The dielectric properties of low porosity polycrystalline marble and granite rocks were investigated using broadband dielectric relaxation spectroscopy (10-2-106Hz) at fixed room temperature (295K). The water content of the specimens was varied between 0 and 0.22% (mass of absorbed water per mass of dry rock material %). The dielectric relaxation spectra were found to exhibit large low-frequency dispersion that depends strongly on the water content. A thorough study of this dispersion reveals that the main part of the enhanced ε* values originates from bulk effects.
The wave transmission through a one-dimensional fractal system is numerically studied. The fractal system is constructed by arranging delta-function planar reflectors with a given polarizability value based on the middle-third Cantor set. The correlation dimension of a set of wave numbers corresponding to complete transmission and the intensity of scalar waves inside the system are calculated. It is found that the correlation dimension of the set depends on the polarizability of reflectors, but not on the number of reflectors, and that the intensity becomes more than ten thousand times larger than that of incident waves in some confined regions of the system. These results suggest possible application to a laser with low threshold and wave-guides for light in optical integrated circuits.
Three-dimensional erasable optical recording in a single crystal of 1, 2-bis(3-methyl-2-thienyl)perfluorocyclopentene (1), which shows a reversible fluorescence change with the photochromic reaction, has been demonstrated. The recorded spot size read by a fluorescence-detection method was approximately 200nm in plane and 1.5μm in depth, which corresponds to the recording density higher than 5Tbit/cm3. The recorded spots were erased by irradiation with visible light. The writing/reading/erasing cycle could be repeated more than 104 times.