Coulomb Blockade in Silicon Devices: Electronic Structure of Quantum Dots

This article presents a self-consistent 3D Poisson-Schrödinger calculation based on the density functional theory for silicon quantum dot under bias voltage. For various shapes and sizes of quantum dot surrounded by silicon dioxide, the energy levels and density are calculated as a function of the applied voltage and the number of stored electrons. The potential properties of such nanostructures for Coulomb blockade operation are deduced.     

220kV GIS组合电器施工中关键环节的控制

在晋丰220 kV变电站的220 kV GIS组合电器施工中,根据施工安装经验对几个关键环节进了专项控制,取得了非常好的效果。     

High Transition Temperature Superconducting Quantum Interference Devices: Basic Concepts, Fabrication and Applications

The performance of superconducting quantum interference devices (SQUIDs) and SQUID based magnetometers made from thin films of high transition temperature superconductors (HTS) has greatly improved since the discovery of HTS more than a decade ago. This fact is related to a steady improvement in the fabrication technology for HTS thin films and Josephson junctions. The state-of-the-art in HTS SQUID fabrication, device concepts and applications is briefly reviewed.     

工业计算机控制：过去，现在和未来（上）

工业计算机发展日新月异,其应用势头正旺,今天,几乎所有的工业自动化系统都是计算机控制系统。飞速发展的计算机技术,网络通信技术和自动控制理论,带来了日新月异,精彩纷呈的计算机控制系统。为此本刊特请这方面的专家肖建教授就计算机控制系统的发展历程、目前的水平和未来的发展,分别介绍了DCS, FCS和基于PC和PLC的自动化系统的系统结构、功能、它们各自的优、缺点和今后的发展动向分三讲进行介绍。     

The Use of Quantum Potentials for Confinement and Tunnelling in Semiconductor Devices

As MOSFETs are scaled to sub 100 nm dimensions, quantum mechanical confinement in the direction normal to the silicon dioxide interface and tunnelling (through the gate oxide, band-to-band and from source-to-drain) start to strongly affect their characteristics. Recently it has been demonstrated that first order quantum corrections can be successfully introduced in self-consistent drift diffusion-type models using Quantum Potentials. In this paper we describe the introduction of such quantum corrections within a full 3D drift diffusion simulation framework. We compare the two most popular quantum potential techniques: density gradient and the effective potential approaches, in terms of their justification, accuracy and computational efficiency. The usefulness of their 3D implementation is demonstrated with examples of statistical simulations of intrinsic fluctuation effects in decanano MOSFETs introduced by discrete random dopants. We also discuss the capability of the density gradient formalism to handle direct source-to-drain tunnelling in sub 10 nm double-gate MOSFETS, illustrated in comparison with Non-Equilibrium Green's Functions simulations.     

Optical and Electrical Properties of Colloidal Quantum Dots in Electrolytic Environments: Using Biomolecular Links in Chemically-Directed Assembly of Quantum Dot Networks

The threshold of the absorption spectra of colloidal cadmium sulfide (CdS) quantum dots in electrolytic solutions is shown to shift as the concentration of the electrolyte is varied. The shift in the absorption threshold as a function of the electrolytic concentration is given by electrolytic screening of the field caused by the intrinsic spontaneous polarization of these würtzite quantum dots. These electrolyte-dependent absorption properties are compared with Fermi-level tuning in carbon nanotubes in electrolytic environments.Moreover, concepts for integrating such colloidal quantum dots in high density networks with biomolecular links are discussed. Such biomolecular links are used to facilitate the chemically-directed assembly of quantum dots networks with densities approximating 10¹⁷ cm⁻³.     

Full Quantum Mechanical Simulation of Ultra-Small Silicon Devices in Three-Dimensions: Physics and Issues

The combination of the need for alternative devices and the improvement in process technology has led to the examination of silicon quantum wires for future MOS technology. However, in order to properly model these devices, a full three-dimensional quantum mechanical treatment is required. In this paper, we present the results of a three-dimensional, fully quantum mechanical, self-consistent simulation of a silicon quantum wire MOSFET (Metal Oxide Field Effect Transistor) with a narrow channel (8 nm). A quasi-standing wave is formed in the narrow channel at certain gate voltages as the electron density is trapped in narrow channel. These effects are the result of two competing effects: (1) the interaction of the propagating electrons with the channel dopants, as well as with the dopants in the source and drain of the device. (2) the reflections from the boundaries that form the narrow channel both on the source side and the drain side.     

工业计算机控制：过去，现在和未来（下）

三、基于PC和基于PLC的自动化系统在经济全球化的浪潮中,降低人力成本,提高生产率,缩短订单处理时间等已成为生产企业的不断追求。为了达到这一目标,它们越来越依赖于新一代的硬件和软件系统。近年来,由于个人计算机(简称PC)的高速率和对硬件与软件的几乎无限制的开放,使得PC的应用迅猛增长。将PC机CPU的高速处理性能和良好的开放性引入到计算机控制领域,形成了基于PC的控制系统。据有关机构和自动化系统生产厂商的预测,到2010年,基于PC的自动化系统在控制系统中将占有30%的份额,它将为工业自动化领域提供一种崭新的发展机遇。通用…     

