| 释义 |
phosphorescence|fɒsfəˈrɛsəns|
[f. next: see -ence. Cf. F. phosphorescence (in Buffon, a 1788; Dict. Acad. 1835).]
The condition or quality of being phosphorescent; the action of phosphorescing or shining in the dark without combustion or sensible heat. In scientific use now distinguished from fluorescence on techn. grounds (see quots.); (the various definitions are all broadly equivalent).
1796Kirwan Elem. Min. (ed. 2) I. 27 [Internal characters of earths and stones:] Phosphorescence. 1836Macgillivray tr. Humboldt's Trav. x. 125 All the meteors left luminous traces,..the phosphorescence of which lasted seven or eight seconds. 1838T. Thomson Chem. Org. Bodies 627 When two pieces of sugar are rubbed against each other in the dark, a strong phosphorescence is visible. 1848Carpenter Anim. Phys. 303 A large proportion of the lower classes of aquatic animals possess the property of luminosity... The phosphorescence of the sea..is due to this cause. 1874tr. Lommel's Light 192 This power of shining in the dark after having been exposed to light is termed phosphorescence. 1949P. Pringsheim Fluorescence & Phosphorescence 5 A photoluminescence process of this type, involving the passage through a metastable level, is called phosphorescence. Ibid., It is no longer possible to define some arbitrary duration of the emission process as the boundary between fluorescence and phosphorescence. Ibid. iv. 292 The duration of a fluorescence process is essentially independent of external conditions insofar as this duration is determined by internal transition probabilities... The duration of a real phosphorescence is fundamentally a function of temperature. 1950H. W. Leverenz Introd. Luminescence of Solids iv. 124 If the excitation and emission process occurs in times approximating the natural lifetimes of excited nonmetastable isolated atoms (about 10-8 sec for optical transitions), the process is called fluorescence, whereas longer-duration processes are called phosphorescence. 1954C. Zwikker Physical Prop. Solid Materials xiii. 228 Fluorescence is the process in which the radiating electron falls back from the same energy level to which it was raised by the impinging photon..; phosphorescence is that in which the electron, after being raised to a higher energy level, first moves to a metastable level from where it can only be moved by external interference. 1971Physics Bull. Oct. 577/2 The terms fluorescence and phosphorescence denote allowed and partially forbidden transitions respectively, though the practical distinction based on lifetimes is largely arbitrary. 1973Sci. Amer. June 51/3 Today the definition is more technical, fluorescence corresponding to ‘spin-allowed’ electric dipole transitions and phosphorescence to ‘spin-disallowed’ transitions. |