| 释义 |
short wave
Also ˈshort-wave, shortwave.
[f. short a. + wave n.]
a. An electromagnetic wave of relatively short wavelength, spec. a radio wavelength of less than about 100 metres, corresponding to a frequency of more than 3000 kilohertz; radio communication or broadcasting employing such waves. Usu. attrib. or as adj.; also in adverbial use.
1839[see long wave s.v. long a.1 18]. 1902Encycl. Brit. XXVIII. 68/2 With very fine wires the condition na small can be fulfilled with quite short waves. 1907J. Erskine-Murray Handbk. Wireless Telegr. i. 5 Short-wave Hertzian telegraphy has never been successful at distances beyond a mile or two. 1928D. Brunt Meteorology v. 40 We have thus to picture a beam of short-wave light from the sun reaching the outer boundary of the earth's atmosphere. 1928Daily Mail Year Bk. 240/2 The B.B.C.'s slowness to recognise the importance of short⁓wave Empire broadcasting. 1941J. Steinbeck Sea of Cortez i. 7 In all the crackle and noise of the short-wave one of our men made contact with another boat. 1943D. Powell Time to be Born xiii. 308 They..drove to N.B.C. studios where he broadcast short-wave to London. 1961Ann. Reg. 1960 447 The mass-produced short-wave transistor. 1972Sci. Amer. Sept. 109/1 Finally it was discovered that ‘shortwave’ frequencies (from three to 30 megahertz) can travel halfway around the earth and more by being repeatedly reflected between the F layer and the earth. 1978W. F. Buckley Stained Glass xviii. 182 The Director rose and turned off the impressive short-wave speaker that had brought in the press conference.
b. Med. Used attrib. or as adj. to denote diathermy in which energy is applied to the tissues by means of oscillating electric fields having frequencies within the short-wave radio range.
1935R. Kovács Electrotherapy & Light Therapy (ed. 2) xviii. 306 Short-wave diathermy comprises wave lengths from 12 to 30 meters... Ultra short-wave diathermy comprises wave lengths below 12 meters. 1935Wilson & Dowse tr. Holzer & Weissenberg's Found. Short Wave Therapy 160 Short wave therapy has been used for about eight years, and..not a single case of irreparable injury has been published. 1965E. D. R. Campbell in C. W. H. Havard Fund. Current Med. Treatment xvi. 596 Short⁓wave diathermy causes heat to be more evenly distributed through the bulk of a limb by two distinct processes. 1965N. Freeling Criminal Conversation i. ii. 18 Dr. Hubert van der Post, neurologist, specialist in short-wave and other electrical treatments. |