Absorption spectra parameters

The absorption spectrum parameters of 3at.%Nd Lu203 sample are listed in Table 1 and the emission spectrum parameters for Nd from the F3/2 to V, levels calculated according to A are listed in Table 11. 

Table 1. Absorption Spectrum Parameters of 3at.%Nd Lu203 Ceramic...

The values of the half-widths of the components of the rotational absorption spectrum of HC1, dissolved in various noble gases, are borrowed from [291]. In order to make this example obvious, a continuous curve is drawn through the calculated points. Comparison between experimental data and calculated results demonstrates, in line with the qualitative agreement, a good numerical coincidence of the observed. /-dependence of the half-widths of the rotational lines with the theoretical one in the case of HC1 dissolved in Kr and Xe. This allows one to estimate the model parameters for these systems dispersion of the potential... 

On this basis = 0.0170 sec , = 0.645 sec , and K = 0.739 mole.P at 25 °C. The corresponding activation parameters were determined also by Es-penson. By a method involving extrapolation of the first-order rate plots at various wavelengths to zero time, the absorption spectrum of the intermediate was revealed (Fig. 1). Furthermore, the value of K obtained from the kinetics was compatible with that derived from measurements on the acid dependence of the spectrum of the intermediate. Rate data for a number of binuclear intermediates are collected in Table 2. Espenson shows there to be a correlation between the rate of decomposition of the dimer and the substitution lability of the more labile metal ion component. The latter is assessed in terms of the rate of substitution of SCN in the hydration sphere of the more labile hydrated metal ion. 

Estimate, n - the value for a component concentration or property obtained by applying the calibration model for the analysis of an absorption spectrum v - this is also a general statistical term referring to an approximation of a parameter based upon theoretical computation. 

Once the UV-absorption spectrum of the compound to be irradiated — and whenever possible of the reaction product as well — is known, the main parameter to be selected is the excitation wavelength. In unsensitized — i.e. direct — irradiations the reaction product should not absorb any light as to avoid secondary photoreactions. The wavelength of the light used can be influenced by three factors the light source, filters and the solvent. 

An excitation-wavelength dependence at the longwave edge of the absorption spectrum has been observed not only for spectral displacement but also for other parameters such as lifetime, quantum yield and apparent rotational rate. Applications to the investigation of polymer rigidity and/or free volume, and to the study of biological systems and excited-state reactions have been developed. 

If the probe display shifts in absorption and/or emission spectra, the apparent dissociation constant will depend not only on the measured parameter but also on the excitation and emission wavelengths. For probes that display a shift in the absorption spectrum on analyte binding, the value of f/ bdepends on excitation wavelength, which affects the value of Koa (see Eq. (10.24)). For probes which display shift in emission spectrum the value of may depend on observation wavelength. The... 

A certain transition metal ion presents two optical absorption bands in a host crystal whose zero-phonon lines are at 600 nm and 700 nm, respectively. The former band has a Huang-Rhys parameter 5 = 4, while for the latter 5 = 0. Assuming coupling with a phonon of 300 cm for the two bands (a) display the 0 K absorption spectrum (absorption versus wavelength) for such a transition metal ion (b) display the emission spectra that you expect to obtain nnder excitation in both absorption bands and (c) explain how you expect these two bands to be affected by a temperature increase. 

A host material is activated with a certain concentration of Ti + ions. The Huang-Rhys parameter for the absorption band of these ions is 5 = 3 and the electronic levels couple with phonons of 150 cm . (a) If the zero-phonon line is at 522 nm, display the 0 K absorption spectrum (optical density versus wavelength) for a sample with an optical density of 0.3 at this wavelength, (b) If this sample is illuminated with the 514 nm line of a 1 mW Ar+ CW laser, estimate the laser power after the beam has crossed the sample, (c) Determine the peak wavelength of the 0 K emission spectrum, (d) If the quantum efficiency is 0.8, determine the power emitted as spontaneons emission. 

We used the dielectric function e of bulk MgO calculated from oscillator parameters determined by Jasperse et al. (1966), together with the dielectric function em of the KBr matrix given by Stephens et al. (1953) (corrected by June, 1972), to calculate the absorption spectrum (12.37) of a dilute suspension of randomly oriented MgO cubes. These theoretical calculations are compared with measurements on well-dispersed MgO smoke in Fig. 12.16c. Superimposed on a more or less uniform background between about 400 and 700 cm-1, similar to the CDE spectrum, are two peaks near 500 and 530 cm- , the frequencies of the two strongest cube modes. It appears that for the first time these two modes have been resolved experimentally. If this is indeed so we conclude that the widths of individual cube modes are not much greater than the width of the dominant bulk absorption band. Genzel and Martin (1972)... 

In Ref. 54, XRD showed the deposit to be hexagonal CuSe. Analysis of the absorption spectrum gave a direct bandgap of 2.02 eV. As commonly seen for these compounds, there was still strong absorption at lower energies (e.g., at 1.9 eV, the absorption coefficient was >7 X 10" cm ), possibly due to an indirect transition but likely due, at least in part, to free-carrier absorption. From Hall measurements, the doping (acceptor) density was ca. 10 cm (heavily degenerate) and the mobility ca. 1 cm V sec The dependence of film thickness and deposition rate on the deposition parameters has been studied in a separate paper [62]. 

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