共查询到20条相似文献,搜索用时 203 毫秒
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应用复平面波展开法对一维光子晶体的光子带隙, 透射特性进行了分析. 通过对色散关系和透射系数的数值计算发现一维光子晶体周期结构个数以及折射率分布对光学晶体透射系数以及光子带隙的影响. 对于含有整数个周期结构的光子晶体有共振点出现在光子帯隙外的频率范围内, 共振点的个数比周期结构个数少1. 带隙倾斜斜率等于折射率的比值. 折射率比值越大, 带隙的范围越大. 相似文献
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应用复平面波展开法对一维光子晶体的光子带隙,透射特性进行了分析.通过对色散关系表透射系数的数值计算发现一维光子晶体周期结构个数以及折射率分布对光学晶体透射系数以及光子带隙的影响.对于含有整数个周期结构的光子晶体有共振点出现在光子带隙外的频率范围内,共振点的个数比周期结构个数少1.带隙倾斜斜率等于折射率的比值.折射率比值越大,带隙的范围越大. 相似文献
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利用传输矩阵法研究了含特异材料的一维超导光子晶体的带隙特性. 研究表明, 这类超导光子晶体同样具有由传统的电介质材料构成的超导光子晶体一样的低频带隙, 且在一定的参数下该低频带隙可以相当宽. 但在一定的结构参数下, 这类超导光子晶体同完全由传统的电介质构成的光子晶体一样不存在低频带隙. 还就超导光子晶体的偏振特性、光子晶体结构参数及环境温度的变化对光子带隙结构的影响进行了研究.
关键词:
超导光子晶体
传输矩阵法
特异材料
光子带隙 相似文献
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V. Ya. Basevich A. A. Belyaev S. N. Medvedev V. S. Posvyanskii F. S. Frolov S. M. Frolov 《Russian Journal of Physical Chemistry B, Focus on Physics》2016,10(5):801-809
This study has been focused on the construction of a detailed kinetic mechanism of oxidation and combustion of isooctane (2,2,4-trimethylpentane) to describe both high-temperature reactions and the low-temperature multistage process with separated stages of “cool” and “blue” flames and hot explosion. In accordance with the proposed mechanism, isobaric autoignition, compression-induced autoignition, and flame propagation characteristics have been calculated; the calculation results have been compared with the experimental data. Satisfactory qualitative and quantitative agreement of the calculation and experimental results has been obtained. 相似文献
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针对近红外透射和吸收双光谱提出一种自适应的去噪方法。同步采集样品的近红外透射谱和吸收谱,在相同分解原则下总体经验模态法分解两组光谱,得到单组分特征模态分量。计算特征模态分量与原透射谱、吸收谱之间相关性,以及两组特征模态分量之间相关性,相关性最小模态分量初判为噪声分量。分析该分量在光谱中点处自相关性,若中点处很大,其他点几乎为零或很小,可以判断该分量为噪声。这种基于模态分量相关性的噪声判别方法称为“3R”法则。剔除噪声分量,重构光谱信号,循环上述分解过程,直到不满足“3R”法则,降噪过程结束。构造理想光谱,叠加噪声,“3R”法降噪效果优于EMD和EEMD低通滤波器,略逊于小波分解。真实光谱实验中,经过上述方法降噪处理过的玉米叶片光谱采用3层BP神经网络建立与叶绿素之间预测模型,“3R”法处理模型具有最大校正相关系数和预测相关系数,最小校正标准差和预测标准差。在四种降噪方法中,“3R”法对光谱谱峰位置和峰高的影响最小。实验表明,“3R”双谱去噪方法无需预设迭代次数,不用考虑分解层数,没有基函数,是自适应的,该方法适合近红外光谱去噪。 相似文献
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The rumpling of anions and cations in the (100) surface layer of various rockSalt-structure alkali halides has been calculated using a simple extension of an original model due to Verwey. It is shown that reasonable agreement with the results of more sophisticated calculations can be obtained when the interionic potentials used in the calculations are derived from shell model calculations based on the elastic properties of the various materials. The idea of a “Surface ionic polarisability” is proposed, and the results of its use in rumpling calculations compared with those obtained using conventional “bulk” polarisabilities. 相似文献
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V. V. Skobelev 《Journal of Experimental and Theoretical Physics》2017,125(6):1058-1064
With the use of the known solution of the Schrödinger equation for an electron in the nucleus field in the polar coordinates, the energy of a “two-dimensional” two-electron atom in the ground state, as well as its single ionization energy, has been calculated both in perturbation theory and with an almost century-old method of variation of the parameter Z in a trial wavefunction of the ground state. Since such two-dimensional atoms, e.g., helium atoms, can in principle be implemented in experiments by “freezing” of one degree of freedom in the phase of Bose–Einstein condensate, the conclusions made in this work can be tested. Fundamental features of the calculation of the energy of “one-dimensional” two-electron atoms and the formation of their Bose–Einstein condensate have also been discussed. The results obtained in this work coincide in a number of particular cases with the results obtained in a previous work, where some results were absent. 相似文献
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虽然用红外光谱显微探针方法研究岩心中碳质物已有很多工作,但是通常对诸如岩心等样品物性的光谱学微探针实验研究多是局限于对经过复杂处理分离出的微小样品或样品中个别位点所得的结果,缺乏对复杂样品各组分(或基团)的空间分布及其相互关系的研究。近年来新发展起来的光谱成像分析系统将光谱技术与成像技术有机地结合起来融为一体,可在光谱和空间两个方面对目标样品进行分析和识别并已得到广泛应用,但是用红外显微成像光谱研究岩心的工作则少有报道。文章报道了应用透射和衰减全反射(ATR)两种方式对含油岩心进行了显微红外光谱成像(Mapping)的研究。从灵敏度、信噪比、光谱分辨率和空间分辨率以及工作效率等方面对两种方式所得实验结果进行了比较和评估。 相似文献
