名詞 half-life:

1. the time required for something to fall to half its initial value (in particular, the time for half the atoms in a radioactive substance to disintegrate)
   同義詞：half life

half-life

n.（名詞）
Physics The time required for half the nuclei in a sample of a specific isotopic species to undergo radioactive decay.
【物理學(xué)】 半衰期：放射性樣品的原子核經(jīng)歷一半放射性衰變所需要的時(shí)間
Biology
【生物學(xué)】
The time required for half the quantity of a drug or other substance deposited in a living organism to be metabolized or eliminated by normal biological processes.Also called biological half-life
生物半衰期： 存儲在活的有機(jī)體內(nèi)的藥物或其它物質(zhì)經(jīng)新陳代謝或被正常的生理活動消失一半所需要的時(shí)間也作 biological half-life
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.
半減期： 被活的有機(jī)體攝入的放射性元素經(jīng)過生物衰減及放射性衰變過程綜合，其劑量減至一半所需要的時(shí)間