ABSTRACT
A very favorable LUMO energy for cathodic electron injection is found in the crystalline state of the mesogenic red fluorescent perylene derivative 1. It is one of the rare cases where the columnar crystal structure of such a compound could be established directly by X-ray investigation.
Subject(s)
Fluorescence , Liquid Crystals/chemistry , Crystallography, X-Ray , Electron Transport , Models, Molecular , Molecular StructureABSTRACT
Thermal variations of the aperture of step-index optical fibers have been studied by measuring the transmitted power when a laser beam is launched with a variable incidence. For not too-long fibers only the rays launched with the higher incidence are affected. The variations of their transmittance have been accurately related to the refractive-index ones. Silicone clad silica fibers are sensitive to temperature because the silicone index varies much more the the silica index. On the contrary, due to a compensation phenomenon between index variations of core and cladding materials, PMMA core fibers have apertures that are nearly insensitive to temperature.
