An Analog Front‐End Circuit for ISO/IEC 14443‐Compatible RFID Interrogators

An analog front‐end circuit for ISO/IEC 14443‐compatible radio frequency identification (RFID) interrogators was designed and fabricated by using a 0.25 µm double‐poly CMOS process. The fabricated chip was operated using a 3.3 Volt single‐voltage supply. The results of this work could be provided as reusable IPs in the form of hard or firm IPs for designing single‐chip ISO/IEC 14443‐compatible RFID interrogators.     

三平板剪切干涉仪自动测试系统

三平板剪切干涉仪是环路剪切干涉仪中最简单的一种,它具有基本等光程、剪切量连续可调、两出射光束恒相互平行等特点。利用三平板剪切干涉仪对激光器出射波面质量进行检测,探讨了由剪切干涉图复原原始波面的1阶微分法,编制了专家辅助软件系统,为光机型的三平板剪切干涉仪配置了实时图像采集、处理系统,实现了光、机、电、算相结合,融硬、软件于一体的数字波面剪切干涉仪,并通过实验验证了方法的重复性精度。     

律师统战工作初探

律师的思想政治特征状态及发展趋势，关系到律师行业的健康发展，影响着改革开放和社会经济发展的大局，左右着建设社会主义法治国家的进程。对此进行认真分析是做好律师统战工作的基础和前提。通过从思想观念、政治态度、道德认识、价值取向等层面分析了律师的现状和特征，揭示了团结、帮助、教育、引导律师对做好律师的统战工作的重要意义。     

加强农建工作 建设和谐围场——围场满族蒙古族自治县“十五”农建工作总结与展望

对围场县“十五”农建工作取得的成就和经验、体会进行了总结，阐述了农建在当地农村经济中的重大支撑作用，并对“十一五”农建工作进行展望。     

Determination of gas dispersion in vapor extraction of heavy oil and bitumen

In this work, a mathematical model is developed and simulated to determine gas dispersion along with solubility during the vapor extraction (Vapex) of live oil from a laboratory scale physical model. The physical model is a rectangular block of homogenous porous medium saturated with heavy oil and bitumen. At a given temperature and pressure, the block is initially exposed on its side to a solvent gas, which diffuses into the medium and gets absorbed. The absorption of gas reduces the viscosity of heavy oil and bitumen causing it to drain under gravity. The low-viscosity “live oil” is produced at the bottom of the porous block. The production of live oil with time is accompanied by the shrinkage of oil in the block as well as its increased exposure to gas from top. These phenomena of Vapex are described by the mathematical model, which is used to calculate live oil production with various values of gas solubility and dispersion. Their optimal values are determined for the vapor extraction of Cold Lake bitumen with butane by matching calculated live oil production with its experimental values published earlier.     

钢丝绳抽油杆抽油超冲程分析

通过对钢丝绳抽油杆和常规钢杆振动模型固有频率的分析，从理论上分析了钢丝绳抽油杆和常规钢杆振动形成谐振(超冲程)的奈件；同时讨论了振动阻尼系数对共振的影响关系，从理论上得出了钢丝绳抽油杆在抽油时更易形成超冲程，进而从理论上解释了钢丝绳抽油杆在抽油过程中的泵效较高的事实，进一步解释了当前人们对钢丝绳应用和研究中的一些疑点和难点，为钢丝绳抽油系统的设计和应用提供了重要的理论指导。     

化纤大型设备支承钢结构的设计与校核

通过大型结构设计及安装实例,演绎各要求计算及校核方法,并对此设计有较好评价,具有推广意义。     

近距离坚硬顶板薄煤层开采支护技术

近距离薄煤层在准备采煤工作面时的巷道掘进中,受上层残余压力的影响,矿压显现突出,采用常规的巷道支护方法不能有效控制矿压。文章根据大同煤矿集团公司晋华宫矿实际情况,介绍了关于近距离采空区下半煤巷掘进工艺、支护和工作面开采期间有效控制矿压的方法。     

Photodegradation mechanism and stabilization of polyphenylene oxide and rigid‐rod polymers

Poly(2,4‐dimethyl‐1,4‐phenylene oxide) (PPO), poly(benzo[1,2‐d:5,4‐d′]bisoxazole‐2,6‐diyl‐1,4‐phenylene) (PBO) and poly(benzo[1,2‐d:4,5‐d′]bisthiazole‐2,6‐diyl‐1,4‐phenylene) (PBZT), which are polymers with extended conjugated structures, undergo a self‐sensitized photo‐induced electron‐transfer reaction. A second component is not required. This article presents many similar observations on these polymers when they are exposed to light and evidence to support the proposed photo‐induced electron‐transfer mechanism. Methods to stabilize these polymers against photo‐oxidation are also described. Workers investigating other conjugated polymeric systems may find the experimental methods, observations and polymer stabilization approaches discussed in this review useful. Copyright © 2005 Society of Chemical Industry