| 释义 |
paracrystal|ˈpærəkrɪstəl|
[f. para-1 + crystal n. and a.]
An assemblage of particles that has some degree of order but is not a true crystal.
1933Trans. Faraday Soc. XXIX. 1019 On addition of acetone to a cold saturated solution in acetic ester of phytosterin valerate the latter..separates out as a paracrystal. 1953S. E. Luria Gen. Virol. v. 94 In the needles, which should more correctly be called ‘paracrystals’, the individual rods are oriented sidewise with great regularity. 1956Nature 10 Mar. 473/1 The great regularity of plant viruses is shown even more strikingly by their ability to form crystals (or paracrystals) which give good X-ray photographs. 1970Jrnl. Biochem. (Tokyo) LXVIII. 885/1 Paracrystals are formed by side-by-side association of F-actin particles in the presence of an excess amount of MgCl2.
Hence paraˈcrystalline a., of the nature of a paracrystal; ˌparacrystaˈllinity.
1933Trans. Faraday Soc. XXIX. 1027 An especially strong paracrystallinity is to be ascribed to the paracrystalline sperm heads of Sepia officinalis. 1950W. J. Moore Physical Chem. xiv. 408 The compound ethyl⁓anisol-paraäminocinnamate passes through three distinct paracrystalline phases between 83° and 139°. 1964G. H. Haggis et al. Introd. Molecular Biol. xi. 283 The haemoglobin in cells which had taken up the sickle shape was in para-crystalline, or tactoid form. 1974Amer. Jrnl. Anat. CXXXIX. 135 Paracrystalline aggregates of microtubules were observed by electron microscopy in some cells of the anterior pituitary glands from ten untreated chinchillas. |