共查询到18条相似文献，搜索用时 200 毫秒
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中国科学院物理研究所韩秀峰研究员带领的“自旋电子学材料、物理和器件”M02课题组,目前主要方向聚焦在巨磁电阻（GMR）和隧穿磁电阻（TMR）材料．物理及其器件原理的研究。该组自2002年成立以来,在国家基金委、科技部973项目、中科院知识创新工程等相关项目课题的资助下．逐步建立了巨磁电阻和隧穿磁电阻材料的制备和微加工实验平台．在磁性隧道结材料和隧穿磁电阻效应、巨磁电阻材料、 相似文献
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《内江科技》2015,(7):56-57
本文综述了黑洞ParikhWilczek量子隧穿辐射的发展,从黑洞霍金隧穿辐射开始,到Parikh-Wilczek量子隧穿辐射理论,再介绍了张靖仪、赵峥等人对此方法的推广。但最近蒋青权等发现,张靖仪、赵峥等人的方法存在缺陷。认为他们将无质量隧穿粒子和有质量隧穿粒子的测地线方程分别求解是不完美的,是与变分原理—第一原理相悖的。因此他们提出利用变分原理从同一个经典的Lagrangian作用量中自然地得到隧穿粒子的测地线方程,该方程能将无质量和有质量隧穿粒子的测地线方程统一地给出,克服了先前工作中将无质量粒子和有质量隧穿粒子测地线方程分别求解的缺点。值得注意的是,通过Lagrangian作用量来定义隧穿粒子测地线方程的方法是对Parikh-Wilczek隧穿方法做出全新的和重要的发展。 相似文献
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基于波函数匹配方法,研究了铁磁-非磁性杂质-铁磁系统的隧道结磁电阻,结果表明,在一定条件下两铁磁结之间分子场的存在导致了准束缚态的形成。当电子入射能量接近准束缚态能级时共振隧穿发生,在其电导中出现一个峰值。非磁性杂质和两铁磁体中的电子有效质量对微分电导有明显的影响,包括影响电导的幅度和共振峰的位置。 相似文献
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设计了一种万用表量程自动转换电路。该电路通过对被测电压的判断和量程选择器的控制,实现了在高精度仪表中量程的自动选择。电路选用低成本的普通元件,在有效范围内能实现电压自动测量。 相似文献
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阐述了巴克码组的定义和7位巴克码识别器的组成框图。在MAX PLUS2软件平台上,给出了利用现场可编程门阵列器件设计7位巴克码识别器电路,为了便于对设计的7位巴克码识别器进行检测,该电路还设计了一个周期为31位长的模拟7位巴克码产生器,并进行了编译和波形仿真。综合后下载到可编程器件EPF10K10LC84-4中,测试结果表明,达到了预期的设计要求。 相似文献
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This paper describes the main protocols that are used for fabricating microfluidic devices from glass and silicon. Methods for micropatterning glass and silicon are surveyed, and their limitations are discussed. Bonding methods that can be used for joining these materials are summarized and key process parameters are indicated. The paper also outlines techniques for forming electrical connections between microfluidic devices and external circuits. A framework is proposed for the synthesis of a complete glass/silicon device fabrication flow. 相似文献
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从适用于ＣＭＯＳ的开关－信号理论着手,建立了具有三值四态输出功能的ＣＭＯＳ输出级电路,提出了基于开关－信号理论指导三值四态门设计的方法和过程,经过ＰＳＰＩＣＥ计算机程序对设计的电路进行了模拟,结果俞垢电路具有正确的逻辑功能,良好的ＤＣ和瞬态性能。 相似文献
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We review the recent progress in the emerging area of devices and circuits operating on the basis of ionic currents. These devices operate at the intersection of electrochemistry, electronics, and microfluidics, and their potential applications are inspired by essential biological processes such as neural transmission. Ionic current rectification has been demonstrated in diode-like devices containing electrolyte solutions, hydrogel, or hydrated nanofilms. More complex functions have been realized in ionic current based transistors, solar cells, and switching memory devices. Microfluidic channels and networks—an intrinsic component of the ionic devices—could play the role of wires and circuits in conventional electronics. 相似文献
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《Information processing & management》2022,59(3):102930
DNS tunneling is a typical attack adopted by cyber-criminals to compromise victims’ devices, steal sensitive data, or perform fraudulent actions against third parties without their knowledge. The fraudulent traffic is encapsulated into DNS queries to evade intrusion detection. Unfortunately, traditional defense systems based on Deep Packet Inspection cannot always detect such traffic. As a result, DNS tunneling is one problem that has worried the cybersecurity community over the past decade.In this paper, we propose a robust and reliable Deep Learning-based DNS tunneling detection approach to mine valuable insight from DNS query payloads. More precisely, several features are first extracted by the DNS flow, and then they are arranged as bi-dimensional images. A Convolutional Neural Network is used to automatically and adaptively learn spatial hierarchies of features to be used in a fully connected neural network for traffic classification. The proposed approach may result in an extremely interesting task in predictive security approaches to attack detection.The effectiveness of the proposal is evaluated in several experiments using a real-world traffic dataset. The obtained results show that our approach achieves 99.99% of accuracy and performs better than state-of-the-art solutions. 相似文献
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从三值ＧａＡｓ逻辑输出级电路的等效开关模型出发,探索了适用于指导ＧａＡｓ极性变换电路的设计。设计的电路已用ＰＳＰＩＣＥ程序予以模型,结果表明,它们具有正确的逻辑功能与理想的瞬态特性。 相似文献
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通过对传统CMOS与绝热CMOS接口电路的研究,在分析传统CMOS信号和绝热信号的时序关系的基础上提出了三种传统CMOS到绝热CMOS(Traditional CMOS to Adiabatic CMOS,TC/AC)接口电路的设计方案,实现了将传统CMOS信号到绝热信号的转变。最后HSPICE模拟验证了所设计的三种TC/AC接口电路逻辑功能的正确性。 相似文献
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从电流型CMOS电路的特点出发,提出了混合开关理论,并将该理论应用于三值电流型CMOS电路的设计.此外,对所设计的极性变换电路利用SPICE程序进行了计算机模拟. 相似文献
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针对目前电子产品元器件贴装工艺高度普及、表面安装器件SMD大量被使用的现状,通过对表面安装器件SMD的介绍,分别研究了SMD分立器件、SMD集成电路以及大规模集成电路的贴装方式,对各种贴装方式加以比较,提出最佳贴装工艺方案。 相似文献