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61.
T. J. Kim S. W. Lee B. K. Kang D. S. Kim A. S. Kim K. H. Shin M. K. Park Y. K. Sin 《Optical and Quantum Electronics》1995,27(5):465-471
High-quality and uniform bulk layers of (Al
x
Ga1–x
)0.5In0.5P (x=0–0.7) and AlGalnP/GainP quantum wells (QWs) are grown on 2°-off (100) GaAs substrates by low-pressure metal organic vapour phase epitaxy at a low growth rate of 0.3 nm s-1. The amount of lattice mismatch and the variation of PL peak energy of (Al0.5Ga0.5)0.5In0.5P on the 50-mm substrate are less than 6×10-4 and 2 meV, respectively. (Al0.5Ga0.5)0.5In0.5P/Ga0.5In0.5P SQWs show narrow PL spectra even from a 0.6 nm well measured at 20 K. The variation of PL peak energy from (Al0.5Ga0.5)0.5In0.5P/Ga0.5In0.5P MQWs is less than 10 meV. Also, as-cleaved AlGalnP/GalnP lasers fabricated by a three-step MOVPE show a pulsed threshold current of 82 mA at room temperature, output power of 12 mW, and the lasing wavelength at 668.2 nm. 相似文献
62.
We propose a color vision model that can be used to predict color appearance in mesopic vision as well as photopic and scotopic vision. It is based on a two-stage model which consists of the cone and opponent stages and it assumes rod intrusion at the opponent stage. The model has the following features to describe the color appearance in mesopic vision. First, it includes a gradual and nonlinear shift in spectral luminous efficiency from V (LD) to V (LD) to cope with the spectral sensitivity difference between photopic and scotopic vision and the nonlinearity of rod influence on the luminance channel. Second, the model assumes decrease of the chromatic component with decreasing illuminance to explain the reduction of saturation at low illuminance levels. Third, it assumes that red/green and yellow/blue components change with illuminance levels independently, thus explaining hue shifts with decreasing illuminance. We applied the model for color appearance simulation of natural scenes in a mesopic visual environment. 相似文献
63.
Jongho Shin Kyungsik Jang Ki-Soo Lim Ik-Bu Sohn Young-Chul Noh Jongmin Lee 《Applied Physics A: Materials Science & Processing》2008,93(4):1015-927
We report the spectroscopic properties of femtosecond laser-irradiated sodium-alumino-borate glass doped with silver and gold
ions. We precipitated gold and silver nanoparticles by laser irradiation and annealing at 400°C for 30 min. The irradiation
and annealing treatment produced different absorption and emission characteristics in Au3+ doped and Au3+, Ag+ codoped glasses, and the possible mechanisms of the observed results are discussed. The size of the nanoparticles was estimated
by TEM and absorption band analysis. 相似文献
64.
In this paper, we propose a method that controls the depth of the three-dimensional (3D) object existing over the depth-of-focus in integral imaging. The depth control method is performed only in a computer by synthesizing the intermediate sub-images between original sub-images obtained by transforming the captured elemental images. In the reconstruction process, we can obtain reconstructed 3D images with the better image quality within depth-of-focus than that reconstructed over the depth-of-focus. To demonstrate the feasibility of our method, optical and computational experiments are carried out and its results are presented. 相似文献
65.
Kikuchi Shin Koga Nobuyoshi Yamazaki Atsushi 《Journal of Thermal Analysis and Calorimetry》2019,137(4):1211-1224
Journal of Thermal Analysis and Calorimetry - Thermal behaviors of two different siliceous concretes used in a sodium-cooled fast reactor were comparatively investigated in a temperature range from... 相似文献
66.
