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Initial population

In the excited state, the redistribution of electrons can lead to localized states with distinct fluorescence spectra that are known as intramolecular charge transfer (ICT) states. This process is dynamic and coupled with dielectric relaxations in the environment [16]. This and other solvent-controlled adiabatic excited-state reactions are discussed in [17], As shown in Fig. 1, the locally excited (LE) state is populated initially upon excitation, and the ICT state appears with time in a process coupled with the reorientation of surrounding dipoles. [Pg.110]

Special patient populations Initial and maintenance dosing should be conservative in patients with advanced age because of the potential for decreased renal function. Base any dosage adjustment on a careful assessment of renal function. Generally, do not titrate elderly, debilitated, or malnourished patients to the maximum dose. Do not initiate metformin IR and ER treatment in patients 80 years of age and older unless measurement of Ccr demonstrates that renal function is not reduced. [Pg.321]

Special populations - Initiate therapy in low doses (15 to 30 mg) in patients... [Pg.347]

Because the Stokes pulse precedes but overlaps the pump pulse, initially Up and all population initially in field-free state 11) coincides with flo(0)- At the final time, ilp Q5 so all of the population in flo(0) projects onto the target state 6). Note that flo(0) has no projeetion on the intermediate field-free state 5 ). The Rabi frequencies of the Stokes and pump pulses that are required for efficient STIRAP-generated population transfer satisfy the condition [66]... [Pg.78]

T. P. Softley There is little doubt that in most ZEKE experiments using nanosecond lasers the Rydberg level structure is so dense that a coherent superposition of levels is populated initially, and the correct description of the dynamics should be a time-dependent one. It is possible that some control over the dynamics could be achieved using some of the methods described earlier in the conference, for example, simultaneous excitation through three-photon and one-photon transitions, using third-harmonic generation. [Pg.723]

Since at t = 0 the first element of U and of U(3) is zero, then the two nontrapped adiabatic states are orthogonal to the initial state [fij) at the beginning of the process. > Hence, the only adiabatic state populated initially is the trapped state ) A, (r)). If there f is no coupling between the three adiabatic states, the system will continue to evolve t fas the trapped state [Ai (/)), executing an adiabatic passage to the E2) state as / t - oo. Thus we can achieve the control objective of complete population transfer k between two bound states. [Pg.203]

Figure 25 (upper plot) A schematic plot of the enantiodiscriminator. The three levels of each enantiomer are resonantly coupled by three fields. The dipole moments of the two enantiomers have opposite signs, (middle plot) The time evolution of the population of the three levels. The D and L enantiomers start in the 1) state. At the end of the process one enantiomer is found in the 3) state and the other in the 1) state, (lower plot) The time-dependence of the eigenvalues of the Hamiltonian of Eq. (73). The population initially follows the E0) dark state. At t rthe population crosses over diabatically to ) for one enantiomer and to E+) for the other. [Pg.96]

While a single-matrix element, T//, suffices for the simple TSA, an extended treatment may be required in cases of degenerate or quasi-degenerate initial and final states associated with open-shell reactants and/or products, since the ET process may then involve a distribution of thermally populated initial states and several possible final states. Even in such a multistate framework, it may be possible to cast the overall rate constants as a superposition of individual processes, each treated at the level of the TSA. [Pg.106]

Figure 2.3.3 also allows us to deduce the qualitative shape of the solutions. For example, if Figure 2.3.3 also allows us to deduce the qualitative shape of the solutions. For example, if <KI l, the phase point moves faster and faster until it crosses N = K/l, where the parabola in Figure 2.3.3 reaches its maximum. Then the phase point slows down and eventually creeps toward N = K. In biological terms, this means that the population initially grows in an accelerating fashion, and the graph of N t) is concave up. But after N = K/l, the derivative N begins to decrease, and so N(t) is concave down as it asymptotes to the horizontal line N = K (Figure 2.3.4). Thus the graph of N t) is S-shaped or sigmoid for TVg < K/l.
Something qualitatively different occurs if the initial condition lies between A /2 and K-, now the solutions are decelerating from the start. Hence these solutions are concave down for all z. If the population initially exceeds the carrying capacity (Nn > K), then N(t) decreases toward N = K and is concave up. Finally, if Nf = 0 or = K, then the population stays constant. [Pg.23]

In the reduced-dimensionality space the dynamics is treated exactly, e.g.. by the quantum coupled-channel approach. The remaining degrees of freedom are described in one of several approximate ways which will be reviewed below. The advantage of this approach is that it is feasible for systems of arbitrary complexity. In addition, it enables one to calculate cross sections, rate constants, etc. that are implicitly averaged over those degrees of freedom not explicitly treated dynamically, thus enabling a direct comparison to experiments which in most cases are not fully state-resolved. The degrees of freedom which are neither state-resolved experimentally nor treated dynamically will often be the same because they are usually the low-frequency motions such as rotation which are widely populated initially and finally in a collision. In the next section we shall review the elements of this theory for reactive systems with particular emphasis on resonances. [Pg.44]

The double differential of Eq. (A2.40) is still specific with respect to the initial states. All the populated initial states will contribute to the experimental observable in proportion to the probability of their being occupied. [Pg.550]

A tentative interpretation of these results may be based on the assumption that in this laser high rotational levels (J > 10) are indeed populated initially 71>. It should also be mentioned that two peaks in the rotational energy distribution are similarly observed in HC1 chemiluminescence experiments under conditions of partial rotational relaxation 9>. A simple rotational relaxation model suggested by Polanyi and Woodall 72) has been applied to fit these observations. In this model the probability P of the relaxation process J + AJ) / is given as... [Pg.47]

Thus, some males could acquire a disproportionate share of matings at the expense of other males. For the highly rapid, directional selection (selection for an extreme) of male courtship traits to proceed, first a small percentage of discriminating females and males with an appropriate trait must be present in the population. Initially, such characters may confer an advantage in reproductive rather than courtship success (Thornhill, 1979). After that, sexual selection could proceed on its own to produce more extreme male scent dissemination structures and increasingly selective females. [Pg.374]

Step 2 The population initialization, randomly generated pop size chromosomes. Since population size has a great influence on the results of genetic algorithm, in order to guarantee the diversity of population and to prevent... [Pg.73]

The classical version of DE algorithm consists of 4 main processes (1) population initialization, (2) mutation process, (3) crossover process, and (4) selection process. Mutation process and crossover process are veiy important processes since these two processes govern the perturbation of DE vectors. The interest of this paper is on the crossover process. The objective of crossover process is to increase diversity of the perturbed vectors. New trial vector is constracted from the mixing of the elements from target vector produced in the previous generation and the elements from the mutant vector according to the chosen crossover process. There are two commonly used crossover processes in DE, namely exponential crossover and binomial... [Pg.365]


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See also in sourсe #XX -- [ Pg.120 ]

See also in sourсe #XX -- [ Pg.142 ]




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