Gaseous radiation bands

Gaseous radiation does not follow the 4th-power law because gases do not radiate in all wavelengths, as do solids (gray bodies). Each gas radiates only in a few narrow bands, as can be seen on a spectrograph in figures 2.17 and 2.18. 

Gaseous H CI has a strong absorption band centered at about X = 3.40 X 10 m in the infrared portion of the electromagnetic radiation spec-tmm. On the assumption that D bonds to Cl with the same str ength that H does, predict the frequency of vibration in Hz and rad of D CI. 

Gaseous Combustion Products Radiation from water vapor and carbon dioxide occurs in spectral bands in the infrared. In magnitude it overshadows convection at furnace temperatures. 

Matrix Isolation Spectroscopy. Gaseous hydrazoic acid and xenon (1/200) were condensed on a Csl disk cooled to 28-35 K. Exposure of the mixture to 254-nm radiation led to the consumption of HN3 and the formation of new vibrational bands at 3131.8, 3120.6, and 3109.0 cm assigned to triplet NH. The use of xenon as the matrix host is crucial to the success of the experiment. The heavy atom host accelerated intersystem crossing in either the excited state of HN3 or NH, which led to good yields of... 

Gaseous emission of Infrared radiation differs in character from solid emission in that the tenner consists of discrete spectrum lines or bands, with significant discontinuities, while the latter shows a continuous distribution of energy throughout the spectrum. The predominant source or molecular radiation in the infrared is the result of vibration of the molecules in characteristic modes. Energy transitions between various stales of molecular rotation also produce infrared radiation. Complex molecular gases radiate intricate spectra, which may be analyzed to give information of the nature of the molecules or of the composition of the gas. 

Absorption of UV/VIS radiation in the solid state is different from UV/VIS absorption in the liquid or gaseous phase with respect to photophysical processes taking place in the crystal lattice and to the metallic, semiconductor (SC) or insulator properties of the absorbing solid (Bottcher, 1991). In crystals, multiple atomic or molecular orbitals are combined to form broad energy bands, i.e. a valence band (vb) fully occupied by electrons and a conduction band (cb) unoccupied or only partly occupied by electrons. Conduction bands and valence bands have different energetic positions relative to one another depending on the specific substrate. In a SC cluster, electronic transitions between the valence band and the conduction... 

Certain gaseous components of the atmosphere, called greenhouse gases, transmit the visible portion of solar radiation but absorb specific spectral bands of thermal radiation emitted by the Earth. The theory is that terrain absorbs radiation, heats up, and emits... 

The spectrum emitted by the lamp corresponds to the superimposition of radiation emitted by the cathode and by the gaseous atmosphere within the lamp. The width of the emission lines, which depends upon different effects (Doppler, Stark (ionization) and Lorentz (pressure)), is narrower than the corresponding absorption band. The monochromator enables the elimination of a large part of the stray light due to the filling gas, and the selection of the most intense spectral line in order to obtain a better sensitivity (Figure 13.8), except for cases of interference caused by other elements. 

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