Color center: also surface

Since its formulation, solid state theory has been concerned also with non-strictly-periodic systems, due principally to the theoretical and technological importance of defects (point impurities, color centers, dislocations, surfaces, etc.). However, most of these theoretical studies and approaches exploit the results of the ideal periodic crystal as the basic ingredient on which to include impurity effects. 

In order to accurately determine the speed of the flash-across phenomenon, the experiment was repeated and recorded by streak camera with color film. Also thinner SPHF plates were used. In the streak camera trace, 8.5 (isec after each initial wave entered the NM, a hot spot appeared at the surface of each plate and flashed to the center of the chge each at the phenomenal speed of 35 mm/fisec. Cook (Ref 3) considers the flash-across phenomenon to be the heat pulse predicted by M.A. Cook, R. Keyes A.S. Filler (Ref 1)... 

The fulvene route was also successfully employed in the preparation of a compound, which can be regarded as one of the most advanced molecular models for a catalytically active titanium center on a silica surface. When Cp Ti(C5Me4CH2) was reacted with the monosilylated silsesquioxane precursor 12 in refluxing toluene a color change from deep purple to amber was observed. Crystallization afforded a bright-yellow material, which was subsequently shown to be the novel mo o(pentamethyleyclopentadienyl) titanium(IV) silsesquioxane complex 126 (69% yield). Its formation is illustrated schematically in Scheme 42. 

Fig. 17A (see color insert) shows a ribbon model of the rhodopsin structure indicating the residues assigned to the interface in each helix by a sphere centered on the corresponding of-carbon. Also shown is a sphere on the a-carbon of residue 314, which is located in the interface (see Section III,F). Clearly, these residues define a unique plane of intersection of the molecule with the membrane-aqueous interface. The shaded band in Fig. 17 represents a phospholipid bilayer with a phosphate-phosphate distance of 40 A, the expected thickness of the bilayer in the disk membrane (Saiz and Klein, 2001). The outer interface of the bilayer is positioned so that the polar head groups coincide with the intersection plane defined by the data in Fig. 16. This procedure then fixes the intersection plane of the molecule on the extracellular surface as well.

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