“luminescence”的概念、定义、翻译、参考文献-科学参考

luminescence

Physics

The emission of light by a substance for any reason other than a rise in its temperature. In general, atoms of substances emit photons of electromagnetic energy when they return to the ground state after having been in an excited state (see excitation). The causes of the excitation are various. If the exciting cause is a photon, the process is called photoluminescence; if it is an electron it is called electroluminescence. Chemiluminescence is luminescence resulting from a chemical reaction (such as the slow oxidation of phosphorus); bioluminescence is the luminescence produced by a living organism (such as a firefly). If the luminescence persists significantly after the exciting cause is removed it is called phosphorescence; if it does not it is called fluorescence. There must always be some delay; in some definitions a persistence of more than 10 nanoseconds (10⁻⁸ s) is treated as phosphorescence.

Chemistry

The emission of light by a substance for any reason other than a rise in its temperature. In general, atoms of substances emit photons of electromagnetic energy when they return to the ground state after having been in an excited state (see excitation). The causes of the excitation are various. If the exciting cause is a photon, the process is called photoluminescence; if it is an electron it is called electroluminescence. Chemiluminescence is luminescence resulting from a chemical reaction (such as the slow oxidation of phosphorus); bioluminescence is the luminescence produced by a living organism (such as a firefly). If the luminescence persists significantly after the exciting cause is removed it is called phosphorescence; if it does not it is called fluorescence. This distinction is arbitrary since there must always be some delay; in some definitions a persistence of more than 10 nanoseconds (10⁻⁸ s) is treated as phosphorescence.

Electronics and Electrical Engineering

The emission of electromagnetic radiation from a substance due to a nonthermal process. The term is also used to describe the radiation itself, particularly when it falls within the visible spectrum. Luminescence occurs when atoms of the material are excited and then decay to their ground state with the emission of radiant energy. If the luminescence ceases as soon as the source of excitation is removed, i.e. the persistence is less than about 10^–8 second, it is termed fluorescence. If it persists for longer than about 10^–8 second it is termed phosphorescence. A luminescent material is known as a phosphor.
The most common source of energy that results in luminescence is other electromagnetic radiation or electrons or other charged particles. Stokes’ law states that the radiation emitted is usually of longer wavelength than that of the exciting radiation (although it may sometimes be shorter). Ultraviolet radiation therefore can produce visible light from a phosphor. The light produced has a characteristic colour for a particular fluorescent material: fluorescene, yellow-green; quinine sulphate, blue; chlorophyll, red.
Fluorescence is used for examining the spectrum in the ultraviolet region, in fluorescent lighting, and for display purposes, such as with the screen of a cathode-ray tube. Phosphorescence is used when longer persistence is required, such as with a long-persistence screen.
Thermoluminescence is an indirect effect of bombardment by ionizing radiation and is seen when the material is heated after subjection to radiation. The radiation releases electrons within the material and these are trapped at defects within the solid. These electrons are released on heating and the energy thus produced is emitted as visible radiation. Other energy sources that excite luminescence include friction (triboluminescence) and chemical reaction (chemiluminescence).

单词	luminescence
释义	luminescence Physics The emission of light by a substance for any reason other than a rise in its temperature. In general, atoms of substances emit photons of electromagnetic energy when they return to the ground state after having been in an excited state (see excitation). The causes of the excitation are various. If the exciting cause is a photon, the process is called photoluminescence; if it is an electron it is called electroluminescence. Chemiluminescence is luminescence resulting from a chemical reaction (such as the slow oxidation of phosphorus); bioluminescence is the luminescence produced by a living organism (such as a firefly). If the luminescence persists significantly after the exciting cause is removed it is called phosphorescence; if it does not it is called fluorescence. There must always be some delay; in some definitions a persistence of more than 10 nanoseconds (10⁻⁸ s) is treated as phosphorescence. Chemistry The emission of light by a substance for any reason other than a rise in its temperature. In general, atoms of substances emit photons of electromagnetic energy when they return to the ground state after having been in an excited state (see excitation). The causes of the excitation are various. If the exciting cause is a photon, the process is called photoluminescence; if it is an electron it is called electroluminescence. Chemiluminescence is luminescence resulting from a chemical reaction (such as the slow oxidation of phosphorus); bioluminescence is the luminescence produced by a living organism (such as a firefly). If the luminescence persists significantly after the exciting cause is removed it is called phosphorescence; if it does not it is called fluorescence. This distinction is arbitrary since there must always be some delay; in some definitions a persistence of more than 10 nanoseconds (10⁻⁸ s) is treated as phosphorescence. Electronics and Electrical Engineering The emission of electromagnetic radiation from a substance due to a nonthermal process. The term is also used to describe the radiation itself, particularly when it falls within the visible spectrum. Luminescence occurs when atoms of the material are excited and then decay to their ground state with the emission of radiant energy. If the luminescence ceases as soon as the source of excitation is removed, i.e. the persistence is less than about 10^–8 second, it is termed fluorescence. If it persists for longer than about 10^–8 second it is termed phosphorescence. A luminescent material is known as a phosphor. The most common source of energy that results in luminescence is other electromagnetic radiation or electrons or other charged particles. Stokes’ law states that the radiation emitted is usually of longer wavelength than that of the exciting radiation (although it may sometimes be shorter). Ultraviolet radiation therefore can produce visible light from a phosphor. The light produced has a characteristic colour for a particular fluorescent material: fluorescene, yellow-green; quinine sulphate, blue; chlorophyll, red. Fluorescence is used for examining the spectrum in the ultraviolet region, in fluorescent lighting, and for display purposes, such as with the screen of a cathode-ray tube. Phosphorescence is used when longer persistence is required, such as with a long-persistence screen. Thermoluminescence is an indirect effect of bombardment by ionizing radiation and is seen when the material is heated after subjection to radiation. The radiation releases electrons within the material and these are trapped at defects within the solid. These electrons are released on heating and the energy thus produced is emitted as visible radiation. Other energy sources that excite luminescence include friction (triboluminescence) and chemical reaction (chemiluminescence).
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