Time off from digital devices. Find out how a school in England challenges students to stay away from their gadgets ...

Scientists researching Alpine glaciers store ice in Antarctica. By analysing air bubbles in the ice they may be able to predict the future ...

▲摘要：物理系统的对称性和拓扑结构与控制拓扑性质的对称性密切相关。准晶体是有序系统，但没有平移或旋转对称性。理论研究表明，准晶体可以理解为高维晶体在低维空间上的投影。