请输入您要查询的英文单词:

 

单词 perforation
释义 perforation|pɜːfəˈreɪʃən|
[ad. late L. perforātiōn-em, n. of action from perforāre to perforate; cf. OF. perforacion, -ation (14th c. in Hatz.-Darm.), perh. the immediate source.]
1. a. The action of perforating, boring through, or piercing; the fact or condition of being perforated; spec. the making of a row or series of small holes in a leaf or sheet of paper, so as to enable a portion to be easily torn off.
c1440Gesta Rom. iv. 10 (Harl. MS.) Sir,..some tyme is suche holiyng and perforacion goode, and not wikkide.1626Bacon Sylva §500 The likeliest way [is] the perforation of the body of the tree in several places one above the other, and the filling of the holes [etc.].1836–41Brande Chem. (ed. 5) 269 The mechanical force..is shown by the perforation of paper.1881Spottiswoode in Nature 6 Oct. 548/1 Gun-cotton itself..merely shows signs of perforation like the card.1891‘Phil’ Penny Post. Jubilee 147 Next follows the perforation [of the sheets of stamps], which is performed by machinery.
b. Surg. The formation, through accident or disease, of a hole through the thickness of any structure, as through the wall of the intestine, etc.
1666Boyle Orig. Formes & Qual. (1667) 16 Bloudy Fluxes occasion'd by the perforation of the Capillary Arteries.1876J. S. Bristowe The. & Pract. Med. (1878) 224 Perforation of the bowel may occur in patients of all ages.Ibid. 229 If signs of perforation manifest themselves, our only hope lies in keeping the patient under the influence of opium or morphia.1882Med. Temp. Jrnl. LI. 108 If perforation should take place let me have large and repeated doses of opium.
2. A hole made by boring, punching, or piercing; an aperture passing through or into anything; a passage, shaft, tunnel; each one of a row or series of small holes punched in a leaf or sheet of paper, or between postage or other stamps in a sheet, in order to facilitate their separation.
1543Traheron Vigo's Chirurg. ix. 241 For remotion of thys aposteme, ye muste make a new and larger perforation or borynge.1599A. M. tr. Gabelhouer's Bk. Physicke 34/1 Inoculated Pearles, or Pearles without perforationes.1665Hooke Microgr. 38 Pipes of Glass, with a very small perforation.1783Pott Chirurg. Wks. II. 18 They have no perforations or apertures.1870Routledge's Ev. Boy's Ann., Suppl. Mar. 4/1 [Stamps] with pin-pricked perforations.1891‘Phil’ Penny Post. Jubilee 150 A simple perforation is that which the perforating machine has produced by punching the paper completely out, leaving a regular series of small round holes between each row of stamps.
3. The natural orifice of an organ or part of the body.
1615Crooke Body of Man 945 The first externall perforation..is called by a proper name, Meatus Auditorus, the hole of Hearing.1688Boyle Final Causes Nat. Things iv. 148 That admirable perforation of the uvea, which we call the pupil.1797M. Baillie Morb. Anat. (1807) 417 The hymen is sometimes found without a perforation in it, so that the vagina is completely shut up at its external extremity.
4. attrib. and Comb., as perforation-sound; perforation-gauge, in Philately, a gauge or rule for readily counting the number of stamp-perforations in a given length (conventionally, two centimetres); perforation plate Bot. (see quot. 1933).
1879St. George's Hosp. Rep. IX. 788 On inflation, air passes into the tympanum without perforation sound.1891‘Phil’ Penny Post. Jubilee 152 In order to ascertain the various sizes of perforations a perforation gauge has been invented.1933Tropical Woods XXXVI. 7 Perforation plate, a term of convenience for the area of the wall (originally imperforate) involved in the coalescence of two members of a vessel.1953K. Esau Plant Anat. xi. 223 The perforations of vessel members commonly occur on the end walls, but they may be present on the lateral walls too. The wall bearing the perforation is called the perforation plate.Ibid. 233 A pitted wall part became a scalariform perforation plate, which changed into a simple perforation plate.1975S. Carlquist Ecol. Strategies of Xylem Evol. i. 13 There are even dicotyledons with simple perforation plates and scalariform lateral-wall pitting.
随便看

 

英语词典包含277258条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。

 

Copyright © 2004-2022 Newdu.com All Rights Reserved
更新时间:2024/11/10 1:00:14