| 释义 |
isobaric, a. and n.|aɪsəʊˈbærɪk|
[f. isobar + -ic. (Not formed on Greek analogies.)]
A. adj.
1. a. Indicating equal barometric pressure; containing or relating to isobars.
1878Huxley Physiogr. 95 Much may be learned about winds by studying the isobaric lines. 1882Standard 26 Dec. 7/4 The daily isobaric charts will receive greatly increased attention. 1883A. Buchan in Encycl. Brit. XVI. 139 Isobaric maps may be considered as furnishing the key to the more important questions of meteorological inquiry.
b. Occurring at or pertaining to a constant pressure.
1903A. Ogg tr. Planck's Treat. Thermodynamics i. i. 7 (heading) Behaviour under constant pressure (isopiestic or isobaric changes). 1933D. J. Martin Introd. Thermodynamics for Chemists xiii. 315 The isobaric heat of adsorption corresponds to the heat of a reaction in a condensed system, the amount adsorbed changes while the pressure remains practically constant. 1937P. S. Epstein Textbk. Thermodynamics iii. 46 The heat function acquires a particular importance in the so-called isobaric process, i.e. a process which takes place without change of pressure. 1966[see isopiestic adj. s.v. iso-].
2. Physics. Of, pertaining to, or being isobars (sense 2); isobaric spin = isospin. Const. with.
1919Nature 18 Sept. 61/2 Elements can be regarded as divisible into three classes:—(1) Isotopic elements, each set of which have different atomic weights but identical chemical properties; (2) isobaric elements which have identical atomic weights but different chemical properties; and (3) normal elements which differ..both in atomic weights and chemical properties. 1933F. W. Aston Mass-Spectra & Isotopes xii. 158 Spectra were obtained which showed four strong isotopes and two very weak ones, one of which is isobaric with W186. 1948Glasstone Textbk. Physical Chem. (ed. 2) ii. 171 With the development of the study of artificial radioactivity it has become apparent that there are more than seventy pairs of such isobaric isotopes, now known as isomeric nuclei. 1953D. R. Inglis in Rev. Mod. Physics XXV. 395/2 One finds the states listed according to the usual quantum numbers L and S of the (LS)-coupling scheme and also according to the isobaric spin quantum number T (or isotopic spin as it has been less aptly called since it was named long ago by Wigner, who agrees to this renaming of his child). 1971Physics Bull. Mar. 137/1 Isobaric spin was first introduced into nuclear interactions by Heisenberg purely as a mathematical convenience.
3. Med. Of, pertaining to, or designating a solution for spinal anæsthesia having the same density as the cerebro-spinal fluid.
1930,1946[see hyperbaric a. a]. 1947J. Adriani Techniques & Procedures Anesthesia v. 222 A 2 ½% solution of procaine in distilled water is nearly isobaric. 1962― Chem. & Phys. Anaesthesia (ed. 2) xxxi. 653/1 The results obtained with isobaric techniques are unpredictable and variable. 1971P. C. Lund Princ. & Pract. Spinal Anesthesia vii. 371 Isobaric solutions have not been popular..because of the difficulty of achieving predictable levels of anesthesia. Ibid., An adaptation of isobaric spinal anesthesia for anorectal surgery was introduced by Jacoby et al. in 1965.
B. n. = isobar 1 b.
1903Engineer 24 July 83/3 The isobarics of evaporation happen to be isothermals. 1937M. W. Zemansky Heat & Thermodynamics iv. 56 The series of short isobarics and isovolumics from i to f and the continuous curve from i to f represent other possibilities. |