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The multielectron theory of exchange interactions taking into account both electrostatic interactions between electrons (“potential” exchange) and electron transfer between magnetic centers (“kinetic” exchange) has been developed on the basis of Bogolubov's procedure using double irreducible operators. The final hamiltonian contains a number of isotropic and anisotropic terms. The exchange interaction parameter variations with the distance have been calculated. The terms determining the dependence on the occupancy of magnetic shells are shown to be of the same order of magnitude as the “potential” exchange and two orders of magnitude less than the “kinetic” exchange. It is shown that in the model adopted the mechanisms of direct exchange interactions always favour the antiferromagnetic spin ordering 相似文献
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Gilbert R. Hoy 《Hyperfine Interactions》2001,135(1-4):191-213
A new model for nuclear-resonant scattering of gamma radiation from resonant matter has been developed and is summarized here. This “coherent-path” model has lead to closed-form, finite-sum solutions for radiation scattered in the forward direction. The solution provides a unified microscopic picture of nuclear-resonant scattering processes. The resonant absorber or scatterer is modeled as a one-dimensional chain of “effective” nuclei or “effective” planes. The solution is interpreted as showing that the resonant radiation undergoes sequential scattering from one absorber “nucleus” or “plane” to another before reaching the detector. For recoil-free processes the various “paths” to the detector contribute coherently. The solution for this case gives calculated results that are indistinguishable from those using the classical optical model approach, although the forms of the solutions are completely different. The coherent-path model shows that the “speed-up” and “dynamical beating” effects are primarily a consequence of the fact that the single “effective” nuclear scattering processes are 180° out of phase with the incident radiation while the double nuclear scattering processes are in phase with the incident radiation. All multiple scattering paths are, and must be, included. The model can also treat the incoherent processes, i.e., processes involving gamma emission with recoil or conversion-electron emission. The source of the resonant gamma radiation can be from a radioactive source or from synchrotron radiation: both cases are treated. The model is used to explain and understand the results when each of the following experimental procedures is applied: time-differential Mössbauer spectroscopy, time-differential synchrotron radiation spectroscopy, enhanced-resolution resonant-detector Mössbauer spectroscopy, and the “gamma echo”. 相似文献
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提出了一种新型的基于非线性光纤环镜(NOLM)的可重构全光逻辑门实现方案。传统的基于NOLM的全光逻辑利用自相位调制效应或交叉相位调制效应,透射传输函数重构的自由度低,可实现的逻辑门种类较少。该方案在传统的结构基础上,分析了NOLM中探测光的偏振态的演化,以及输入光偏振态和环内偏振控制器对NOLM的传输特性的影响。理论分析和数值仿真结果表明在考虑NOLM中的非线性偏振旋转效应的情况下,可以更加自由地构建不同透射传输函数,从而利用单一NOLM结构,仅通过调节偏振控制器,即能够可重构地实现绝大部分基础组合逻辑。实验中,完成了两路40Gb/s的数据信号之间的"非"、"与"、"或"、"或非"、"同或"、"异或"等各种基础组合逻辑,验证了方案的可行性。 相似文献
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用密耦计算方法及T.T(Tang-Toennies)势模型分别计算了入射能量E=0.05 eV、0.15 eV、0.25 eV时He、Ne、Ar、Kr、Xe-T2碰撞体系的00-00弹性碰撞和00-02非弹性碰撞分波截面,结果表明:对00-00弹性碰撞,分波截面随量子数J的增加不断振荡, 并随入射原子的相对碰撞能量的变化,振荡极大值的位置、收敛分波数等均有不同的变化. 相似文献
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Angle resolved secondary electron emission spectra from tungsten contain fine-structure which to a large extent can be correlated with high density-of-states regions in the bulk band structure. In addition to such structure, strong “extra” peaks have been observed. The “anomalous” peaks, which are particularly dominating in the W{111}-spectra, occur when the “emitting” bulk Bloch state has a group velocity that equals the group velocity of the emitted electron. These particular peaks reflect structure in the transmission probability function and can only be explained by considering the wave-matching at the surface. 相似文献