双相钛合金表面等离子渗铬强化层疲劳行为研究

为改善钛合金的耐磨性,使用真空辉光等离子体表面合金化技术,对双相钛合金TC4样品进行了等离子体铬化处理.通过纳米压痕对试样的局部硬度和模量进行了测定,并在给定载荷下利用旋转弯曲疲劳机对试样的疲劳性能进行评估.结果 表明:850 ℃下渗铬处理5h后获得的铬合金层由四个子层组成,即Cr沉积层,TiCr2层,Ti4 Cr层和...     

磁场条件下砷酸钠冷却结晶动力学

目前分离提纯锑冶炼过程中产生的砷酸钠的主要方法仍是结晶法。在粒数衡算方程的基础上,在模拟结晶器外,外加0.6T磁场,通过测定晶体的粒度分布,利用分离变量法求得粒数密度函数。利用优化后的ΔL定律研究砷酸钠的冷却结晶行为。结果表明,砷酸钠成核速率和生长速率在外加磁场作用下可以得到加快,使得晶体的粒度分布更加均匀。     

Auto-detection of strip area in 3D measurement

3D measurement is an important task for modern manufacturing, because 2D measurement cannot meet the increasing requirements for quality control in engineering. Among all, 3D recovery methods, by using structural lighting system are the most popular methods because of its non-destructive character. The acquiring of lighting strips, which have to be projected on the object is the most important work to ensure later matching work. In the former research, the position of the stripes in the image was very difficult to locate and must be drawn manually. Therefore, the aim of our research is to find a method to auto-detect the strip area. FFT (fast Fourier transform algorithm) are used to analyze the image character by row and by column. From the FFT result, in the power spectrum the strip area and non-strip area can be distinguished clearly. So the strip area can be marked exactly on the image, and image process algorithm can be used to pick up the strips only on this area. After the matching and 3D recovery algorithm, the 3D shape of the object can be plotted. The auto-detection strip algorithm can save a lot of time for the 3D measurement, automatically complete the 3D recovery procedure, and bring convenience to operators.     

Mapping the magnetic field in the solar corona through magnetoseismology

Science China Technological Sciences - Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the...     

三维动画模拟有机化学反应机理

利用3DMAX软件对烷烃的自由基取代、烯烃的亲电加成、芳烃的亲电取代、卤代烃的亲核取代及消除、羰基的亲核加成、羧酸衍生物的亲核加成-消除等7类重要的有机化学反应机理进行了动态模拟．生动、直观地表现了有机反应中化学键的断裂和生成,结构的变化以及中间体的生成等全过程。制作的动画文件可用作有机化学多媒体辅助教学课件的素材．可加深学生对教学内容的理解,具有很好的教学效果。     

氮硅涂层陶瓷刀具切削铸铁磨损机理研究

为研究氮硅涂层陶瓷刀具切削性能及磨损机理,采用物理气相沉积(PVD)工艺分别在氮化硅刀具表面沉积TiAlN和CrAlN涂层,利用切削灰铸铁HT200实验对刀具寿命和磨损机理进行了系统研究,探讨不同切削深度、进给率、切削速度下刀具的磨损情况.着重关注陶瓷涂层车削铸铁的最佳切削速度,分析了不同切削速度下刀具的切削性能.结果...