利用Matlab和Simulink对DSP进行系统级的设计方法

本文介绍了利用Matlab和Simulink中Developer‘s Kit for TI DSP工具对DSP进行系统级设计的方法。     

添加剂硫对Ni-Mn-Co粉末触媒合成金刚石的影响

本研究考察了高温高压条件下添加剂硫对Ni-Mn-Co粉末触媒合成金刚石的影响，并在此基础上，考察了含硫金刚石的机械性能。研究表明：硫对Ni70Mn25Co5粉末触媒合成金刚石的成核有明显的抑制作用，随着硫含量的增加，成核呈减少趋势；添加剂硫影响晶体的颜色和晶形，随添加剂含量的增加，晶体的颜色呈加深趋势，硫的添加使晶体的表面出现孔洞缺陷，当硫含量较低时，孔洞缺陷多分布在（100）晶面上，当硫含量较高时，（111）晶面上也出现孔洞，致使晶体的完整性受到制约；添加剂硫影响金刚石的机械性能，随着添加剂硫含量的增加，含硫金刚石的冷冲击强度（TI）和热冲击强度（TTI）呈明显的下降趋势。     

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Matlab的TMS320LF2407程序快速设计

在Matlab/Si mulink环境下,用图形化的方式设计DSP程序,可简化程序的设计。利用Embedded Targetfor TI C2000DSP工具包,设计DSP的ADC转换程序;利用Si mulink的数字信号处理工具包,设计FIR滤波器进行滤波处理;给出在修改生成的C语言程序时如何使DSP能正确运行。设计的程序在TMS320LF2407A处理器上运行正确。     

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).     

存在装配误差时TI蜗杆传动接触分析

利用三维图形和数值分析相结合的方法,研究了存在装配误差时TI蜗杆传动齿面接触的求解问题.借助蜗杆蜗轮齿面接触的三维直观效果,采用数值逼近的方法确定了TI蜗杆传动齿面接触位置,在此基础上分析了装配误差对TI蜗杆传动啮合接触性能的影响.     

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。     

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.