五氧化二钽薄膜的制备及其I-U特性

本文利用脉冲直流反应磁控溅射的方法制备了五氧化二钽 (Ta2 O5)薄膜 ,俄歇电子能谱仪测试了薄膜的成分含量 ,椭偏仪测试了Ta2 O5薄膜的厚度和折射率 ,XRD分析了薄膜的晶体结构 ,并且分别研究了氧气含量、基底温度等成膜工艺对薄膜的影响。研究结果表明薄膜的成分主要是由氧气含量决定的。利用金属 绝缘体 (介质膜 ) 金属 (MIM)结构初步对Ta2 O5薄膜进行了电学性能的测试 :皮安电流电压源测试了薄膜的I U特性 ,制备出的薄膜折射率在 2 1～ 2 2 ,MIM的I U特性曲线显示了较好的对称性和低的漏电流密度     

网上查询选课系统及XML

从不同的角度来阐述新一代的Web语言－XML。     

Effect of magnesium content on the ageing behaviour of water-chilled Al-Si-Cu-Mg-Fe-Mn (380) alloy castings

A study of the effect of magnesium concentration on the ageing behaviour as measured by the hardness of 380 alloy was conducted for three levels of magnesium, namely 0.06 (base alloy), 0.33 and 0.5 wt%, for water-chilled castings (dendrite arm spacing ∼ 10–15 μm). Differential scanning calorimetry analysis of as-cast samples was carried out to determine the changes in the reactions of the phases obtained during alloy solidification, employing heating rates of 0.1 and 1.0°Cs⁻¹, up to approximately 700°C. Two heat treatments were applied to the as-cast alloys: T5 comprising ageing at 25 (room temperature), 155, 180, 200 and 220°C, for times up to 200 h, and T6 comprising solution heat treatment at 480 °C or 515°C for 8 h, followed by quenching in warm water at 60°C, followed by immediate artificial ageing at 155 or 180°C for varying times up to 100h. The results show that the higher hardness values obtained with T6 treatment can be explained by the excess precipitation of magnesium-containing phases in the as-solidified alloys. This precipitation could be eliminated under the high cooling-rate conditions prevalent in die-casting operations so that T5 treatment may be used to replace T6 treatment to produce the same hardness values. In addition, solution heat treatment in the low-temperature range (480–515°C) is adequate to produce the required changes in silicon morphology and dissolution of magnesium in the matrix. No significant difference in hardness behaviour was observed when the magnesium content was increased beyond 0.3 wt%.     

Possibilities and extension of XRD material response analysis in failure research for the advanced evaluation of the damage level of Hertzian loaded components

Due to clearly distinguishable damage symptoms, it is differentiated between the surface and sub‐surface failure mode of rolling bearings. Material states red out by X‐ray diffraction (XRD) residual stress measurements point to a variety of loading conditions especially at raceway surfaces that are associated with several competing failure mechanisms. The corresponding lifetime reduction can range from the lower fatigue strength region to material ratcheting in extreme cases. Relevant position of the microstructural changes and nature of the failure mechanisms are characterized. The time alteration of the XRD material parameters measured at or near the surface and at the depth of the maximum equivalent stress correlates, in a different manner, with the statistical parameter of the 10 % bearing life. Both failure modes are illustrated by concrete examples. Contaminated lubricant and boundary lubrication, which represent practically important surface‐induced failures, are discussed in more detail. Gray staining, i.e. shallow pitting, often occurs without distinct indication of global material aging by means of XRD characteristics. Here, scanning electron microscopy observations and electron microprobe analyses point to corrosion fatigue as acting surface failure mechanism. The interaction between material and lubricant under complex loading regimes particularly of mixed friction and corrosion opens further failure research areas in the field of tribology.     

可编程光学二值双轨逻辑门

基于双轨逻辑,本文提出一种可级联的并行二值逻辑门。所有十六种二值逻辑运算可以采用偏振半波相延编程来实现。也提出了用电光晶体实现实时编程的方法。本文中给出了实验结果。     

现代企业制度条件下企业管理的内涵

论述了在社会主义市场经济体制和现代企业制度条件下企业管理的主要内涵，提出了加强企业管理的途径和对策。     

降低精炼钢中氢氧含量的探索

主要介绍通过优化炼钢生产工艺,使产品满足新的技术要求:S≤0.010％,P≤0.015％.[H]≤0.0002％,[O]≤0.0045％,[N]≤0.0055％。     

First-principles study of the tensile and fracture of the Al/TiN interface

Employing the density functional theory, we investigate the tensile and fracture processes of the Al/TiN(0 0 1) interface. The simulation presents directly the strain–stress relationship, the ideal tensile strength and the process of bond breaking of the system. Through the analysis of deformation, we find that the softer Al layers deform larger than the harder TiN layers during the tensile process. And fracture occurs between the interface and the sub-interface Al layers. In addition, the results show that during the tensile process, the ripple of the interfacial TiN layer decreases gradually with the increment of the strain. Charge transfer was detected from the Al to TiN layers near the interface area during the tensile process by means of charge density and density of states analyses. The charge transfer affects the fracture process. Compared to our previous study of the Al/TiN(1 1 1) interface, the Al/TiN(0 0 1) interface has smaller work of adhesion and larger tensile strength than the Al/TiN(1 1 1) interface. Our investigation shows that the fractures of the Al/TiN(0 0 1) and (1 1 1) interface systems both happen in the Al layers near the interface.     

Hierarchical Self‐Assembly of Peptide‐Coated Carbon Nanotubes

Numerous applications, from molecular electronics to super‐strong composites, have been suggested for carbon nanotubes. Despite this promise, difficulty in assembling raw carbon nanotubes into functional structures is a deterrent for applications. In contrast, biological materials have evolved to self‐assemble, and the lessons of their self‐assembly can be applied to synthetic materials such as carbon nanotubes. Here we show that single‐walled carbon nanotubes, coated with a designed amphiphilic peptide, can be assembled into ordered hierarchical structures. This novel methodology offers a new route for controlling the physical properties of nanotube systems at all length scales from the nano‐ to the macroscale. Moreover, this technique is not limited to assembling carbon nanotubes, and could be modified to serve as a general procedure for controllably assembling other nanostructures into functional materials.     

A fuzzy-based impulse noise detection and cancellation for real-time processing in video receivers

In this paper, a simple fuzzy-based algorithm to remove the impulse noise from images is proposed. To achieve real-time applications, the proposed filter architecture, which combines fuzzy noise detection and noise filtering, is also designed. With low computational complexity, simulation results show that the proposed filters effectively remove the impulse noise.