In all of these 60.(case), the device that generates radio waves is called the transmitter(发射机)61.the device that picks radio waves up is called the 62.(receive).But technology is not the only thing that can create radio waves. Lightning gives off radio waves.63.do lots of objects...
Alpha radiationoriginates from what are classed as relatively heavy particles, more specificallyhelium atomswithout electrons, which can only travel a short distance of a few centimeters through the air. Typical alpha emitters include radium-226, radon-222, uranium-238, plutonium-236, thorium-232, ...
2025年托福考点真题库 [单项选择题]radiation 关键词: radiation A:n.刻痕;裂缝;记号 B:n.发光,放热,辐射线(热,能) C:n.系统;配合;组织 D:例句Even low doses of radiation are dangerous. E:即使低剂量的辐射也是危险的。 本题来源:2014年托福考试考前冲刺卷(7) ...
The greatest health consequences of a nuclear accident or explosion are linked toradioactive materials(radio-nuclides) that can travel through air and water for thousands of miles, contaminating the world with radioactive particles. Once the human body is exposed to nuclear fallout, radioactive isoto...
Beta radiationis made up of beta particles, which are electrons ejected from the nucleus of a radioactive atom. Beta particles are smaller and more penetrating than alpha particles, but their range in tissue is still limited. Beta radiation can travel several meters in air and is only mod...
Based on the definition of interaction cross-section, the dependence of gamma rays intensity on the thickness of absorber material can be derived. Ifmonoenergetic gamma raysare collimated into anarrow beamand if the detector behind the material only detects ...
Unlike X rays and gamma rays, some high-energy radiations travel at less than the speed of light. Some of these were identified initially by their particulate nature and only later were shown to travel with wavelike character. One example of this kind of radiation is theelectron, first estab...
location becomes shaded, photosynthetic production can be halted. Not only does this stop oxygen production, but it increases oxygen consumption through plant respiration1. The decrease in infrared light will also cool the shaded surface or body of water, which in turns cools the surrounding air. ...
(21)). Two common RICH designs can be distinguished, according to the value of n: 1. If a dense medium (large n) is used, only a thin radiator layer (∼1cm) is required to emit a sufficient number of Cherenkov photons. The photon detector is located some distance away behind the ...
The loss can be controlled through the size of the vacuum core region. Here, the propagation length can extend into cm scale. Effective generation and coupling of the harmonics requires overlap of the modes in both vacuum and material, and thus implies loss. The efficiency requires a balance ...