half life

简明释义

半衰期

英英释义

例句

1.The radioactive material has a half life of five years, meaning it will take that long for half of it to decay.

这种放射性物质的半衰期为五年，这意味着它需要五年时间才能衰变一半。

2.Knowing the half life of a substance is crucial for understanding its long-term effects on the environment.

了解一种物质的半衰期对于理解其对环境的长期影响至关重要。

3.Carbon-14 has a half life of about 5,730 years, which makes it useful for dating ancient artifacts.

碳-14的半衰期约为5730年，这使它在古物测年方面非常有用。

4.The half life of iodine-131 is only eight days, which is why it is used in medical treatments.

碘-131的半衰期只有八天，这就是它在医疗治疗中被使用的原因。

5.In pharmacology, the half life of a drug determines how often it needs to be administered.

在药理学中，药物的半衰期决定了需要多长时间给药一次。

作文

The concept of half life is crucial in various scientific fields, particularly in chemistry and physics. It refers to the time required for a quantity to reduce to half its initial value. This term is most commonly associated with radioactive decay, where it describes the time taken for half of the radioactive atoms in a sample to decay into a different element or isotope. Understanding half life is essential not only for scientists but also for industries that rely on radioactive materials, such as medicine and energy production.In the field of medicine, half life plays a significant role in pharmacology. When a patient is administered a drug, understanding the half life of that drug helps determine how often it should be taken to maintain effective levels in the bloodstream. For example, if a medication has a half life of four hours, it means that every four hours, the concentration of the drug in the body will decrease by half. Therefore, doctors can use this information to create a dosing schedule that ensures the drug remains effective without causing toxicity.Moreover, the half life concept extends beyond radioactivity and medicine. In environmental science, it is used to assess the persistence of pollutants in the environment. For instance, if a chemical contaminant has a half life of two years, it indicates that after two years, half of the original amount will still be present in the ecosystem. This knowledge is vital for environmental management and remediation efforts, guiding decisions on how to mitigate the impact of hazardous substances.In the context of nuclear power, understanding the half life of nuclear fuels and waste is critical for safety and sustainability. Nuclear reactors rely on materials with specific half lives to produce energy efficiently. However, the management of nuclear waste, which can have half lives ranging from a few years to thousands of years, poses significant challenges. Knowing the half life of these materials helps in planning long-term storage solutions and ensuring that they do not pose a risk to human health or the environment.On a broader scale, the concept of half life can also be applied metaphorically to various aspects of life. For example, one might consider the half life of relationships, where the intensity or connection between individuals diminishes over time. Just as radioactive materials decay, personal connections may fade, requiring effort and nurturing to maintain their strength.In conclusion, the term half life encompasses a wide range of applications across different disciplines. Its importance in understanding decay processes, whether they are physical, chemical, or even metaphorical, cannot be overstated. By grasping the implications of half life, individuals can better navigate the complexities of both scientific inquiry and everyday life. The knowledge of how quickly things change or diminish over time allows us to make informed decisions, whether in healthcare, environmental conservation, or personal relationships. Thus, the study of half life is not just an academic exercise; it is a fundamental aspect of understanding the world around us.

“半衰期”这一概念在多个科学领域中至关重要，尤其是在化学和物理学中。它指的是一个数量减少到其初始值一半所需的时间。这个术语通常与放射性衰变相关，它描述了样本中一半的放射性原子衰变成另一种元素或同位素所需的时间。理解半衰期不仅对科学家至关重要，对依赖放射性材料的行业（如医学和能源生产）也同样重要。在医学领域，半衰期在药理学中发挥着重要作用。当患者服用药物时，了解该药物的半衰期有助于确定应多长时间服用一次，以维持血液中的有效浓度。例如，如果一种药物的半衰期为四小时，这意味着每四小时，体内药物的浓度将减少一半。因此，医生可以利用这一信息制定给药计划，以确保药物保持有效而不引起毒性。此外，半衰期的概念超出了放射性和医学的范围。在环境科学中，它用于评估污染物在环境中的持久性。例如，如果一种化学污染物的半衰期为两年，这表明经过两年后，原始数量的一半仍将在生态系统中存在。这一知识对于环境管理和修复工作至关重要，为减轻有害物质影响的决策提供指导。在核能的背景下，了解核燃料和废物的半衰期对于安全性和可持续性至关重要。核反应堆依赖具有特定半衰期的材料以高效产生能量。然而，核废物的管理可能面临重大挑战，其半衰期可以从几年到数千年不等。了解这些材料的半衰期有助于规划长期储存解决方案，并确保它们不会对人类健康或环境构成风险。从更广泛的角度来看，“半衰期”的概念也可以隐喻地应用于生活的各个方面。例如，人们可能会考虑关系的半衰期，即个人之间的强度或联系随着时间的推移而减弱。正如放射性材料衰变一样，个人关系可能会逐渐消退，需要努力和培育来保持其强度。总之，半衰期这一术语涵盖了不同学科中广泛的应用。它在理解衰变过程方面的重要性，无论是物理的、化学的还是隐喻的，都是不可低估的。通过掌握半衰期的含义，个人可以更好地应对科学探究和日常生活的复杂性。了解事物如何随着时间的推移而变化或减少，使我们能够做出明智的决定，无论是在医疗保健、环境保护还是个人关系中。因此，研究半衰期不仅仅是一项学术活动；它是理解我们周围世界的基本方面。