TR组件发射波形畸变批次故障分析

在某批次收发组件(TR组件)随整机系统测试时,出现发射波形畸变故障现象.通过对该故障的分析,暴露出TR组件测试系统衰减器与整机测试系统的衰减器类型和衰减量不同,造成测试结果不一致;TR组件的相关检验文件只按技术协议要求施加标准激励,无静态测试,从而造成小信号输入产生自激的批次故障;TR组件所用功放在脉冲供电方式下防过冲措施不到位等3方面问题.     

自适应粒子群优化算法及其在测试数据生成中的应用研究

针对粒子群算法易陷入局部最优解及搜索精度低的问题,本文提出一种约简的自适应粒子群优化算法并应用于测试数据的自动生成.首先对粒子群进化方程约简,提出无速度项的粒子群进化方程;然后,对约简后的方程提出基于惯性权重的自适应调整方案,将惯性权重直接作用于粒子的位置,并根据粒子的适应度及聚集度将种群划分为三部分.实验表明,该方法可以有效地提高自动生成测试数据的效率.     

PCB企业要在“降污减排”上“升级”和打漂亮仗

文章概述了PCB企业在生产和发展的过程中必须坚持“环保优先”原则,在“降污减排”和“清洁生产”上不断“升级”,坚决走PCB“清洁生产”的世界强国的道路!     

基于TFDS-4系统运用研究

为进一步提高货车车辆检测效率,及时准确发现货车运行中的故障,确保车辆运行安全,太原铁路局在湖东车辆段试运用一套货车故障图像自动识别预警系统(TFDS-4),通过相机模块在线对货车侧下部及货车底部的图像采集,图像传输至服务器,自动拼图、与标准模型进行整幅比对,自动识别货车隐蔽性故障和常见故障,大大降低室内作业人员的看图压力,有效提高货车车辆检测效率,确保货车运行安全,同时,适当精减湖东集中检测中心看图工位,解决列检人员紧张问题,节约人力成本。     

MIMO雷达收发两级STAP 原理与性能讨论

提出了一种基于多输入多输出雷达的收发两级空时自适应处理(STAP)算法。收发两级STAP 与收发联合STAP 不同在于:分别对等效发射端与接收端进行空时处理,从而达到降低运算量效果。文中给出收发两级STAP 所构造的协方差矩阵与收发联合STAP 协方差矩阵关系,并且给出输出信杂噪比(SCNR)表达式。从仿真结果看,收发两级法SCNR 性能与收发联合STAP 相近,且计算量有明显降低。此外,收发两级STAP 也可应用到收发联合降维算法中,得到与收发联合降维算法一样的性能,且运算量进一步降低。     

多光子Jaynes-Cummings模型场熵的演化

本文研究了多光子Jaynes-Cummings(J-C)模型场熵的演化性质、光场涨落的量度以及模型的有效性.     

Photoreduced Graphene Oxide as a Conductive Binder to Improve the Water Splitting Activity of Photocatalyst Sheets

Photocatalyst sheets consisting of H₂ evolution photocatalyst (HEP) and O₂ evolution photocatalyst (OEP) particles applied to an underlying conductive layer show promise with regard to promoting efficient and scalable water splitting. One of the most important challenges in enhancing the performance of such systems is establishing efficient charge transfer between photocatalyst particles that are often thickly stacked on the conductive layer. In this study, reduced graphene oxide (RGO) is investigated as an additional solid mediator to the conductive layer to bridge particulate photocatalysts and thus ensure effective charge transfer. Photocatalyst sheets made of RhCrO_x/LaMg_1/3Ta_2/3O₂N as the HEP and BiVO₄:Mo as the OEP are applied to an Au layer together with RGO. The activity of this system is 3.5 times greater following the incorporation of the RGO. Charaterization analyses reveal that RhCrO_x/LaMg_1/3Ta_2/3O₂N particles tens of nanometers in size are fixed on larger, micrometer‐sized, BiVO₄:Mo particles by RGO photoreduced from GO in situ. The RGO facilitates charge transfer between particles that are distant from the underlying Au layer and thus involves more photocatalyst particles in the water splitting reaction. It is concluded that the incorporation of conductive materials into the photocatalyst particle layer can effectively enhance the water splitting activity of photocatalyst sheets.     

电磁脉冲作用下PIN二极管的响应

采用自主开发的二维半导体器件效应模拟软件,对电磁脉冲作用下PIN二极管的响应进行了数值模拟研究,分析了PIN管在脉冲电压上升沿时间内出现的电流过冲现象。结果表明:过冲电流与高频下PIN二极管的电容性有关,过冲电流的峰值与上升沿时间有关,上升沿时间越短,峰值越大;PIN管的掺杂也会对过冲电流产生影响,P层、N层的掺杂浓度越高,过冲电流的峰值越大,过冲电流的波形下降越快;I层掺杂浓度对过冲电流也有一定影响,但并不显著。     

Payne Effect and Weak Overshoot in Rubber Nanocomposites

Payne effect and its associated weak overshoot are of importance for understanding and regulating the softening of rubber nanocomposites under large amplitude oscillations.Herein,Payne effect in diverse filled vulcanizates is investigated for generalizing the common characteristics.Master curves of strain amplitude dependent storage modulus are created with respect to microscopic strain amplitude of the matrix,revealing a matrix-dominated elastic nonlinearity being independent of type and dispersity of filler,crosslinking density and sol fraction of matrix and filler-rubber interfacial interactions.However,carbonaceous fillers with higher affinity to the rubber matrices yield lower strain amplification and higher overshoot behavior in comparison with siliceous silica.The investigation would be illuminating for preparing rubber nanocomposites with optimized reinforcement and softening performances.     

一体化GPS磁窗天线的设计与实验研究

设计了一种用于减缓高超声速飞行器通信中断的、中心频率为1.575 GHz、一体化GPS磁窗天线,并开展了静态验证实验。设计的磁窗天线由贴片微带天线和永磁体一体化组成,结构尺寸为100 mm100 mm75 mm,并设计了防护结构。磁窗天线的贴片微带天线不会对永磁体磁场产生影响,而永磁体也不会改变贴片微带天线谐振频率;设计的磁场防护装置对天线轴向的磁场强度没有减弱,对非传播方向完全屏蔽,起到了保护作用。针对厚度为25.5 mm、电子密度为61010～11011 cm－3的等离子体,设计的磁窗天线能将1.575 GHz电磁波透射系数从－19～－23.5 dB提高到－11～－16 dB。研究结果表明：设计的一体化GPS磁窗天线能够一定程度减缓电子密度为61010～11011 cm－3的等离子体对1.575 GHz电磁波通信影响,且实现了磁窗天线的小型化,并提高了安全性。