| 单词 | doubly magic |
| 释义 | > as lemmasdoubly magic 3. Nuclear Physics. (Of each of a set of numbers) corresponding to the number of protons or neutrons in nuclei of exceptional stability (the set now taken to be 2, 8, 20, 28, 50, 82, 126, and perhaps 184); (of a nucleus) containing such a number of protons or neutrons or ( doubly magic) both. ΚΠ 1949 O. Haxel et al. in Physical Rev. 75 1766/1 A simple explanation of the ‘magic numbers’ 14, 28, 50, 82, 126 follows at once from the oscillator model of the nucleus. 1956 Nature 28 Jan. 159/1 The current work on fast-neutron capture..refines the earlier studies by D. J. Hughes of the variation of cross-section with atomic weight which..throws more light on the magic-number nuclei. 1969 Physics Lett. 28 b. 544/2 Since the nucleon shells at Z = 114, N = 184 are not as ‘magic’ as those at Z = 82, N = 126, we would not expect an unusually small capture cross section for 294110. 1969 Nature 27 Dec. 1253/2 In calcium-40 which, like lead-208, is doubly magic and so a suitable isotope for nuclear structure calculations, the protons have been found to bunch together towards the centre of the nucleus. 1971 Nature 12 Feb. 451/2 One complication is that for heavier nuclei, the magic numbers probably differ for neutrons and protons. 1971 Physics Bull. Dec. 711/2 Much interest has been aroused by the prediction that the nucleus (A = 298, Z = 114) may be a doubly magic nucleus.., which could involve an island of stability in the mass region around 300. 1986 Sci. Amer. July 77/1 Would the spherical magic numbers that yield closed-shell nuclear structures lose their magic character in regions of the periodic table far from stability? 1997 Science 24 Oct. 571/3 Lead-208 is the largest known isotope that is ‘doubly magic’, also possessing a magic number of neutrons (126). < as lemmas |
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