| 释义 |
ˈradio-frequency
Also radio frequency, radiofrequency.
[f. radio n. + frequency.]
1. A frequency in the range used for telecommunication; greater than that of the highest audio-frequency and less than that of the shortest infra-red waves (i.e. between about 104 and 1011 or 1012 Hz).
1915Electrician 2 July 463/1 Mercury arc rectifiers can be operated at a good efficiency even at radio frequencies. 1937Discovery Mar. p. xxiii/1 Loud Speaker output at radio frequencies. 1976A. White Long Silence xi. 95 You can often get close enough..without them being aware of it, especially if they're listening to a radio frequency.
2. attrib. Pertaining to (electromagnetic radiation having) such a frequency; operating at or having such a frequency; employing alternating current having such a frequency.
1915Engin. Mag. XLIX. 253/2 The usual radio frequency transformers. 1919Wireless World May 75/1 The arc transforms.. the 1,500-volt direct current power into radio frequency energy. 1922Nature 20 May 650/2 A six-tube amplifier having three stages of radio-frequency amplification. 1943Electronic Engin. XV. 344/2 When the bridge goes off balance a radio-frequency current flows through the meter. 1946Nature 10 Aug. 194/1 Radio-frequency heating is not an economic proposition for heating stable liquids, but may prevent serious losses of activity in heat-sensitive ones. 1955J. G. Davis Dict. Dairying (ed. 2) 828 The use of radio-frequency heating for the pasteurization of milk. 1957Endeavour XVI. 187/1 Electronic equipment to generate the radio-frequency radiation and to measure its absorption by the sample. 1965B.B.C. Handbk. 116 For best results on short waves, a receiver should incorporate a tuned radio-frequency amplifier preceding the frequency-changer stage. 1967M. Chandler Ceramics in Mod. World ii. 76. Other methods of drying, of more limited and special application, include infrared and radio-frequency drying. 1970G. K. Woodgate Elem. Atomic Struct. viii. 148 Many precise measurements of gJ..have now been made by the methods of radio-frequency spectroscopy. |