Band fitting

Ethanol-dimethoxypropane solutions of either 1-formylisoquinoline or 2-formylquinoline thiosemicarbazone and cobalt(II) salts yield [Co(L)A2] complexes where A = Cl, Br, I, NO3, NCS, or NCSe [147]. All are non-electrolytes, have magnetic moments of 4.30-4.70 B.M. and are five coordinate with approximate trigonal bipyramidal stereochemistry involving NNS coordination based on electronic and infrared spectra. [Co(21-H)2] 2H2O was isolated from a cold methanolic solution of cobalt(II) chloride and 1-formylisoquinoline thiosemicarbazone [187]. Infrared spectral studies show NNS coordination the electronic spectral bands fit a distorted octahedral symmetry, and the magnetic moment is 4.48 B.M. 

Figure 3.20. TR spectra of fluoranil in 2-propanol obtained (after band fitting and deconvolution) at various time delays (Ap nip 355 nm, Apj bs 416 nm) (a) 10 ns, (b) 50ns, (c) 100ns, (d) 150ns, (e) 250ns, (f) 500 ns, (g) 1.3 ps, (h) 3.0 ps, [a] dots - original spectra and line-fitted spectra, [b] after the deconvolution of each band - the bands indicated as lines belong to the ketyl radical and the bands indicated as dots belong to the radical anion. See text for more details. (Reprinted from reference [91]. Copyright (1997), with permission from Elsevier.)...

Figure 5 Raman spectra of orthorhombic ethylene 1-hexene copolymer with band fitting. The crystalline band at 1,416 cm-1, and amorphous bands at 1,303 cm- and 1,080 cm- are used to compute the crystallinity content ac = 0.52, and the amorphous content aa = 0.42. (See Color Plate Section at the end of this book.)...

The F center in sodium fluoride (NaF) shows a broad absorption band that peaks at 335 nm (77 K). The shape of this absorption band fits a Huang-Rhys parameter of 28 and coupling with a phonon mode of 0.0369 eV. Estimate the peak position of the F center emission in NaF. 

Opaque minerals like iron oxides are frequently examined in the reflectance mode - and usually give diffuse reflectance spectra. Reflectance spectra provide information about the scattering and absorption coefficients of the samples and hence their optical properties. The parameters of reflectance spectra may be described in four different ways (1) by the tristimulus values of the CIE system (see 7.3.3) (2) by the Kubelka-Munk theory and (3) by using the derivative of the reflectance or remission function (Kosmas et al., 1984 Malengreau et ak, 1994 1996 Scheinost et al. 1998) and, (4) more precisely, by band fitting (Scheinost et al. 1999). 

There are also combination RO closures that have the metal shell and then a plastic TE band fitted into a holding collar shaped into the shell. This arrangement has the advantage that the plastic band can be a different colour from the shell and so can make it more evident whether the bottle has been tampered with. 

In the case of recoilless rifle projectiles, the rotating band is preengmved, with the band fitted to the projectile and containing grooves to fit the rifling of the weapon. The grooves are formed as part of the manufacture of the projectile... 

FIGURE 27 The temperature dependence of the upper critical field of YNi2B2C measured by susceptibility with applied field parallel to c at ambient pressure, 2.3, 3.3, 5.4,7.6, 9.0, and 11.7 GPa (from top to bottom). The solid lines correspond to two-band fits (after Suderow et al., 2004). 

Additional information can be obtained by XPS (X-ray Photoelectron Spectroscopy). Figure 14.7 shows the N(ls) core level spectra of samples, degassed at 973 K and 1123 K. The most important assignments are presented in table 14.2. The band fitting was based on a 10/90 linear combination of Lorentzian and Gaussian curves. 

Figure 2. Band-fits for the conducting band of LSCO of [6], corresponding to the Fermi surfaces of Fig. 1, illustrating the spectral weight transfer from the lower (oxygen) band to the resonant band upon doping...

In the spectra of macromolecules, the overlapping bands cannot be resolved by instrumental manipulation alone. Instead, mathematical techniques such as deconvolution, derivative spectroscopy, and band fitting are used for improving the spectral quality. 

Band fitting (curve fitting, or band shape analysis) is conveniently performed with commercially available software packages which fit, interactively or automatically, Gaussian or Lorentzian line shapes (or their combinations) to an unknown band profile. The applicability of this technique to lignin chemistry is not known at present. 

