| 释义 |
frequency
fre·quen·cy F0320700 (frē′kwən-sē)n. pl. fre·quen·cies 1. The property or condition of occurring at frequent intervals.2. Mathematics & Physics The number of times a specified periodic phenomenon occurs within a specified interval, as:a. The number of repetitions of a complete sequence of values of a periodic function per unit variation of an independent variable.b. The number of complete cycles of a periodic process occurring per unit time.c. The number of repetitions per unit time of a complete waveform, as of an electric current.3. Statistics a. The number of measurements or observations having a certain value or characteristic.b. See relative frequency.
[Latin frequentia, multitude, from frequēns, frequent-, crowded, numerous, frequent.]frequency (ˈfriːkwənsɪ) n, pl -cies1. the state of being frequent; frequent occurrence2. the number of times that an event occurs within a given period; rate of recurrence3. (Mathematics) physics the number of times that a periodic function or vibration repeats itself in a specified time, often 1 second. It is usually measured in hertz. Symbol: ν or f 4. (Statistics) statistics a. the number of individuals in a class (absolute frequency)b. the ratio of this number to the total number of individuals under survey (relative frequency)5. (Biology) ecology a. the number of individuals of a species within a given areab. the percentage of quadrats that contains individuals of a species Also called (for senses 1, 2): frequence [C16: from Latin frequentia a large gathering, from frequēns numerous, crowded]fre•quen•cy (ˈfri kwən si)
n., pl. -cies. 1. Also, fre′quence. the state or fact of being frequent; frequent occurrence. 2. rate of occurrence. 3. Physics. a. the number of periods or regularly occurring events of any given kind in a unit of time, usu. one second. b. the number of cycles or completed alternations per unit time of a wave or oscillation. Symbol: F; Abbr.: freq. 4. Math. the number of times a value recurs in a unit change of the independent variable of a given function. 5. Statistics. the number of items occurring in a given category. [1545–55; < Latin] fre·quen·cy (frē′kwən-sē)1. Physics The number of complete cycles of a wave, such as a radio wave, that occur per second. See more at wave.2. Mathematics The ratio of the number of occurrences of some event to the number of opportunities for its occurrence.Frequency (See also DURATION, TIME.) once in a blue moon Very rarely. A blue moon occurs when there is a full moon twice in the same month, an unusual event, but one that takes place from time to time. rare as hen’s teeth See scarce as hen’s teeth, ABSENCE. when two Fridays come together Never. Since two Fridays never come together, this expression is usually used as a sarcastic quip when one is asked when he intends to do something of an onerous nature such as complete a project, pay back a personal loan, or the like. frequencyNumber of cycles or waves per second.Thesaurus| Noun | 1. | frequency - the number of occurrences within a given time period; "the frequency of modulation was 40 cycles per second"; "the frequency of his seizures increased as he grew older"frequence, oftennessaudio frequency, audio - an audible acoustic wave frequencyradio frequency - an electromagnetic wave frequency between audio and infraredinfrared, infrared frequency - the infrared region of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range; "they could sense radiation in the infrared"wave number - the reciprocal of the wavelength of a waveattendance - the frequency with which a person is present; "a student's attendance is an important factor in her grade"count per minute, counts/minute - frequency per minutesampling frequency - (telecommunication) the frequency of sampling a continuously varying signalrate - a magnitude or frequency relative to a time unit; "they traveled at a rate of 55 miles per hour"; "the rate of change was faster than expected" | | 2. | frequency - the ratio of the number of observations in a statistical category to the total number of observationsrelative frequencyratio - the relative magnitudes of two quantities (usually expressed as a quotient)incidence, relative incidence - the relative frequency of occurrence of something | | 3. |  frequency - the number of observations in a given statistical categoryabsolute frequencycardinal number, cardinal - the number of elements in a mathematical set; denotes a quantity but not the order |
frequencynoun recurrence, repetition, constancy, periodicity, commonness, frequentness, prevalence The cars broke down with increasing frequency.Translationsfrequent (ˈfriːkwənt) adjective happening often. He made frequent journeys. 時常發生的 时常发生的 (friˈkwent) verb to visit often. He used to frequent the George Hotel. 常去 常去ˈfrequency – plural ˈfrequencies – noun1. the state of happening often. The frequency of her visits surprised him. 頻繁 频繁2. (in electricity, radio etc) the number of waves, vibrations etc per second. At what frequency does the sound occur? 周率 周率3. a set wavelength on which radio stations regularly broadcast. I regularly listen to this frequency in order to hear my favourite music. 頻率 频率ˈfrequently adverb often. He frequently arrived late. 經常地 经常地frequency
frequency: see harmonic motionharmonic motion,
regular vibration in which the acceleration of the vibrating object is directly proportional to the displacement of the object from its equilibrium position but oppositely directed.
