“fluorescence”的概念、定义、翻译、参考文献-科学参考

fluorescence

Physics

See luminescence.

Astronomy

The emission of light from a gas whose atoms have been excited by a source of higher-energy radiation, such as a nearby hot star. The atoms of the gas are first excited to higher energy levels when they absorb energetic photons, especially those at ultraviolet wavelengths. Subsequently, the electrons cascade down to lower energy levels, re-emitting the energy as a series of lower-energy photons, usually at visible or infrared wavelengths. Nebulae glow as a result of fluorescence. See also Bowen Fluorescence.

Science and Technology

The emission of light by certain substances which occurs when those substances absorb photons of electromagnetic radiation. The absorbed photons raise electrons, atoms, molecules, or other components to a higher energy level, and as they relax to their ground state they emit the excess energy in the form of photons in the visible part of the spectrum. Usually, there is a loss of energy between the time one photon is absorbed and another released, with the result that the emitted light is at a longer wavelength and lower energy than the energy that was absorbed. There are exceptions, however, and the emitted light may be at the same or shorter wavelength than the absorbed radiation.
Mike Allaby

Chemistry

See luminescence.

Electronics and Electrical Engineering

See luminescence.

Geology and Earth Sciences

Kind of luminescence, in which an atom or molecule emits radiation when electrons within it pass back from a higher to their former, lower energy state. The term is restricted to the phenomenon in cases where the interval between absorption and emission is very short (less than 10⁻³ s). See also phosphorescence; x-ray fluorescence; x-ray fluorescence spectrometry.

单词	fluorescence
释义	fluorescence Physics See luminescence. Astronomy The emission of light from a gas whose atoms have been excited by a source of higher-energy radiation, such as a nearby hot star. The atoms of the gas are first excited to higher energy levels when they absorb energetic photons, especially those at ultraviolet wavelengths. Subsequently, the electrons cascade down to lower energy levels, re-emitting the energy as a series of lower-energy photons, usually at visible or infrared wavelengths. Nebulae glow as a result of fluorescence. See also Bowen Fluorescence. Science and Technology The emission of light by certain substances which occurs when those substances absorb photons of electromagnetic radiation. The absorbed photons raise electrons, atoms, molecules, or other components to a higher energy level, and as they relax to their ground state they emit the excess energy in the form of photons in the visible part of the spectrum. Usually, there is a loss of energy between the time one photon is absorbed and another released, with the result that the emitted light is at a longer wavelength and lower energy than the energy that was absorbed. There are exceptions, however, and the emitted light may be at the same or shorter wavelength than the absorbed radiation. Mike Allaby Chemistry See luminescence. Electronics and Electrical Engineering See luminescence. Geology and Earth Sciences Kind of luminescence, in which an atom or molecule emits radiation when electrons within it pass back from a higher to their former, lower energy state. The term is restricted to the phenomenon in cases where the interval between absorption and emission is very short (less than 10⁻³ s). See also phosphorescence; x-ray fluorescence; x-ray fluorescence spectrometry.
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