- cesium atomic beam frequency standard
- 铯原子射束的频率标准
English-Chinese electricity dictionary (电气专业词典). 2013.
English-Chinese electricity dictionary (电气专业词典). 2013.
Atomic clock — Nuclear clock redirects here. For the clock as a measure for risk of catastrophic destruction, see Doomsday Clock. For a clock updated by radio signals (commonly but inaccurately called an atomic clock ), see Radio clock. For the album by Zion I … Wikipedia
atomic clock — an extremely accurate electronic clock regulated by the resonance frequency of atoms or molecules of certain substances, as cesium. [1935 40] * * * ▪ instrument type of clock that uses certain resonance frequencies of atoms (usually cesium… … Universalium
Time in physics — In physics, the treatment of time is a central issue. It has been treated as a question of geometry. One can measure time and treat it as a geometrical dimension, such as length, and perform mathematical operations on it. It is a scalar quantity… … Wikipedia
quantum mechanics — quantum mechanical, adj. Physics. a theory of the mechanics of atoms, molecules, and other physical systems that are subject to the uncertainty principle. Abbr.: QM Cf. nonrelativistic quantum mechanics, relativistic quantum mechanics. [1920 25]… … Universalium
spectroscopy — spectroscopist /spek tros keuh pist/, n. /spek tros keuh pee, spek treuh skoh pee/, n. the science that deals with the use of the spectroscope and with spectrum analysis. [1865 70; SPECTRO + SCOPY] * * * Branch of analysis devoted to identifying… … Universalium
Caesium — xenon ← caesium → barium Rb ↑ Cs ↓ Fr … Wikipedia
NIST-F1 — NIST F1, source of the official time of the United States NIST F1 is a cesium fountain clock or atomic clock in the National Institute of Standards and Technology (NIST) in Boulder, Colorado, and serves as the United States primary time and… … Wikipedia
Speaking clock — A speaking clock service is used by people who wish to know the correct and accurate time. Speaking clock services are most commonly accessed by telephone.The format of the service is somewhat similar to those in radio time signal services. Every … Wikipedia
Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… … Universalium
radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… … Universalium
mass spectrometry — or mass spectroscopy Analytic technique by which chemical substances are identified by sorting gaseous ions by mass using electric and magnetic fields. A mass spectrometer uses electrical means to detect the sorted ions, while a mass spectrograph … Universalium