单词half-life
n.: 半衰期；（放射性物质的）半衰期
网络: 半条命；战栗时空；半生期
（放射性物质的）半衰期:
the time taken for the radioactivity of a substance to fall to half its original value
半衰期:
the time taken for the concentration of a reactant to fall to half of its original value in a chemical reaction
【原子能】半衰期
半寿期
复数：half-lives
But the half-life of market domination seems to be dwindling.
但是似乎这些公司的垄断半衰期一直在缩短。
It accumulates in the cooling water of nuclear reactors and is often vented in small amounts to the environment. Its half-life is 12 years.
氚聚集在核反应堆的冷却水中，通常以微量排放到环境中，其半衰期为12年。
When Hazen"s team put oil samples in a laboratory setup designed to mimic Gulf conditions, it had a half-life of between one and six days.
当黒曾团队将油样放入模拟的海湾背景下的实验室，油样有一个在一天和六天之间的半衰期。
"Half-Life 2" , which came out in 2004, took six years to develop, whereas new episodes can be put together in a year or so.
2004年发行的《半条命2》花费了六年时间开发，而游戏的新章节仅需一年左右就可完工。
In particular, the half-life of ethyl mercury is short (less than 1 week) compared with that of methyl mercury (1. 5 Months).
特别是乙基汞的半衰期较短（少于1周），而甲基汞的半衰期为1.5个月。
Furthermore, the long half-life of the metabolites could cause their accumulation and induce apparent injuries of target organs.
而且，此代谢物的半衰期极长。故极易累积于体内造成标的器官明显的伤害。
Iodine-131 has a half-life of about a week, meaning that levels in water could fall quickly if new doses aren"t introduced.
碘-131的半衰期在一个星期左右，所以如果没有新的剂量进入，水中的放射性可能就会很快下降。
Scientists estimate the half-life of CO2 might be close to a hundred years.
科学家估计，二氧化碳的半衰期可能接近于100年。
Iodine-131 has a half-life of roughly a week, which means levels could fade if new radioactive material isn"t added.
碘-131的半衰期约为一周，也就是说如果没有新的放射性物质加入，辐射水平有望降低。
Half-life is the time required for half the quantity of the protein to be broken down and eliminated from the joint space.
半衰期指一半蛋白从关节腔中分解和消失用的时间。