| 释义 |
semiˈpermeable, a.
[tr. G. halbdurchlässig (J. H. van't Hoff 1887, in Zeitschr. für physik. Chem. I. 482), f. halb- half, semi- + durchlässig pervious, permeable.]
Of a membrane or other structure: selectively permeable to certain atoms and molecules; spec. permeable to molecules of water but not to those of any dissolved substance. Also in extended use.
1888W. Ramsay tr. J. van't Hoff in Phil. Mag. XXVI. 82 The porous membrane..will be termed in the following pages a ‘semipermeable membrane’. 1895W. C. D. Whetham Solution & Electrolysis iv. 34 These semi⁓permeable membranes are made by filling a porous pot with the solution of a salt such as potassium ferro⁓cyanide, and surrounding the outside with another solution..which gives an insoluble precipitate when in contact with the first. 1930Engineering 28 Nov. 670/1 Each droplet [of sap] being subject to forces equivalent to the osmotic pressure acting on a plant cell within a semi⁓permeable membrane. 1974L. Thomas Lives of Cell (1975) 162, I am glad to have a semipermeable memory after getting into this. 1978P. W. Atkins Physical Chem. viii. 222 The chemical potential of the solvent on both sides of the semipermeable membrane must be equal.
Hence ˌsemipermeaˈbility, the property or condition of being semipermeable.
1900W. H. Howell Text-bk. Physiol. (ed. 2) I. ii. 66 The semi-permeability is only approximately complete. 1974L. Thomas Lives of Cell (1975) 173 Oxygen filters out the very bands of ultraviolet light that are most devastating for nucleic acids and proteins, while allowing full penetration of the visible light needed for photosynthesis. If it had not been for this semipermeability, we could never have come along. |