QENS spectra

Fig. 5. The QENS spectra for the aqueous solution of LiC1.6.0H]O at diiferent temperatures. The dots are experimental values and the solid lines the fitted values by eq.(7).

The results of QENS measurements for TaV2H [76] are consistent with this microscopic picture of H motion. First, on the frequency scale of tf the measured QENS spectra S(Q, co) are well described by the sum of a narrow elastic line and a broader quasielastic line having Q-dependent intensity, but Q-independent width. These features are typical of the case of spatially-confined (localized) motion [14]. 

The elastic (f = 0) and quasi-elastic incoherent structure factors for the isotropic rotation of methane are shown in Fig. 3. It appears from this figure that only the first three terms of the summation in expression 23 have to be considered in the Q range, which is usually covered by QENS instruments. The self-diffusivity will be obtained by first fitting the QENS spectra with expression 23 and then from the broadening of As with Q. 

The protein powder model discussed for the low T crossover, was thus used to analyze measured QENS spectra of the protein hydration water for temperatures ranging from 290 to 380K, covering the first stage of the denaturation process, occurring at the reversible protein denaturation temperature around 34 5K. In Joint was also developed a MD simulation study for the same process, the main obtained results are exposed in the following. Details are the following lysozyme... 

This result is illustrated by Fig. 26.15 showing the width of the quasielastic component of the QENS spectrum for ScHqk as a function of temperature. Since this width is proportional to the H jump rate, it can be seen that the temperature dependence of the H jump rate for a-ScH is similar to that for Nb(OH) and... 

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