. v. 105 These various perturbations of mind, which are characteristic of a bad conscience.
2. a. Disturbance of the regular order or course; irregular variation, disorder.
1567J. Maplet Gr. Forest 10 Auaylable against diseases and consumption of the Splene, and other perturbations Melancholike. 1621Burton Anat. Mel. To Rdr. (1624) 11, I require a fauourable censure of all faults omitted..Perturbations of Tenses, numbers [etc.]. 1722Wollaston Relig. Nat. v. 85 The magnificence of the world admits of some perturbations; not to say, requires some variety. 1848Mill Pol. Econ. iii. iii. §2 Perturbations of value during a period which cannot exceed the..time necessary for altering the supply. 1881Huxley in Nature 11 Aug. 344/1 Disease..is a perturbation of the normal activities of a living body.
b. Astron. The deviation of a heavenly body from its theoretically regular orbit, caused by the attraction of bodies other than its primary, or by the imperfectly spherical form of the latter.
1812Woodhouse Astron. xix. 216 The perturbation of the Earth caused by the attracting force of the Moon and planets. 1834M. Somerville Connex. Phys. Sc. iii. (1849) 25 Neptune produces a periodical perturbation in the motion of Uranus. 1853Herschel Pop. Lect. Sc. iii. §25 (1873) 114 The calculation of the planetary perturbations..had then been brought to great perfection. 1946H. & B. S. Jeffreys Methods Math. Physics xvi. 464 Without the disturbance due to other planets, the motion of any planet would be an ellipse, specified by six constants... To allow for perturbations these constants are taken as variables.
3. A cause or factor of disturbance or agitation.
1597Shakes. 2 Hen. IV, iv. v. 23 Why doth the Crowne lye there, vpon his Pillow, Being so troublesome a Bed⁓fellow? O pollish'd Perturbation! Golden Care! 1614R. Tailor Hogge hath lost Pearle v. G ij, Cressus royall selfe..is not tortured there as Poets feine With molton Gold and sulphrie flames of fire Or any such molesting perturbation.
4. Physics and Math. A slight alteration of a physical system, esp. of the conditions which a solution of Schrödinger's equation must satisfy, or of a set of equations, from a relatively simple form to one which is to be studied by comparison with the simpler form. Freq. attrib., as perturbation calculation, perturbation expansion, perturbation method, perturbation series; perturbation theory, the method of investigating solutions of equations of state by relating them to solutions of similar but simpler equations which can be solved directly.
[1868Phil. Mag. XXXVI. 135 The motions [of molecules] are, however, not altogether free from perturbation. ]1899Q. Jrnl. Math. XXX. 47 In this paper it is proposed to follow the theory of perturbations in the problems of mechanics in the order of its historical development from Lagrange to Lie. 1926Proc. R. Soc. A. CXI. 301 If the [magnetic] field is weak we may use perturbation theory, according to which the change of energy of the stationary states is given, to the first order, by the constant term in the Fourier expansion of the energy of the perturbation in terms of the uniformising variables for the undisturbed system. 1937E. C. Kemble Fund. Princ. Quantum Mech. xi. 380 In quantum mechanics, as in the Bohr theory, perturbation methods are of fundamental importance due to the fact that so few problems can be rigorously solved by direct methods. Ibid. xiv. 526 The usual method of approach to the problem of the many-electron atom is through a perturbation calculation in which the unperturbed problem..is of the central-field type. 1956R. H. Atkin Math. & Wave Mech. xi. 241 The method of perturbations is a practical technique for approximating to such solution. 1957Technology Apr. 73/2 Perturbation theory and electron spin are studied, and used to explain the periodic table of elements and chemical bonds. 1961Powell & Crasemann Quantum Mech. xi. 381 We shall begin by deriving..the result of Section 5–8, giving the effect of a small perturbation on the energy levels of a system with discrete stationary states. Ibid. 403 A system subject to a weak time-dependent perturbation can be described approximately by a Hamiltonian of the form H = H0 + V(t). Ibid., Since the perturbation is time-dependent, the system does not, in general, have stationary states. 1968Fox & Mayers Computing Methods for Scientists & Engineers ii. 17 We accept the ‘solution’..and try to find a ‘neighbouring’ problem, a ‘perturbation’ of the given problem. 1972G. E. Brown Many-Body Probl. ii. 25 The two types of perturbation theory most commonly used are the Brillouin-Wigner perturbation expansion and the Rayleigh-Schrödinger one. 1973Alonso & Valk Quantum Mech. v. 202 Expressions (5.8–19) through (5.8–23) constitute the Rayleigh-Schroedinger perturbation series.
Hence perturbation-theoretic, -theoretical adjs., of, pertaining to, or involving perturbation theory.
1964Physical Rev. CXXXIII. A1070 (heading) Perturbation theoretic calculation of polaron mobility. 1968C. G. Kuper Introd. Theory Superconductivity i. 2 Early attempts to construct a perturbation-theoretical model based on Fröhlich's interaction encountered severe mathematical difficulties. |