ZnO single crystal thin films were grown on c-plane sapphire using oxygen microwave plasma assisted molecular beam epitaxy. Atomically flat oxygen-terminated substrate surfaces were obtained by pre-growth cleaning procedures involving an oxygen plasma treatment. A two dimensional nucleation during the initial growth which is followed by a morphology transition to three dimensional nucleation was observed by in situ reflection high energy electron diffraction. X-ray diffraction (XRD) and photoluminescence investigations suggest that the ZnO epilayer consists of a high quality layer on top of a transition layer containing a high density of defects in the interfacial region. A full width at half maximum (FWHM) of 0.005° is obtained for the ZnO(0002) diffraction peak in an XRD rocking curve, while a broad tail extending from the peak can also be observed. The photoluminescence spectra exhibit dominant bound exciton emission with a FWHM of 3 meV at low temperatures and free exciton emission combined with a very weak deep level emission at room temperature. Recently, these high quality ZnO epilayers have allowed the observation of optically pumped lasing at room temperatures as well as stimulated emission up to 550 K, both of which are due to an exciton related mechanism.

The structure of a stable decagonal quasicrystal with 0.4 nm periodicity, formed in a conventionally solidified alloy with composition Al 71.6 Ni 23.7 Fe 4.7 , was investigated by high-resolution electron microscopy. It was found that this decagonal phase is one of the best-ordered quasicrystals, without any detectable linear phason strain and with only weak random phason strain. The structure is interpreted as an aperiodic tiling of decagonal atom columns with a diameter of about 1.2 nm. The atomic arrangements in special local regions are discussed on the basis of computer simulations.

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In this paper, we propose a novel dehazing method for effectively enhancing complex texture regions by using entropy information. The proposed method improves a drawback of an existing method due to estimating an incorrect transmission map. The proposed method consisted of two steps. In the first step, for effectively estimating a transmission map, an entropy map is generated from YCbCr color space. Then, by applying a threshold value to the entropy map, an input image is divided into complex texture regions and others. In the second step, in order to generate a transmission map, an averaging filter is applied to complex texture regions. And two edge filters are applied to non-texture regions. Consequently, a correct transmission map preserving more details in complex texture regions is generated. Experimental results have shown that the proposed method achieves better performance of image dehazing than existing methods.

We study the spectrum of an asymmetric warped braneworld model with different AdS curvatures on either side of the brane. In addition to the RS-like modes we find a resonance state. Its mass is proportional to the geometric mean of the two AdS curvature scales, while the difference between them determines the strength of the resonance peak. There is a complementarity between the RS zero-mode and the resonance: making the asymmetry stronger weakens the zero-mode but strengthens the resonance, and vice versa. We calculate numerically the braneworld gravitational potential and discuss the holographic correspondence for the asymmetric model.