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961.
Based on electro-optic switch effect in crystal, a novel laser ranging method is proposed. CW-laser emitted by laser transmitter propagates forward to the measured target, after being reflected by the target, and then goes back to the transmitter. Close to the transmitter, a special mono-block LiNbO3 crystal is added into the round-trip light beams. High-voltage pulses with the sharp enough changes in rising edges are loaded on the crystal. Based on electro-optic effect, double refraction and internal double reflection effect in crystal, the crystal cuts off the round-trip light beams, and reflects a light pulse cut out by the crystal to a detector aside from the original beam path. The pulse width T is the period that laser propagates forward and back between the crystal and the target. The feasibility of the new idea is proved by our experiments and a brand-new way for the laser ranging is provided. 相似文献
962.
Heping Yang 《Journal of Computational and Applied Mathematics》2006,190(1-2):287-303
In this paper, we study the singular perturbation problemwhere 0<ε1 is a small positive parameter, p(x) and q(x) are sufficiently smooth and strictly positive functions. The main feature of this equation is that there are two second-order turning points in the interval (0,1). Based on the rigorous results on singular perturbation problems with one second-order turning point in our previous work, we obtain a uniform asymptotic approximation for the general solution of the above equation by means of a matching technique. 相似文献
963.
We use analytic methods to analyze the discrete spectrum for the problem (Z1eZ2)2 in the united-atom limit (R ≪ 1) and obtain asymptotic expansions for the quantum defect and energy terms of the system (Z1eZ2)2 at small intercenter distances R up to terms of the order O(R6). We investigate the effect of the dimensionality factor on the energy spectrum of the hydrogen molecular ion H
2
+
.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 148, No. 2, pp. 269–287, August, 2006. 相似文献
964.
Steady free convection boundary layer about a truncated cone embedded in a porous medium saturated with pure or saline water at low temperatures has been studied in this paper. The governing coupled partial differential equations are solved numerically using a very efficient finite-difference method. Several new parameters arise and the results are given for some specific values of these parameters. The obtained results for a Boussinesq fluid are compared with known results from the open literature and it is shown that the agreement between these results is very good. 相似文献
965.
966.
HUANG Yuangqing 《Chinese Journal of Lasers》1998,7(1):11-16
StudyofaWaveguideCO2LaserwithTwoParalelTubesHUANGYuangqing(Dept.ofSci.Instr.andPrecisionMech.ofXiamenUniv.,Xiamen,361005,Chin... 相似文献
967.
K. Ramamoorthy M. Jayachandran K. Sankaranarayanan Pankaj Misra L. M. Kukreja C. Sanjeeviraja 《Current Applied Physics》2004,4(6):679-684
Intrinsic epitaxial zinc oxide (epi-ZnO) thin films were grown by laser-molecular beam epitaxy (L-MBE), i.e., pulsed laser deposition (PLD) technique using Johnson Matthey “specpure”-grade ZnO pellets. The effects of substrate temperatures on ZnO thin film growth, electrical conductivity (σ), mobility (μ) and carrier concentration (n) were studied. As well as the feasibility of developing high quality conducting oxide thin films was also studied simultaneously. The highest conductivity was found for optimized epi-ZnO thin films is σ=0.06×103 ohm−1 cm−1 (n-type) (which is almost at the edge of semiconductivity range), carrier density n=0.316×1019 cm−3 and mobility μ=98 cm2/V s. The electrical studies further confirmed the semiconductor characteristics of epi-n-ZnO thin films. The relationship between the optical and electrical properties were also graphically enumerated. The electrical parameter values for the films were calculated, graphically enumerated and tabulated. As a novelty point of view, we have concluded that without doping and annealing, we have obtained optimum electrical conductivity with high optical transparency (95%) for as deposited ZnO thin films using PLD. Also, this is the first time that we have applied PLD made ZnO thin films to iso-, hetero-semiconductor–insulator–semiconductor (SIS) type solar cells as transparent conducting oxide (TCO) window layer. We hope that surely these data be helpful either as a scientific or technical basis in the semiconductor processing. 相似文献
968.
Zhou Mingru 《Annals of Differential Equations》2005,21(4):639-647
This paper is concerned with boundary and corner layer behavior of the singularly perturbed Robin boundary value problem(RP) for the second-order nonlinear differential equations. The existence and asymptotic estimate of solutions of (RP) is discussed by appropriately constructing the bounding functions and using the theory of differential inequality. 相似文献
969.
970.
Effects of shaded facets on the performance of metal-coated etched diffraction grating demultiplexer
A finite-difference time-domain (FDTD) method combined with a periodic boundary condition is used to analyze the diffraction efficiency of an etched diffraction grating (EDG) demultiplexer coated with a metallic film at the backside. The numerical results show that the diffraction loss is mainly due to the scattering effect of shaded facets of a metal-coated grating at both the polarizations. However, the same shaded facets can produce a higher loss for a TM polarization than that for a TE polarization, which induces a higher polarization dependent loss (PDL) of the demultiplexer. 相似文献