| 释义 |
irradiance|ɪˈreɪdɪəns|
[f. irradiant: see -ance.]
1. The fact of irradiating; the emission of rays of light, emitted radiance. Also fig. in reference to spiritual or intellectual radiance.
1667Milton P.L. viii. 617 Do they mix Irradiance, virtual or immediate touch? 1735–6H. Brooke Univ. Beauty vi. 339 Thou awful Depth of Wisdom unexplor'd! Thou Height, where never human fancy soar'd! Supreme Irradiance! a1760I. H. Browne Poems, Design & Beauty (1768) 106 They, from irradiance of thy genial beam Prolific, with immortal offspring teem. 1888B. W. Richardson Son of a Star III. xi. 176 A kingdom to which the world will come for irradiance.
2. The flux of radiant energy per unit area, esp. an area normal to the direction of travel through a medium.
1956A. Hollaender Radiation Biol. III. iii. 129 ‘Irradiance’ is the intensity term applicable to the interception of radiant energy by objects and is power per unit area. Frequently ‘intensity’ is used loosely as a substitute for ‘irradiance’. Ibid. 136 The U.S. Weather Bureau..still uses the calorie per minute per square centimeter for the specification of solar irradiance. 1966McGraw-Hill Encycl. Sci. & Technol. XII. 105/2 At a depth of 64 m where the irradiance is 0·5 watt/m2..approximately 0·04 watt of radiant power is absorbed by every cubic meter of sea water. 1969Physics Bull. Oct. 409/2 Outside the earth's atmosphere..the annual mean irradiance of the sun is about 270 W m–2 on a plane parallel to the earth's surface at latitude 52° N. 1973Nature 9 Feb. 402/1 The total irradiance of the unattenuated light..was approximately 4·5 × 103 µW/cm2. |