| 释义 |
Appleton layer Physics.|ˈæp(ə)ltən ˈleɪə(r)|
[f. the name of Edward V. Appleton (1892–1965), British physicist + layer.]
The upper, or F, stratum of the ionosphere above the Heaviside (or E) layer.
Appleton himself used the term ‘F layer’ for this stratum (Proc. Internat. Scientific Radio Union, Washington Meeting, 1927).
1932Techn. Tables & Gloss. (B.B.C.) 44/1 Appleton Layer, an ionised layer of the upper atmosphere thought to exist above the Kennelly–Heaviside layer. It has been suggested that it is this layer which is responsible for the reflection of short waves which are attenuated but not reflected in their passage through the Kennelly–Heaviside layer. The height of the Appleton layer above the earth has been measured as approximately 230 kilometres. 1943Electronic Engin. XV. 342 Presumably the Heaviside, Appleton..etc. layers in the upper atmosphere also give rise to harmonics of radio waves. |