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| a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
rf.
R.F.
r.f.
Based on the Random House Dictionary, © Random House, Inc. 2012.
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| rf | |
| —abbreviation for | |
| Also: rfz rinforzando | |
| Rf | |
| —the chemical symbol for | |
| rutherfordium | |
| RF | |
| —abbreviation for | |
| radio frequency | |
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RF abbr.
releasing factor
rheumatoid factor
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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| Rf
The symbol for rutherfordium. |
rutherfordium  (rŭ 'ər-fôr'dē-əm) Pronunciation Key
Symbol Rf A synthetic, radioactive element that is produced by bombarding plutonium with carbon or neon ions. Its most stable isotope is Rf 261 with a half-life of 62 seconds. Atomic number 104. See Periodic Table. |
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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| Rf rutherfordium |
RF
|
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Rf
an artificially produced radioactive transuranium element in Group IVb of the periodic table, atomic number 104. Soviet scientists at the Joint Institute for Nuclear Research at Dubna, Russia, U.S.S.R., announced in 1964 the discovery of element 104, which they named kurchatovium, symbol Ku (for Igor Kurchatov, a Soviet nuclear physicist). In 1969, a group of American researchers at the Lawrence Radiation Laboratory of the University of California at Berkeley announced that they had identified isotopes of the element, different from the one identified by the Soviets; the Americans then proposed the name rutherfordium, in honour of the British physicist Ernest Rutherford
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