基于DRFM的卷积干扰技术研究

针对利用常规干扰手段对宽脉冲线性调频雷达干扰时假目标密集度难以提高的现实问题,提出了一种新的干扰样式产生技术,即将接收到的雷达信号样本存入数字射频存储器（DRFM）中,然后对DRFM中的样本延时读出,通过卷积运算后,生成射频干扰信号转发出去。从原理和工程上分别对该技术进行了分析与设计,并进行半实物仿真,验证了这一干扰产生技术的有效性。     

多路UART总线与CAN总线通讯系统设计

主要利用TI公司的多路异步收发器,TLl6C554和PHILIPS公司的SJAl000设计一个多路总线协议转换通讯系统。为了实现4路UART总线与CAN总线之间的相互转换过程,采用微控制器AT89S51来控制通讯数据转换,通过硬件电路实验和软件调试算法,得到了4路串行总线与CAN总线之间的相互透明转换过程。该电路系统大大方便了具有UART接13的设备进行远距离、多节点传输,增强了系统的通讯可靠性。     

基于LTC1068光纤电流互感器的二次侧信号处理

介绍了基于法拉第效应的光纤电流互感器的基本原理,并利用开关电容滤波器LTC1068进行光纤电流互感器二次侧信号处理的设计方法。给出的测试结果表明,利用LTC1068进行二次侧信号的处理方法实用有效,完全满足测量要求。     

基于Kalman预测的四轮转向状态估计算法

针对车辆运动状态测量存在的成本高、难度大问题,提出了一种基于Kalman预测技术的车辆状态估计算法,该估计算法以线性二自由度的车辆模型为基础,对四轮转向过程中车辆横摆角速度、车辆侧向加速度分别进行估计,并与实测结果对比分析,结果表明,Kalman预测算法能准确估计四轮转向时车辆的横摆角速度、侧向加速度,并结合车速信息对4WS转向车辆采用低速时,前后轮采用反向转向、高速时前后轮采用同向转向的控制策略,以实现汽车低速行驶的机动性和高速行驶的操作稳定性。     

电子类基础实验课程混合式教学模式探索

针对电子类基础实验课程教学的特点和不足,本文提出了“线上教学+自主实验+翻转课堂”的混合式教学模式,阐述了集约化线上教学资源平台、智能化翻转教学环境以及多元化过程性考核评价机制三个环节。研究发现,学生的课堂主动参与度、自主学习能力、创新思维能力以及教师的教学创造力得到全面提升。教学环境支持课堂互动和全周期教学行为数据采集,实现了信息技术与实验教学的深度融合。     

多站联合测控中USB跟踪链路快速切换的实现

介绍了统一S频段(USB)测控设备跟踪链路切换的原理,针对多站联合测控中手动切换链路效率低的不足,为满足任务高难度、严要求的需要,缩短切换时间,提高切换准确性,提出以宏命令方式进行链路切换操作,应急状态下直接调用宏文件的方法,并在C#语言和.NET环境下采用用户数据报协议(UDP)实现快速切换,较原手动切换方法速度提高了约4倍.     

基于图像匹配的定位分析

图像匹配是一种重要的图像处理技术,在导航、定位等领域有着广泛的应用。首先给出了图像匹配问题的原理描述,分析了基于区域匹配算法的一般思路,研究了图像匹配算法的组成要素。算法中采用相关系数作为相似性测度。为减小搜索空间提高算法性能,采用由粗到精分层匹配的控制策略进行算法优化,实现了算法的加速。通过匹配仿真试验,验证了算法的可行性、有效性。     

音频信号高速率采样中混沌实时加密的实现

通过对音频信号高采样率采样过程中实时加密的研究,提出了一种结合异或运算和循环移位操作的双重置乱混沌加密算法,对高采样率音频信号进行加密和信息掩盖.加密序列和循环移位序列均由混沌系统产生,整个过程在数字信号处理器(DSP)平台进行了验证.此方法运算速度快,安全性高,易于在嵌入式系统中进行应用.     

Growth of CdS Nanoneedles by Pulsed Laser Deposition

CdS nanoneedles have been grown on Ni-coated Si (100) substrates by pulsed laser deposition. Substrate temperature and Ni-catalyst layer thickness were found to have great effects on the density and morphology of the as-grown CdS nanoneedles. Crystalline CdS nanoneedles with middle diameter and length of about 40?nm to 100?nm and 400?nm to 1000?nm, respectively, could be obtained at 350°C to 450°C on Ni-coated silicon (100) substrates, and nanoneedles with good shapes were obtained at 400°C substrate temperature. From the cross-section morphologies, it was found that the CdS nanoneedles grew out of the base CdS crystallite layer with thickness of about 500?nm. Based on the experimental results, vapor?Csolid and vapor?Cliquid?Csolid growth modes describe the CdS nanoneedle growth.     

Influence of Substrate Temperature on Structural Properties and Deposition Rate of AlN Thin Film Deposited by Reactive Magnetron Sputtering

Aluminum nitride (AlN) thin films with c-axis preferred orientation have been prepared by reactive direct-current (DC) magnetron sputtering. The degree of preferred crystal orientation, the cross-sectional structure, and the surface morphology of AlN thin films grown on Si (100) substrates at various substrate temperatures from 60°C to 520°C have been investigated by x-ray diffraction, scanning electron microscopy, and atomic force microscopy. Results show that the substrate temperature has a significant effect on the structural properties, such as the degree of c-axis preferred orientation, the full-width at half-maximum (FWHM) of the rocking curve, the surface morphology, and the cross-sectional structure as well as the deposition rate of the AlN thin films. The optimal substrate temperature is 430°C, with corresponding root-mean-square surface roughness (R _rms) of 1.97?nm, FWHM of AlN (002) diffraction of 2.259°, and deposition rate of 20.86?nm/min. The mechanisms behind these phenomena are discussed. Finally, film bulk acoustic resonators based on AlN films were fabricated; the corresponding typical electromechanical coupling coefficient (k _t ² ) is 5.1% with series and parallel frequencies of 2.37?GHz and 2.42?GHz, respectively.