Line width broadening

The interaction of adsorbed thiol molecules with gold nanoparticles as a function of the mean particle size has also been studied [180]. Monochromated X-ray Photoelectron Spectroscopy (MXPS) measurements showed the attachment of the thiol sulfur headgroup onto the cluster surface leading to a positive BE shift in the Au 4f corelevel. No line width broadening could be observed indicating that the thiol-gold interaction affects the whole... 

Lineweaver-Burk equation, 14 627 Line widths, broadening, 23 131 Linewidth studies, 14 621-622 Linezolid, 3 26, 30, 36 17 733, 735 year of disclosure or market introduction, 3 6t... 

Fig, 26. Experimental dispersion curve of the Kr monolayer and measured line width broadening As of the Kr creation phonon peaks. The solid line in the dispersion plot is the clean Pt(lll) Rayleigh phonon dispersion curve and the dashed line the longitudinal phonon bulk band edge of the Pt(l 11) substrate, both in the r Mn azimuth which is coincident with the r Kk, azimuth. 

Similar studies on N-alkyl-substituted benzylamines show a sudden increase in line width broadening at a chain length of about Q (Figure 3.40). The sudden increase in strength of interaction corresponding to a n-value of about 3 is paralleled by a strong increase in negative inotropic activity [135],... 

Cation flux rates were assessed for 10 directly in phospholipid vesicles using a dynamic 23Na NMR method. In this procedure, addition of a Dy3+ shift reagent to an aqueous vesicle solution prepared in the presence of Na+ results in an external Na+ signal shifted with respect to internal Na+. With the incorporation of a channel former, the line width broadens, reflecting dynamic exchange between internal and external Na+ through the membrane channel. Consequently, the linewidth varies directly with cation flux and a plot of [channel] versus linewidth permits determi-... 

Line-width broadening may also be caused by other fast relaxation mechanisms in addition to a small particle size. For example, it is well known that, for spherical particles, radiation losses become more pronounced with increasing radius. In some metals, these relaxation mechanisms are so strong that a well-defined plasmon resonance is not observed, as in Fe, Pd, and Pt. Nanosized particles are interesting because the optical resonance can be designed in. For example, in a nanoshell consisting of a dielectric core surrounded by a metallic outer layer, the relative dimensions of these components can be varied. This, in turn, varies the optical resonance, possibly over several-hundred nanometers in wavelength. 

For dilute solutions, tI is large and the line width is narrow (on the order of Hz). As the solution viscosity increases, T2 decreases and line width broadens (in solids, line widths are 10 -10" Hz). For dilute solutions of small rapidly tumbling molecules Ti = T2 however, as the solution viscosity or the molecular weight increases, T2 decreases whereas T increases. 

Nuclear magnetic relaxation rates have been used to investigate the coordination number. In an investigation of the line-width broadening of La in various perchlorate solutions, Nakamura and Kawamura (1971) attributed the decreases in the values of (Av is the relaxation rate and is the relative viscosity) to a possible equilibrium between the nonahydrates and octahydrates for lanthanum ion. This conclusion was disputed by Reuben (1975) who proposed that this apparent anomaly reflected an erroneous estimate of the corrections of the linewidths for peaks due to the effect of the finite modulation amplitude and/or of partial saturation. Measurement of the transverse relaxation rates by the pulse method gave results consistent with a constant hydration number for lanthanum ion (Reuben 1975). 

ESR line width broadening (0.5 G) was observed on cooling to 77 K, probably due to a smaller libration motion of different parts of the polymer chains. The data obtained have no simple interpretation because at this frequency it is impossible to discern the difference between localized and mobile n -radicals with close magnetic parameters. 

In asphaltenes the hyperfine interaction is generally between the electron spin delocalized in an aromatic k orbital and the nuclear magnetic moments of H attached to the aromatic C. The line width broadening of the free radical cannot be attributed unequivocally to the unresolved hyperfine structure of the EPR spectrum. In petroleum asphaltenes, the effects of the aromaticity and the different degrees of substitution on the hne width and the line shape probably overlap, and different number of spins can also contribute to the line width by dipolar interaction (Scotti Montanari, 1998). 

Hydrogen Hydrogen is difficult to detect with many surface analytical methods. In HREELS, the adsorption of hydrogen and deuterium is relatively easy, both experimentally, and in first instance interpretation of the spectral features. In the case of hydrocarbons and other molecules, the CH, NH or OH modes are often studied. The CH modes in aromatic molecules are observed to be partially impact modes. Figure 7 shows several OH modes in particular it is possible to observe natural line width broadening for the 8(0-H) mode on Ag(llO) with the new high resolution spectrometers. 

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