..... Click the link for more information. ; wavewave,
in physics, the transfer of energy by the regular vibration, or oscillatory motion, either of some material medium or by the variation in magnitude of the field vectors of an electromagnetic field (see electromagnetic radiation).
..... Click the link for more information. .Frequency (wave motion) The number of times which sound pressure, electrical intensity, or other quantities specifying a wave vary from their equilibrium value through a complete cycle in unit time. The most common unit of frequency is the hertz (Hz), which is equal to 1 cycle per second. In one cycle there is a positive variation from equilibrium, a return to equilibrium, then a negative variation, and return to equilibrium. This relationship is often described in terms of the sine wave, and the frequency referred to is that of an equivalent sine-wave variation in the parameter under discussion. See Frequency measurement, Sine wave, Wave motion frequency Symbol: f , ν. The number of oscillations per unit time of a vibrating system. Frequency is measured in hertz. The frequency of a wave is the number of wave crests passing a point per unit time. For light and other electromagnetic radiation, it is related to wavelength λ by ν = c /λ, where c is the speed of light.Frequency The frequency of an event A is the ratio m/n of the number m of occurrences of A in a given series of trials to the total number n of trials. If the trials are independent and there is a definite probability p of the occurrence of A in an individual trial, then, for arbitrarily small ∊ > 0, at sufficiently large m it is practically certain that the frequency m/n satisfies the inequality 
(seeLARGE NUMBERS, LAW OF and PROBABILITY). The term “frequency” is used in mathematical statistics to designate the number of elements of a set that have a specified attribute. frequency[′frē·kwən·sē] (physics) The number of cycles completed by a periodic quantity in a unit time. (statistics) The number of times an event or item falls into or is expected to fall into a certain class or category. frequencyThe number of oscillations per second (a) of the current or voltage in an alternating-current electric circuit, or (b) of a sound wave, or (c) of a vibrating solid object; expressed in hertz (abbr. Hz) or in cycles per second (abbr. cps).frequency i. The number of recurrences of a periodic phenomenon in a unit of time.
ii. The number of cycles completed in one second. One cycle per second is the basic unit of measurement of frequency and is called a hertz.
iii. The number of services operated by an airline per day or per week over a particular route.frequency1. Physics the number of times that a periodic function or vibration repeats itself in a specified time, often 1 second. It is usually measured in hertz. 2. Ecologya. the number of individuals of a species within a given area b. the percentage of quadrats that contains individuals of a species frequencyThe number of oscillations (vibrations) in one second. Frequency is measured in Hertz (Hz), which is the same as "oscillations per second" or "cycles per second." For example, the alternating current in a wall outlet in the U.S. and Canada is 60Hz. Electromagnetic radiation is measured in kiloHertz (kHz), megahertz (MHz) and gigahertz (GHz). See wavelength, frequency response, audio, carrier and space/time.
