双包络TI-环面蜗杆传动的二次包络分析

在一次包络分析的基础上,着重进行了二次包络齿面接触分析,推导出了蜗杆和蜗轮齿面方程。齿面接触分析表明：齿面呈双线接触,润滑条件好,承载能力大,在重型机械传动装置中具有实用价值。     

嵌入式多媒体播放器USB驱动程序设计

本文首先从基于TI DM320的PMP(Portable Multimedia Player,便携式多媒体播放器)解决方案入手,分析了该方案的软、硬件体系框架.接着,仔细研究了嵌入式Linux.然后,以TI DM320平台为例,探讨了嵌入式Linux驱动程序的设计.同时,设计了PMP USB的驱动程序.     

基于移位读写指令的冲床控制系统设计

设计了一种基于移位读写指令的冲床控制系统,该控制系统中,PLC将来自触摸屏、外部开关信号通过输入、输出接口控制三相交流异步电机、伺服电机、步进电机,进而实现十字滑台X轴和Y轴运动、冲头升降、冲头冲孔等操作;通过采用移位写入SFWR、移位读出SFRD写指令,有效解决了选择加工模式时,孔随机选择,难以排序的问题,通过绝对定位指令DRVA,化解了随机选择时加工孔之间位置不确定性,无法准确定位的问题。借助于嵌入版MCGS软件中安全机制,采用凭账号密码登陆,避免无关人员误操作,触摸屏TPC7062TI中直观显示冲床加工孔的位置,实时显示各电机的运行状态,便于实现远程监控。实践表明,该冲床控制系统能够实现控制要求,具有工程应用的价值。     

Joining of Cf/SiC composite to Ti alloy using composite filler materials

Abstract

C_f/SiC was successfully joined to Ti alloy with Ag–Cu–Ti–W, Ag–Cu–Ti–SiC and Ag–Cu–Ti–TiC mixed powders by some suitable brazing parameters. Microstructure and shear strengths of the preformed joint were investigated. The results showed that the W particulate and reaction products can uniformly distribute in the brazing layer of the performed joint. These composite brazing layers relaxed the thermal stress of the joint effectively. These characteristics were beneficial to the joint, which had shear strengths that were significantly higher than the optimal shear strengths of the joint brazed with pure Ag–Cu–Ti at room temperature and 500°C.     

Production of MgAl2O4 – Ti(C,N) composite ceramics by aluminothermic reduction in reducing atmosphere

Abstract

In the presence of N₂ and CO gases, MgAl₂O₄ – Ti(C,N) composite has been synthesised by aluminothermic reduction. The phase characterisation and microstructure of this novel composite were investigated by powder X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The results show that the nitridation reaction begins at 1100°C. With an increase of temperature, TiC starts to appear and forms Ti(C,N) solid solution with TiN; the grain size of Ti(C,N) grows with increasing temperature and the final product is MgAl₂O₄ – Ti(C,N).     

TI蜗杆传动齿面接触误差的计算与分析

采用CAD三维造型技术与数值计算相结合的方法计算分析了各种加工误差及装配误差对TI蜗杆传动齿面接触的影响。其结果对有效提高TI蜗杆副的制造精度有指导意义。     

ST谈产品策略：传感、绿色能源和控制

正数字化时代将造就更多模拟产品的商机,2009年TI(德州仪器)全球模拟业务占总体业务41%,并且还在持续增长。TI高性能模拟产品部高级副总裁Art George日前在接受EDN China专访时表示,TI每年有800多种模拟产品推出,他的部门每年推出300种。但尽管如此,TI同样     

Effect of additions of Ti,B and Ce on microstructural stability,creep strength and creep damage in austenitic stainless steel

Abstract

Optical and transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis of bulk extracted precipitate residues were carried out on long term (more than 80 000 h) creep tested (at 1023 K) type 304 austenitic stainless steels with different levels of Ti content to assess the microstructural stability and creep strength. B and Ce were added to the steels to suppress the creep cavitation. Finer Ti(C,N) particles with higher density and narrower size distribution were observed in steels with a higher Ti content, resulting in an increase in the creep rupture strength. However, higher Ti content increased the intergranular precipitation of the σ phase on longer creep exposure, resulting in the increase in creep cavitation and in the decrease in creep rupture strength. The study indicated an optimum level of Ti and {C + (6/7)N} content with the Ti/{C + (6/7)N} ratio close to the stoichiometric value of the Ti(C,N) precipitate particles that should also be close to their solubility limit at the solution heat treatment temperature.     

触摸按键在LED平板电视上的应用

本文主要介绍了触摸按键工作原理，以及在LED平板电视产品中硬件电路和软件程序是如何实现的过程，为今后在平板电视产品中设计触摸按键提供一些参考。     

未来市场:功能级SoC加可编程DSP

董永红表示,未来的市场可能是功能级的SoC,加一个可编程的DSP。由上游半导体厂完成80%的工作,下游的系统厂完成剩下的20%工作。他把这种变化形象比喻成DSP2.0时代,其标志是不再以运算能力为出发点,而是讲求功能为主。