half-life
US /ˈhæf.laɪf/
UK /ˈhɑːf.laɪf/
名词
1.
半衰期
the time taken for the radioactivity of a specified isotope to fall to half its original value.
示例:
•
The half-life of carbon-14 is about 5,730 years.
碳-14的半衰期约为5,730年。
•
Scientists calculate the half-life to determine the age of ancient artifacts.
科学家计算半衰期以确定古代文物的年代。
2.
半衰期
the time required for a quantity to reduce to half its initial value (e.g., in pharmacology, the time for a drug's concentration in the body to be reduced by half).
示例:
•
The drug has a half-life of 8 hours, meaning its concentration in the bloodstream will halve every 8 hours.
该药物的半衰期为8小时，这意味着其在血液中的浓度每8小时减半。
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Understanding the half-life of a substance is crucial in environmental science for assessing pollutant persistence.
了解物质的半衰期对于环境科学评估污染物持久性至关重要。