Dynamic identification using chatter motion†

This paper is an analysis based on the behaviour of an on-off control system whose second-order transfer function,$ is unknown: it is associated with another transfer function whose coefficients are controlled in such a way that the system is functioning with a chatter motion. A systematic study of the existence conditions for this behaviour leads to the determination of the control laws and shows how it is possible to obtain the coefficients identification of the unknown transfer function, even when these are varying with time. Moreover, it is shown how it is possible to analyse this system without the non-linear element, with the same global behaviour of the system. A digital simulation is given to check the conclusions of this analysis     

2010年上海世博会设施管理的组织策划

设施管理是一种＂超越＂物业管理、确保建筑环境功能的集成管理模式。基于设施管理基本理论,结合2010年上海世博会项目管理实践,分析了其运营阶段设施管理的特点,并从范围界定和组织设计角度,建立了设施分解结构与三级组织体系,为类似项目运营管理的组织策划提供借鉴。     

梅州市清凉山水库水情自动测报系统建设与管理

本文介绍清凉山水库工程概况,结合工程实际需要,全面总结水情自动测报系统功能设计、设备选型、系统配置和运行管理经验。实践表明,系统运行稳定、各项功能和性能指标满足规范和用户要求,为类似工程水情自动测报系统改造提供了有益的参考。     

基于自适应模拟退火遗传算法的多目标最优潮流

采用自适应遗传算法来确定基本遗传算法的交叉率和变异率,保证遗传算法的收敛性.同时引入模拟退火法思想,通过拉伸目标函数的适应度使优秀个体在产生后代时具有明显的优势,从而加速寻优的过程,形成一种新的算法:自适应模拟退火遗传算法.应用该算法进行电力系统多目标最优潮流计算,IEEE30试验系统计算结果表明了该算法的灵活性和有效性.     

洁净手术室空调的低频噪声控制

对洁净空调中风机的低频噪声产生和控制作了介绍,重点介绍了微穿孔消声器和阻尼减振技术。并提出医院、生物安全和动物试验用L或C计权计量室内噪声,并考核倍频程的噪声参数。     

电力通信中异构网络实时通信的研究

针对电力系统通信网的互联和实时通信这两方面的问题，提出了异构网络的同构化思想，并给出了基于客户机／服务器模式的套接字实现框架。     

励磁涌流鉴别方法在变压器保护中的应用

励磁涌流的鉴别一直是变压器保护中的一个关键问题 ,文中针对目前国内外学者提出的励磁涌流识别原理和方法进行了分析和综述。并对目前现场采用的方法和一些现代智能理论鉴别中的应用进行了比较 ,指出了变压器励磁涌流在鉴别方法的研究和应用动向     

Pharmacokinetics of 2-oxothiazolidine-4-carboxylate, a cysteine prodrug, and cysteine

The pharmacokinetics of both 2-oxothiazolidine-4-carboxylate (OTZ), a prodrug of cysteine, and total blood cysteine (cysteine plus cystine) were investigated in 18 healthy volunteers. OTZ was given either as a single, 2-hour intravenous infusion (56-66 mg/kg) or similarly infused (70-100 mg/kg) every 8 hours for four doses. Blood was assayed for OTZ, total blood cysteine, and glutathione. The pharmacokinetics of OTZ were analyzed alone and simultaneously with total cysteine using the NONMEM software package (University of California at San Francisco. The pharmacokinetics of OTZ were best described by Michaelis-Menten kinetics with parallel first-order elimination. OTZ was efficiently removed from the plasma. The Michaelis-Menten route of elimination was attributed to conversion of OTZ to total cysteine. At plasma OTZ concentrations equal to the Michaelis constant Km, 84% of OTZ was converted to total cysteine. These findings suggest that OTZ administered intravenously is an efficient means of increasing total blood cysteine.     

Increasing incidence of carcinoma of the gastric cardia in Sweden from 1970 to 1985

Several American, Japanese and European centres have reported an increase in carcinoma of the gastric cardia, contrary to the general trend in the incidence of gastric cancer. The aim of this nationwide population-based study was to describe trends in the incidence of tumours of the gastric cardia in Sweden over the 16-year period from 1970 to 1985. The Swedish cancer register, which is more than 95 per cent complete, was used to identify cases. There were 1514 men and 481 women with cancer of the gastric cardia. The age-standardized rates increased in men from 1.9 per 10(5) population in 1970-1973 to 3.0 per 10(5) in 1982-1985, corresponding to a mean annual increase of 2.5 per cent (95 per cent confidence interval (c.i.) 1.6-3.4 per cent). In women, the age-standardized rates increased from 0.5 per 10(5) in 1970-1973 to 0.8 per 10(5) in 1982-1985, the mean annual increase being 0.9 per cent (95 per cent c.i. 0.0-1.8 per cent). The highest incidences were found in southern Sweden, contrary to the geographical distribution of gastric cancer in general, which shows a south-to-north gradient. The disparate epidemiological features of cancer of the cardia and gastric cancer at other sites suggest that the aetiologies may also be different. Since little is known about the aetiology of cancer of the cardia, and the incidence seems to be rising rapidly, analytical studies are urgently needed.