The residual stress formed on the surface of rolling bearing in superfinish hard turning will influence the fatigue life of rolling contacting after stress decay.

超精硬态切削在滚动轴承表面形成残余压应力,经工作应力衰减后才成为影响滚动应力状态。

U-Shape pillow designs based on the curve of human's head and neck and it is suitable for this part when having a resupine sleeping.

U型是根据人体头颈部位曲线设计，颈椎枕仰卧睡眠时能贴切配合头与颈部，使人感到舒适，缓解白天因工作导致颈肌、韧带。