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The current-voltage (I-V) characteristics and the transmission spectrums of zigzag graphene nanoribbon with different spin-configurations are investigated by using the first-principles calculations. It is shown that the current-voltage curves and the transmission spectrums strongly depend on the spin-configurations of the two sides of the ribbon. For the spin-parallel configuration structure, the curve is linear under lower bias voltage; For the spin-antiparallel configuration structure, there is a strong spin-polarization-dependent transmission which implies the ribbon can be used as a spin filter; while for other spin-configurations structures, the curve has the characteristic of semiconductor. It is found that there is a large magneto-resistance(MR) when the bias voltage is small. The impurity in the central scattering region significantly influences the spin-dependent current and the spin filter efficiency, which may lead the large MR to disappear. 相似文献
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企业结构调整与优化是新时期企业形成市场竞争有时必须面对的问题。企业信息化建设是企业结构与调整的重要组成内容。本文讨论了信息企业化建设对企业结构调整与优化的重要作用,介绍了在企业结构调整与优化中企业信息化建设应解决的问题及任务。 相似文献
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介绍了利用新型砌块240mm厚混凝土小型空心砌块建造承重墙或作为多层房层外墙时,有关砌体设计和构造建设的技术和要求。最新提出了在U型砌块内放置水平钢筋现浇混凝土以形成墙内钢筋混凝土水平浇带的技术设想。 相似文献
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利用第一性原理研究了含有BN纳米点的扶手椅型石墨烯纳米带的电子结构和输运性质。研究发现,能带结构与BN纳米点的几何形状、尺寸以及纳米点浓度密切相关。由于电子-空穴对的对称性,使得费米能级附近的价带和导带几乎关于费米能级是对称的。对于含有三角形BN纳米点的石墨烯纳米带,当B和N交换时,价带和导带正好关于费米能级相互倒置。而且,由于C原子和多余B原子(或多余N原子)之间的轨道杂化,使得在费米能级附近形成一条局域的能带。另外,当电子在含有BN纳米点的石墨烯纳米带中输运时,在电导谱中会出现一系列的共振峰,其依赖于BN纳米点之间的距离和纳米点的形状。由此通过控制这些参数可以调制系统的电子响应。 相似文献
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The current-voltage(I-V) characteristics and the transmission spectra of zigzag graphene nanoribbon with different spin-configurations are investigated by using first-principles calculations.It is shown that the I-V curves and transmission spectra strongly depend on the spin-configurations of the two sides of the ribbon.For the spin-parallel configuration structure,the curve is linear under lower bias voltage;for the spin-antiparallel configuration structure,there is a strong spin-polarization-dependent transmission which implies that the ribbon can be used as a spin filter;while for other spin-configuration structures,the curve has the characteristics of a semiconductor. It is found that there is a large magneto-resistance(MR) when the bias voltage is small.The impurity in the central scattering region significantly influences the spin-dependent current and the spin filter efficiency,which may lead the large MR to disappear. 相似文献
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一种新型多模干涉型光子晶体波分解复用器 总被引:1,自引:1,他引:0
基于二维光子晶体中多模干涉效应(MMI)设计了一种新型的三波长波分解复用器,该结构能有效分离1310/1500/1550nm三个波段的波长。并且,当我们改变该波分解复用器的相关结构参数时,该结构能拓展至其他波段。除此之外,该结构也能单独作为两波长波分解复用器对1310/1550nm实现分离。通过计算,该波分解复用结构三个波长的透射率均在91%以上。与此同时,借助于平面波展开法及时域有限差分法,我们对光波在该结构的传播效率及传播行为进行了计算及模拟。 相似文献