| 释义 |
ultrasonic, a.|ʌltrəˈsɒnɪk|
[f. ultra- 2 + sonic a.]
1. a. The more usual synonym of supersonic a. 1.
1923Proc. & Trans. R. Soc. Canada XVII. iii. 145 The wave-lengths of ultra-sonic waves are very convenient for experiment. 1926Encycl. Brit. III. 592/1 The utilisation of ultrasonic waves by Professor Langevin..in connection with deep-sea sounding. 1928Observer 30 Dec. 3/6 This was the first occasion in this country on which the ‘ultra⁓sonic’ waves have been shown to an audience. 1938,1948[see hypersonic a. 1]. 1957New Scientist 9 May 26/3 Owing to the restricted frequency response of the human ear, those organisms which produce ultra-sonic sounds, as do many insects and bats, for example, have in particular been thought of as ‘dumb’. 1976R. Dawkins Selfish Gene iv. 67 The..song of the humpback whale, with..its frequencies spanning the whole of human hearing from subsonic rumblings to ultrasonic squeaks. 1985Sunday Times 27 Jan. 80/8 An ultrasonic beam passed through liquid generates bubbles which act as a cleansing agent.
b. Employing or operated by sound waves or vibrations having a frequency above the range of human hearing (i.e greater than 15–20 kHz); used esp. with reference to devices and techniques which make use of the reflected echo of an ultrasound pulse.
1923Proc. & Trans. R. Soc. Canada XVII. iii. 142 Two ultra-sonic generators..were placed facing one another, 60 cms. apart, in a large tank of water. 1935[see reflectometer]. 1949A. R. Weyl Guided Missiles 25 Photo⁓electric, magnetic, acoustic (ultra-sonic) and other methods have been successfully used for proximity fuses. 1961Lancet 30 Sept. 750/1 Ultrasonic methods have been described for the detection of intra-abdominal masses, breast tumours, [etc.]. 1976Offshore Platforms & Pipelining 174/1 Ultrasonic inspection followed the completion of the welds.
2. Designating speeds above that of sound; supersonic. rare—1.
1942[see infrasonic a. 2].
Hence ultraˈsonically adv., by means of ultrasound.
1955Sci. News Let. 26 Mar. 206/3 Ultrasonically treated honey..showed no signs of crystallizing. 1968Amer. Mineralogist LIII. 1558 Samples of the ash were cleaned ultrasonically. 1974Nature 2 Aug. 410/2 Electrodeposition in an ultrasonically agitated solution. |