| ultrasonic |
Term applied to sound frequencies above 20000 hertz, the normal upper limit of human hearing.
출처: www.nksd.net/schools/nkhs/staff/john_daneau/cp_glo...
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| ultraviolet radiation |
electromagnetic radiation between the violet end of the visible spectrum and X-radiation.
출처: www.advancedforecasting.com/weathereducation/weath...
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| ultrasonic |
Sound waves that are too high for humans to hear are "ultrasonic". The hearing range of many animals, including rodents, extends much higher than for humans.
출처: www.ccac.ca/en/CCAC_Programs/ETCC/GlossaryEng.htm
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| ultrasonic |
Having frequencies above the normal range of human hearing, ie, higher than about 20kHz.
출처: www.dilettantesdictionary.com/index.php
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| ultraviolet |
A form of electromagnetic radiation. UV radiation has shorter wavelengths than visible light and it therefore carries more energy. It is divided into three broad categories: A, B and C. UV-A has the longest wavelength and is the least damaging form, although sufficient exposure will cause sunburn. UV-B damages proteins in unprotected organisms and can cause cancer, while UV-C is extremely dangerous because it can cause mutations in DNA.
출처: www.science.org.au/nova/004/004glo.htm
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