| 释义 |
ultracentrifuge
ul·tra·cen·tri·fuge U0010100 (ŭl′trə-sĕn′trə-fyo͞oj′)n. A high-velocity centrifuge used in the separation of colloidal or submicroscopic particles.
ul′tra·cen·trif′u·gal (-trĭf′yə-gəl, -trĭf′ə-gəl) adj.ul′tra·cen·trif′u·gal·ly adv.ul′tra·cen′tri·fu·ga′tion (-fyo͝o-gā′shən) n.ultracentrifuge (ˌʌltrəˈsɛntrɪˌfjuːdʒ) chemn1. (Chemistry) a high-speed centrifuge used to separate colloidal solutions2. (Tools) a high-speed centrifuge used to separate colloidal solutionsvb (Chemistry) (tr) to subject to the action of an ultracentrifuge ultracentrifugal adj ˌultracenˈtrifugally adv ultracentrifugation nul•tra•cen•tri•fuge (ˌʌl trəˈsɛn trəˌfyudʒ)
n., v. -fuged, -fug•ing. n. 1. a high-speed centrifuge for subjecting sols or solutions to forces many times that of gravity and producing concentration differences depending on the weight of the micelle or molecule. v.t. 2. to subject to the action of an ultracentrifuge. [1925–30] ultracentrifuge
Past participle: ultracentrifuged
Gerund: ultracentrifuging
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| ultracentrifuge | | ultracentrifuge |
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| I ultracentrifuge | | you ultracentrifuge | | he/she/it ultracentrifuges | | we ultracentrifuge | | you ultracentrifuge | | they ultracentrifuge |
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| I ultracentrifuged | | you ultracentrifuged | | he/she/it ultracentrifuged | | we ultracentrifuged | | you ultracentrifuged | | they ultracentrifuged |
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| I am ultracentrifuging | | you are ultracentrifuging | | he/she/it is ultracentrifuging | | we are ultracentrifuging | | you are ultracentrifuging | | they are ultracentrifuging |
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| I have ultracentrifuged | | you have ultracentrifuged | | he/she/it has ultracentrifuged | | we have ultracentrifuged | | you have ultracentrifuged | | they have ultracentrifuged |
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| I was ultracentrifuging | | you were ultracentrifuging | | he/she/it was ultracentrifuging | | we were ultracentrifuging | | you were ultracentrifuging | | they were ultracentrifuging |
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| I had ultracentrifuged | | you had ultracentrifuged | | he/she/it had ultracentrifuged | | we had ultracentrifuged | | you had ultracentrifuged | | they had ultracentrifuged |
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| I will ultracentrifuge | | you will ultracentrifuge | | he/she/it will ultracentrifuge | | we will ultracentrifuge | | you will ultracentrifuge | | they will ultracentrifuge |
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| I will have ultracentrifuged | | you will have ultracentrifuged | | he/she/it will have ultracentrifuged | | we will have ultracentrifuged | | you will have ultracentrifuged | | they will have ultracentrifuged |
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| I will be ultracentrifuging | | you will be ultracentrifuging | | he/she/it will be ultracentrifuging | | we will be ultracentrifuging | | you will be ultracentrifuging | | they will be ultracentrifuging |
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| I have been ultracentrifuging | | you have been ultracentrifuging | | he/she/it has been ultracentrifuging | | we have been ultracentrifuging | | you have been ultracentrifuging | | they have been ultracentrifuging |
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| I will have been ultracentrifuging | | you will have been ultracentrifuging | | he/she/it will have been ultracentrifuging | | we will have been ultracentrifuging | | you will have been ultracentrifuging | | they will have been ultracentrifuging |
| Past Perfect Continuous |
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| I had been ultracentrifuging | | you had been ultracentrifuging | | he/she/it had been ultracentrifuging | | we had been ultracentrifuging | | you had been ultracentrifuging | | they had been ultracentrifuging |
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| I would ultracentrifuge | | you would ultracentrifuge | | he/she/it would ultracentrifuge | | we would ultracentrifuge | | you would ultracentrifuge | | they would ultracentrifuge |
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| I would have ultracentrifuged | | you would have ultracentrifuged | | he/she/it would have ultracentrifuged | | we would have ultracentrifuged | | you would have ultracentrifuged | | they would have ultracentrifuged |
Thesaurus| Noun | 1. |  ultracentrifuge - a high speed centrifuge used to determine the relative molecular masses of large molecules in high polymers and proteinscentrifuge, separator, extractor - an apparatus that uses centrifugal force to separate particles from a suspension | | Verb | 1. |  ultracentrifuge - subject to the action of an ultracentrifugecentrifugate, centrifuge - rotate at very high speed in order to separate the liquids from the solids |
Ultracentrifuge
