emission spectrum

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emission spectrum:

see spectrumspectrum,
arrangement or display of light or other form of radiation separated according to wavelength, frequency, energy, or some other property. Beams of charged particles can be separated into a spectrum according to mass in a mass spectrometer (see mass spectrograph).
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emission spectrum

A spectrum formed by emission of electromagnetic radiation by matter. Energy has first to be supplied, either as heat (high temperature) or by some other mechanism such as absorption of electromagnetic radiation by the matter or by impact of electrons. The energy raises the atoms or molecules to higher energy levels. In a simple example, the electron in a hydrogen atom may ‘jump’ from its normal orbit to one farther from the nucleus (see hydrogen spectrum). The emission spectrum of hydrogen, or any other emitting material, is formed by transitions from such excited states to lower energy states, the excess energy appearing in the form of photons with characteristic frequencies.

The emission spectrum therefore consists of a specific pattern of narrow peaks – emission lines – that occur at these frequencies. These lines may be superimposed on a continuum, but not necessarily so. Emission lines can occur in stellar spectra if, for example, the star is surrounded by a hot shell of diffuse gas. They also occur, for example, in the spectra of emission nebulae, the interstellar medium (see molecular-line radio astronomy), and quasars. See also absorption spectrum; excitation.

emission spectrum

[i′mish·ən ‚spek·trəm]
Electromagnetic spectrum produced when radiations from any emitting source, excited by any of various forms of energy, are dispersed.
References in periodicals archive ?
Fig 5 shows considerable overlap to the fluorescence emission spectrum of HSA with absorption spectrum of cisplatin.
Therefore, although radiant exposure has enormous importance, (23) the correlation between the absorption spectrum of the photo-initiator and the emission spectrum of the LCU also plays an essential role.
The emission spectrum of pigmented Porites compressa tissue extract is distinct from that of the healthy tissue (Fig.
Barman says his finding can be reconciled with the lack of water in Spitzer's dayside emission spectrum if the planet's atmosphere is the same temperature at both high and low altitudes, unlike the atmospheres of planets in our own solar system.
The size and location of peaks in the emission spectrum correlate with the composition and other properties of the test material.
Nevertheless, it has to be mentioned that in the case of feldspars difficulties are expected when applying protocols that are connected with all kinds of preheating as the emission spectrum of many feldspars changes already at moderate (80[degrees]C, 353 K) heating (Fig.
The subject of the public contract is the supply of a spectral monochromatic flow cytometer, Which broadens the possibilities of combining a wide spectrum of fluorochromes for analytical panels, Allows the reading of cell autofluorescence and other standard cytometric applications without limitation given by the emission spectrum of fluorochromes.
As the emission spectrum is proportional to the excitation spectrum, this higher light output means stronger fluorescent signals.
In this regard, the intensity of the chromospheric emission spectrum can provide some sense of material densities in this layer.
Washington, April 19 ( ANI ): New observations of the blazar known as PKS 1424+240 showed that it is the most distant known source of very-high-energy gamma rays, but its emission spectrum now appears highly unusual in light of the new data.
The orange glass sample is a NIST standard reference material 2490, SRM 2490, which has a certified relative emission spectrum for excitation at 412 nm.
In these blends, energy transfer occurs, provided with the emission spectrum of the donor component overlaps with the absorption spectrum of the acceptor, and the dipoles are sufficiently close to each other.

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