共查询到20条相似文献,搜索用时 156 毫秒
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对变阻器在分压、限流电路中的负载特性进行了讨论,并对其调节灵敏度进行了分析,给出了实验结果,表明理论分析与实验结果较好的符合。 相似文献
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在分析"热线法"测定气体热导率原理的基础上,以干燥空气为例对其热导率进行了测量,用"线性外推法"进行数据处理,并用Origin7.0软件对测量结果进行了数据分析,可快捷精确地获得测量结果。 相似文献
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对负啁啾脉冲在正常色散光纤中的频域特性进行了实验研究,并对实验结果进行了数值分析,实验和数值分析结果基本一致. 相似文献
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本文用数值计算的方法对炽热平板点火问题进行了研究,并将计算结果与实验结果加以比较,在层流流动中与实验结果的吻合令人满意,在湍流流动中也进行了计算,并对结果加以了讨论。 相似文献
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We consider a model of convection in which five hydrodynamic modes interact. We show the existence of oscillations in which the sign of rotation of the rolls is periodically reversed. When the Rayleigh number is increased, these oscillations exhibit a sequence of period doublings which is not of the Feigenbaum type. 相似文献
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Peter K. Anastasovski T. E. Bearden C. Ciubotariu W. T. Coffey L. B. Crowell G. J. Evans M. W. Evans R. Flower S. Jeffers A. Labounsky D. Leporini B. Lehnert M. Mészáros J. K. Moscicki P. R. Molnár H. Múnera E. Recami D. Roscoe S. Roy 《Foundations of Physics Letters》1999,12(3):251-265
The general theory of gauge fields is used to develop a theory of electrodynamics in which the fundamental structure is non-Abelian and in which the internal gauge field symmetry is O(3), based on the existence of circular polarization and the third Stokes parameter. The theory is used to provide an explanation for the Sagnac effect with platform at rest and in motion. The Sagnac formula is obtained by considering the platform in motion to be a gauge transformation. The topological phases can be described straightforwardly with non Abelian electrodynamics, which produces a novel magnetic field component for all types of radiation, a component which is proportional to the third Stokes parameter. The theory provides a natural explanation for the inverse Faraday effect without phenomenology. 相似文献
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L. A. Apresyan 《Radiophysics and Quantum Electronics》1991,34(10-12):875-881
A classification is provided for the principal backscattering-enhancement mechanisms, which are divided into singleparticle and collective mechanisms, which, in turn, consist of geometrical mechanisms and mechanisms associated with phase coherence. A distinction is made between dynamic mechanisms, which appear in nearly all realizations, and statistical mechanisms, which are observed only after averaging. 相似文献
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D. M. Sedrakian D. A. Badalyan L. R. Sedrakyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2014,49(2):43-49
A problem of finding the energy of ground state of a quantum particle in a nanostructure with axial symmetry is considered. It is assumed that there is a point defect inside the nanostructure, which is given by δ-potential. A transcendent equation, which defines the lowest level of energy of the particle, is obtained. Corresponding formulas are used for calculation of the threshold frequency of interband absorption of light in semiconductor nanocrystals, which are dispersed in transparent dielectric matrix. Absorption spectrum edge dependence on location and power of δ-potential is obtained. It is shown that the effective length of the cylindrical nanocrystal is decreased in case of existence of δ-potential, which leads to increase in the threshold frequency of the optical spectrum of absorption. 相似文献
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A method of optically recording and reconstructing electrical signals in the form of one-dimensional holograms is described. For this purpose a pulsed laser beam is modulated according to the information to be stored. This beam is superimposed on a spatially and temporally constant reference beam, and the resulting interference pattern is recorded on a film which is moved past the light distribution. The one-dimensional holograms thus recorded appear arranged in narrow tracks which partially overlap.For reconstruction the film is driven past a spatially and temporally constant reconstructing wave. The illuminated holograms reconstruct a closely spaced chain of points which successively pass by a detector in which they produce an alternating current which, after appropriate amplification and filtering, presents the original signal. 相似文献
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A. M. Bonch-Bruevich T. A. Vartanyan S. G. Przhibel’skiĭ V. N. Smirnov V. V. Khromov 《Optics and Spectroscopy》2000,89(4):487-489
An experimental study is reported about the quenching of electronic excitation of Cs atoms caused by their collisions with a glass surface. The energy with which they are scattered from the surface after quenching has been measured to be 0.5 eV, which is about one-third of the excitation energy. A discussion is given of the mechanisms by which the excitation energy is partitioned between the atom and the surface in two different cases, namely, in the excitation of the atom adsorbed on the surface and in the collision of the preexcited atom with the surface. 相似文献
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Detection of cavitation in situ operation of kinetic pumps: Effect of cavitation on the characteristic discrete frequency component 总被引:1,自引:0,他引:1
Cavitation within a pump causes structural vibration with noise, among other by-products. Experiments have shown that there is a discrete frequency or broadband peak within the audible noise spectra, which is in strong correlation with the development of the cavitation process in the pump. Furthermore, the peak of the discrete frequency, or broadband peak, coincides with the net positive suction head (NPSH) critical value, which corresponds to a 3% drop in the total delivery head. Therefore, the discrete frequency tone can be used to detect the incipience of cavitation and its development as well as to determine the NPSH required or critical value with in situ operation of a pump. In this study, we wanted to clarify the mechanism of noise generation, which is responsible for the discrete frequency component and on which cavitation has an important effect. For this purpose, three different measurement methods were used: the first is based on measurement of the sound pressure level (SPL) in the surrounding air, the second is based on measurement of the underwater acoustics and the third is based on measurement of the structural vibration. Experiments have shown that the characteristic discrete frequency tone, which is in close correlation with the cavitation process, is a result of structural vibrations (modes) or resonances caused by implosion of bubbles and bombardment of the inner surfaces of the pump. 相似文献
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新近提出的光学色散元件"之"字形光栅具有优越的衍射特征,在光谱测量和分析中具有重要的应用价值.本文基于卷积定理,采用一种新的数值计算方法对应用于X射线波段的"之"字形光栅的衍射模式进行了模拟计算,并将其衍射模式与传统光栅以及正弦光栅的衍射模式进行了比对研究,结果表明:"之"字形光栅可以将高级衍射抑制到低于一级衍射四个量级的水平,具有比传统光栅优越得多的衍射模式,与理论预期结果一致.在此基础上,又分析了实际应用过程中吸收体对X射线的吸收情况给"之"字形光栅衍射模式带来的影响,最终证实了"之"字形光栅具有较强
关键词:
之字形光栅
卷积定理
衍射模式
光谱测量 相似文献