球化退火态钢脱碳层深度的金相法测定

论述了国内外金相测定球化退火钢脱碳层深度的标准方法和常用方法存在的不准确性和不适用性问题,提出了解决问题的途径——定量金相法。     

激光法合成SiC超细粉末物理化学过程的研究——Ⅰ.实验规律及粉末特性

用50W连续波CO_2激光器为热源,诱发SiH_4和C_2H_4反应,合成SiC超细粉末。实验确定了反应腔体内压力p、气源中的C/Si原子比、喷嘴内径2r以及激光功率密度与粉末特性之间的关系,并对合成的产物进行物理、化学表征。     

Influences of artificial pre-stressing on ply stresses and tensile properties of Vinylon fibre-reinforced aluminium laminates (VIRALL)

A simple micromechanical model based primarily upon the rule-of-mixtures is developed which allows prediction of the effects of fibre preload on the ply stresses (i.e., the initial residual stresses of fibre, adhesive and matrix) induced within VIRALL laminates, and the tensile stress-strain curves and mechanical properties of VIRALL laminates. The analysis of the ply stresses of VIRALL laminates indicates that pre-stressing will dramatically influence the ply stresses. The predicted tensile stress-strain curves of VIRALL laminates are in good agreement with the experimental curves and the results show that the stress-strain curves of VIRALL laminates move upwards when the prestress increases. The predicted tensile mechanical properties of VIRALL laminates at room temperature show good agreement with those obtained experimentally; both show that prestress can improve the tensile properties (i.e., elastic limit strength, 0.2% yield strength and failure strength) of VIRALL laminates.     

6—10kV电力系统氧化锌避雷器的选择

本文就6～10kV配电系统中常见设备用氧化锌避雷器的选择做一简要阐述。 氧化锌避雷器按被保护的对象大体可以分为以下几种类型: 配电型:主要用于保护相应电压等级的开关柜、箱式变、柱上油开关、电缆头等免受大气和操作过电压。 电站型:保护发电厂、变电站中交流电气设备免遭大气和操作过电压的破坏。 电器型(并联补偿电容器型):主要用于保护并联电容器、电流互感器和高频阻波器等。     

光传操纵系统综述

在简要回顾飞机操纵系统的发展历史的基础上,详细介绍了光传操纵系统的发展状况和应用前景。针对航空领域光纤传输的特点,对光传操纵系统中光电器件的选择及关键技术等进行了分析。     

非线性半导体SiC微粉及其半导体漆（带）特性试验方法的研究

本文介绍了非线性半导体 SiC 微粉及其半导体漆(带)伏安特性的测量方法,以及用微机程序计算其非线性特征参数的方法,从而为研究新型防晕结构提供了科学有效的手段。     

浅析两种分布式路由选择算法

本文介绍及分析了两种基本的动态路由选择算法.     

破片式战斗部优化设计技术研究

侧重研究了破片式战斗部装药外形的优化设计技术。提出了装药外形与破片飞散特性（如破片飞散角，分布带宽等）之间的数学描述；建立了圆弧和对数螺线装药外形母线与战斗部其他设计参数间的数学模型。在假定约束条件下，优化设计了破片了聚焦式战斗部的结构参数；静爆试验结果表明，破片分布与理论计算吻合较好。     

Thermal and mechanical properties of epoxy composites reinforced by a natural hydrophobic sand

If a low weight percentage of crude fine fillers can improve properties of polymer materials directly without complicated chemical treatment process involved, it will be significant for many industrial applications. Our previous study indicated that a kind of Cancun natural sand could be an effective filler material for polymer composites. In this current work, the epoxy composites reinforced by this kind of natural sand particles were prepared and thermal and mechanical properties of the composites containing up to 5 wt % of the sand particles were characterized. Results showed that the highest flexural strength appears in the epoxy composite containing 1 wt % sand particles. A damage model was used to interpret the flexural properties, which showed an acceptable agreement with the experimental results. The glass transition temperature, high temperature storage modulus, and dimensional stability of the sand/epoxy composites monotonically increased with the addition of the sand particles. The sand particle/epoxy composites also displayed a noticeable enhancement in thermal conductivity. Theoretical analysis showed that in addition to conduction, other heat transport mechanisms played roles in the improved heat transmission through the composites. As a natural porous micron-scale material, Cancun sand has the potential for applications in cost-effective composites with enhanced mechanical and thermal properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

管线油电损耗的灰色模型及预测

对于管道运输来说，影响输油成本变化的因素有很多，但是对总成本影响最大的是油电损耗费用。由于来自现场的输量和相关参数样本数据不足，只知道连续几年的流量、油电损耗，要预测将来每年的油电损耗，经典经济数学不能满足这样的研究。然而灰色系统理论要求的研究样本较少，只要知道连续几年的流量、油电损耗，就能预测将来每年的油电损耗，估算其输油成本，且模型精度较高。利用灰色系统理论，以输油管线每年的输量、相应的电耗和油耗为时间序列，建立了三元素非等间距GM(1，1)模型，该模型为预测管线年输油成本提供了可靠的依据。