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结合FMC标准与IEEE 802.3ae协议标准,设计了一种基于FPGA夹层卡(FPGA Mezzanine Card,FMC)标准的万兆以太网卡,满足现代工业大数据量传输应用的要求。FMC标准接口可实现多通道高速接口,解决应用母板与网卡之间的数据传输瓶颈。使用Verilog硬件描述语言设计了地址解析协议(Address Resolution Protocol,ARP)与用户数据报协议(User Datagram Protocol,UDP)的硬件协议栈,实现开放式系统(Open System Interconnect,OSI)模型的传输层;Xilinx 10 G Ethernet subsystem IP与小型化可热插拔(Small Form-factor Pluggable,SFP)光接口实现OSI模型的网络层、数据链路层、物理层。通过FMC母板、万兆以太网卡、PC上位机组建的网络成功测试了万兆以太网通信。 相似文献
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根据两种具有巨磁阻抗(GMI)效应的磁性材料实验样品,提出了两种理论模型(同轴电缆结构——Cu丝外覆软磁材料的圆柱形;三明治结构——Cu或Ag为中间层外包软磁层的三明治膜),利用Maxwell方程和Landau_Lifshitz方程对其GMI效应的机理进行了理论研究.证明了两种模型的差别仅仅是形状因子的不同,从而由理论上证实了两种结构GMI效应增强的内在一致性.证实了在同种磁性材料情况下,双层结构具有结构方面的优越性.并对照实验数据讨论了参数的影响,得到与实验定性相符的结果.
关键词:
巨磁阻抗效应
三明治膜
Maxwell方程
Landau_Lifshit 相似文献
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Investigation of ultra—thin ferromagnetic films with a simple cubic lattice 总被引:1,自引:0,他引:1
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Using Green‘s function method,we investigate ferromagnetic films with a simple cubic lattice containing up to ten monolayers.The Hamiltonian includes the Heisenberg exchange term,surface anisotropy (SA) and dipole interaction (DI).We calculate the magnetization as a function of temperature and film thickness,and we analyse the behaviour of spin canting.The result is in agreement with experiments.We calculate phase diagrams of SA versus DI to show the conditions under which spontaneous magnetization can occur.As a special case,we discuss the Heisenberg model without SA and DI. 相似文献
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A superconducting mechanism for K3C60 and Ba1-xKxBiO3 has been suggested. This is the combining picture of the Cooper pair and the Ogg pair. Numerical calculations within the framework of this picture have been done for K3C60 and Ba1-xKxBiO3, and the overall consistency with the experimental data of superconducting properties is good. 相似文献
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Effects of interplay between metal subwavelength slits on extraordinary optical transmission
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In this paper we study the extraordinary optical transmission of one-dimensional multi-slits in an ideal metal film.The transmissivity is calculated as a function of various structural parameters.The transmissivity oscillates,with the period being just the light wavelength,as a function of the spacing between slits.As the number of slits increases,the transmissivity varies in one of three ways.It can increase,attenuate,or remain basically unchanged,depending on the spacing between slits.Each way is in an oscillatory manner.The slit interaction responsible for the oscillating transmission strength that depends on slit spacing is the subject of more detailed investigation.The interaction most intuitively manifests as a current distribution in the metal surface between slits.We find that this current is attenuated in an oscillating fashion from the slit corners to the center of the region between two adjacent slits,and we present a mathematical expression for its waveform. 相似文献
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根据具有巨磁阻抗(GMI)效应的实际三明治样品的状况,提出三明治结构作为理论计算的模型,考虑了磁性层的各向异性场,利用一定边界条件下的Maxwell方程和Landau-Lifshitz方程对模型进行了理论计算,得到了阻抗与频率、各向异性场等因素间的函数关系.在此基础上,着重讨论了各向异性场Hk的作用.Hk的大小、方向均会对GMI效应造成影响,最佳的Hk应在400A/m左右,位于面内并与电流垂直.还证实了三明治结构中磁性层的磁致伸缩只会减弱G
关键词:
巨磁阻抗(GMI)效应
三明治膜
Maxwell方程
Landau-Lifshitz方程 相似文献
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本文提供了一个精确设计麦克斯韦速率分布演示仪的理论方法,可以精确计算出伽尔顿模板底部的滑行曲线.以铊原子蒸汽的麦克斯韦速率分布为实例设计演示仪,给出滑行曲线的解析式. 相似文献
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