GaAs／AlGaAs双势垒结构间接电子隧穿的研究

研究双势垒ＧａＡｓ／ＡｌＧａＡｓ结构在与时间有关的交变电场的作用下电子间接共振隧穿的几率和隧穿电流密度。采用转移矩阵方法给出电子在不同空间位置的波函数，用微扰的方法求出电子波函数的含时系数，最终给出电子隧穿几率和隧穿电流密度、计算结果表明电子隧穿几率曲线中出现附加的隧穿峰和隧穿峰变低，并且随穿电流密度曲线巾出现附加的隧穿台阶，隧穿峰变低和展宽，这主要是由于外加突变电场与Ｅ±ｎω的电子态耦合，为电子隧穿提供间接的通道和路径、这也是设计双势垒电子隧穿器件不可忽略的、上述方法也可以推广到多量子阶系统。     

M(POR)与M(PC)催化过程中的电子转移机理——电子的隧道迁移

本文是M(POR)与M(PC)类化合物催化作用的微观电子转移机理系列研究之一。简述催化过程基本特征,电子隧道迁移模型与主要结果。     

足球快速反击战术刍议

快速反击战术是当今足球比赛的重要特征之一，影响运动员快速能力的因素体现在跑速、动作结构、动作速率、传球速度等六个方面，足球比赛中应注重培养运动员的快速反击意识、节奏感和抢截能力。     

Self-assembled structure of alkyloxy substituted benzoic acid methyl ester on HOPG：An STM study

Self-assembled structures of 3,4,5-tris-dodecy-loxy benzoic acid methyl ester (E12), 3,4,5-tris-tetradecy-loxy-benzoic acid methyl ester (E14) and their mixture (E12/E14) have been studied on HOPG by scanning tunneling microscopy (STM). Dimer-like patterns induced by dipole-dipole interaction are observed in E12 and E14 monolayers. The molecules form close-packed rows and interdigitate with the alkyl chains in adjacent molecules. The structural differences are proposed to be from the different length of substituted alkyl chains. Owing to similar adsorption energy, phase separation is observed in the E12 and E14 mixed adlayer with different domains.     

Quick trickle permutation based on quick trickle characteristic sequence

0　IntroductionAblockcipherwithoutdataextensionorexpressionisaper mutation .Thesecurityofablockcipherschemeiscorrela tivewiththe permutations.Quicktrickle permutation[1 ] canmakethedatadisorderedwhenactingatthedataandmakeallprobabledistancebetweentwoelementsappear,soithasgoodcryptographicpropertiesandcanbeusedintheblockcipherwhichrequireshighsecurity.Aprivatekeyblockcipherisapermutationinn dimensionvectorspaceoverF2 atthecontrolofakey[2 ,3] .Moreover,manyblockciphersusepermutationstoexecuteso…     

Study of β—amyloid adsorption and aggregation on graphite by STM and AFM

The scanning tunneling microscopy(STM) and the atomic force microscopy(AMF) have been applied to the direct study of the adsorption and aggregation of β-amyloid(1-42)(Aβ42)on the hydrophobic graphite surface.It was found that Aβ42 were preferentially adsorbed on graphite defects such as the edges.Aβ42 peptides self-assembled into intermediate protofibrils,which in turn self-associated to form fibrils.Usually,two or more fibrils intertwined to form the helical structure.These results will provide an important clue to studying the aggregation process of β-amyloid.     

TBM工作原理及设备选型

结合山西省万家寨引黄工程中隧洞工程的实践,介绍了全断面掘进机(TBM)的工作原理及设备选型等问题。     

浅析从IPv4到IPv6的过渡技术

介绍了IPv4和IPv6,阐述了IPv4向IPv6的过渡的必要性,提出了IPv4向IPv6的过渡的方法以及各种方法的实际应用情况,提出了一些有关IPv4向IPv6过渡的建议。