Review on auxetic materials

Although a negative Poisson's ratio (that is, a lateral extension in response to stretching) is not forbidden by thermodynamics, for almost all common materials the Poisson's ratio is positive. In 1987, Lakes first discovered negative Poisson's ratio effect in polyurethane (PU) foam with re-entrant structures, which was named anti-rubber, auxetic, and dilatational by later researchers. In this paper, the term 'auxetic' will be used. Since then, investigation on the auxetic materials has held major interest, focusing on finding more materials with negative Poisson's ratio, and on examining the mechanisms, properties and applications. Therefore, more materials were found to have the counter-intuitive effect of auxeticity due to different structural or microstructrual mechanisms. The present article reviews the latest advances in auxetic materials, their structural mechanisms, performance and applications.     

驾束制导激光信息场的动态测试

本文根据驾束制导激光信息场的特点提出了一种新颖的在野外条件下快速检查激光信息场质量指标的方法,运用本方法可以在一个激光工作周期内检测出每一时刻信息场主要参数,测量快速操作简便.文中对测试系统组成、测试原理及数据处理流程进行了介绍.其设备可以作为制导装置系统的快速检测维护设备.     

架空避雷线分流变电站入地电流的简易计算

高压送电线路的架空避雷线因防雷直接联接到变电站和线路杆塔的接地网,从而也将变电站内接地故障的入 地电流分流到站外,减少站内的入地电流。本文对分流作用提出一个简易的计算方法,可供变电站设计时作参考。     

论电力基建企业实施质量、环境、职业健康安全一体化管理体系的可行性与有效性

本文作者以本单位的具体工作实践为依据,论述了在电力基建企业建立和实施“三标一体”管理体系的可行 性与有效性。     

ISA法铜电解槽槽面水平误差的控制

本文介绍了通过采用找平装置来控制ISA法铜电解槽槽面水平误差的方法,通过现场测量及工艺操作证明是行之有效的。     

CuO／CeO2 Catalysts for Selective Oxidation of Carbon Monoxide in Excess Hydrogen

CuO/CeO2 catalysts were prepared by a coprecipitation method and tested for CO removal from reformed fuels via selective oxidation. The influence of the calcination temperature on the chemical compositions and catalytic performance of CuO/CeO2 catalysts were studied. It was found that CuO/CeO2 catalysts exhibit excellent CO oxidation activity and selectivity, and the complete removal of CO is attained when the catalysts are calcined at appropriate temperatures. XRD, TPR and XPS results indicate that CuO/CeO2 catalysts exhibit higher catalytic performance in CO selective oxidation due to the strong interaction between copper oxide and cerium dioxide, which promotes the dispersion and hydrogen reduction activity of copper.     

欧盟SMP判定评估体系

随着市场开放竞争，各国电信管制者首先要面对的问题是如何防止在市场上具有支配地位的企业左右市场，破坏竞争。这个问题解决得好坏直接关系到电信市场开放竞争的有效性。针对这个问题，欧盟提出了SMP判定和评估体系，它是针对电信领域具有显著市场力的企业的认定程序和评估标     

Program Adaptation via Output-Constraint Specialization

In component-based software development, gluing of two software components is usually achieved by defining an interface specification, and creating wrappers on components to support the interface. We believe that interface specification provides useful information for specializing components. An interface may define constraints on a component's inputs, as well as on its outputs. In this paper, we propose a new approach to program specialization with respect to output constraints. We provide the form in which an efficient specialized program should be after such specialization, and consider a variant of partial evaluation to achieve it. In the process, we translate an output constraint into a characterization function for a component's input, and define a specializer that uses this characterization to guide the specialization process. We believe this work will broaden the scope of program specialization, and provide a framework for building more generic and versatile program adaptation techniques.     

A New Navigation Method for an Automatic Guided Vehicle

This paper presents a new navigation method for an automatic guided vehicle (AGV). This method utilizes a new navigation and control scheme based on searching points on an arc. Safety measure indices are defined and are generated from the output of a fuzzy neural network which define the actions the AGV is to take when in the presence of obstacles. The proposed algorithm integrates several functions required for automatic guided vehicle navigation and tracking control and it exhibits satisfactory performance when maneuvering in complex environments. The automatic guided vehicle with this navigation control system not only can quickly process environmental information, but also can efficiently avoid dynamic or static obstacles, and reach targets safely and reliably. Extensive simulation and experimental results demonstrate the effectiveness and correct behavior of this scheme. © 2004 Wiley Periodicals, Inc.     

Read/write mechanisms and data storage system using atomic force microscopy and MEMS technology

Information storage system that has a potentially ultrahigh storage density based on the principles of atomic force microscopy (AFM) has been developed. Micro-electro-mechanical systems (MEMS) technology plays a major role in integration and miniaturization of the standard AFM. Its potential application for ultrahigh storage density has been demonstrated by AFM with a piezoresponse mode to write and read information bits in ferroelectric Pb(Zr(x)Ti(1 - x))O3 films. With this technique, bits as small as 40 nm in diameter have been achieved, resulting in a data storage density of simply more than 200 Gb/in2. Retention loss phenomenon has also been observed and investigated by AFM in the piezoresponse mode. Finally, local piezoelectric measurements of PZT films by different processing technologies are discussed in detail.