Simulation of the Spectra

Fig.3. Fs DFWM spectrum of the acetic (a, b) and per-deuterated acetic (aD, bD) acid dimer. Magnified regions around J-type recurrences obtained at room temperature (300K). a) and aD) are the experimental spectra b) and bD) are the fitted simulation of the spectra.

Fig. 2. CO internal stretch frequency and width as a function of time, as extracted from the numerical simulation of the spectra. Contributions of the frustrated rotation and the frustrated translation are also shown.

The results of computer simulations of the spectra recorded at different temperatures are shown in figure 7. The simulations have been carried out following eq. (1) and the individual lineshape has been chosen in the form of the first derivative of that of eq. (18). The following set of parameters provides the best fits in the whole temperature range of this study A0 = 0.2944 T, DVm= 6.8 nm, cr = 0.40, Vs = 6370 nm3, N -N = 0.33. 

Computer simulation of the spectra assuming a monoclinic dimer model with the... 

Diffuse-reflection spectroscopy is a widely used experimental technique which, different from the previously mentioned techniques, is not only based on reflection and refraction but additionally on diffraction. The exact description, e.g. assuming Mie scattering, and quantitative simulation of the spectra is at least difficult (Grosse, 1990). The most comprehensive overview on all related aspects was given by Kortiim (1969). Experimental examples refer mostly to the visible spectral range, more recent reviews deal with near infrared (Osborne and Feam, 1986), infrared (Korte, 1990b), and far infrared spectroscopy (Ferraro and Rein, 1985). 

Simulation of the spectra of the adsorbed species as a mixture of rj - and / -coordinated species showed that no more than 5-10% of the thiophene could be present as sulfur-bound thiophene. 

Figure 7. ESR spectra of 5.4 x IQ- M (C6H5Cl)2Cr+ in DMSO at 22 °C. (a) No added (CeHsClljCfO. (c) Added ca. 0.04 M (CgHsClljCr". (e) Added ca. 0.08 M (C6H5Cl)2Cr . (g) added ca. 0.1 M (Cf H5Cl)2Cr . Panels (b), (d), (f), and (h) are computer simulations of the spectra immediately above them. Reprinted with permission from T, T.-T. Li and C. H. Brubaker, Jr., J. Organomet. Chem. 1981, 216, 223. Copyright 1981 Elsevier.

Analysis of the EXAFS region of the spectra of VFe proteins allowed simulation of the spectra, with backscattering contributions from three compound shells, V-(0 or N), V-(S), and V-(Fe). These types of atoms and their distances from the V atom in the VFe protein are very similar to those of Mo in MoFe proteins (see Table III). 

A detailed quantitative analysis of timescale and angle distribution requires numerical simulation of the spectra acquired with the solid and the alignment echoes. To this end the time-domain signal is written as a vector. The components of which correspond to the different molecular orientations [Abrl, Andl],... 

It is relatively difficult to resolve such spectra as presented in Figure 6. This is mainly due to not knowing which components should be present, the slope of the baseline and the presence of the 0 Is Ka satellite lines. However, such an attempt is shown in Figure o This is an unoptimised simulation of the spectra with 8 Gaussian components and a base line due to inelastic scattering. The position of. l e two V 2p. components corresponds to V 0 and V 0. (1 ). The V ratio calculated from these is 0.5o. The first... 

On exposure, the Ols/Cls ratios in the surface layers of the films, obtained from simulation of the spectra, rapidly increase initially with exposure time and then plateau to essentially constant values, see example for 6FDA/DAB in Figure 7. This observation of a plateau in the ratio is consistent with the ablation of the surface layers of the film during photo-oxidation. 

Radical species during inclusion polymerization can readily be detected by ESR spectroscopy, indicating that the radicals are thermally stable in the channels. The reason is that the radicals in the channels do not meet with each other due to the host walls. y-Irradiation produces radicals of the host component as well as the monomers. Monomeric and propagating radicals were observed in the case of urea, while only the propagating radicals were observed in the case of perhydrotriphenylene, deoxycholic acid, and apocholic acid. Simulation of the spectra clarified that the propagating radicals do not rotate freely, indicating that mobilities of the radicals are constrained in the channels. 

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