Transition rate

Theoretical models of the film viscosity lead to values about 10 times smaller than those often observed [113, 114]. It may be that the experimental phenomenology is not that supposed in derivations such as those of Eqs. rV-20 and IV-22. Alternatively, it may be that virtually all of the measured surface viscosity is developed in the substrate through its interactions with the film (note Fig. IV-3). Recent hydrodynamic calculations of shape transitions in lipid domains by Stone and McConnell indicate that the transition rate depends only on the subphase viscosity [115]. Brownian motion of lipid monolayer domains also follow a fluid mechanical model wherein the mobility is independent of film viscosity but depends on the viscosity of the subphase [116]. This contrasts with the supposition that there is little coupling between the monolayer and the subphase [117] complete explanation of the film viscosity remains unresolved. 

Note that if we identify the sum over 8-fimctions with the density of states, then equation (A1.6.88) is just Femii s Golden Rule, which we employed in section A 1.6.1. This is consistent with the interpretation of the absorption spectmm as the transition rate from state to state n. 

Gillam M J 1987 Quantum-classical crossover of the transition rate in the damped double well J. Phys. C Solid State Phys. 20 3621... 

Levine R D 1987 Fluctuations in spectral intensities and transition rates Adv. Chem. Phys. 70 53-95... 

If B Bq first-order perturbation theory ean be employed to ealeulate the transition rate for EPR (at resonanee)... 

In equation (bl. 15.7) p(co) is tlie frequeney distribution of the MW radiation. This result obtained with explieit evaluation of the transition matrix elements oeeurring for simple EPR is just a speeial ease of a imieh more general result, Femii s golden mle, whieh is the basis for the ealeulation of transition rates in general ... 

This chapter deals with qnantal and semiclassical theory of heavy-particle and electron-atom collisions. Basic and nsefnl fonnnlae for cross sections, rates and associated quantities are presented. A consistent description of the mathematics and vocabnlary of scattering is provided. Topics covered inclnde collisions, rate coefficients, qnantal transition rates and cross sections. Bom cross sections, qnantal potential scattering, collisions between identical particles, qnantal inelastic heavy-particle collisions, electron-atom inelastic collisions, semiclassical inelastic scattering and long-range interactions. 

Rule A. The transition rate (probability per unit tune) for a transition from state O of a quanPim system to a number p( ) of continuum states 4) by an external perturbation V is... 

Abstract. A stochastic path integral is used to obtain approximate long time trajectories with an almost arbitrary time step. A detailed description of the formalism is provided and an extension that enables the calculations of transition rates is discussed. 

Before elosing this ehapter, it is important to emphasize the eontext in whieh the transition rate expressions obtained here are most eommonly used. The perturbative approaeh used in the above development gives rise to various eontributions to the overall rate eoeffieient for transitions from an initial state i to a final state f, these eontributions inelude the eleetrie dipole, magnetie dipole, and eleetrie quadrupole first order terms as well eontributions arising from seeond (and higher) order terms in the perturbation solution. 

Applying the first-order eleetrie dipole transition rate expressions... 

IV. Time Correlation Function Expressions for Transition Rates... 

The golden rule is a reasonable prediction of state-crossing transition rates when those rates are slow. Crossings with fast rates are predicted poorly due to the breakdown of the perturbation theory assumption of a small interaction. 

Protein Computers. The membrane protein bacteriorhodopsin holds great promise as a memory component in future computers. This protein has the property of adopting different states in response to varying optical wavelengths. Its transition rates are very rapid. Bacteriorhodopsin could be used both in the processor and storage, making a computer smaller, faster, and more economical than semiconductor devices (34). 

That means that the transition rate is equal to the relative probability of being an activated reactant state times the average forward flux... 

Recently, Chandler and coworkers [46,47] revisited this idea and developed an elegant and promising methodology for the computation of reaction pathways and transition rates in molecular systems. 

In order that CLTST be valid, in addition to conditions (1.1) it is necessary that friction, while leaving the transition rate unaffected, should maintain thermal equilibrium in the initial state. This leads to the additional requirement... 

Markov modeling is a technique for calculating system reliability as exponential transitions between various states of operability, much like atomic transitions. In addition to the use of constant transition rates, the model depends only on the initial and final states (no memory). 

By denoting a -i and py as the forward and backward transition rates between the states y - 1 and y, respectively, the net transition rateJ between the states... 

In this model, it is assumed that, except for the first step that has transition rate pairs o and jSi, the following steps have the same transition rate pairs ot and 2- The net transition rates are ... 

In Eq. (12), the fourth term results from the increased volume available to the ends of the polymer chains on melting and the fifth term results mainly from the requirement that the ends of the molecules should stay out of the crystallites. Both terms are entropy terms giving the molecular weight dependence of the formation of bundle-like nucleus. Thus, the net transition rate J can be determined by the following equations ... 

In the primary nucleation stage of crystallization at small supercoolings and high pressures, the growth rate G and net transition rate J can be correlated by the following relation ... 

By using Eq. (12), the transition rates were chosen in the following way. 

Actually, we are always interested only in the transition probability per unit time to a group of final states with density pf = dnfldEf. This transition rate is given by... 

In an ensemble containing Nn(t) systems with patches of n stems and Nn+l(t) systems with patches of n + 1 stems at time t the flux (net transition rate) between the n,h and (n + l)th stages is ... 

Fig. 3.11. Illustration of fine- and coarse-grained approaches. There are m substages and their associated transition rates (small letters) corresponding to one stage...

However, the transition rates down and up are equal, as in Eq. (4.19), only in the high-temperature limit. In general the master equations are... 

We make use of the assumption which is conventional in kinetic theory of the harmonic oscillator [193] as well as in energy-corrected IOS [194]. All the transition rates from top to bottom in the rotational spectrum are supposed to remain the same as in EFA. Only transition rates from bottom upwards must be corrected to meet the demands of detailed balance. In the same way the more general requirements expressed in Eq. (5.21) may be met ... 

---