迎接物联网时代的来临

受益于多项技术的成熟发展,现在正是迈向＂物联网＂（IoT）时代的绝佳时刻。这些技术包括：高速蜂窝网络、蓝牙和Wi-Fi等短距离无线通信技术的快速成长,以及IPv6标准的导入,可为全球各种装置提供足够的IP地址。除此之外,几乎可提供无限计算与存储容量的云计算技术,让即使最普通的终端设备也能支持功能非常强大的应用程式。一个完美的生态系统为着＂物联网＂的兴起应运而生。     

基于振动检测的输送带纵向撕带监测系统

分析了现有的几种输送带纵向撕带的数字化监测方法,提出了振动检测方案,在输送带一侧增加激振信号,通过无线振动信号采集系统采集输送带另一侧的振动信号,通过相关分析去除信号噪声后,应用小波分析检测奇异点,准确判断发生纵向撕带故障的时刻点。介绍了振动检测方案的体系结构,采用无线数据采集装置,应用MatLab软件分析处理数据,使用数字化振动监测方案,有效提高了纵向撕带的故障检测率。     

基于非线性渐增原理获得抛物线型自相似脉冲的研究

采用理论推导和数值模拟相结合的方法研究了脉冲在指数渐增的非线性渐增光纤(NIF)中的自相似演化。结果表明,与双曲渐减的正色散渐减光纤(ND-DDF)类似,利用指数渐增的NIF也可获得具有严格线性啁啾的抛物线型自相似脉冲。同时深入研究了ND-DDF和NIF两种增益等效方式对自相似演化特性的影响,结果表明:1)等效增益决定了脉冲自相似演化的结果,等效方式决定了脉冲自相似演化进程快慢;2)在具有相等的等效增益条件下,脉冲在指数渐增NIF和双曲渐减ND-DDF中演化为相同的自相似脉冲,但是前者对脉冲的自相似演化更高效,即前者实现自相似演化所需光纤长度更短;3)两种增益等效方式所需光纤长度的关系是使得各自具有相同的光纤有效放大因子。     

End-Hall与APS离子源辅助沉积制备的薄膜特性

利用离子束辅助沉积(IAD)技术制备了单层HfO2薄膜,离子源分别为End-Hall与APS离子源。采用Lambda900分光光度计、可变角光谱椭圆偏振仪(V-VASE)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)、ZYGO干涉仪和激光量热计测试了薄膜的透射光谱、光学常数、晶体结构、表面形貌和吸收(1064nm)。实验结果表明,薄膜特性与辅助离子源及起始膜料有着密切的关系。End-Hall离子源辅助沉积制备的薄膜出现轻微的折射率不均匀性。两种离子源辅助沉积制备的薄膜折射率均较高,吸收损耗小,薄膜均为单斜晶相。不同离子源辅助沉积条件下,利用金属Hf为起始膜料制备的薄膜表面平整度较好,其均方根粗糙度和总积分散射均相对较小。与End-Hall离子源相比,APS离子源辅助沉积制备的薄膜吸收相对较小。     

Analysis of secondary throughput and optimization in cooperative spectrum sensing

In cooperative spectrum sensing,more secondary user makes more opportunity for detecting the vacant spectrums,which resulting the spectrum utilization improved,however much bandwidth would be occupied for sending the local observation results,inducing the reduced secondary throughput.In this paper,an adaptive algorithm for selecting detection threshold was proposed,where the maximized secondary throughput can always be achieved while assuring sufficient protection to primary user,regardless of the number of...     

互连设计中的功率完整性

市场对占用空间越来越小的大电流电源互连解决方案的需求不断快速增长,随着对大功率小封装产品的需求增长,要解决新结构和系统平台的功率平衡问题,OEM系统和功率工程师遇上了电气和机械设计方面的挑战,他们需要选定能够确保信号和功率完整性的互连组件。信号连接器的传送速度不断提高,而体积则变得更小;但电源连接器却与之不同,需要一定量的传导材料来传送     

D-PHY MIPI双相机/双显示屏应用中的模拟开关

移动行业处理器接口联盟（MIPI）标准在移动设备行业日益流行。现在的移动设备普遍都带有双屏显示和/或双相机架构,尤其是在中高端产品中。MIPI标准最初定义为点到点架构,故第一代处理器、传感器模块和显示屏都只有单个MIPI端口。     

"产生效益的电力驱动"-客车和重型车辆的动力电子设备

商用车辆传动系统的电气化是ZF公司的基本策略之一.ZF Electronics的动力电子设备不仅经久耐用,而且处于不断创新之中.低运行成本意味着混合动力将能够为重型车辆和公共汽车带来效益.     

Mobility Analysis of Altmann Overconstrained Linkages by Modified Grübler-Kutzbach Criterion

Developing a general mobility method/formula is a hot topic lasting for more than 150 years in kinematics. It is necessary to apply any mobility method to puzzling overconstrained mechanisms for verification of its generality. Altmann linkages are such recognized puzzling mechanisms that their mobility analysis is of important significance. A necessary condition for judging a general mobility method is that the method can be fit for Altmann linkages. Firstly, this study classes Altmann linkages into 17 types in terms of the numbers and types of kinematic pairs, and then Altmann overconstrained linkages are further classified into 4 types. Secondly, the mobility of Altmann overconstrained linkages is systematically analyzed by the Modified Grübler-Kutzbach criterion based on screw theory, where passive freedoms are defined as limb passive freedoms and mechanism passive freedoms. In addition, the full-cycle mobility is judged, which overcomes the shortcoming of instantaneous property of screw theory. It is shown that Modified Grübler-Kutzbach criterion not only obtains the correct numerical mobility, but also gives the mobility character by resolving reciprocal screws for the constraint system. This study lays the foundation of verification for the generality of Modified Grübler-Kutzbach criterion. Besides, Altmann overconstrained linkages almost comprise all kinds of modern parallel mechanisms and some classical mechanisms, which provides an important reference for mechanism mobility calculation.