Furthermore, the intensity of an absorption peak depends on the path length, concentration, and strength of the absorption band
In the region attributed to the symmetrical stretching of C-H bonds, mainly of methyl (-C[H.sub.3]) groups, the FTIR spectra of the five organic substrates showed a sharp and well-defined absorption band
centered at 2940 [cm.sup.-1].
Our results reveal two major absorption bands
with maximum around 230 and 260 nm, corresponding to di- and poly-aromatic regions, also called polycyclic aromatic hydrocarbons, PAHs.
Figure 5(b) shows IR absorption band
of C-O groups present in alcohols, 1200-1010 [cm.sup.-1], of LDPE films irradiated by C[O.sub.2] laser radiation.
The absorption bands
attributed to the vibrations in C[O.sup.2-.sub.3] anions are located in the range of ~400-1600 [cm.sup.-1] .
For example, a decrease in the pH when adding trifluoroacetic acid to acetonitrile solution of 4 results in the appearance of wavelength absorption band
at 419 nm and a decrease in the absorption intensity of the initial 374 nm band (Figure 7).
The stretching vibration absorption bands
of C=O and C-O were detected at 1740 [cm.sup.-1] and 1068 [cm.sup.-1], respectively.
6A) was obtained for an optical fibre, containing 8 x [10.sup.15] [Cl.sub.2]/[cm.sup.3], as calculated from the amplitude of the 3.73 eV absorption band
These sensitizers have some advantages over organic dyes such as: tunable absorption bands
due to the quantum-size effect, by a single incident photon it shows multi-electron- hole pair generation and it has high extinction coefficient.
Three characteristic absorption bands
are observed in the spectra of pani at 269 nm, 368 nm and 618nm wavelength, n-Alpani composite had absorption peaks at 270 nm, 371 nm and 633nm which are attributed to [pi] -[[pi].sup.*]conjugated ring systems, polaron -[[pi].sup.*] and [pi]-polaron benzenoid to quinoid excitonic transition respectively.
These dispersion relations are based on a harmonic oscillator atom (Lorentz) model and remain exact at any wavelength, even in the absorption band
region and whatsoever the oscillator strength of this band.
The loading plot shows the role of the band at 1230 [cm.sup.-1] (C-O stretching) that can be ascribed to a natural resin (data not shown); such an absorption band
in layer 4 is also visible in the extracted spectrum (Figure 10(d)).
All absorption band
edges were blue-shifted between 500 and 600 nm, suggesting that the synthesized nanoparticles were relatively small.
Typically, such interaction leads to the short-wavelength shift of the absorption band
Co(II) gives absorption bands
also at different wavelengths: due to the [S.sup.-] [right arrow] Co(II) ligand-to-metal charge transfer (LMCT), an intense absorption band
in the near UV, between 316 and 340 nm, can be observed.