half-life

Tanımlar (İngilizce)

1. isim The time required for half the nuclei in a sample of an isotope to undergo radioactive decay.

   “O₂^(•−) and OH^• are highly unstable (half-life at the level of microseconds and nanoseconds, respectively) and cannot cross membrane, while H₂O₂, though not a free radical but a ROS, is relatively stable (half-life around 1 ms) (Møller et al. 2007) and can cross membranes through aquaporins.”

2. isim In a chemical reaction, the time required for the concentration of a reactant to fall from a chosen value to half that value.
3. isim The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacological, physiologic, or radiological activity.

   “For nonporous surfaces such as steel, in a dark and low-humidity environment, the CCP virus has an 18-hour half-life—the time required for it to decrease by half , according to the researchers' findings.”

4. isim The amount of time it takes for an idea or a fashion to lose half of its influential power.

   “Most books of scholarship have surprisingly short intellectual half-lives during which they make a difference"”