Line width variations

An even more useful property of supercritical fluids involves the near temperature-independence of the solvent viscosity and, consequently, of the line-widths of quadrupolar nuclei. In conventional solvents the line-widths of e. g. Co decrease with increasing temperature, due to the strong temperature-dependence of the viscosity of the liquid. These line-width variations often obscure chemical exchange processes. In supercritical fluids, chemical exchange processes are easily identified and measured [249]. As an example. Figure 1.45 shows Co line-widths of Co2(CO)g in SCCO2 for different temperatures. Above 160 °C, the line-broadening due to the dissociation of Co2(CO)g to Co(CO)4 can be easily discerned [249]. 

Analysis of line width variation with respect to initial I and I2 concentrations gave values of... 

Figure 2.16, Scanning electron micrograph of resist images generated in a trilayer process. This figure shows the vertical walls and the absence of line width variations where the pattern crosses topographic features. Reproduced from reference 3. Copyright 1984 American Chemical Society)...

Figure 4. Line width variations versus Nxe for Col5 NaY-Tt.

The Use of 0.1-mm Cells. For routine use, we recommend the 0.05-mm sealed-demountable cells because some of their absorbances in 0.1-mm cells are in the nonlinear range for optical null instruments and the standard deviations rise significantly. Furthermore, a single sealed cell changes with continued use, particularly when some intractable spill samples may have traces of residual water. We have demonstrated that triplicate analyses of a No. 2 fuel oil show not even line width variations in a properly used sealed-demountable cell. 

Top antireflection coatings serve multiple functions reflectivity control (Fig. 9.1), defectivity control (although they can also be a source of defects), across-wafer line width variation control, improvement of process latitude... 

C.F. Lyons, R.K. Leidy, and G.B. Smith, Practicing the top antireflector process, Proc. SPIE 1674, 523 (1992) M. Gehm, P. Jaenen, V. van Driessche, A.M. Goethals, N. Samarakone, L. Van den Hove, and B. Denturck, Evaluation of methods to reduce line width variation due to topography for i line and deep UV lithography, Proc. SPIE 1674, 681 (1992). 

Table 2.4 tabulates some variations of overall thicknesses that can be configured with the previously stated four increments of tape thicknesses. This gradation of overall thickness coupled with line width variation results in the ability to meet a wide variety of impedance values. 

The NMR data from Sect. 7,1 were used and the alkyl radicals were trapped by y-irradiation of UPEC in vacuo (1.3 x 10 Pa) up to 3 Mrad. Irradiated UPEC was heat treated so that only the alkyl radicals were trapped. Line widths of ESR spectra observed at various temperatures were determined by comparing the observed spectra and the best-fitted simulated spectra at various temperatures. The alkyl radicals show a sextet ESR spectrum as repeatedly shown (e.g., Fig. 5.1.). Since ESR spectra of alkyl radicals in powdered materials show a so-called amorphous pattern caused by the anisotropy of the hyperfine splitting due to a-protons (refer to Sect. 2), computer simulation is indispensable in order to determine the true line widths. Variations of line widths of NMR and ESR spectra with temperature are shown in Fig. 8.1., in which the temperature dependence of hyperfine splitting of the ESR spectrum is also shown by open rectangulars to be described at a later point. 

Carrington, A., and H. C. Longuet-Higgins Mol. Phys. 5 Line width variations... 

Influence of orbitally degenerate states Saturation effects Line width variations... 

In fact, the suggested librational motion causes little change in the calculated splitting above 77 K. This, along with the line width variation, implies that the librational motion may be very fast above 77 K and therefore difficult to detect except at low temperatures. ... 

To explain the line width variation at 300 K, it is necessary to assume (] ) that the transitions occurring for radical I and II are averaged according to the scheme given in Figure 6 for the crystal directions H//b and H//c. Notably, at 300 K lines i, j, k and 1 can occur at the magnetic field observed, only if... 

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