“X-rays”的概念、定义、翻译、参考文献-科学参考

X-rays

Physics

Electromagnetic radiation of shorter wavelength than ultraviolet radiation produced by bombardment of atoms by high-quantum-energy particles. They were discovered by William Roentgen in 1895. The range of wavelengths is 10⁻¹¹ m to 10⁻⁹ m. Atoms of all the elements emit a characteristic X-ray spectrum when they are bombarded by electrons. The X-ray photons are emitted when the incident electrons knock an inner orbital electron out of an atom. When this happens an outer electron falls into the inner shell to replace it, losing potential energy (Δ‎E) in doing so. The wavelength λ‎ of the emitted photon will then be given by λ‎=ch/Δ‎E, where c is the speed of light and h is the Planck constant. See also Bremsstrahlung.

X-rays can pass through many forms of matter and they are therefore used medically and industrially to examine internal structures. X-rays are produced for these purposes by an X-ray tube.

Astronomy

Electromagnetic radiation with wavelengths between those of ultraviolet and gamma rays, approximately 0.01–10 nm. At these short wavelengths it is more usual to talk in terms of photon energies. The energy range for X-rays is approximately 0.1–100 keV.

Chemistry

Electromagnetic radiation of shorter wavelength than ultraviolet radiation produced by bombardment of atoms by high-quantum-energy particles. The range of wavelengths is 10⁻¹¹ m to 10⁻⁹ m. Atoms of all the elements emit a characteristic X-ray spectrum when they are bombarded by electrons. The X-ray photons are emitted when the incident electrons knock an inner orbital electron out of an atom. When this happens an outer electron falls into the inner shell to replace it, losing potential energy (Δ‎E) in doing so. The wavelength λ‎ of the emitted photon will then be given by λ‎ = ch/Δ‎E, where c is the speed of light and h is the Planck constant.
X-rays can pass through many forms of matter and they are therefore used medically and industrially to examine internal structures. X-rays are produced for these purposes by an X-ray tube.

Electronics and Electrical Engineering

Electromagnetic radiation of frequencies ranging approximately between those of ultraviolet radiation and gamma rays. They are produced when matter is bombarded with sufficiently energetic electrons and were first observed by Roentgen in 1895. X-rays can be produced as a result of electron transitions from higher to lower energy levels within an atom. X-rays resulting from transitions have a frequency that is characteristic of the material and are therefore termed characteristic X-rays. X-rays are also produced during the rapid decelerations of electrons as they approach the nucleus. These X-rays, a form of bremsstrahlung radiation, have a relatively wide frequency range and are known as continuous X-rays. X-rays of relatively low energy are termed soft X-rays; those at the high-energy portion of the frequency spectrum are hard X-rays.
X-rays can be reflected, refracted, and polarized and also exhibit interference and diffraction. They interact with matter to produce relatively high energy electrons: the mechanism is the same as in the photoelectric effect. These electrons are usually of sufficiently high energy to ionize a gas or to produce secondary X-rays from the matter. The ionization of a gas can be utilized, in the ionization chamber, to measure the intensity of an X-ray beam.
X-rays are widely used in radiography to investigate materials that are opaque to visible light but relatively transparent to X-rays. Radiography is used to detect flaws in structures and for diagnostic examinations. Sufficiently high intensities of X-rays of higher energies damage human tissue and X-rays are used in radiotherapy for the therapeutic destruction of diseased tissue. X-rays are also used in X-ray crystallography to investigate and determine crystal structures by using the crystal as a three-dimensional diffraction grating. X-ray lithography systems are being developed.

Biology

Electromagnetic radiation of shorter wavelength than ultraviolet radiation and longer wavelength than gamma radiation. The range of wavelengths is 10⁻¹¹ m to 10⁻⁹ m. X-rays can pass through many forms of matter and they are therefore used medically and industrially to examine internal structures. X-rays are produced for these purposes by an X-ray tube.

单词	X-rays
释义	X-rays Physics Electromagnetic radiation of shorter wavelength than ultraviolet radiation produced by bombardment of atoms by high-quantum-energy particles. They were discovered by William Roentgen in 1895. The range of wavelengths is 10⁻¹¹ m to 10⁻⁹ m. Atoms of all the elements emit a characteristic X-ray spectrum when they are bombarded by electrons. The X-ray photons are emitted when the incident electrons knock an inner orbital electron out of an atom. When this happens an outer electron falls into the inner shell to replace it, losing potential energy (Δ‎E) in doing so. The wavelength λ‎ of the emitted photon will then be given by λ‎=ch/Δ‎E, where c is the speed of light and h is the Planck constant. See also Bremsstrahlung. X-rays can pass through many forms of matter and they are therefore used medically and industrially to examine internal structures. X-rays are produced for these purposes by an X-ray tube. Astronomy Electromagnetic radiation with wavelengths between those of ultraviolet and gamma rays, approximately 0.01–10 nm. At these short wavelengths it is more usual to talk in terms of photon energies. The energy range for X-rays is approximately 0.1–100 keV. Chemistry Electromagnetic radiation of shorter wavelength than ultraviolet radiation produced by bombardment of atoms by high-quantum-energy particles. The range of wavelengths is 10⁻¹¹ m to 10⁻⁹ m. Atoms of all the elements emit a characteristic X-ray spectrum when they are bombarded by electrons. The X-ray photons are emitted when the incident electrons knock an inner orbital electron out of an atom. When this happens an outer electron falls into the inner shell to replace it, losing potential energy (Δ‎E) in doing so. The wavelength λ‎ of the emitted photon will then be given by λ‎ = ch/Δ‎E, where c is the speed of light and h is the Planck constant. X-rays can pass through many forms of matter and they are therefore used medically and industrially to examine internal structures. X-rays are produced for these purposes by an X-ray tube. Electronics and Electrical Engineering Electromagnetic radiation of frequencies ranging approximately between those of ultraviolet radiation and gamma rays. They are produced when matter is bombarded with sufficiently energetic electrons and were first observed by Roentgen in 1895. X-rays can be produced as a result of electron transitions from higher to lower energy levels within an atom. X-rays resulting from transitions have a frequency that is characteristic of the material and are therefore termed characteristic X-rays. X-rays are also produced during the rapid decelerations of electrons as they approach the nucleus. These X-rays, a form of bremsstrahlung radiation, have a relatively wide frequency range and are known as continuous X-rays. X-rays of relatively low energy are termed soft X-rays; those at the high-energy portion of the frequency spectrum are hard X-rays. X-rays can be reflected, refracted, and polarized and also exhibit interference and diffraction. They interact with matter to produce relatively high energy electrons: the mechanism is the same as in the photoelectric effect. These electrons are usually of sufficiently high energy to ionize a gas or to produce secondary X-rays from the matter. The ionization of a gas can be utilized, in the ionization chamber, to measure the intensity of an X-ray beam. X-rays are widely used in radiography to investigate materials that are opaque to visible light but relatively transparent to X-rays. Radiography is used to detect flaws in structures and for diagnostic examinations. Sufficiently high intensities of X-rays of higher energies damage human tissue and X-rays are used in radiotherapy for the therapeutic destruction of diseased tissue. X-rays are also used in X-ray crystallography to investigate and determine crystal structures by using the crystal as a three-dimensional diffraction grating. X-ray lithography systems are being developed. Biology Electromagnetic radiation of shorter wavelength than ultraviolet radiation and longer wavelength than gamma radiation. The range of wavelengths is 10⁻¹¹ m to 10⁻⁹ m. X-rays can pass through many forms of matter and they are therefore used medically and industrially to examine internal structures. X-rays are produced for these purposes by an X-ray tube.
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