放射物英语单词（Radiation Vocabulary）

Radiation Vocabulary Radiation is the emission of energy through space or matter. From natural sources such as the sun to man-made sources such as medical diagnostic tests, radiation is all around us. Here are some key terms to help you better understand the world of radiation. I. Types of Radiation Radiation exists in various forms, each with different properties and characteristics. The three main types of radiation are: 1. Alpha Radiation: This type of radiation consists of alpha particles, or clusters of two protons and two neutrons. Alpha particles have a positive charge and are the heaviest of the three types of radiation. Its penetration power is weak and can be stopped by a piece of paper or clothing, but alpha particles can be harmful if they enter the body. 2. Beta Radiation: Beta particles are negatively charged and have a lighter and smaller mass than alpha particles. They have a penetration power that is greater than alpha radiation and can be stopped by plastic, but can also harm the body if they enter it. 3. Gamma Radiation: Gamma radiation is a form of electromagnetic radiation, which makes it similar to X-rays or light. Gamma rays have no mass or charge, and are therefore deeply penetrating. They can be stopped only by dense materials such as lead or concrete. Gamma radiation is the most dangerous type of radiation to humans. II. Units of Radiation Measurement Radiation is measured in different units depending on the type and amount of radiation being measured. Common radiation units include: 1. Gray (Gy): This is the unit that measures the amount of radiation energy absorbed by a material or human tissue. For example, a dose of 1 gray means that one joule of radiation energy has been absorbed by one kilogram of tissue. 2. Becquerel (Bq): This unit measures the amount of radioactive decay per second of a material. One becquerel equals one radioactive disintegration per second. 3. Sievert (Sv): This is the unit that measures the biological effects of radiation on living tissue. The sievert takes into account the type and energy of the radiation, as well as the sensitivity of the tissue being exposed. It is used to measure both the harmful effects of radiation exposure and the amount of exposure that can be considered safe. III. Radiation Protection Exposure to radiation can be harmful to humans, which is why radiation protection is important. Some methods of radiation protection include: 1. Time: limiting the amount of time spent near a radiation source. The longer the exposure, the greater the risk. 2. Distance: staying as far away from the radiation source as possible. The further away, the weaker the exposure. 3. Shielding: using materials that block radiation, such as lead or concrete barriers or personal protective equipment like lead aprons. In conclusion, radiation plays a vital role in many aspects of our lives, from medical diagnostic tools to nuclear energy. By understanding its properties, units of measurement, and protection methods, we can better ensure our safety and well-being in environments where radiation is present.