ultracentrifuge[‚əl·trə′sen·trə‚fyüj] (engineering) A laboratory instrument which develops centrifugal fields of more than 100,000 times gravity, used for the quantitative measurement of sedimentation velocity or sedimentation equilibrium, or for the separation of solutes in liquid solutions to study high polymers, particularly proteins, nucleic acids, viruses, and other macromolecules of biological origin. Ultracentrifuge a device for separating particles less than 100 nanometers in size, such as colloids, subcellular particles, and macromolecules of proteins, nucleic acids, lipids, polysaccharides, and synthetic polymers, which are suspended or dissolved in a liquid. This is achieved by the rapid rotation of a rotor, which creates a centrifugal field with an acceleration many orders greater than the acceleration of gravity. Ultracentrifuges are classified as preparative, analytical, or preparative-analytical according to their purpose and design. Preparative ultracentrifuges are equipped with fixed-angle rotors, which have recesses for test tubes, beakers, or bottles, tilted at an angle of 20°-40° to the vertical axis of the rotor. Some have swinging-bucket rotors, with beakers that tilt 90° upon rotation. There are also ultracentrifuges with zonal or continuous-action rotors, with a single large vessel for the liquid being fractionated. Preparative ultracentrifuges are used to isolate individual components from complex mixtures. Analytical ultracentrifuges have rotors with through-cylindrical recesses, in which special transparent vessels are inserted for the solutions or suspensions to be analyzed. The redistribution of particles in the solutions and suspensions may be observed directly during rotor rotation with the aid of special optical systems, such as refractometric or absorption devices. Some analytical ultracentrifuges are connected to electronic computers, which carry out the automatic processing of experimental data. The first ultracentrifuge, designed for studying the motion of particles invisible under a microscope, was constructed by the Swedish scientist T. Svedberg in 1923 (discovery announced in 1924). This ultracentrifuge, in which a centrifugal force of up to 5,000 g was achieved, had an absorption optical system and was used to study the motion of gold particles with a diameter of approximately 5 nanometers. In 1926, Svedberg built the first highspeed ultracentrifuge (41,000 rpm, acceleration up to 105 g), which made possible the analytical study of proteins in solutions, particularly the study of hemoglobin. In 1939 he designed an analytical ultracentrifuge with a steel rotor (65,000 rpm). The vast majority of modern laboratory ultracentrifuges are electrically driven and have aluminum or titanium rotors. In the USSR and abroad many types of ultracentrifuges are being produced in which accelerations of up to 500,000 g are created, and the separation of particles and molecules is carried out in volumes measuring tens and hundreds of milliliters. REFERENCESLotts, Iu. A., and A. Ia. Ozherel’ev. “Analiticheskaia ul’tratsentrifuga.” Unikal’nyepribory, 1970, no. 5.
Svedberg, T, and K. O. Pedersen. The Ultracentrifuge. Oxford, 1940.A. D. MOROZKIN ultracentrifuge
ultracentrifuge [ul″trah-sen´trĭ-fūj] the centrifuge used in ultracentrifugation.ul·tra·cen·tri·fuge (ŭl'tră-sen'tri-fyūj), A high-speed centrifuge (up to 100,000 rpm) by means of which large molecules, for example, of protein or nucleic acids, are caused to sediment at practicable rates; used for determinations of molecular weights, separation of large molecules, criteria of homogeneity of large molecules, conformational studies, etc.ultracentrifuge (ŭl′trə-sĕn′trə-fyo͞oj′)n. A high-velocity centrifuge used in the separation of colloidal or submicroscopic particles.
ul′tra·cen·trif′u·gal (-trĭf′yə-gəl, -trĭf′ə-gəl) adj.ul′tra·cen·trif′u·gal·ly adv.ul′tra·cen′tri·fu·ga′tion (-fyo͝o-gā′shən) n.ul·tra·cen·tri·fuge (ŭl'tră-sen'tri-fyūj) A high-speed centrifuge by means of which large molecules (e.g., of protein or nucleic acids) are caused to sediment at practicable rates. ultracentrifuge A device for rotating small containers at extremely high speed so as to expose the liquid contents to powerful centrifugal force, of the order of 100,000 g. Ultracentrifuges are used to separate particles of molecular size and determine molecular weights.ultracentrifuge a machine capable of spinning a rotor at speeds of up to 50 000 revolutions per minute, producing up to 500 000 g forces. The high speeds enable the separation of tiny particles, which are identified by the rate at which they move down the centrifuge tube. The unit of rate is called the Svedberg (S), after the inventor of the ultracentrifuge. Thus RIBOSOMES are found to consist of two subunits after ultracentrifugation, called 30S and 50S. See also DENSITY-GRADIENT CENTRIFUGATION, DIFFERENTIAL CENTRIFUGATION, MICROSOMAL FRACTION.ul·tra·cen·tri·fuge (ŭl'tră-sen'tri-fyūzh) A high-speed centrifuge by means of which large molecules sediment at practicable rates. ultracentrifuge
Words related to ultracentrifugenoun a high speed centrifuge used to determine the relative molecular masses of large molecules in high polymers and proteinsRelated Words- centrifuge
- separator
- extractor
verb subject to the action of an ultracentrifugeRelated Words |