Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Spectrum extended exponential

As already pointed out by Jauch [30], the series appearing in the exponential factor that modulates m (x) in (6) has a finite number of terms, and can therefore give rise to series termination artefacts. In particular, although the exponentiation will ensure positivity of the resulting density, series termination ripples will be present in the reconstructed map whenever the spectrum of the modulation required by the observations extends significantly past the resolution of the series appearing in the exponential. This in turn will depend both on the true density whose Fourier coefficients are being fitted, and on the choice for the prior prejudice. [Pg.19]

This generic procedure affords the powder EPR absorption spectrum, which should be differentiated to get the powder EPR spectrum. Note that the whole procedure consists of three nested loops with the computation of an exponential (Equation 4.8) within the inner loop. Coded in a higher language (C, FORTRAN95) and run on a standard PC, this program will generate the EPR spectrum of a simple S = 1/2 or an effective S = 1/2 system in a split second (of the order of 10 ms or less). It is, however, useful to think about ways to make it as fast as possible, because extending... [Pg.102]

Stability considerations also play a role in molecular ion formation. Figure 15 illustrates that the intensity of MC1+ and MBr+ signals varies approximately exponentially with the bond dissociation energy. The mass spectrum of ice is dominated by H+(H20)n cluster ions, and M+(MX)n and X (MX)n clusters prevail in the spectra of MX alkali halides with n extending up to at least 100 [16]. [Pg.56]

In order to describe the fluorescence kinetics at F (PS II centers closed), four exponential components were required. The corresponding DAS are shown in Fig. 1. The fastest component (t =100 ps) has been attributed to PS I previously (7,8). The second component (x =380 ps) has been resolved for the first time and together with the 1.34 ns and 2.08 ns component we attribute it, based on its spectrum and its dependence on the state of the PS II center, to PS II (8). No lifetime >2.1 ns could be resolved. Extending the fitting window from 6 ns to 18 ns yields virtually identical results, indicating the absence of any longer-lived fluorescence component within the limits of resolution. [Pg.443]

A typical high-harmonic spectrum is shown in Fig. 4.4 for the helium atom. The squares represent experimental data taken from [66], and the solid line was obtained from a calculation using the EXX/EXX functional [67]. The spectrum consists of a series of peaks, first decreasing in amplitude and then reaching a plateau that extends to very high frequency. The peaks are placed at the odd multiples of the external laser frequency (the even multiples are dipole forbidden by symmetry). We note that any approach based on perturbation theory would yield a harmonic spectrum that decays exponentially, i.e. such a theory could never reproduce the measured peak intensities. TDDFT, on the other hand, gives a quite satisfactory agreement with experiment. [Pg.176]

It is important to emphasize that the assumptions that Fpp is a constant and that the / manifold extends from —oo to oo are not essential for irreversibility but only for the simple single exponential decay (9.24). In fact, as discussed above, the spectrum Ei never extends to — oo because it is bounded from below by the ground state. A more general evaluation starts from and uses the identity (cf Eq. (1.71))... [Pg.310]


See other pages where Spectrum extended exponential is mentioned: [Pg.234]    [Pg.510]    [Pg.527]    [Pg.427]    [Pg.623]    [Pg.90]    [Pg.99]    [Pg.85]    [Pg.102]    [Pg.127]    [Pg.84]    [Pg.289]    [Pg.548]    [Pg.310]    [Pg.236]    [Pg.28]    [Pg.131]    [Pg.376]    [Pg.90]    [Pg.326]    [Pg.99]    [Pg.119]    [Pg.116]    [Pg.580]    [Pg.127]    [Pg.366]    [Pg.115]    [Pg.201]    [Pg.898]    [Pg.91]    [Pg.468]    [Pg.420]    [Pg.126]    [Pg.410]   
See also in sourсe #XX -- [ Pg.141 ]




SEARCH



Extended-spectrum

© 2024 chempedia.info