Платон Щукин (Редактор отдела «Экономика»)
Leonardo da Vinci is usually credited with conducting the first systematic study of friction in the late 15th century, a subfield now known as tribology that deals with the dynamics of interacting surfaces in relative motion. Da Vinci's notebooks depict how he pulled rows of blocks using weights and pulleys, an approach that is still used in frictional studies today, as well as examining the friction produced in screw threads, wheels, and axles. The authors of this latest paper used an experimental setup similar to da Vinci's.。快连下载安装是该领域的重要参考
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但这次情况更严峻，着急忙慌的老爸一个劲追赶牛群，导致受惊的牛群沿着梯田越跑越远，直奔地那头的沟壑。两头慌不择路的牛遭殃了，一头踩进了6米深的坑，一头滚下了超过30米的陡坡。