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851.
Luis M. Murillo-Mora Katsuyuki Okada Toshio Honda Jumpei Tsujiuchi 《Optical Review》1994,1(2):195-197
An image processing technique to display a distortion-free reconstructed image from a rainbow type conical holographic stereogram is proposed. The method consists of forming a new set of 2D images from the original set by applying an image process. The image processing method is made through ray tracing equations. The results show that the performance of the proposed method is good as it removes distortion of the image. 相似文献
852.
We study third harmonic generation in layered configuration when the fundamental exhibits bistable response. We consider two
geometries, namely, a Fabry-Perot cavity with reflection coatings and a distributed feedback structure with alternate nonlinear
layers. In both the cases for suitable choice of frequency, the power response at the fundamental frequency is bistable. We
show that bistability of the fundamental leads to a multivalued character of the generated third harmonic in both the forward
and backward directions. Moreover, we study frequency response in the case of the Fabry-Perot cavity and show that additional
structures arise in the generated third harmonic due to frequency bistability of the fundamental. Our calculations suggest
the possibility of an all optical switch at third harmonic frequency controlled by the parameters (like intensity, frequency)
of the fundamental. 相似文献
853.
854.
A new methodology for the determination of the fluorescence quantum yield of dyes adsorbed onto microcrystalline cellulose is presented and applied to rhodamine 101, cresyl violet and auramine O. It is based on a previously reported method by Ruetten and Thomas (J. Phys. Chem., 1998, 102, 598-606), which is not applicable to the dyes used in the present study. It uses ground-state diffuse reflectance spectra obtained with and without filters, which prevents the luminescence of the dye from reaching the integrating sphere and the photodetector. New equations are presented here, correcting for the fluorescence emission of the dye, which depends on the detector sensitivity. Cut-on filters, which have a transmittance close to unity in the absorption region, and close to zero in the emission region, of the dye are used to obtain corrected reflectance spectra. The influence of the substrate was also taken into account. This methodology may be applied to other probes and surfaces or emissions of a different nature (i.e., phosphorescence or delayed fluorescence), and constitutes a very simple and general procedure to solve the important problem of luminescence quantum yield determination of probes adsorbed onto solid powdered surfaces. 相似文献
855.
Cesium-137 is a fission product of 235U and 239Pu. After a major nuclear accident, it is released into the atmosphere and in the far field region it will produce radioactively contaminated food and drinking water. This paper will study the specific activity of 137Cs in three Costa Rican export products: tuna fish, coffee and powdered milk. The average specific activities found are as follows: 0.89±0.41, 1.16±0.76 and 4.53±2.00 Bq kg−1. They represent low values compared to their derived intervention levels: 1.25 × 107, 1.25 × 107 and 2.44 × 105 Bq kg−1, respectively. 相似文献
856.
Roberto O. Aquilano Mario A. Castagnino Luis P. Lara 《General Relativity and Gravitation》1994,26(5):525-530
The conclusions of paper [2] are modified: using the shell formalism, relativistic effect could eventually be detected in X-ray bursters. 相似文献
857.
Nicolás de la Rosa-Fox Manuel Piñero Rocío Litrán Luis Esquivias 《Journal of Sol-Gel Science and Technology》2003,26(1-3):947-951
CdS semiconductor nanocrystals were grown as quantum dots (QDs) inside a silica matrix obtained by the sol-gelmethod and assisted in the mother liquid by high powerultrasounds. Small-angle neutron scattering (SANS) accountsfor a 3.6 nm crystal size homogeneously distributed. Optical excitation from the third harmonic of a Nd:YAG ns laser wasfocused on the sample to study the photoluminescence (PL) atroom temperature. The PL spectrum shows radiative processfrom intrinsic transitions and a broad band corresponding tothe traps. Variable stripe length (VSL) method was used to measure the optical gain spectra by the growth of theamplified luminescence. A broad optical gain spectrumproduced by the biexciton-exciton transitions revealing thestimulated emission from the CdS QDs. It is also observed ared-shift of the PL emission crystal size-dependent. 相似文献
858.
Luis Rodríguez-Marín 《Journal of Mathematical Analysis and Applications》2007,327(2):745-762
In this paper we analyze some questions concerning the contingent epiderivative. When the ordering cone is not necessarily pointed we introduce the notion of family of contingent epiderivatives. We also investigate the relationship between the contingent derivative and the generalized epiderivative. Furthermore, we give existence theorems with respect to Daniell cones. As a particular case, we study set-valued maps that take values in Rn. 相似文献
859.
The vapour pressuresof liquid cyclohexane + N, N, N′, N′-tetramethylalkanediamine, (CH3)2 N(CH2)uN(CH3)2 (u = 1,2) + cyclohexane mixtures were measured by a static method between 303.15 and 343.15 K at 10 K intervals. The excess molar enthalpies at 303.15 K were also measured.
The molar excess Gibbs energies, calculated from the vapour-liquid equilibrium data, and the molar excess enthalpies compare satisfactorily with group contribution (DISQUAC) predictions.
The proximity effect of N atoms produces a regular decrease of the interactional parameters. 相似文献
860.
An integral formula is derived, relating the six irreducible components of the intrinsic torsion of an SpnSp1 structure on a compact 4n-dimensional manifold with the Riemann curvature tensor. Some consequences of the formula are studied. 相似文献