(A) engineering applications: underwater positioning and communication, underground resource exploration, etc.
(B) biological applications: shear macromolecules, bioengineering and treatment of seeds, etc.
(C) diagnostic applications: A-type, B-type, M-type, D-type, bi-effective and color ultrasound, etc.
(D) therapeutic applications: physical therapy, cancer treatment, Surgery, extracorporeal lithotripsy, dentistry, etc.
Expanded InformationUltrasonic wave is a frequency higher than 20,000 hertz sound waves, it is a good directionality, penetrating ability, easy to get a more concentrated sound energy, in the water propagation distance is far, it can be used for distance measurement, speed measurement, cleaning, welding, lithotripsy, sterilization and disinfection, and so on. There are many applications in medicine, military, industry and agriculture. Ultrasound is named because its lower frequency limit is greater than the upper limit of human hearing.
Scientists call the number of vibrations per second the frequency of sound, which is measured in hertz (Hz). Our human ears can hear sound waves with a frequency of 20Hz-20,000Hz, so we call sound waves with a frequency higher than 20,000 Hz "ultrasound". The frequency of ultrasound used for medical diagnosis is 1 MHz-30 MHz.
Theoretical studies have shown that, under the same conditions of amplitude, the energy of an object vibration is proportional to the frequency of vibration, ultrasound propagation in the medium, the medium of mass vibration of the high frequency, and therefore a lot of energy. In the dry winter in northern China, if the ultrasonic waves into the water tank, the intense vibration will make the tank of water broken into many small droplets, and then a small fan to blow the droplets into the room, you can increase the indoor air humidity, which is the principle of ultrasonic humidifier.
ReferencesUltrasonic_Baidu Encyclopedia