The rotational temperatures which are obtained from the Q—branch of the v = 0 — v" = 0 transition in the hydrogen spectra of Fig. 4.1 are Trot (X) = 6000 K and 4500 K for H2 and D2, respectively. Evaluation of the v = 1 — v" = 1 transition yields lower temperatures Trot(X) = 2000 K (H2) and Trot(X) = 1500K (D2) typically decreasing with increasing vibrational quantum number. Detailed experimental investigations of laboratory plasmas have shown that the v = 2 — v" = 2 transition should be used preferentially for gas temperature determination. For CH and CD molecules, the dissociative excitation mechanism contributes to the rotational population and therefore, Trot represents the temperature of the excited state only. Calculated spectra of CH and CD bands fit best to the measurements shown in Fig. 4.1 for Trot = 3000 K. 

Energy bands for germanium. Part (a) shows the LCAO bands fitted by Chadi and Cohen (1975), based on nearest-neighbor matrix elements. Part (b) shows the nearly-frce-electron bands. Two energy difTerences are shown in part (a) which can be matched immediately with part (b) to obtain predictions for the corresponding interatomic matrix elements. [After Froyon and Harrison, 1979.]... 

An external heater can be made by winding a length of fiat nichrome strip round the boiler, securing the ends with brass bands fitted with terminals and enclosing the heater in a layer of asbestos cloth. Sodium silicate is sometimes used to enclose the nichrome strip however, it attacks the glass and is therefore undesirable. 

Figure 1 Diffuse reflectance spectra of octahedral Ni2+ in the spinels Mg0.5Nii.5GeO4 (I) and ZnNiSn04 (II). Band fitting with the parameters given in the text for D3d and with B = 850 cm-1, C/B = 4.2 the A value for...

For the first reduction the IR shifts point to a porphyrin-centred electron transfer. This is supported by further spectroscopy on the anion radical complexes [(Por)Ru(CO)(L)]. The observed EPR lines are narrow, unstructured, with g values around 2. The UV-Vis-NIR spectra of the radical anions are characterised by redshifted Soret bands of reduced intensity, a weak structured band system around 600 nm and weak broad absorptions around 800 or 900 nm (see Figure 4.15). Further support comes from resonance Raman investigations on [(OEP)Ru(CO)(THF)] for which the observed Raman bands fit perfectly to those of the [(OEP)VO] radical anion. There is some evidence that if the spectroelectrochemistry is not carried out in very aprotic and unpolar solvents or traces of water are present, the radical anionic complexes are readily transformed. This has been investigated for the [(OEP)Ru(CO)(L)] system, where the use of solvents like MeOH or nitriles for the electrochemical reduction leads to altered species with unreduced porphyrin ligands (see Figure 4.15)." ... 

In addition to the band assignments, mathematical approaches such as deconvolution [85,86], band fitting [87], and derivatization [88] have been used extensively in the literature as aids to interpreting spectra. Althongh these techniqnes are generally useful, some have limitations or potential for introdncing artifacts [87], The nser of these approaches is cautioned and is advised to make informed choices. 

At least three classes of spectrum-fitting programs exist that are suitable for reducing line spectra to molecular constants the term-value method (Aslund, 1974), the direct approach (Zare, et al., 1973), and merging of separate band-by-band fits (Albritton, et al., 1977 Coxon, 1978 Tellinghuisen, 1996). 

The method of merging separate band-by-band fits can simplify the fitting process with no sacrifice in accuracy of parameter determination. One of the reasons for considering a simultaneous multiband fit is that parameter correlations and standard errors can be significantly reduced. The merge process takes the band-by-band fitted parameters and variance-covariance matrices and combines them to obtain global constants that are identical to those that would have been obtained from a global fit. 

Jack Bt ed Gun. (Ordnance.) One strengthened by bands fitted or shrunk on to the tube proper. It is now a common mode of making ordnance a good instance may be seen in the Broad-well gun, Eii iueerinr) xxi. IG. Also the Armstrong gun. 

The best method to use for the estimation of protein secondary structure involves band-fitting the amide I band. The parameters required, and the number of component bands and their positions are obtained from the resolution-enhanced spectra. The fractional areas of the fitted component bands are directly proportional to the relative amounts of structure that they represent. The percentages of helices, -structures and turns are estimated by addition of the areas of all of the component bands assigned to each of these structures and then expressing the sum as a fraction of the total amide I area. The... 

The FT-IR spectrum of MBP protein after reconstitution in myelin (with all proteins removed) was also recorded. The results of deconvolution and band-fitting the amide I band of MBP in myelin are shown in Figure 6.4b, with the corresponding data for. the frequency and the fractional area of each component being listed in Table 6.4b. 

How well do observed charge transfer bands fit this simple model The data suggest that the photosynthetic reaction center fits the model reasonably well and allow an extraction of Wg of approximately 200 cm. Cupane et al. also find (for hemoglobin) that the data for band III may be fit, yielding a value of Wg of about 240 cm However, they also find that the case of deoxymyoglobin is more complicated and is not consistent with the simple model. They find in addition that the solvent composition has a strong influence on the nature of the charge transfer band. 

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