Principal maxima

In the usual treatment the apparent intensities of the rings play only a minor part, in that some use is made of them in the decision among models by qualitative comparison of photograph and curves. Numerical values of estimated intensities are needed for the new method it is found empirically, however, that the positions of the principal maxima are not very sensitive to changes in the estimated intensities, as long as the rings are kept in correct qualitative relation to one... 

In the calculations reported in this paper the curves were evaluated at intervals of 0.1 A. except in the neighborhood of the principal maxima, where smaller intervals (usually 0.02 A.) were used. The values of (sin si) /si were obtained from tables prepared by Dr. P. C. Cross with the aid of Sherman s (sin x)/x tables.7... 

The mean of the values given for the C=C distance by the four principal maxima is 1.339 A. A similar comparison for the four principal maxima with curve B gives 1.346 A, Considering also the radial distribution value 1.34 A., we accept for the C=C doublebond distance in allene the value 1.34 = = 0.02 A. the C-H distance was assumed to be within 0.04 A. of 1.06 A. and the H-C-H bond angle close to 109°28, their independent evaluation being impossible because of the small contribution of the C-H terms to the diffraction pattern. 

Once the efficiency of normal fluorescence had been determined, the efficiencies of phosphorescence and delayed fluorescence under the same conditions were derived without reference to any other solution. The ratio of the efficiencies of delayed fluorescence (6) to that of normal fluorescence was simply caculated by comparing the intensities at one of the principal maxima in the spectra, which were, of course, identical in shape. Due correction was made for the phosphorimeter factor (assumed to be 3 for lifetimes greater than 1 msec.) and also for the different instrumental sensitivities at which the two spectra were measured. Phosphorescence efficiencies were determined in a similar manner, except that the spectra first had to be corrected and the areas under the corrected curves compared with those of the corresponding normal fluorescence spectra. The phosphorimeter and instrumental sensitivity factors were then applied as before. 

Values of nc at the gas-liquid critical point aft derived from radii corresponding to the principal maxima in the radial distribution functions using relativistic wave functions. 

But the observed image is given by g (x ), which is plotted in Figure 1.12(c). Removing the central beam has made the heights of the subsidiary maxima equal to the heights of the principal maxima, and so the... 

Radii for the Qd transition elements are given by Fricke and Wdber (85). Their atomic and ionic radii were obtained using the principal maxima of the outermost electrons from DFS calculations. The metaUic radii were obtained by complicated extrapolations of comparisons of the experimental trends as well as of the calculated trends of the radii of the outermost s and d electrons, taking into accormt empirically the fact that the outer electrons become more or less itinerant conduction electrons and are distributed over the cr5 tal. 

The (photo)chemical and physical properties of fullerenes, spherical carbon molecules, are an important topic in current research, especially in nanotechnology. The molecule with 60 carbons, C(,o. having properties of an electron-deficient alkene, undergoes for example [2 + 2] photocycloaddition similar to aromatic moieties. The absorption spectrum of C[Pg.282]

APC tablets are a mixture of aspirin, phenacetin, and caffeine. Each of these substances has characteristic absorption in the ultraviolet region, with the principal maxima lying at 277 nm for aspirin, 275 nm for caffeine, and 250 nm for phenacetin. In the procedure, a powdered tablet is dissolved in methylene chloride, and the aspirin is separated from the phenacetin and caffeine by extracting it into aqueous sodium bicarbonate solution. The separated aspirin is back-extracted into methylene chloride by acidifying the aqueous layer and is then measured spectrophoto-metrically at 277 nm. The phenacetin and caffeine that remain in the original methylene chloride layer are determined in mixture as described in Chapter 16 (Equations 16.16 and 16.17). 

H stretching Vs Very broadband with two principal maxima and a shoulder V 3280 V 3490 v 3920 Very broad band with two principal maxima vw3615 vw 3746 Very broad band with principal maximum at vw 3439 Veiy broad band with principal maximum at vw 3583... 

There are thus N — I minima between two principal maxima. This implies N — 2 secondary maxima. Figure 3.5 shows for N = 11. 

This result can be accounted for by the fact that the principal maxima of have a value of iV and a width of 1/iV. Hence, for N large, converges towards... 

With increasing numbers of particles, the principal maxima becomes still narrower and higher. Thus a large one-dimensional lattice leads to discrete diffraction ma.xima whose width are related to the size of the lattice. The... 

Moreover in polyalkylazulenes these shifts are additive, e.g, azulene, 1,5-dimethylazulene and 1,8-dimethylazulene have principal maxima at 580, 623 and 599 nm respectively. In consequence extensive use has been made of visible spectra in the determination of structures of azulenes. These differences are associated with the different electron densities at the different sites in the molecule. 

UV stability studies indicate virtually no change in the chemical constitution of sucrose benzoate when it is subjected to prolonged exposure to a filtered, carbon arc light source at 140°F, The principal maxima of this light source is between 340 - 440 my. As noted previously, the Xmax, of sucrose benzoate is around 230 my which is well below the wavelength which will penetrate air. It is completely transparent above 300 my. 

This intensity distribution is plotted in Fig. 4.21 for two different values of the total groove munber N. Note that for real optical gratings 10 The principal maxima occur for which is, according to (4.23), equivalent... 

Color tests specific for higher molecular-weight polynuclear hydrocarbons and having their principal maxima in the very near infrared... 

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