跟踪问题控制器设计的一种新方法及应用

本文提出一种模型跟踪控制器设计方法使得线性时不变装置输出对参考模型系统输出具有良对好的跟踪特性。根据这种设计方法形成的控制器由参考模型系统状态(或估计状态)的前馈和受控装置状态(或估计状态)的反馈两部分组成。前馈增益和反馈增益计算简单且设计过程高度程序化。使用这种方法设计BTT导弹自动驾驶仪获得了满意的结果。     

坝内钢管强度设计的问题及改进

坝内钢管在水电站中应用广泛,但现行的设计理论和方法一般偏于保守,更难于适应大容量、高水头电站的发展,本文根据理论分析和试验研究,提出了改进坝内钢管强度设计的具体措施和方向,对工程设计和进一步开展科学研究,具有实际意义。     

采用调速型液力耦合器是火力发电厂节能的有效措施

本阐述了火电厂给水泵、送引风机采用调速型液力耦 合器，改善给水泵调节特性，节约大量厂用电等优点，并指出了这是我国当前火力电厂节约厂电的有效措施。     

我国热价设计理论方法的研究(Ⅱ)──热、电成本分摊的符号经济学方法

利用符号经济学理论与方法，建立热电厂联合生产的热、电成本分摊的分析模型，开发了计算机计算软件，在石景山热电厂试用，得到良好的结果。目前正在进行开发该厂２００ＭＷ供热机组的能（）耗分析与主要技术经济指标在线处理装置。     

电厂用高压大型异步电机变频调速经济效益和技术问题分析

本文在广泛调研的基础上，综述了国内外电厂用变频调速装置开发生产状况和技术特点及所取得的技术经济效果。分析了我国研制开发适合电厂使用的高压大型变频调速装置的技术经济意义和社会经济效益以及需解决的主要技术问题。     

发电厂厂用电系统可靠性研究及其计算

本文根据电力系统可靠性的基本理论,结合发电厂的专业知识,对发电厂厂用电系统的可靠性计算的判据,数学模型和方法进行探讨,并用FORTRAN—77语言编写了计算程序。可对发电厂主系统接线(包括电气主接线和厂用电系统),在任意的运行方式下,计算出其厂用电系统的几个可靠性指标,如厂用系统的停运概率,停运频率,期望电量不足EENS,停电平均时间等。并能检查系统在正常运行和一阶事故时的系统潮流分布,由此找到过负荷元件。这在设计厂用电系统时,为寻找可靠性较高的方案提供了数量依据。     

Field response of Ips paraconfusus,Dendroctonus brevicomis,and their predators to 2-methyl-3-buten-2-ol,a novel alcohol emitted by ponderosa pine

Methylbutenol (MBO) is a major component of the aggregation pheromone of the European spruce beetle Ips typographus and also has been found to be emitted in large amounts by several species of pine native to western North America. This study investigates the influence this signal may have on the behavior of North American bark beetles and examines whether MBO functions as a defensive compound for emitting pines. The response of two North American bark beetles (Ips paraconfusus and Dendroctonus brevicomis) and their predaceous beetles (Trogositidae and Cleridae) to MBO, pheromone, and monoterpenes in varying release rates was investigated in the field using Lindgren funnel traps. MBO exhibited no repellent properties when tested alone, nor did MBO appear to have any effect on the aggregation response of these bark beetles and their predators to their pheromones. These results provide no support for a defensive function of MBO.     

A Novel Function of the Triterpene Squalene in a Tritrophic System

Changes in apple leaf chemistry after infestation by leafminers and their effect on both host location and host habitat location of the generalist parasitoid Pholetesor bicolor were investigated. Chemical analysis of leaf solvent extracts from healthy and leafminer-damaged leaves revealed that herbivory increased the amount of the triterpene squalene (C₃₀H₅₀), whereas quantities of all other identified compounds were similar in both plant treatments. To assess the response of parasitoids to host location cues, contact bioassays were conducted with naïve females. Results showed that parasitoids performed a characteristic ovipositional probing more often on the mine-damaged than on the healthy leaf. This behavior was triggered by a hexane extract of the mine-damaged leaf, but not by a healthy leaf extract. A synthetic mixture of the compounds identified in the extract triggered a similar response. A mixture devoid of squalene was not active, whereas squalene alone elicited the probing behavior. To assess the use of the identified compounds in habitat location, Y-tube olfactometer experiments were conducted with naïve and experienced females. Results showed that squalene is not involved in habitat location and has no priming effect on P. bicolor. While other triterpenes are known to mediate habitat location of parasitoids, this is the first report in which a plant triterpene is shown to mediate host location of a parasitoid. The biological and ecological functions of squalene on all three trophic levels are discussed.     

Constraints on effectiveness of cyanogenic glycosides in herbivore defense

Cyanogenesis is the process by which hydrogen cyanide is released from endogenous cyanide containing compounds. Many cyanogenic plants release HCN in sufficient quantities to be toxic and, as a result, tend to be avoided by herbivores. However, there are many exceptions with some herbivores either immune to the cyanogenic status of the plant, or in some cases attracted to cyanogenic plants. This has led to a certain degree of scepticism regarding the role of cyanogenic glycosides as defense compounds. In this review, we examine evidence showing that differences in the effectiveness of cyanogenic glycosides in deterring herbivory can usually be reconciled when the morphology, physiology, and behavior of the animals, together with the concentration of cyanogenic glycosides in the host plant, are taken into account. Cyanogenic glycosides are not effective against all herbivores, and not all cyanogenic plants release enough cyanide to be considered toxic. Nevertheless, they do form part of the broad spectrum of toxic and distasteful compounds that herbivores must accommodate if they are to feed on cyanogenic plants.     

A modernized and versatile startup reactivity measuring system installed at NPP Paks and its application for subcritical systems

In 2004 the Hungarian Paks NPP completed a project for upgrading the reactivity measuring system applied during reactor startup experiments. Almost all components of the previous system were replaced, only ex-core ionisation chambers remained unaltered. New hardware and software components were introduced for neutron flux signal handling, for data acquisition, as well as for measurement evaluation and data presentation. High-precision picoamper meters were installed at each reactor unit, current signals are handled by a portable signal processing unit. The system applies an accurate on-line reactivity calculation algorithm based on the point-kinetic model with six delayed neutron groups. Detailed off-line evaluation and analysis of startup measurements can be performed on the portable unit, as well.The paper describes the architecture, data acquisition modules, services and man–machine interface of the new system. Functions and results are illustrated with measured data recorded during a startup of Unit 3. In 2003 and 2004 the RMR was installed and tested at all Paks NPP units successfully and now it is in regular use during unit startups.The second part of the paper illustrates an extension of the new system to perform reactivity measurements using the well-known Rossi-α and Feynman-α statistical methods. The modified system was needed to estimate the reactivity of a subcritical system formed by damaged fuel assemblies stored at the fuel service pit of Paks Unit 2. Theoretical background of the applied algorithms is outlined, then results of validation tests and on site measurements are treated. The measurements have shown that the subcriticality of the damaged fuel was sufficiently deep if the high boron concentration in the fuel service pit was maintained.