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.

超精硬在滚动轴承表面形成的残余压应力,经工作应力衰减后才成为影响滚动接触疲寿命的应力状。

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型是根据人体颈部位曲线设计，颈椎枕仰卧睡眠时能贴配颈部，使人感到舒适，缓解白天因工作导致的颈肌、韧带疲。