基于企业规模的食品安全诚信监管博弈分析

本文在详细阐述食品质量安全政府监管部门职能划分基础上,运用博弈论的研究方法构建了地方监管部门与不同规模食品企业之间关于食品质量安全诚信监管的博弈模型,博弈分析说明了小规模食品企业失信经营现象严重且地方监管部门对其放松监管的深层原因,阐释了在地方政府影响下地方监管部门与大规模食品企业的博弈机理.结合博弈分析结果得出了促使不同规模食品企业诚信经营的对策建议.     

基于自校正的供暖系统启动控制

供暖系统最佳启动控制的重点在于准确预测预热时间,获取供暖系统的准确预热时间,并以其控制供暖系统的启动,有助于整个供暖系统能耗最小化.针对具有间歇供暖系统供暖的建筑物,分析其内部温度在外界环境和热源影响下的变化过程和规律,从热力学角度建立了间歇供暖预热过程的数学模型.基于该模型,在间歇供暖的启动控制中引入了自校正控制,并进行了仿真和实验.结果表明,将自校正控制用于供暖系统的启动控制效果较好,能够节约能源.     

植物生长调节剂与杀菌剂互作对棉花立枯病的影响

采用温室盆栽方法，测定了5种植物生长调节剂分别与7种杀菌剂混用拌种对棉苗立枯病的影响，结果表明：水杨酸 三唑酮、水杨酸 甲基立枯磷、萘乙酸 三唑酮、萘乙酸 烯唑醇、氯化胆碱 甲基立枯磷、氯化胆碱 烯唑醇、油菜素内酯 三唑酮、油菜素内酯 丙环唑、油菜素内酯 多菌灵、多效唑 福美双对棉苗立枯病均有增效作用；水杨酸 福美双有拮抗作用；其它植物生长调节剂与杀菌剂互作为相加作用。     

广州设计大厦建筑设备节能改造方案简陈

介绍广州设计大厦节能改造项目中所采用的控制策略,对机电设备进行的节能控制管理,及针对部分标准楼层的风机盘管、新风机采取的节能控制方式。     

电压反馈型BUCK变换器环路补偿设计

文章在介绍电压反馈型BUCK变换器的主拓扑和反馈控制模式的基础上，进一步探讨了反馈控制的传递函数和环路参数的设计，说明了双极点一双零点补偿网络的设计原理与具体过程。     

核电封头五轴数控加工刀具路径规划研究

核电封头机械加工余量大,并且球面上非对称的分布这若干管嘴端面,这给高效刀具路径规划造成了极大的难度。在NURBS方法基础上,针对核电水室封头等形状复杂大型工件,从加工效率和稳定性的角度,建立环形铣刀加工曲面的运动几何学模型并应用加工域规划法进行刀具路径规划。合理的刀具路径规划可以有效的避免刀具干涉,缩短刀具路径,提高加工精度。     

基于粒子群算法的自整定PID控制器

粒子群算法是一种基于群智能的全局寻优方法,方法简单易于实现,寻优效果好.本文设计了一种基于粒子群算法的自整定PID控制器.它可以根据系统参数的变化实现在线的PID参数优化.仿真结果证明其性能良好.     

Phytoecdysteroids: Distribution,Structural Diversity,Biosynthesis, Activity,and Crosstalk with Phytohormones

Phytoecdysteroids (PEs) are naturally occurring polyhydroxylated compounds with a structure similar to that of insect molting hormone and the plant hormone brassinosteroids. PEs have a four-ringed skeleton composed of 27, 28, 29, or 30 carbon atoms (derived from plant sterols). The carbon skeleton of ecdysteroid is known as cyclopentanoperhydrophenanthrene and has a β-sidechain on C-17. Plants produce PEs via the mevalonate pathway with the help of the precursor acetyl-CoA. PEs are found in algae, fungi, ferns, gymnosperms, and angiosperms; more than 500 different PEs are found in over 100 terrestrial plants. 20-hydroxyecdysone is the most common PE. PEs exhibit versatile biological roles in plants, invertebrates, and mammals. These compounds contribute to mitigating biotic and abiotic stresses. In plants, PEs play a potent role in enhancing tolerance against insects and nematodes via their allelochemical activity, which increases plant biological and metabolic responses. PEs promote enzymatic and non-enzymatic antioxidant defense systems, which decrease reactive oxygen species in the form of superoxide radicals and hydroxyl radicals and reduce malondialdehyde content. PEs also induce protein biosynthesis and modulate carbohydrate and lipid synthesis. In humans, PEs display biological, pharmacological, and medicinal properties, such as anti-diabetic, antioxidant, anti-microbial, hepatoprotective, hypoglycemic, anti-cancer, anti-inflammatory, antidepressant, and tissue differentiation activity.     

A study of voltage and reactive power control methods for high‐efficiency operation of distribution networks

Transformers with on‐load tap changer and step voltage regulators are most often used for regulating the distribution network voltage. Their use, however, creates certain problems, namely, the voltage control is in discrete steps and the response time is not satisfactory enough. In addition, the power factor (p.f.) compensation relies on capacitors installed by electricity users which creates additional problems manifesting themselves in unexpected overvoltages during light load and increase of power losses. To solve these problems, the authors have proposed a new voltage and p.f. control system for distribution networks based on sophisticated power electronics technology. This paper describes our study on the operating theory of inverter‐controlled regulators and thyristor‐controlled reactors, which play important roles in this system, and the results of simulation through which the usefulness of these equipment has been ascertained. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 76–87, 2000