C／C复合材料摩擦磨损特性的研究

在Ａｍｓｌｅｒ环块式磨损试验机上，进行了Ｃ／Ｃ复合材料与Ｃ／Ｃ复合材料、聚四氟乙烯（ＰＴＦＥ）及不锈钢（１Ｃｒ１８Ｎｉ９Ｔｉ）三对摩擦副的摩擦磨损试验。测定了在相同转速、载荷、磨损时间条件下，三对摩擦副的摩擦系数及磨损率。用扫描电子显微镜（ＳＥＭＭ）观察了三对摩擦副的磨损表面形貌。初步探讨了Ｃ／Ｃ复合材料的摩擦、磨损特性及机理，为Ｃ／Ｃ复合材料磨擦件制作提供了实验依据。     

热解碳界面层对碳＼碳化硅复合材料拉伸性能的影响

本文研究了用化学气相渗工艺的均热法制备炭纤维增强碳化硅（Ｃ／ＳｉＣ）复合材料，其中有部分材料在沉积碳化硅之前先沉积少量热解碳，以作为界面层。对有界面层和无界面层的材料进行了拉伸试验。用金相显微镜和扫描电镜观察了材料微观结构及继口形貌。结果表明，Ｃ／ＳｉＣ材料力学性能主要取决于纤维与基体的界面。有热解碳界面层的Ｃ／ＳｉＣ材料，在拉伸断裂时出现大范围脱粘，断口类似毛刷，材料强度大，断裂功也大，有很大的     

同轴连接器S参数建模及退化机理

以Sub-Miniature-A（SMA）型连接器为例,建立了基于等效电路法的同轴连接器S参数模型,给出了模型参数的计算方法,模拟了连接器的高频特性.特别是针对连接器接触表面退化,计算出了接触表面的高频电参数,建立了S参数与退化表面的关系,可作为连接器故障特征应用于连接器的寿命预测、可靠性评估以及故障诊断的研究.     

Lifetime prediction of electrical connectors under multiple environment stresses of temperature and particulate contamination

Electrical connectors play a significant role in the electronic and communication systems. As they are often exposed in the atmosphere environment, it is extremely easy for them to cause electrical contact failure. It is essential to carry out the reliability modeling and predict the lifetime. In the present work, the accelerated lifetime testing method which is on account of the uniform design method was designed to obtain the degradation data under multiple environmental stresses of temperature and particulate contamination for electrical connectors. Based on the degradation data, the pseudo life can be acquired. Then the reliability model was established by analyzing the pseudo life. Accordingly, the reliability function and reliable lifetime function were set up, and the reliable lifetime of the connectors under the multiple environment stresses of temperature and particulate contamination could be predicted for electrical connectors.     

一种超宽带高场强的生物电磁效应实验装置

对生物电磁效应相关实验工作的回顾表明,当前实验装置主要为窄频电磁辐射装置和脉冲电磁辐射装置,通用性不足.随着无线系统的发展,电磁环境频谱将横跨数千赫兹到毫米波,且为多频段复合电磁场,其中包含超宽带矢量调制的电磁场,有一些具有脉冲时隙特征,显然生物电磁效应实验需要模拟、复现这样的电磁环境,而传统的电磁辐射实验装置具有显著...