Component ratio, negative

The relationship between sensitivity and component ratio in copolymer negative resists was studied theoretically on the basis of Charlesby s gel formation theory. The formulas for sensitivity as a function of component weight ratio are derived for a nonchain reaction and for a chain reaction, respectively. Copolymer sensitivities for any component ratio can be estimated numerically using the derived formulas, from the data on sensitivities for homopolymers composed of individual constituent monomers in the copolymer. The calculated results are in good agreement with the experimental data reported. 

In the course of the research on copolymer negative resists, numerous experimental data on sensitivities have been reported as a function of component ratio in order to optimize each resist system. Summarizing these data, it is found that the relationship between sensitivity and component ratio can be divided into two groups. In one group, sensitivity increases steeply at first as the mole fraction of highly sensitive monomer in the copolymer increases, and then it tends to saturate. In the other group, sensitivity saturation does not occur. It has been presumed that these different dependences on component ratio result from the difference in crosslinking reaction scheme, i.e., a nonchain reaction or a chain reaction. 

In late 1985, radar observations of comet Halley, which was much more active than IRAS-Araki-Alcock, yielded echoes with a substantial broadband component presumed to be from a large-particle swarm, but no narrowband component, a negative result consistent with the hypothesis that the surface of the nucleus has an extremely low bulk density. In 1996, Goldstone obtained 3.5-cm echoes from the nucleus and coma of comet Hyakutake (C/I996 B2). The coma-to-nucleus ratio of radar cross section is about 12 for Hyakutake versus about 0.3 for lAA. The radar signatures of these three comets strengthen impressions... 

The phase-twisted peak shapes (or mixed absorption-dispersion peak shape) is shown in Fig. 3.9. Such peak shapes arise by the overlapping of the absorptive and dispersive contributions in the peak. The center of the peak contains mainly the absorptive component, while as we move away from the center there is an increasing dispersive component. Such mixed phases in peaks reduce the signal-to-noise ratio complicated interference effects can arise when such lines lie close to one another. Overlap between positive regions of two different peaks can mutually reinforce the lines (constructive interference), while overlap between positive and negative lobes can mutually cancel the signals in the region of overlap (destructive interference). 

Ueno et al. [172] observed that CuInSe2/Ti with a composition close to the stoichiometric ratio (slight excess of metallic components) could be deposited exclusively at a specific potential value (-0.8 V vs. SCE) from a pH 1 bath of uncom-plexed precursors at 50-55 A positive shift in the potential was seen to result in the co-deposition of a Cu3Sc2 phase (umangite), while a negative shift led to contamination by metallic indium. On the basis of measured electrolysis charge, the overall reaction of the optimum cathodic process was considered to involve the transfer of 13 electrons per mole of the product ... 

Membrane System Design Features For the rate process of permeation to occur, there must be a driving force. For gas separations, that force is partial pressure (or fugacity). Since the ratio of the component fluxes determines the separation, the partial pressure of each component at each point is important. There are three ways of driving the process Either high partial pressure on the feed side (achieved by high total pressure), or low partial pressure on the permeate side, which may be achieved either by vacuum or by introduction of a sweep gas. Both of the permeate options have negative economic impHcations, and they are less commonly used. 

If the same column is operated at a constant reflux ratio R, the concentration of the more volatile component in the top product will continuously fall. Over a small interval of time At, the top-product composition with respect to the more volatile component will change from xd to Xd + Axd, where Axd is negative for the more volatile component. If in this time the amount of product obtained is ADb, then a material balance on the more volatile component gives ... 

It is evident that at very negative potential values (compared to Eeq) the anodic component is zero, so that the current is due only to the reduction process. The inverse effect occurs for very positive potentials (compared to Eeq). On the other hand, moving away from the equilibrium potential in either direction, even only slightly, the current rises rapidly as a consequence of the exponential terms in the equation. However, at high values of q the current reaches a limiting value (yV), beyond which it can rise no more. This happens because the current is limited by the rate of the mass transport of the species Ox or Red from the bulk of the solution to the electrode surface, rather than from the rate of the heterogeneous electron transfer. Hence, one can say that the effect of the exponential factors in the equation is restrained by the ratios COx(0,t)/Cox and CRed(0,t)/C ed, which... 

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