Changes in Diet May Have Led to Humans Having Smoother Skulls
了解有关人类头骨形状及其数百万年来如何变化的更多信息。
Physicists can now take control of 'hidden' friction in devices
即使两个完全光滑的表面相互移动，一种类型的摩擦也会浪费能量，但研究人员正在研究如何减弱或完全阻止它
