消防水箱设计中常见错误及改正措施

根据现行消防技术规范的有关规定，结合建筑工程消防监督审核的工作实践，指出了消防水箱设计中常出现的错误并提出了相应的改正措施。     

提高500 kV电网向北京输送能力的措施

为确保北京电网经济、可靠地供电,文章从规划的角度论述了已经使用与即将规划使用的各种提高电网输送能力的措施,主要包括改善500kV电网结构,加强和扩大以北京电网为中心的受端电网;送端适当互联;加强北京电网中的无功电源建设;在北京电网中建设电源以提供电压支撑;采用串联补偿技术和紧凑型线路送电等.并对应用柔性交流输电（FACTS）技术和缩短保护动作时间以提高电网输送能力进行了展望.     

单周期控制Boost PFC变换器

单周期控制是一种用于功率变换器的新型非线性控制策略，当输入电压发生扰动或负载快速变化情况时．仅在一个周期内就可实现控制目标。本文将单周期控制引入Boost变换器，实现了功率因数校正。在阐述单周期控制原理的基础上．总结了单周期控制实现的控制目标。详细给出了单周期控制Boost变换器实现功率因数校正的控制目标和实现方式。实验结果表明，单周期控制适用于Boost变换器实现功率因数校正。     

基于小波包分解实时检测电机振动信号

小波包分解本身对信号的奇异点十分敏感，此特点可以用来跟踪电机振动速度信号。在虚拟仪器（VI）LabVIEW6．i平台上，基于小波包分解算法设计了VI程序，实现了电动机振动速度信号实时检测系统。Y630-10／1180型大型三相异步电动机的振动速度信号，实测效果优于P3562A动态信号分析仪的测量结果。结果表明，该方法是可行的和有效的。     

An Interval Maximum Entropy Method for Quadratic Programming Problem

1 IntroductionThe maximum entropy method, also calledaggregate function method, is mainly based on theentropy function theory in information science. Ituniformly approximates the primitive function viaconstructing maximum entropy function. Owing tothe favorable properties of the maximum entropyfunction, it is convenient to do theory and algorithmresearch. In recent years, many good results insolving nonlinear programming problems such asmini-max problems, nonlinear ill-posed problems andnonlin…     

Proton exchange membrane fuel cells modeling based on artificial neural networks

To understand the complexity of the mathematical models of a proton exchange membrane fuel cell (PEMFC) and their shortage of practical PEMFC control, the PEMFC complex mechanism and the existing PEMFC models are analyzed, and artificial neural networks based PEMFC modeling is advanced. The structure, algorithm, training and simulation of PEMFC modeling based on improved BP networks are given out in detail. The computer simulation and conducted experiment verify that this model is fast and accurate, and can be used as a suitable operational model for PEMFC real-time control.     

Analysis on the Logarithmic Model of Relationships

The logarithmic model is often used to describe the relationships between factors.It often gives good statistical characteristics.Yet,in the process of modeling of soil and water conservation,we find out that this“good”model cannot guarantee good result.In this paper we make an inquiry into the intrinsic reasons.It is shown that the logarithmic model has the property of enlarging or reducing model errors,and the disadvantages of the logarithmic model are analyzed.     

NDLC通信中的数据转发原理及实现

网络化配电载波通信（Network of Distribution Line Carrier）是配电网通信中的一种新形式，数据转发是实现其中的核心内容。本文探讨了一种用软件实现的数据转发方案，并且给出了NDLC通信的数据转发原理、数据冲突的处理方法及应用实例。通过设置各个通信子站的站号、记录下网络中的数据流方向，并按照一定的通信规则处理收发数据，可以将数据成功转发到目的站点。     

Plasma Sprayed Hydroxyapatite Coatings with Nano-hydroxyapatite Prepared by Ultrasonic Precipitation Process

1Introduction Bioceramicsarespeciallydesignedceramicsforthe repairandreconstructionofdamagedpartsofthehuman body.Applicationsincludereplacementsforhips,knees,teeth,etc.Hydroxyapatite(HA)issuchabioceramics material.HAisabioactivematerialwithacalcium to pho…     

并行加工条件下作业排序方法研究

对单工序并行加工条件下的作业排序问题进行了深入研究，在给出该问题的整数规划模型的基础上，找出了一种新的启发式算法，并编写了相应的计算机程序，示例和模拟结果表明，新算法优于LPT算法并可以通过自迭代求出较优的完工期。同时还可以降低零件的平均完工时间。