| 释义 |
pulsation|pʌlˈseɪʃən|
[ad. L. pulsātiōn-em, n. of action f. pulsāre: see pulsate.]
I. The action, or an act, of pulsating or pulsing.
1. The movement of the pulse in a living animal body; rhythmic dilatation and contraction, as of the heart, an artery, etc.; beating, throbbing.
1541R. Copland Galyen's Terap. 2 F ij b, Yf there be all redy vehement pulsacyon, in such wyse that there is no more hope of the curacyon of the sayd partyes. 1615Crooke Body of Man 859 This motion of the Arteries is called pulsus or pulsation..which is absolued by dilatation and contraction. 1664Power Exp. Philos. i. 9 In a greater Louse you might see this pulsation of her heart through her back also. 1804Abernethy Surg. Obs. 229 The pulsation of the artery was not felt. 1876J. S. Bristowe The. & Pract. Med. (1878) 501 Dilatation and pulsation of the larger veins.
b. with pl. A beat, throb (of the heart, an artery, etc.); = pulse n.1 1 c.
c1645Howell Lett. i. i. xxxvii, The Physitians hold, that in evry well dispos'd body, ther be above 4000 Pulsations evry hour. 1747H. Brooke Fables, Female Seducers Poems (1810) 413/2 Her frame with new pulsations thrill'd. 1834J. Forbes Laennec's Dis. Chest (ed. 4) 659 The affection is distinguished by the pulsations of the heart appearing more audible in the back..than in the region of the heart itself.
c. fig. Cf. pulse n.1 2.
1765Sterne Tr. Shandy VIII. xvi, It could neither give fire by pulsation, nor receive it by sympathy. 1848H. Rogers Ess. (1874) I. vi. 327 The pleasure..of beholding the pulsations, so to speak, of intellectual life. 1885Manch. Exam. 15 Apr. 3/1 A little book..warm with the pulsation of individual thought.
2. gen. Rhythmical beating, vibration, or undulation: cf pulse n.1 4.
1658J. Rowland Moufet's Theat. Ins. 1104 They [worms] move from place to place with a certain drawing and pulsation. 1850Tennyson In Mem. xii, As a dove..Some dolorous message knit below The wild pulsation of her wings. 1870Emerson Soc. & Solit., Art Wks. (Bohn) III. 17 The pulsation of a stretched string or wire gives the ear the pleasure of sweet sound.
b. with pl. A beat, a vibration, an undulation; = pulse n.1 4 b.
1831Brewster Nat. Magic ix. (1833) 243 A low continuous murmuring sound beneath his feet, which gradually changed into pulsations as it became louder. 1840R. H. Dana Bef. Mast xviii. 52 No sound heard but the pulsations of the great Pacific! 1866Duke of Argyll Reign Law iii. (1867) 137 The pulsations of the wing in most birds are so rapid that they cannot be counted. 1878Huxley Physiogr. xi. 171 In the open sea, the wave or pulsation is propagated, but the mass of the water..remains stationary.
II.
3. The action of striking, knocking, or beating; with pl. A stroke, knock, blow; in quot. 1891 one made by a pulsator (see pulsator 2).
1656Blount Glossogr., Pulsation, a beating, striking, knocking or thumping. 1768Blackstone Comm. III. viii. 120 The Cornelian law de injuriis prohibited pulsation as well as verberation; distinguishing verberation, which was accompanied with pain, from pulsation, which was attended with none. 1891Blackw. Mag. Sept. 322 A large flap of wood bestows a smart box on the ear,..on the surface of no. 2 pan. I estimated the number of these pulsations at 110 per minute.
Hence pulˈsational a., of, pertaining to, or characterized by pulsation; also pulˈsationally adv.
1882Contemp. Rev. Oct. 636 The striations seen athwart the tail..would be explained..as due to the observed pulsational manner in which the envelopes are raised. 1969Nature 19 July 279/1 Despite the trend of recent evidence..that radial pulsations may not be the source of variation in pulsars, the pulsational hypothesis has still not been disproved. Ibid. 280/1 Thermonuclear reactions are extremely effective in pulsationally destabilizing a degenerate star. 1976Ibid. 15 Jan. 88/2 Periods decrease with increase of λ and of polytropic index n..for all different modes of oscillations (pulsational, transverse shear, and toroidal, modes). |