工业计算机控制：过去、现在和未来（中）

二、现场总线控制系统虽然DCS系统在工业过程控制中取得了很大的成功。但是在实际应用中,还是普遍存在一些问题。主要表现在:(1) 网络只延伸到控制/传感层以前。I/O单元与现场设备的联系由点对点的4~20mA电流环通讯电缆实现,接线复杂。(2) 每个CPU都有固定任务,决策只能在最高层进行,对于下层很少授权,因此下层设备的主动性发挥不充分,在高层设备出现故障时,下层设备只能维持现状运行。(3) 整个体系必须协同工作,往往局部最优不一定全局最优,彼此的目标利益经常会发生冲突。(4) 底层各装置之间相互通信能力很差,接线复杂,各厂家设备互连…     

预测控制算法的研究现状及展望

本文简要回顾了预测控制的发展过程，对当前引起控制界广泛重视的几种预测控制算法进行了比较，着重对该领域的热点课题：鲁棒性问题、非线性系统控制、多变量系统控制、实用化问题和综合功能预测控制器的研究现状及发展趋势进行了讨论。     

PLC软件位置控制在初轧机自动位置控制(APC)系统中的应用

本介绍了引进设备初轧机压下和推床的自动位置控制（APC）的工艺要求及工作原理，提出了采用软件位置控制算法实现APC控制的实际应用。     

量子密钥分发的变电站间测控信号一次一密光纤传输方案

为了探索变电站间测控信号传输更理想的安全通信方式,解决量子密钥分发与一次一密结合中的工程实用化问题,提出了一种解决方案,将明文、密文和密钥都统一为标准的E1接口信号,满足真正的一次一密体制要求。量子密钥分发基于偏振态编码,采用诱骗态协议,能根据光纤信道的质量,通过选择压缩比1,128,1 024来调整量子密钥分发的速率,并支持中国和国际标准的商用密码加密算法。模拟仿真表明:与经典密钥分发系统相比,所提方案在机密性、完整性和可识别性等方面都具有优势,而且具备密性强化的独特性。     

微电网控制技术的研究现状及发展方向

提出微电网作为大电网的有益补充,已经成为众多国家解决电力系统安全性和可靠性问题的重要辅助手段。就微电网的研究现状特别是其控制技术进行了深入分析,基于目前已有的三类微电网经典控制方法,分析了并网和孤网两种不同运行模式下的控制策略,并对微电网研究中存在的问题和未来研究方向进行了探讨。     

The Effect of Tension on the Lateral Dynamics and Control of a Moving Web

Experimental studies of lateral motion of a moving web were carried out. For some typical operating conditions, it was found that the existing model does not properly describe the lateral behavior of the moving web with this simulator in the laboratory. It was found out that there is a critically correlated zone of operating conditions which exerts influence on the lateral behavior of the web, and that it is also associated with slippage phenomena between the moving web and a roller surface. If the web tension is not sufficiently high, the lateral dynamic motion is seriously related with web tension and increases lateral position error in a lateral position control system. A factor to describe the influence of the slippage on the lateral dynamic response of the web was derived based on a widely known traction-coefficient estimation model. The traction coefficient can be estimated from an air-gap thickness model with which slip condition can be determined. The slip condition is a function of web tension and speed and velocity of a roller. The ratio of the axial displacement of a guider roller and the lateral position of the web was measured in an open-loop condition for many different operating tension and speed, and the factor was fitted and verified from the experimental data which represents the effect of web tension on a lateral behavior of the web. Finally, the new factor was used in designing a cross-couple controller which includes the effect of operating tension or the variation of it on the lateral motion to properly regulate disturbances generated by web tension. The proposed factor is updated at each sampling period from measured signals such as web tension and velocity of web and roller, and used to calculate variable control gain     

时代集团：制造业的未来属于中国

只有越来越高水平的制造业的“夕阳产品”而没有“夕阳产业”，制造业永远是在进步，而不是衰退。     

对电力电子学的再认识——历史、现状及发展

该文通过对电力电子系统起源及定义的历史演绎,探讨了电力电子学的内涵和外延及其未来走向,分析了电力电子发展脉络、微电子与电力电子的关系及差异、以及电力电子未来的发展有可能给电能变换带来哪些实质性的变化。基于这些探讨分析,尝试提出一种对电力电子学的再认知框架,以使对电力电子系统建模、分析、设计及其控制的研究有一个更为清晰的背景和统一的基础。     

中国未来酸雨和SO2控制规划

介绍中国未来酸雨与ＳＯ２控制规划,其中包括降水酸度、城市ＳＯ２排放、ＳＯ２排放源和排放总量等控制目标,以及限制高硫煤开采与利用、加强动力煤洗选、促进ＳＯ２排放源控制及调整ＳＯ２排放源空间布局、实行排污许可证制度与交易政策和修订ＳＯ２排放标准。     

The Education and Training of Future Protection Engineers: Challenges, Opportunities, and Solutions

It is becoming increasingly clear that electric power systems are undergoing rapid changes due to deregulation, the penetration of new technologies, and the adoption of efficient computation, communications, and control mechanisms. The primary goal of this paper is to recognize the importance of education and the training of future protection engineers and, second, to suggest course content needed to meet this challenge.      

多功能测控装置实现关键技术研究

研究了面向间隔的多功能二次装置整合技术,提出一种基于多总线协作处理技术的多CPU组态架构、功能可灵活部署的多功能测控装置实现关键技术解决方案,并对测控测量功能、电力系统同步相量测量(PMU)功能、电度计量、电能质量以及故障录波功能的主要技术要求及特点进行归纳总结,为多功能二次设备功能集成融合提供了软硬件平台支撑。