Scaling and technological limitations of 1/f noise and oscillator phase noise in SiGe HBTs

This paper examines the impact of SiGe HBT scaling on 1/f noise and phase noise of oscillators and frequency synthesizers. The increase of transistor speed with scaling is shown to significantly increase the sensitivity of oscillation frequency to 1/f noise and, thus, degrade close-in phase noise, but decrease the sensitivity of oscillation frequency to base current shot noise and base resistance thermal noises. The results show that corner offset frequency defined by the intersect of the 1/f³ and 1/f² phase noise has little to do with the traditional 1/f corner frequency. The relative importance of individual noise sources in determining phase noise is examined as a function of technology scaling, device sizing, and oscillation frequency. The collector current shot noise and base resistance noise are shown to set the fundamental limits of phase noise reduction. A methodology to identify the maximum tolerable 1/f K factor is established and demonstrated for the HBTs used     

大池干井构造带含气特征及勘探方向

按气田勘探应抓准宏观控矿规律的思路,此文以实钻资料为基础,并应用水文地质学的渗流理论,对控制气藏分布的气水分异、构造圈闭、岩溶水水侵等主要因素进行了分析论证,指出:阳新统岩溶裂缝性气藏是主要挖潜方向,“平衡钻进”理论不适用于裂缝性气藏。     

关于乡镇广电站管理与发展的几点思考

广电企业拓展乡镇业务必须抓好乡镇全员学习,全面提升职工素质,并大力引进专业技术人才。广电企业创新服务理念推动乡镇产业健康有序发展必须做好乡镇用户市场调研,加快网络双向改造,在确保基本业务的同时拓展增值业务。广电企业在乡镇打造优质服务品牌必须建立健全奖惩激励机制,抓好片区经理制建设,强化"五心"服务,推行"首问负责制"。     

脉冲功率电容器用PbLa(ZrTi)O_3陶瓷性能研究

采用固相反应法制备了Pb0.96La0.06(Zr1-xTix)O3陶瓷,研究了Ti含量对所制陶瓷的电性能和储能特性的影响。结果表明,PbLa(ZrTi)O3陶瓷介电常数与电场强度呈非线性变化关系。当Ti含量x为0.08时,所测电滞回线细长狭窄,并呈下凹趋势,此时极化强度为22.18×10–6 C/cm2,储能密度为1.06 J/cm3。通过流延法制备的脉冲功率电容器击穿电压可大幅度提升,储能密度达1.95 J/cm3,具有高能量转换效率。     

基于MetaEdit+的eFFBD建模工具设计

eFFBD是当前一种主流的功能分析工具,本文研究eFFBD可视化建模工具的设计,使用特定领域语言(DSL)在MetaEdit+平台上进行开发。文中首先对DSL的开发流程和具体步骤进行了总结,然后按照此流程分别设计了eFFBD的核心语言模型,行为模型和具体语法,最后一个功能分析实例演示了该eFFBD建模工具的应用。     

防欺诈域名安全管理系统的研究和应用

本文分析了当前移动互联网信息欺诈的特征,提出了基于域名系统的防欺诈安全快速处置方案和系统,并介绍了该系统在网络上应用的效果。     

基于云计算技术的广电桌面云在智慧社区中的应用实现

随着智慧城市的发展,智慧社区已成为未来的发展趋势,社区的信息化能够利用先进的技术,提供智慧的服务.云计算技术为智慧社区信息化发展提供了很好的技术手段.江苏有线无锡分公司采用先进的云计算技术,针对传统PC部署中的问题提出了云的解决方案,利用计算资源虚拟化和桌面虚拟化技术,把用户需要的桌面和数据以服务的方式提供,用户可以像使用水电一样尽情享用桌面云服务.桌面云技术能够很好地实现集中式管理,提高运维效率,降低维护成本的同时,还能节能降噪,为居民、社工提供一个安全、舒适、便利的办公、生活环境,从而推进智慧社区的发展,构建和谐社会.     

Effects of breed and sire on carcass characteristics and fatty acid profiles of crossbred wagyu and angus steers

In a two-year experiment, 54 steers sired by seven Wagyu bulls [American Wagyu Association (AWA) sire numbers 331, 384, 388, 411, 429, 433 and 488] and 15 steers sired by two Angus bulls, all out of Angus-Hereford cows, were used to evaluate the effects of sire and breed on carcass characteristics and fatty acid composition. Steers were given ad-libitum access to a high-concentrate diet (15 % alfalfa cubes and 85 % barley supplement) for at least 170 days. Breed and individual sire effects were analysed. Wagyu-sired steers had higher marbling, maturity and quality scores, more estimated kidney, pelvic and heart fat, larger longissimus dorsi muscle areas, lower fat thicknesses and yield grades than Angus-sired steers (p < 0.05). Steers sired by 388, 411 and 433 had lower fat thicknesses than steers sired by Angus, 429 and 488 (p < 0.05). Steers sired by 384 and 388 had higher marbling scores per cm subcutaneous fat than steers sired by Angus, 429 and 488, and lower fat thickness per 100 kg of carcass weight than Angus-sired steers (p < 0.05). For both subcutaneous fat and longissimus dorsi muscle, Wagyu-sired steers had higher (p < 0.05) percentages of 14:0, 14:1, 16:0, 16:1, and lower percentages of 18:0 than Angus-sired steers. The genetic differences in carcass characteristics among Wagyu sires may enable us to select for improved marbling with less fat in the Wagyu breed. Some statistically significant (p < 0.05) but small differences existed in fatty acid profiles between breeds and among sires.     

Controllable persistent spin-polarized charge current in a Rashba ring

We theoretically predict the appearance of a persistent charge current in a Rashba ring with a normal and a ferromagnetic lead under no external bias. This charge current is the result of the breaking of the time inversion symmetry in the original persistent pure spin current induced by the Rashba spin-orbit coupling (RSOC) in the ring due to the existence of the ferromagnetic lead. With the Keldysh Green''s function technique, we find that not only the magnitude and sign but also the spin polarization of the generated charge current is determined by the system parameters such as the magnetization direction of the ferromagnetic lead, the tunneling coefficient, the strength of the RSOC and the exchange energy of the ferromagnetic lead, which are all tunable in experiments, that is, a controllable persistent spin-polarized charge current can be obtained in such a device.