BP网络在加热炉效率评定中的应用

以工艺管式炉有关数据为例，将BP网络有效应用于数据的压缩存储和快速计算，为加热炉效率评定软件提供了BP网络模型。利用MATLAB软件实现了BP网络的训练及仿真分析，并讨论了应用过程中参数的选择以及训练数据的特点对网络训练产生的影响。     

A fundamental study on the control of the HCCI combustion and emissions by fuel design concept combined with controllable EGR. Part 1. The basic characteristics of HCCI combustion

This article investigates the basic combustion parameters including start of the ignition timing, burn duration, cycle-to-cycle variation, and carbon monoxide (CO), unburned hydrocarbon (UHC), and nitric oxide (NO_x) emissions of homogeneous charge compression ignition (HCCI) engines fueled with primary reference fuels (PRFs) and their mixtures. Two primary reference fuels, n-heptane and iso-octane, and their blends with RON25, RON50, RON75, and RON90 were evaluated. The experimental results show that, in the first-stage combustion, the start of ignition retards, the maximum heat release rate decreases, and the pressure rising and the temperature rising during the first-stage combustion decrease with the increase of the research octane number (RON). Furthermore, the cumulative heat release in the first-stage combustion is strongly dependent on the concentration of n-heptane in the mixture. The start of ignition of the second-stage combustion is linear with the start of ignition of the first-stage. The combustion duration of the second-stage combustion decreases with the increase of the equivalence ration and the decrease of the octane number. The cycle-to-cycle variation improved with the decrease of the octane number.     

硫化橡胶压缩应力松弛试验及对制品密封效果的探讨

应用ＡＧ５００Ａ型电子拉力机对硫化橡胶在不同速度、温度下的压缩过程及压缩恒定后的应力变化进行了试验。该结果应用于橡胶油封研制中，取得很好的效果。同时对压缩应力应化对密封效果进行了讨论。     

Effects of diacrylate monomers on the mechanical properties of polymer concrete made with wet aggregates

Because normal polymer concrete does not work well with wet aggregates, diacrylate (DA) monomers were evaluated for improving the mechanical properties of polymer concrete made with wet aggregates. Zinc diacrylate (ZDA) and calcium diacrylate (CDA) were each used as an additive to resins (two epoxies). The variables were the amount of diacrylate monomers and the aggregate conditions (wet or dry). Compressive strength, flexural strength, workability, working time, and curing time were measured. ZDA was found to improve the workability and the working time, and CDA was found to improve the compressive and the flexural strength. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1077–1085, 2004     

Structural material from waste plastic

In efforts to contribute to community development, particularly in the context of Egyptian communities, waste plastics materials were successfully recycled without the difficult task of separation and reused to economically produce new structural material. Recycling was performed by mixing molten waste plastics with sand to produce these new materials. Samples with different percentages of plastics and different particle sizes of sand were used in the process. Materials showed acceptable density and high compressive strength, which was shown to be at a maximum with contents of about 30–40% waste plastic. Furthermore, certain types of sand having different colors were used to produce attractive materials, suitable for decorative uses. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2543–2547, 2004     

Modification of sandy soil using water‐borne polymer

A new polymeric system has been applied for structural modification of (noncompactable) sandy soils. The system is based on a water‐borne styrene acrylic polymeric formulation (emulsion) containing varying amounts of solid polymer. The present work deals with system optimization and measurements designed to examine the effects of polymer content on hydraulic conductivity and compressive strength. Samples were prepared from prescribed amounts of polymer, water, and sand by using two different preparations methods (mixing and spraying). Measurements of hydraulic conductivity for both sets of samples were conducted in a flexible membrane test apparatus. For the first set of samples, the permeability coefficient of the sand was noted to be reduced 10‐fold (from 10^?5 to 10^?6 m s^?1) upon the incorporation of about 2% polymer. In the second set (samples prepared with the spraying method), the hydraulic conductivity was further reduced to 7.2 × 10^?7 at a polymer concentration of about 2%. Stress–strain measurements made on dry cylindrical specimens disclosed remarkable enhancement in the mechanical behavior of the system. For both types of preparation methods, the compressive strength and modulus of elasticity increased linearly with the polymer concentration in the sample. Scanning electron microscopic examination revealed that the dramatic reduction in the permeability and the improved mechanical properties are attributed to the polymer coverage of the sand particles and the development of interconnecting ties between them. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2484–2491, 2003     

几种合成橡胶的共混、硫化特性与性能的研究

研究了PUR／CR，CSM／NBR，EPDM／IIR几种合成橡胶的共混和硫化特性，以及共混比对共混胶力学性能、耐热老化性能、耐油性能、压缩永久变形和动态力学性能的影响。     

面向能力组件的项目管理系统研究

当前企业面临的多项目管理环境日益突出,如何结合管理创新,搭建有效的项目管理平台,支撑多项目目标实现是众多企业面临的突出问题。文章结合装备研制,分析了多项目环境下传统管理方式存在的不足,提出了能力组件和计划视图的概念,构建了一种基于能力组件的项目管理方法和分级计划管理模型,设计并开发了面向能力组件的项目管理系统。详细说明了系统的技术架构、功能组成和关键技术,并结合应用实践,介绍了一种基于能力组件的项目管理组织模式和计划制定过程。     

基于前向预测并行追踪的视频压缩传感方法

为了减小视频信号采集端的负担,提出一种基于压缩传感理论的视频压缩算法模型。该模型采用广义轮换矩阵获取视频帧的测量值,再结合视频压缩的运动补偿预测关键技术,消除视频帧间冗余。然后在并行贪婪追踪算法中引入前向预测技术作为重构算法,最终获取重构的压缩图像。实验对比了在不同算法下的重构图像和不同采样比下不同算法的重构PSNR值,然后利用所提方法得到视频序列的重构压缩图像。实验结果表明,该算法模型能较精确地获取压缩的视频图像,适合在视频压缩中应用。     

基于压缩的大规模图的割点求解算法

割点求解是图应用中的一个重要操作.深度优先搜索树算法可以解决割点求解问题.但是该算法存在缺点,导致它不能在实际问题中得到很好的应用.这是因为当今数据的两大特点,一是数据规模庞大,对于很多图操作提出了挑战性的要求;二是数据多变,每天数据的大量更新使得传统算法必须依据更新重复计算,浪费了时间和空间.深度优先搜索树算法的时间复杂度为O(|V|+|E|),其中,|V|和|E|分别为图的顶点的数目和边的数目.它能够很好地适应第1个特点,但是对于第2个特点该算法则无能为力.提出一种基于压缩的割点求解算法来解决这个问题.该算法通过点的朴素相似来压缩图,时间复杂度为O(|E|).在得到的无损压缩图上进行割点求解,同时在压缩图上动态地维护点和边的更新,在不解压图的情况下完成图的更新,在更新后的图上进行割点求解,极大地降低了时间和空间消耗.该压缩算法得到的压缩图对其他图操作同样适用.