Line shape measurements

Investigation of Collision Processes from Line Shape Measurements... 

The relaxation results (1) for the LP sample can be summarized. Line-shape measurements indicated that motional narrowing started at around 60°C, and by 110°C, the lines appeared completely Lorentzian. The activation energy obtained from T2 above 120°C was 16.3 1.2 kcal/mol. 

Since it was admitted that Fermi resonances may play a role in crystalline adipic acid [102], they were incorporated in the model by using the Fourier transform of Eq. (304) in place of Eq. (279). Note that Yaremko et al. [105] also studied these spectra in a rather formal way with the aid of a general formalism [106-108], which is not without connection with that used by the Witkowski school. The left column of Fig. 24 reports the comparisons between the experimental line shapes measured by Auvert and Marechal [101] and the corresponding theoretical ones calculated by Eq. (279) in this way [98]. In this figure, the line shapes are reproduced up to down, for, respectively, 10, 100, 200, and 300 K. For each temperature, the right part is devoted to the O—H species and the left one to the O D isotopomer. The values of the parameters used for the calculations are reported in the caption of the figure. 

The Raman FID for this mode (Fig. 13) is a single exponential with T2 = 0.82 ps, as expected from previous line shape measurements. Corresponding Raman echo results are shown in Fig. 14. The fit curves are derived from the FID by assuming that all the frequency modulations are fast. Simulations show that a slow component with a width of > 1 cm-1... 

Complementary spin-lattice relaxation measurements corroborate the observations made using the 2H line-shape measurements. Based on these measurements the low temperature relaxation times are dramatically shorter in the intercalated sample as compared to the bulk, indicating enhanced polymer re-orientation dynamics in the intercalated samples. Furthermore, the temperature dependence of the relaxation time in the bulk and intercalated sample show dramatic differences. While the relaxation time for the intercalated sample passes smoothly from low to high temperatures, the bulk sample shows a break between the crystalline state and melt state, with the melt state relaxation times at least one order of magnitude faster than those observed in the intercalated sample at the same temperature. 

ID NMR parameters such as SLR time and line shape measurements give information about the dynamics of the intra-bond O-H-O motion along with reorien-tational motion of symmetric groups in the dipolar glasses. However, the information obtained from such studies is limited hence reports of such studies are meagre. In the corresponding deuterated analogues much more information... 

The fully saturated pyrazolidines have been utilized as models for the study of the nitrogen inversion of hydrazines. For instance, (75), a 2,3-diazabicyclo[2.2.1]heptene derivative, presents a consecutive inversion process at two nitrogen atoms with an activation barrier of 59 kJ moF determined by proton line-shape measurements (67JA81). Monocyclic... 

NMR experiments are capable of probing motions in the range from about 10 to about 10 Hz and the methods employed fall into three principal groups two-dimensional exchange measurements, line-shape measurements and relaxation-rate measurements. The three types of measurement are applicable in the approximate frequency ranges of motion... 

Fig. 12.8 Comparison of the linear and nonlinear (at A = 5) G(t) line shapes, measured (o for the linear A for A = 5) and calculated (lines), for sample F40. Also shown are the separate contributions of the Mx(f), PbH), and /tc( ) processes (see...

Extremely exciting experimental data for glasses are now beginning to emerge. It has been shown that line shape measurements, fluorescence intensity fluctuations, and spectral diffusion trajectories can all be used to probe TLS dynamics on different time scales. Furthermore, as has been emphasized already, these experiments on individual molecules will provide information complementary to that obtained from more traditional echo and hole burning experiments. At this point what we need is more data. In an ideal world all three of the above experiments would be performed on the same individual molecule at a variety of temperatures, and then would be repeated on many molecules, and all of the above would be repeated for several different systems. Although the basic theoretical apparatus is in place for analyzing these experiments, more refined theoretical results will surely be needed. 

Assignment could be reversed. ) Spectrum of Cu(II) complex. Spectrum in da(N)/dr=0.189pTK- for CCI4 and 0 Line shape measurements of nitroxide ad pyridine has linewidth 6.2 mT.. 202nTK- for CH3OCH2CH2OCH3. sorbed onto silica gel in aqueous solution. ... 

Note high g-value not substantiated. ) Measurements (in several other liquid crystals) of line-shapes. ) Measurements in discotic mesophase of hexakis(hexyloxy)triphenylene. ... 

Figure 9. The signal line-shapes measured for a-partioles and gamma-rays in a r xl LaBrs. Ce (left Panel) and in a 6 x4 LaCl3-.Ce (right panel) detector. Each pulse is the result of an average of 1500 pulses with the same energy measured. In the inset the ratio between the difference of the two signals and the alpha one, calculated in the interval 20-180ns, is displayed, (from ref [35])...

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