他研究了摆线 、 圆外旋轮线和四点圆的旋轮线的几何性质.He investigates geometrical properties of cycloids , epicycloids, and hypocycloids.由于这个缘故,摆线又叫做等时曲线.For this reason the cycloid is called the tautochrone.分析摆线钢球行星传动减速器的振动特性.The vibration perfo...
Police, weary and increasingly sour in mood, wonder aloud why the situation has been allowed to deteriorate.警察们疲惫不堪，心情也越来越糟糕，他们不禁满腹狐疑地问：为什么听凭情况不断地恶化下去？There are fears that the situation might deteriorate into full-scale ...