连续刚构箱梁剪力滞效应分析

以靖远黄河大桥这一五跨连续刚构箱梁桥为工程背景,运用当量截面法计算靖远桥的剪力滞系数。分析其简化计算,将结果与ANSYS分析结果进行比较。     

Preparation of BaTiO3-Based Nonreducible X7R Dielectric Materials Via Nanometer Powders Doping

Nonreducible X7R dielectric materials, which can be cofired with Ni electrode, were obtained by doping nanometer additives to BaTiO₃ powders synthesized by employing a sol-gel method. The crystallization process, structure and constituent of nanometer additives, as well as morphologies were studied via differential thermal and thermogravimetric analyses (DTA/TG), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effects of the calcining temperature of dopants on the dielectric properties were also discussed. The experiment results proved that higher-performance X7R dielectric materials could be obtained via nanometer doping compared with conventional doping. At room temperature, dielectric constant is more than 3000; dielectric loss lower than 1.0% and insulation resistance more than 10¹¹Ω ⋅cm.     

加工配送，钢铁企业营销新战略

加工配送是当前一种新型的钢材物流服务方式，在营销战略方面已经越来越受到钢铁企业的高度重视。对当前国内钢材加工配送的市场状况的成因进行了分析，对部分生产企业的基本特点进行了描述，并对钢材加工配送未来的发展方向进行了阐述。     

Effect of Hot Band Annealing on Magnetic Properties in 3% Si Grain‐oriented Electrical Steels

Hot band annealing is known to be a prerequisite for good magnetic properties irrespective of manufacturing methods in grain‐oriented Fe‐3 wt.% Si electrical steels. In this study, the effects of hot band annealing on magnetic properties were investigated in 3% grain‐oriented electrical steels of low soluble AI contents and one‐stage cold rolling. Microstructure and precipitate distribution were compared with hot band annealing conditions. Secondary recrystallization behaviour with hot band annealing condition was also discussed.     

爪式无油增压传输真空泵的设计

爪式无油增压传输真空泵的设计和制造,使其成功的应用于各种气体物料在真空负压条件下的增压传输工艺作业,成为核燃料浓缩工业等现代高新技术领域最新的科技成果,对于化工和其他工业应用爪式无油真空泵进行气体物料增压传输工艺作业也具有指导意义.本文简要的叙述了爪式无油增压传输真空泵的设计依据、技术要求、驱动传动系统、结构选择及其工作原理.该系列产品在实际应用中也取得了良好的效果.     

机械设计制造及其自动化专业高素质人才培养探讨

简要介绍机械设计制造及其自动化专业人才的培养目标和业务规格，特别对如何培养专业水平高、实践能力强、综合素质全面的高层次专业人才进行详细探讨。     

用ANN决定电力系统的切负荷控制

将神经网络用于电力系统切负荷实时稳定控制，分析了神经网络输入量的选取问题，并给出了陕西关中电网切负荷稳定控制的算例。     

行为经济学——一门新兴的学科

进入９０年代以来，经济的发展又一次推动着经济理论的发展和演变．新经济的现象不断出现，使得经济学靠模型和计算机未能找到解决问题的答案，正统经济学再次受到严峻的挑战．与此同时，行为经济学，以人类的行为作为基本研究对象的经济理论，正逐步发展起来．本文将介绍行为经济学的产生和发展、主要理论观点以及一些行为分析对中国社会经济发展的启示．     

基于图象识别的水泥预加水成球闭环控制方法

分析现有参加水成球开环控制系统存在的问题，提出一种基于计算机图象识别的技术的水泥预加水成球闭环控制方法。