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The conductive path formed by the interstitial Ag or substitutional Ag in HfO2 was investigated by the Vienna ab initio simulation package (VASP) based on the DFT theory. The calculated results indicated that the ordering of interstitial Ag ions at special positions can form a conductive path while it can not form at other positions. Then the orientation dependence of this conductive path was investigated. Some types of super cells are also built to study the rupture of path, corresponding to some possible “off” states. 相似文献
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这篇文章证明了在图形、图像数据库中基于模糊集合的检索方法可以实现精确的检索和控制检索范围,达到控制连续语义变化检索的目的,并用模糊对象分层树的方法实现了图形、图像数据库中的模糊检索,最后给出一个例子。 相似文献
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Based on first principle calculations, a comprehensive study of substitutional oxygen defects in hexagonal silicon nitride (β-Si3N4) has been carried out. Firstly, it is found that substitutional oxygen is most likely to form clusters at three sites in Si3N4 due to the intense attractive interaction between oxygen defects. Then, by using three analytical tools (trap energy, modified Bader analysis and charge density difference), we discuss the trap abilities of the three clusters. The result shows that each kind of cluster at the three specific sites presents very different abilities to trap charge carriers (electrons or holes): two of the three clusters can trap both kinds of charge carriers, confirming their amphoteric property; While the last remaining one is only able to trap hole carriers. Moreover, our studies reveal that the three clusters differ from each other in terms of endurance during the program/erase progress. Taking full account of capturing properties for the three oxygen clusters, including trap ability and endurance, we deem holes rather than electrons to be optimal to act as operational charge carriers for the oxygen defects in Si3N4-based charge trapping memories. 相似文献
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从图像处理方法的角度对红外图像中小目标的检测、跟踪进行了研究,给出了系统总体设计框图,整个检测算法的前端图像滤波预处理采用FPGA实现,识别跟踪采用DSP实现。详细介绍了系统各功能模块的设计方法。实验表明该系统实现了小目标检测跟踪的功能,工作稳定可靠。 相似文献
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电荷陷阱存储器(CTM)由于其分离式电荷存储原理,可以使存储器件尺寸持续小尺寸化,理论上解决了传统浮栅存储器小尺寸化瓶颈的限制。基于第一性原理,从理论上对CTM材料及相关结构进行了模拟计算,采用Material Studio软件包,对多种电荷俘获材料进行改性,引入陷阱,并对其能带、状态密度、缺陷态密度等方面展开模拟研究。为CTM实验提供了非常有效的理论依据与方法,从该角度出发研究存储器是一个全新的视角,提出可以通过陷阱态密度曲线的部分积分来确定CTM的存储窗口等衡量指标。 相似文献
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本文详细地分析了LDD结构高温CMOS集成电路闩锁效应.文中提出了亚微米和深亚微米CMOS集成电路闩锁效应的模型.在该模型中,针对器件的尺寸和在芯片上分布情况,我们认为CMOS IC闩锁效应的维持电流有两种模式:大尺寸MOST的寄生双极晶体管是长基区,基区输运因子起主要作用;VLSI和ULSI中MOST的寄生双极晶体管是短基区,发射效率起主要作用.但是他们的维持电流都与温度是负指数幂关系.文章给出了这两种模式下的维持电流与温度关系,公式在25℃至300℃之间能与实验结果符合. 相似文献
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