系统级封装新型埋入式电源滤波结构的研究

在高密度小尺寸的系统级封装(SiP)中,对供电系统的完整性要求越来越高,多芯片共用一个电源网路所产生的电压抖动除了会影响到芯片的正常工作,还会通过供电网路干扰到临近电路和其他敏感电路,导致芯片误动作,以及信号完整性和其他电磁干扰问题.这种电压抖动所占频带相当宽,几百MHz到几个GHz的中频电源噪声普通方法很难去除.结合埋入式电容和电源分割方法的特点,提出一种新型高性能埋入式电源低通滤波结构直接替代电源/地平面.研究表明,在0.65～4GHz的频带内隔离深度可达-40～75 dB,电源阻抗均在0.25ohm以下,实现了宽频高隔离度的高性能滤波作用.分别用电磁场和广义传输线两种仿真器模拟,高频等效电路模型分析这种低通滤波器的工作原理以及结构对隔离性能的影响,并进行了实验验证.     

汽油机掺醇燃烧进气油膜湿壁温度预测

对进气口喷射汽油机进气门处传热过程进行了分析,建立了进气油膜吸附壁面温度模型.通过冷机状态起动试验和温升过程数据分析,对已有模型结构进行了细化和改进,并基于试验数据及MATLAB参数辨识工具箱对模型参数进行了辨识.根据模型结构及试验数据,分析了油膜吸附壁面温度的关键影响因素和影响规律,以及不同掺混比例乙醇汽油下的差异.油膜吸附壁面温度变化规律类似一阶惯性系统特性,其温升时间常数可视为进气流量的单值函数,但稳态项与多个发动机工况参数有关,而不同乙醇汽油下油膜吸附壁面温度则差异不大.改进与辨识后油膜吸附壁面温度模型在纯汽油及掺醇汽油下均具有较高的预测精度,可直接用于油膜动态补偿器设计.     

高速电路板的电磁兼容性分析

文章介绍了基于信号完整性（SI）、电源完整性（PI）与电磁兼容性（EMI）的高速PCB的设计方法,并利用Cadence软件针对高速PCB设计中的信号完整性、电源完整性及电磁兼容性中的基本问题进行仿真与分析。     

The Korea Advanced Manufacturing System (KAMS) Project

The Korea Advanced Manufacturing System (KAMS) is one of the Highly Advanced National (HAN) Projects planned to achieve significant technological advances in Korea. The aim of this project is to create new processes and technologies for managing and integrating manufacturing systems. The key to sustaining economic growth and surviving global competition is to develop advanced manufacturing systems technology. The Korea Institute of Industrial Technology (KITECH) began this project in 1992 with support from the Ministry of Trade, Industry and Energy and the Ministry of Science and Technology. The project is divided into three phases, each phase consisting of project groups which include several research projects. The main project groups are ‘next-generation machining system' and ‘assembly and inspection system for electronic products'. The names of research projects are listed, and brief explanations are also introduced in this paper. The KAMS Project is expected to result in many benefits for manufacturing industry. The increase in productivity and system accuracy, and reduction in lead-time, will give renewed vitality to Korean manufacturing industry.     

EPG的监测

本文介绍了构成电子节目指南(EPG)的主要业务信息表，并对最复杂的事件信息表(EIT)表结构及其播发的过程进行了阐述。作者从多年的数字电视方面的工作经验出发，深深地感觉到EIT本身结构及其播发过程的复杂性，认为对EIT的监测应该给予更多的关注。提出了一种监测EPG的解决方案，对监测数据的层次进行了划分，并且介绍了对监测结果的显示要求。     

数字电视传输流中PSI/SI信息构成和作用

主要介绍了数字电视系统中传输流采用MPEG-2标准进行压缩时,传输流的有效载荷中PSI/SI信息的构成,以及组成PSI/SI的各种表的主要作用.     

Synthesis and characterisation of Si3N4p/Cu nanocomposite powders by high energy ball milling

Abstract

The present work reported the preparation of Cu–25 wt-%Si₃N₄ nanocomposite powders via high energy ball milling (HEBM). The phases and morphologies of as-milled powders with various milling times were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results showed that with increasing the milling time, the irregularly shaped Cu powder became flattened, and, subsequently, refined and near spherical. After 12 h milling, the particle size of Cu–Si₃N₄ composite powders was in the range of 200–300 nm, while the grain size of Si₃N₄ particulates, 10–25 nm, was well within a nanometre scale. A uniform distribution of the nanosized Si₃N₄ reinforcing phase throughout the Cu matrix was successfully obtained. A reasonable mechanism for the formation of Cu–Si₃N₄ nanocomposite powders during HEBM was also proposed.     

SI基本单位量子化重新定义及其意义

第26届国际计量大会(CGPM 2018)表决通过了国际单位制(SI)中7个基本单位的重新定义,其中千克、安培、开尔文和摩尔的定义基于新的物理概念,米、秒和坎德拉的定义表述进行了重新修订;运用自然法则创建测量规则,自此,新修订后的SI基本单位的定义来自一组定义常数,实现了量子化定义。新SI更具有稳定性和普适性,新SI的实现为各国计量领域将带来机遇与挑战。     

开关电流电路及其误差分析

开关电流(SI)技术是有望取代开关电容技术的一种新的采样数据技术。首先介绍了开关电流技术的概念及优点,然后以SI电路基本存储单元为例分析了开关电流电路中可能存在的误差。最后,针对电路中存在的失配误差、传输误差、噪声误差及电荷注入误差等提出了一些解决方法,如S2I技术等。     

发动机自动测试台架的数据采集系统

本文提出了“动作流水、时间并行”的数据采集方式，并且在工业控制机上用该方式实现对汽车发动机参量的数据采集，保证了发动机自动测试台架精确、稳定、可靠。