共查询到10条相似文献,搜索用时 140 毫秒
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The magnetic structure of the compensated ferromagnet-multiferroic interface has been considered. The law governing the decrease of distortions of magnetic order parameters with increasing distance from the interface has been found. An expression for the energy of interlayer interaction of magnetic order parameters has been derived, and it has been shown that its magnitude is determined by the exchange interaction. The condition for magnetization switching of the ferromagnetic layer by an electric field applied to the multiferroic layer has been formulated. It has been demonstrated that the magnetoelectric effect and weak ferromagnetism are not prerequisites to the development of electric field-switchable magnetoresistive memory. 相似文献
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An optically addressed parallel-aligned nematic-liquid-crystal spatial light modulator (PAL-SLM) has been studied as a dynamic phase-only modulation device. A computer control feature of the spatial light modulator is strongly desired for practical applications. For those demands, an electrically-addressable phase-only spatial light modulator has been developed to combine a liquid crystal display (LCD) with a PAL-SLM (LCD-coupled PAL-SLM) and its performance has been reported. However, a temporal characteristic especially two-dimensional (2D) response has not been discussed before. In this paper, 2D response analysis system has been constructed by using a high-speed complementary Metal-Oxide-Semiconductor (CMOS) camera (1000 frames/sec) and the 2D-modulation characteristic of the LCD-coupled PAL-SLM has been observed. As a result, the LCD has a spatially non-uniform modulation characteristic due to a scanning addressing. It has the potential to cause problems in high speed switching for a computer generated hologram. On the other hand, the spatial non-uniformity has not been observed with the LCD-coupled PAL-SLM. 相似文献
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The thermoluminescence of x-irradiated CaSO4: Dy phosphors has been studied for diverse activator concentrations. The concentration-dependence of these phosphors on the
increase of glow peak intensities has been found to be remarkable. For higher concentration of dysprosium the concentration
quenching effect has been observed. This has been attributed to the resonant transfer of energy from one activator atom to
another, bringing the possible migration of energy in a solid, which is likely to get dissipated without luminescence, at
the quenching site itself. The effect of irradiation time on the glow peak intensities reveals the initial linearity and a
subsequent decrease indicating the possible radiation damage. The role of Na2SO4 as a charge compensator has been studied in detail. An attempt has been made to unravel the type of kinetics involved in
the process, by calculating the activation energies by different methods. It has been concluded that the type of kinetics
involved in the process is bimolecular. 相似文献
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聚对苯撑亚乙烯/SiO2块状溶胶-凝胶非线性光学材料的研究 总被引:2,自引:0,他引:2
我们制作了一种由π-共轭聚合物聚对苯撑亚乙烯(PPV)均匀掺杂SiO2的块状溶胶-凝胶材料,该材料具有良好的光学品质和光学加工性能。通过扫描隧道显微镜(STM),紫外-可见吸收光谱和付氏红外光谱(FTIR)等方法研究了它的非线性光学特性。在对材料进行的光学两波耦合实验中,观察到了非对称能量耦合现象,并对此进行了分析。从吸光度和两波耦合衍射效率两方面对比了含PMMA和不含PMMA的两批不同掺杂浓度的PPV/SiO2 sol-gel材料的不同特性。 相似文献
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The phase-sensitive nature of polarization modulation instability has been demonstrated in optical fibers whose birefringence has been manipulated to generate phase mismatches. Quasi-phase-matched modulation instability has been demonstrated, and the gain of the quasi-phase-matched sidebands has been investigated. The results are in good agreement with experiment. 相似文献
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The effect of angular momentum on an excited paired nucleus has been studied. The BCS Hamiltonian, modified to include the z-projection of angular momentum has been diagonalized and expressed in terms of the quasiparticle occupation numbers. The grand partition function and all the relevant thermodynamical functions as well as the level-density expression have been derived for the general case of an arbitrary set of single-particle levels. Furthermore, the formalism has been applied to the uniform model and, whenever possible, analytical expressions have been derived. In particular the zero-temperature angular momentum dependence of the gap parameter, the critical angular momentum as well as the yrast line have been calculated. The critical temperature as a function of angular momentum, which defines the phase transition between paired and unpaired systems, has been calculated. A new effect called the thermally assisted pairing correlation, involving an increase of pairing with increasing temperature has been predicted. The completeness of the formalism as applied to spherical or deformed nuclei has been discussed. 相似文献
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Using M?ssbauer spectra and x-ray diffraction patterns, annealed mechanically alloyed Fe - Cu has been investigated in this paper. It is found that in [Formula: see text], after it has been milled, fcc-Cu has transformed into bcc-Cu, and some Cu atoms have diffused into the Fe. After the alloy has subsequently been annealed, it is found that bcc-Cu has transformed back into fcc-Cu, while the Cu atoms in the Fe have been separated. In [Formula: see text], after being milled, an fcc-Fe-rich phase has been formed, and after the alloy has subsequently been annealed, this has transformed back to bcc-Fe. The shorter the milling time and the higher the annealing temperature, the faster the transformation. In [Formula: see text], after it has been annealed, the fcc-Fe-rich phase has transformed to bcc-Fe also, and the fcc-Cu-rich phase remains when the annealing temperature increases. All of these results show that the fcc-Fe-rich phase in the milled samples is a metastable phase - it will transform to stable bcc-Fe when it is annealed - while the long-milling-product fcc-Cu-rich phase is a stable phase. 相似文献