澳大利亚2001～2002年度Internet业务市场回顾

在2001－2002年度中，澳大利亚Internet用户已超过总人口的50％。用户订购业务的类型有较大程度的变化，按月、季度和年度订购Internet业务的用户数量不断增长，免费订房、按小时付费和按容量接入的用户在减少。网上商业交易和政府业务在增加，政府积极实施公共Internet接入项目。澳大利亚各州和地区的ISP及相应的接入点数量逐渐减少，通信基础设施则进一步改善。     

思科电信运营商战略--助电信运营商通过创新服务扩大收入

随着电信市场竞争的加剧以及用户对数据业务需求的不断扩大,电信运营商加快了迈向基于IP的下一代网络（IPNGN）的步伐,希望通过构建融语音、数据、视频于一体的下一代网络,快速部署创新的业务和应用,同时有效降低整体拥有成本.为此,电信运营商需要融合基础设施,在提高现有业务供应水平的同时,为未来的业务提供生命力更长久的框架,并且拥有提供增值化和个性化业务的手段,最终为用户带来全新的通信体验.     

Broad-band SiGe MMICs for phased-array radar applications

This paper reports the performances of several broad-band monolithic SiGe monolithic microwave integrated circuits (MMICs) suitable for phased-array radar applications. The amplitude and phase control MMIC designs are based on an optimized SiGe p-i-n diode offered by the IBM 5HP SiGe foundry process. Utilizing this diode, several control circuitries including a broad-band (1-20-GHz) monolithic single-pole double-throw switch, a five-port transfer switch, a 6-bit phase shifter, and a 5-bit attenuator, all operating over 7-11 GHz, are designed. Also, the design and performance of an SiGe heterojunction bipolar transistor variable-gain cascode amplifier that combines the functionality of an amplifier and an attenuator into one MMIC is described.     

二阶加纯滞后过程的非脆弱PID稳定化控制器设计

根据Hermite-Biehler定理在准多项式稳定性问题上的推广，研究用PID控制器镇定二阶加纯滞后过程的问题，给出了使闭环系统稳定的PID参数区域，并以稳定的PID参数区域内切圆半径为目标函数，寻优得到非脆弱PID控制器参数，最后通过线性规划给出了非脆弱PID稳定化控制器的设计方法。     

A SiGe MMIC 6-bit PIN diode phase shifter

A 6-bit PIN diode phase shifter has been successfully demonstrated at microwave frequencies in a SiGe bipolar technology. A post-silicon polymer dielectric interconnect technology is implemented to achieve low loss microstrip structures on the silicon substrate. The monolithic microwave integrated circuit exhibits flat phase shift, low VSWR, and low insertion loss variation, over the 7- to 11-GHz band. This phase shifter demonstrates the feasibility of integrating SiGe technology into microwave systems.     

RE hybrid systems: Improving competitiveness for RE

Naturally, the main reason for creating any type of hybrid system is a wish to create a whole that is greater than the sum of its parts; one in which the shortcomings of one element is offset by another. The combination of wind and solar energy is familiar to us all from a range of applications, including power supply to private households. This combination is also used for more specific purposes, however, many of them every bit as vital. Britt Johansen, Grundfos, Denmark describes how hybrid systems can help promote use of renewable energy within off-grid water supply, and addresses recent technological developments within this area.     

海水与淡水冲灰系统灰水闭路循环结垢机理

通过试验、分析和比较,探讨火力发电厂海水冲灰系统与淡水冲灰系统的共异性,以及海水冲灰系统灰水闭路循环结垢的机理。通过灰在海水和除盐水中的深出特性试验,得出：相对于除盐水,灰中结垢离子在海水中的溶出量要小得多,pH值变化范围也小,通过海水冲灰水系统灰水闭路循环模拟试验,得出：灰水中CaCO3和CaSO4的过饱和程度比在淡水冲灰水系统中大得多;经过多次循环,灰水会产生结垢,垢的主要成分是CaCO3,另外还有占5％的CaSO4,因此对阻垢剂的阻垢性能要求较高。     

建设ERP就绪的网络

就制造业信息化最关键的应用之一ERP系统的计划与实施进行探讨。帮助制造业用户更好的规划和实施ERP系统应用。