In this paper influence of geometric excentric balltrack of rolling bearing of spindle of machine tool on machining accuracy of workpiece is discussed.
文章讨论了机床主轴滚动轴承滚道的几何偏心对工件加工精度的影响。
2
If touch isn't your thing, the phone also has a slide-out keyboard that works well enough, as well as five navigation buttons and a trackball.
如果对你来说屏幕不是问题的话，这个手机还有一个工作的够好的滑盖键盘以及五维导向按钮和轨迹球。
3
Dopamine receptors seem to track possibilities—an arcing tennis ball that may land in or out—and how expected or unexpected they are.