用于千兆以太网基带铜缆接收器均衡的甚高频自适应 连续时间Gm-C 二阶带通滤波器的研究和设计

本文设计了用于千兆以太网基带铜缆接收器均衡的甚高频自适应连续时间Gm-C二阶带通滤波器。基于最陡梯度下降算法，带通滤波器的零点在57－340MHz的频率范围内可以自适应地调节，中心频率为1.278GHz。通过外接电阻伺服环路，滤波器中跨导转换器的跨导值不受工艺偏差和温度变化的影响，采用CSMC－HJ0.6μm CMOS工艺器件模型，用Cadence Spectres仿真器仿真了设计的自适应滤波器电路，仿真结果验证了设计原理和设计的电路。系统的最长学习时间为880个参考时钟周期。     

Automated High Throughput Screening of Fluorescent Imaging Plate Reader (FLIPR) Assays Using Assay Platform™ Integrated with Activity Base for ‘on the fly’ Compound Reconfirmation

Advances in the field of automation have meant hitherto complex manual cell-based assays can now be automated. These improvements have brought significant enhancements in throughput, data fidelity and consistency, and allowed a reallocation of constrained resources.Building upon these improvements, we have linked our automated cell-based screening system, Assay Platform™, to Activity Base (IDBS), a software package designed to automate the analysis of HTS data. Customisation of this package has resulted in software that can identify ‘active’ compounds and re-pick them ‘on the fly’ from the original compound plates for triplicate re-testing without operator intervention.Based on an operator initially defining ‘normal’ parameters for assay activity in Activity Base, combined with an automated quality control software module that checks data fidelity, wells containing ‘active’ compounds can be re-picked and re-tested at the end of an automated screening run. Automating cell-based assays has significantly improved productivity, and, with the synergism of Activity Base, has given us greater power to complete each screening run and report ‘active’ compounds to Chemistry more rapidly. This article presents our approach to the automation of cell-based Fluorescent Imaging Plate Reader (FLIPR) screening together with automated active re-test confirmation using Activity Base.     

支持HTTP代理的分布式监测终端的设计与实现

提出了一种低成本、高可靠性的分布式信息远程传输解决方案。在低速处理器上通过对TCP/IP协议的裁减开发了简化的HTTP协议,并采用BASE64编码设计了用于代理服务器基本验证的加密算法。在此基础上,研制出支持HTTP代理的分布式监测终端,实现了本地的嵌入式设备与远程监测服务器的网络通讯。     

湖南怀化双向城域网络建设实施方案

本文就湖南有线怀化网络有限公司双向网络改造的具体实施方案进行分析，着重介绍网络设计、网络架构等环节。讨论根据不同的户型采用不同的接入网方式。     

基于收发器FT3120的新型智能节点设计

基于国内最新型的智能收发器FT3120,设计成采用HOSTBASE结构的新型智能节点的方。利用双口RAM(CY7C026)芯片成功地解决了将下位机数字信号处理器(DSP)控制信息传送到上位节点,而该节点又可将信息通过Lonworks现场总线发送给中央控制机系统,系统的信号传递由于是双向的,所以该节点系统可以通过总线完成数据的智能上传和上位机对下位节点智能编程,它具有智能在线编程控制(IC)的先进特性。通过研究和分析表明,该系统具有广阔的推广前景。     

一种定制的出口退税远程申报邮件收发系统

在TCP/IP协议上 ,定制一套SMTP、POP3、ADDRESSBOOK协议 ,从而实现了定制的电子邮件收发系统     

Laser brazing of alloy 600 with precious filler metals

Abstract

The diode laser brazing of Ni base heat resistant alloy with precious filler metals has been conducted using the tandem beam for preheating and brazing. A couple of 1 mm thick plates of alloy 600 (Inconel 600) were butt brazed using Au–18Ni, Ag–10Pd and Ag–21Cu–25Pd filler metals of 0·5 mm diameter with a brazing flux. Sound butt joints which were free from brazing defects such as porosity and lack of penetration could be obtained at brazing clearances of 0·1–1·5 mm. The tensile strength of the braze joint produced using Ag–Pd filler metal increased with decreasing brazing clearance and reached ～70% of the base metal strength at a brazing clearance of 0·1 mm while those obtained by using Au–Ni and Ag–Cu–Pd filler metals were comparable with the base metal strength at any clearances between 0·1 and 1·5 mm. The laser brazing technique could be successfully applied to the brazing of Ni base superalloy to attain a joint with high performance and reliability.     

Solidification paths in modified Inconel 625 weld overlay material

Abstract

Inconel 625 is commonly used for overlay welding to protect the base metal against high temperature corrosion. The efficiency of corrosion protection depends on effective mixing of the overlay weld with the base metal and the subsequent segregation of alloy elements during solidification. Metallographic analysis of solidified samples of Inconel 625 with addition of selected elements is compared with thermodynamic modelling of segregation during solidification. The influence of changes in the melt chemistry on the formation of intermetallic phases during solidification is shown. In particular, focus is put on how the composition of the dendrite core is affected by modifications to the alloy. It has previously been shown that when the overlay material corrodes, the corrosion take place in the dendrite core. Therefore, the discussion will be directed towards explaining the extent to which the variations in chemical compositions influence the composition of the dendrite core of the weld overlay.     

Microbial Biofouling: A Mechanistic Investigation

Microbial biofouling is important in a variety of applications including reverse osmosis membranes and in-situ bioremediation. The initial microbial adhesion plays the key role in microbial biofouling on abiotic surfaces, which can be explained in terms of microbial surface properties. This research investigated the interactions of three indigenous bacteria with the porous medium of silica sand and their corresponding initial attachment. Traditional and extended DLVO forces were calculated based on independently measured bacterial and medium surface thermodynamic properties and were related to bacterial attachment observations. Lifshitz–van der Waals, electrostatic and Lewis acid/base forces were found to be strongly dependent on the separation distance between bacteria and the medium surface. It was concluded that the electrostatic force served as the barrier preventing the bacterial strains from getting close to the medium. Once the bacterial strains overcame the barrier with the aid of hydrodynamic forces, Lifshitz–van der Waals force and electrostatic force dropped while Lewis acid/base force increased with the decrease of separation distance. Consequently, Lewis acid/base force became the dominating force controlling bacterial adhesion.     

高速网络1000BASE—T的协议与实现技术研究

文章详细分析了基于五类ＵＴＰ电缆的千兆以太网１０００ＢＡＳＥ－Ｔ的网络协议与实现技术,对１０００ＢＡＳＥ－Ｔ具体实现的各个环节进行讨论。