含硼微合金钢的静态及动态软化行为

运用gleeble-1500热模拟试验机November对含硼微合金钢进行了单、双道次压缩模拟,并通过非线性回归分析得到了静态与动态软化百分比(X)与变形温度(T)、变形程度(ε)、变形速率(ε·)、原始晶粒尺寸(d0)、道次间隔时间(t)之间的关系。     

软件抗干扰技术在工控系统中的应用

在工业控制领域中各种干扰信号很多。阐述了如何通过软件技术来提高单片机系统的稳定性。     

活齿端面谐波齿轮啮合状态的几何模型

活齿端面谐波齿轮是综合现有的谐波齿轮传动和活齿传动的优点而发明的一种新型传动装置．可以在保留现有谐波齿轮传动所有优点的基础上．大幅度地提高所传递的功率。建立了描写活齿端面谐波齿轮啮合状态的几何模型．并利用该几何模型推导出了活齿端面谐波齿轮实现连续传动的条件。     

Effect of synthesis temperature on density and microstructure of MgB2 superconductor at ambient pressure

The experimental thermodynamic of MgB₂ synthesis process and phase compositions have been investigated by diffraction thermal analysis (DTA) technology and X-ray diffraction. The fabrication of MgB₂ bulks and superconducting properties at the temperatures range from 600 to 800°C were reported. And microstructure of MgB₂ bulks were observed by scanning electron microscope (SEM). A method was developed to determine the porosity of MgB₂ and the highest density can be obtained in MgB₂ prepared at 650°C at ambient pressure. It is found that the vapor pressure of Mg increases remarkably at high temperature, leading to the high porosity in MgB₂ samples. MgB₂ bulk with good superconducting property and fine microstructure was synthesized at 750°C.     

R∞关系的几个重要性质

在二元关系R的基础上构造了R^∞关系，给出并证明了R^∞关系的几个重要性质。这些性质在粗糙集理论中研究R^∞领域系统及其近似算子时甚为重要。     

微机控制流量及热耗量积算仪的研制

本文介绍了一种采用单片微机构成的流量积算仪。该仪表具有两路流量信号及两路温度信号输入，不仅能对流量，还能对热（冷）耗量进行精确的检测及累计。仪表可靠性好，精度高，操作方便，适用于各种需对热（冷）耗量进行计量的场合。     

数值模拟地震形变力场

本文提出用有限元方法和按距离加权平均法数值构造地震形变力场,比较了这两种方法的优点和存在的主要问题,并结合计算机口形学的技术描述组成具体实用的系统．     

GaN Nanorods Catalyzed with Mo: Effect of Ammoniating Time on Microstructure,Morphology, and Optical Properties

GaN nanorods have been successfully grown on Si (111) substrates by magnetron sputtering through ammoniating Ga₂O₃ thin films catalyzed with Mo. The influence of the ammoniating time on the growth of GaN nanorods was analyzed, in particular, by X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Fourier transform infrared (FT-IR) spectrometer, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectrum. The results demonstrate that the GaN nanorods are single crystal with hexagonal wurtzite structure, which have high crystalline quality. The GaN nanorods after ammoniation at 1223 K (950 °C) for 20 minutes have good emission properties and the highest crystalline quality with 100- to 200-nm diameter and several-micron length. The growth direction of these nanorods is along the orientation of (100) crystal plane. A small red shift occurs because of the band-gap change caused by the tensile stress of the one-dimensional GaN nanorods along the axial direction.     

TC4合金锥体模锻过程的数值模拟

采用刚塑性有限元法对钛合金锥体的模锻成形进行有限元数值模拟,分析了锥形件模锻过程中的金属流动规律,应力场、应变场、变形区的压力分布,压力的变化规律等。模拟结果表明,锥体模锻成形分为3个阶段:初期变形过程是圆柱体变形为一个小曲率壳体的阶段,应力主要集中在上模的正下方,应变主要发生在此变形区;变形中期是与下模相接触的部分参与变形的体积逐渐增大,直至最后形成所需要的锥体形状;变形后期由于摩擦作用产生严重的不均匀壁厚减薄现象。