Primary jump rate

In reality, one should calculate the corresponding electron-phonon interaction matrix elements to obtain more accurate results for the primary jump rates. 

A pure hopping model is considered here, that is, the conduction is due to electrons in localized states with energies near the Fermi energy. The primary jump rate Wi j, i.e., the number of jumps from one localized state i to another j per unit time, is given to an acceptable approximation by ... 

TABLE 9.13. Characteristic Primary Jump Rates (in s ) Calculated from Equation (9.78)"... 

It should be noted, however, that in this second calculation a tenfold larger phonon frequency was chosen than the one that is realistic in the case of proteins, and a Boltzmann factor of the order of unity seems to be rather overestimated. These two facts certainly account for at least two orders of magnitude in the difference of three orders of magnitude in the primary jump rates between their and our calculations. 

Finally, we note that after determining the primary jump rates between different sites of a multicomponent disordered polypeptide, these data can be used as input in a stochastic (random walk) theory of hopping conductivity in random media. Since, however, this theory has not yet been applied to any real polymers, we do not describe this method here but refer to the appropriate papers. ... 

With M = He, experimeuts were carried out between 255 K aud 273 K with a few millibar NO2 at total pressures between 300 mbar aud 200 bar. Temperature jumps on the order of 1 K were effected by pulsed irradiation (< 1 pS) with a CO2 laser at 9.2- 9.6pm aud with SiF or perfluorocyclobutaue as primary IR absorbers (< 1 mbar). Under these conditions, the dissociation of N2O4 occurs within the irradiated volume on a time scale of a few hundred microseconds. NO2 aud N2O4 were monitored simultaneously by recording the time-dependent UV absorption signal at 420 run aud 253 run, respectively. The recombination rate constant can be obtained from the effective first-order relaxation time, A derivation analogous to (equation (B2.5.9). equation (B2.5.10). equation (B2.5.11) and equation (B2.5.12)) yield... 

Phase dissolution in polymer blends. The reverse process of phase separation is phase dissolution. Without loss of general validity, one may assume again that blends display LCST behavior. The primary objective is to study the kinetics of isothermal phase dissolution of phase-separated structures after a rapid temperature-jump from the two-phase region into the one-phase region below the lower critical solution temperature. Hence, phase-separated structures are dissolved by a continuous descent of the thermodynamic driving force responsible for the phase separation. The theory of phase separation may also be used to discuss the dynamics of phase dissolution. However, unlike the case of phase separation, the linearized theory now describes the late stage of phase dissolution where concentration gradients are sufficiently small. In the context of the Cahn theory, it follows for the decay rate R(q) of Eq. (29) [74]... 

For these reactions, AG° 0. The experimental measurement of cross-reaction rates is generally more straightforward than the measurement of self-exchange rates. Either the reactants are simply mixed together, or a thermodynamically unstable system is generated rapidly (via pulse radiolysis, flash photolysis, or temperature-jump relaxation) to initiate the redox reaction. Absorption spectroscopy has almost always been used to monitor the progress of protein cross reactions. The primary goal of theory, as will become evident, is to provide a relationship between AG° and AG" " for cross reactions. 

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