The half-life (T½) of a radioactive substance is the time required for a population of atoms to decay to half the original number. From:Leibel and Phillips Textbook of Radiation Oncology (Third Edition),2010 Chapters and Articles
Half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay, or, equivalently, the time interval required for the number of disintegrations per second of a radioactive material to decrease
1.(General Physics) the time taken for half of the atoms in a radioactive material to undergo decay. Symbol:τ 2.(Biology) the time required for half of a quantity of radioactive material absorbed by a living tissue or organism to be naturally eliminated (biological half-life) or removed...
Half-Life, stylized as HλLF-LIFE, is a science fiction first-person shooter developed and published by Valve. The player takes the perspective of the scientist Gordon Freeman who struggles to escape an underground research facility after a failed experiment causes a massive alien invasion through...
HALF LIVES half-life: 1: the time required for half of something to undergo a process: as a: the time required for half of the atoms of a radioactive substance to become disintegrated b: the time required for half the amount of a substance (as a drug, radioactive tracer, or pesticide...
Also called biological half-life. b. The time required for the radioactivity of material taken in by a living organism to be reduced to half its initial value by a combination of biological elimination processes and radioactive decay. The American Heritage® Medical Dictionary Copyright © 2007...
半衰期half lifeHalf life is the time required for half the amount of a substance (such as a drug, radioactive tracer, or pesticide) in or introduced into a living system or ecosystem to be eliminated or disintegrated by natural processes.半衰期是指生命系统和生态系统中存在或注入的一种物质,比如...
1.The half-life of francium is 22 minutes.钫的半衰期是22分钟。 2.radioactive half life放射性物质的半衰期 3.half-life of recurrent selection process轮回选择过程的半衰期 4.Half-lives of the newly synthesized nuclei in~(263)Hs and ~(260)Bhα-decay chains新核素~(263)Hs,~(260)Bh及其α衰变...
orhalf′ life`, n.,pl.-lives(-ˌlaɪvz) 1.the time required for one half the atoms of a given amount of a radioactive substance to decay. 2.the time required for the activity of a substance taken into the body to lose one half its initial effectiveness. ...
:the time required for half the amount of a substance (as a drug or radioactive tracer) in or introduced into a living system or ecosystem to be eliminated or disintegrated by natural processes the serumhalf-lifeis about 2 days— The Journal of the American Medical Association ...