half-life
US /ˈhæf.laɪf/
UK /ˈhɑːf.laɪf/
名詞
1.
半衰期
the time taken for the radioactivity of a specified isotope to fall to half its original value.
範例:
•
The half-life of carbon-14 is about 5,730 years.
碳-14的半衰期約為5,730年。
•
Scientists calculate the half-life to determine the age of ancient artifacts.
科學家計算半衰期以確定古代文物的年代。
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).
範例:
•
The drug has a half-life of 8 hours, meaning its concentration in the bloodstream will halve every 8 hours.
該藥物的半衰期為8小時，這意味著其在血液中的濃度每8小時減半。
•
Understanding the half-life of a substance is crucial in environmental science for assessing pollutant persistence.
了解物質的半衰期對於環境科學評估污染物持久性至關重要。