基于netX50芯片的Ethernet／IP接口设计

主要对工业以太网进行了初步的阐述,并提出了一种基于netX50网络控制的实现工业以太网协议Ethernet／IP通信接口的设计。该设计采用C8051F020作为主控制器,netX50作为辅助控制器,MCU通过DPM双端口内存访问netX50并实现网络通信。     

Determination of threshold stress intensities: fatigue of low alloy steel BS4360-50D

An experimental method for obtaining the effective stress intensities necessary for cyclic crack growth prediction is described. Also, it is shown that the critical threshold value, ΔK_{c, th}, can be estimated using simple energetic considerations, leading to an equation:

$\text{Δ}\text{K}{}_{\mathrm{c,th}}\text{=}\text{4π}\text{E}\text{λ}{}_{\mathrm{s}}\text{2?}\text{(θ}{}_{\mathrm{uts}}\text{?}{}_{\mathrm{f}}\text{)}\text{((1+}\text{n}\text{)θ}{}_{\mathrm{yc}}\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$

The threshold values obtained compare well with the experimentally observed values for a structural steel BS 4360-50D and for other steels.     

A model for fatigue crack growth in a threshold region

The prediction of fatigue crack growth at very low ΔK values, and in particular for the threshold region, is important in design and in many engineering applications. A simple model for cyclic crack propagation in ductile materials is discussed and the expression

$\text{da}\text{dN}\text{=}\text{2}{}^{\mathrm{1+n}}\text{(1?2v)(ΔK}{}^2{}_{\mathrm{eff}}\text{?ΔK}{}^2{}_{\mathrm{c,eff}}\text{)}\text{4(1+n)π σ}{}^{\mathrm{1?n}}{}_{\mathrm{yc}}\text{E}{}^{\mathrm{1+n}}\text{?}{}^{\mathrm{1+n}}{}_{\mathrm{f}}$

developed. Here, n is the cyclic strain hardening exponent, σ_yc is cyclic yield, and ε_f is the true fracture strain. The model is successfully used in the analysis of fatigue data BS 4360-50D steel.     

当代美国军事文化热点问题研究

军事文化,是军队战斗力的基础。冷战结束后,世界局势相对缓和,而军事任务却没有减少反而更加繁重,美国则更加深入地研究军事文化在新形势下的改革应对,从而确保美国军事人为维护超级大国的堡垒地位而作好准备。     

Effect of annealing on the characteristics of Au layers grown on the high-temperature deposited Ni50Fe50 layers

80 nm-thick Ni₅₀Fe₅₀ layers were sputter-deposited on glass substrates at 400 °C and then Au layers were sputter-deposited on the Ni₅₀Fe₅₀ layers. The Au/Ni₅₀Fe₅₀ bilayer films were annealed in a vacuum of 5×10⁻⁴ Pa from 250 to 450 °C for 30 min or 90 min. The characteristics of the Au layers were studied by Auger electron spectroscopy, field emission scanning electron microscopy, X-ray diffraction and a four-point probe technique. When the annealing temperature reaches 450 °C, Fe and Ni atoms diffuse markedly into the Au layer and the Fe content is more than the Ni content. When the annealing temperature is lower than 450 °C, the grain size of the Au layers does not change markedly with annealing temperature. However, as the annealing temperature reaches 450 °C, the annealing promotes the grain growth of the Au layer. As the annealing temperature exceeds 300 °C, the resistivity of the bilayer films increases with increasing annealing temperature. The diffusion of Fe and Ni atoms into the Au layer results in an increase in the resistivity of the annealed bilayer film. Large numbers of Fe and Ni atoms diffusing into the Au layer of the annealed Au/Ni₅₀Fe₅₀ bilayer film lead to a significant decrease in the lattice constant of the Au layer.     

基于模式聚类的二级电压控制分域方法研究

为更好解决二级电压控制分域问题,研究一种基于可视化自组织特征映射网络聚类技术的分域方法.根据自组织特征映射网络的拓扑保持、信息融合和高维数据矢量量化的特性,建立系统电压分域可视拓扑映射模型,以拓扑映射图为基础进行二级电压控制分域.在此基础上,提出以熵作为测度搜索主导节点.该分域算法融合了节点电压、相角和灵敏度等信息,利于分区间的控制解耦.该方法可离线训练,在线计算.     

McBSP在语音信号处理中的应用与实现

以语音处理中基本的A/D、D/A转换为例,采用TMS320C54x数字信号处理器的外围扩展芯片TLC320AD50作为语音采样信号的输入和处理后的语音信号的输出通道,给出了DSP与TLC320AD50的接口设计.详细介绍了TMS320C54x的多缓冲串口（McBSP）软硬件设计并提出如何用McBSP在语音通信中降低传输带宽,并提出了具体的设计思想和实现方法.通过使TLC320AD50工作在主方式,DSP工作在从方式,可以实现高速实时的A/D、D/A转换和实现处理后的语音信号低带宽传输.     

基于TMS320LF2407 DSP控制器语音模块的设计与实现

本文着重介绍了DSP芯片的SPI同步串行接口及SPI与语音转换芯片AD50的通信方式,给出了硬件电路设计。针对AD50的特点,软件设计时通过DSP的SPI口对其进行初始化配置,使其正常工作。DSP在内部对语音信号予以处理并通过AD50输出。     

影响中厚板成材率因素的量化分析及对策

本文量化分析了影响中厚板成材率的因素,并介绍了通过措施降低加热炉氧化烧损、提高负偏差控制水平、优化坯料结构实现倍尺轧制、扩大倍尺板生产比例和加强50mm晋级管理等措施,明显提高了中厚板成材率.     

由西点军校成为企业家摇篮所引发的思考

提起西点，人们会自然而然地联想到这座举世闻名的军校所培养造就的无数杰出军事人才。在世人眼中，这里是军事家的摇篮，是荣誊和胜利的象征。然而，许多人并不清楚，西点除了为美国培养出众多的军事人才外，也造就了无数的企业家和商业精英。结合西点的成功，从职业伦理道德、心理素质训练、领导能力训练三方面入手，简要分析了高等教育中重“做事”教育轻“做人”教育的危害以及“做事”教育与“做人”教育紧密结合的重要性。