K. Kanai T. Nishi T. Iwahashi Y. Ouchi K. Seki Y. Harada S. Shin 《Journal of Electron Spectroscopy and Related Phenomena》2009,174(1-3):110
Electronic structures of ionic liquids formed by 1-buthyl-3-alkylimidazolium ion [Cnmim]+ (n = 4 and 8) with various inorganic and organic anions have been investigated by ultraviolet photoemission, X-ray photoemission, inverse photoemission and soft X-ray emission spectroscopies (SXES). The comparison of the calculated density of states with the observed spectra revealed that the molecular orbital energies of these ionic liquids are significantly affected by the electrostatic Madelung potential among the ions. The SXES results clearly show that the both highest occupied and lowest unoccupied states of [C4mim]+PF6− are derived from the cation as a result of strong Madelung potential. On the other hand, the SXES results show the valence electronic structures of ionic liquids with larger anion molecules, [Cnmim]+Tf2N− and [Cnmim]+OTf− are contributed from the both cation and anion. 相似文献
67.
In earlier studies, one has successfully developed three different source methods (SSM, similar source method; IPSM, internal parallel source method; ISM, internal source method) to estimate radiation and scattering sound fields. All these methods are estimations of exterior sound fields. In the present study, the similar source method is modified to estimate an interior sound field. The modification is to move the imaginary sources outside the boundary surface. In addition, general boundary conditions in terms of acoustic admittance or impedance are considered by introducing the suitable least square error functions. Finally, a two-dimensional interior sound field with alternative boundary conditions is evaluated to simulate sound fields inside a car. The results are in agreement with those of boundary integral method. 相似文献
68.
Kong Hong Jin Lee Jae Yong Shin Yun Sup Byun Jae Oh Park Hee Su Kim Hyogun 《Optical Review》1997,4(2):277-283
Beam recombination characteristics were numerically investigated in array laser amplification using stimulated Brillouin scattering phase conjugation. To clarify the effect of piston errors due to imperfect phase locking, spatial intensity profiles of the beam recombination output were calculated in both the near and the far field on the basis of Rayleigh-Sommerfeld diffraction theory. The analyses indicate that piston errors are seriously detrimental to the quality of a beam recombination output and should be eliminated by a proper phase locking. It is also found that the gap between the beam splitting-combining wedges has a negligible effect.Presented at 1996 International Workshop on Interferometry (IWI ‘96), August 27-29, Saitama, Japan. 相似文献
69.
Hiroshi OKAMOTO Shin TAKASAWA 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2021,97(8):423
In pancreatic islet cell culture models and animal models, we studied the molecular mechanisms involved in the development of insulin-dependent diabetes. The diabetogenic agents, alloxan and streptozotocin, caused DNA strand breaks, which in turn activated poly(ADP-ribose) polymerase/synthetase (PARP) to deplete NAD+, thereby inhibiting islet β-cell functions such as proinsulin synthesis and ultimately leading to β-cell necrosis. Radical scavengers protected against the formation of DNA strand breaks and inhibition of proinsulin synthesis. Inhibitors of PARP prevented the NAD+ depletion, inhibition of proinsulin synthesis and β-cell death. These findings led to the proposed unifying concept for β-cell damage and its prevention (the Okamoto model). The model met one proof with PARP knockout animals and was further extended by the discovery of cyclic ADP-ribose as the second messenger for Ca2+ mobilization in glucose-induced insulin secretion and by the identification of Reg (Regenerating gene) for β-cell regeneration. Physiological and pathological events found in pancreatic β-cells have been observed in other cells and tissues. 相似文献
70.
Shin Ichi Aihara 《Acta Appl Math》1994,35(1-2):131-151
The purpose of this paper is to study the identification problem of a spatially varying discontinuous parameter in stochastic hyperbolic equations. In previous works, the consistency property of the maximum likelihood estimate (MLE) was explored and the generating algorithm for MLE proposed under the condition that an unknown parameter is in a sufficiently regular space with respect to spatial variables.In order to show the consistency property of the MLE for a discontinuous coefficient, we use the method of sieves, i.e. the admissible class of unknown parameters is projected into a finite-dimensional space. For hyperbolic systems, we cannot obtain a regularity property of the solution with respect to a parameter. So in this paper, the parabolic regularization technique is used. The convergence of the derived finite-dimensional MLE to the infinite-dimensional MLE is justified under some conditions. 相似文献