如果说文化上的早期中国孕育于史前时期，秦汉国家则确立了政治与疆域上的“大一统”。作为秦人经略西部边疆的见证，秦“采药昆仑”石刻（尕日塘秦刻石）的公布一度引起学界广泛争论。理不辩不明，仝涛结合严谨的文字识读与地望考证，确认其是现存于原址的唯一一处秦代刻石。这一成果表明，早在2000多年前，大一统王朝国家就已将其意志贯彻到了高原之巅、黄河之源。
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.
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