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| The frequency is the number of oscillations per second. The higher the frequency (the closer the ripples would be in this diagram) and the shorter the wavelength. |
See frequencyfrequency
frequency [fre´kwen-se] 1. the number of occurrences of a periodic or recurrent process in a unit of time, such as the number of electrical cycles per second measured in hertz. In pacing" >cardiac pacing terminology, frequency is expressed by the formula: frequency = ½ × pulse width.2. the number of occurrences of a particular event or the number of members of a population or statistical sample falling in a particular class.3. relative frequency.radio frequency the range of frequencies of radiation" >electromagnetic radiation between 10 kilohertz and 100 gigahertz, used for radio communication.relative frequency the ratio of the number of occurrences of a specified phenomenon in a population to the total size of the population.urinary frequency urination at short intervals without increase in daily volume of urinary output, due to reduced bladder capacity or cystitis.fre·quen·cy (ν), (frē'kwen-sē), The number of regular recurrences in a given time, for example, heartbeats, sound vibrations. [L. frequens, repeated, often, constant] frequency The number of cycles or repetitions of a periodic wave or signal per unit time. In electromagnetic radiation, frequency is usually expressed in units of hertz (Hz), where 1 Hz = 1 cycle per second.frequency Statistics The number of times that a particular periodic event occurs in a unit time. See Collision frequency, Cumulative frequency, Larmor frequency, Observed frequency, Order frequency, Pulse repetition, Recombination frequency, Relative frequency. fre·quen·cy (ν) (frē'kwĕn-sē) 1. The number of regular recurrences in a given time, e.g., heartbeats, sound vibrations. 2. acoustics the number of cycles of compression and rarefaction of a sound wave that occur in 1 second, expressed in hertz (Hz). 3. The rate of vocal fold vibration (i.e., the number of times the glottis opens and closes in 1 second) during phonation; perceived as voice pitch. [L. frequens, repeated, often, constant]frequency An informal term referring to the condition in which urine is passed more often than normal (frequency of urination). Frequency may be due to excessive fluid intake, bladder infection, pregnancy, the use of DIURETIC drugs, or, in men, to an enlarged prostate gland obstructing the urinary outflow so that the bladder can only be partially emptied. Frequency is occasionally of psychological origin.FrequencySound, whether traveling through air or the human body, produces vibrations—molecules bouncing into each other—as the shock wave travels along. The frequency of a sound is the number of vibrations per second. Within the audible range, frequency means pitch—the higher the frequency, the higher a sound's pitch.Mentioned in: Abdominal Ultrasoundfre·quen·cy (frē'kwĕn-sē) The number of regular recurrences in a given time, e.g., heartbeats, sound vibrations. [L. frequens, repeated, often, constant]Patient discussion about frequencyQ. What foods or liquids, juices, proteins, fruits, are good for Male Prostate or Urinary Frequency? I am 53 YO Male with exessive urinary frequency. Is there a fruit, food, drink, pill, mojo, that would help me with this problem? I am talking about urinating 3 to 4 times every night, and or while watching TV, every hour or so. No pain, yet, an occacional after drip that is very anoying. Perhaps I have a prostate problem and should consuld with my Urologist. Yet, before I go there, does anyone know of something I can eat or drink to fix or aleviate this problem?A. Thanks for the heads-up. One of my issues is that I LOVE coffee, thus, reducing my daily consumption of 2-3 cups could be a problem. More discussions about frequency
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Related to frequency: frequency modulation, Sound frequencySynonyms for frequencynoun recurrenceSynonyms- recurrence
- repetition
- constancy
- periodicity
- commonness
- frequentness
- prevalence
Synonyms for frequencynoun the number of occurrences within a given time periodSynonymsRelated Words- audio frequency
- audio
- radio frequency
- infrared
- infrared frequency
- wave number
- attendance
- count per minute
- counts/minute
- sampling frequency
- rate
noun the ratio of the number of observations in a statistical category to the total number of observationsSynonymsRelated Words- ratio
- incidence
- relative incidence
noun the number of observations in a given statistical categorySynonymsRelated Words |