It’s surprisingly difficult to prove one of the most basic properties of a number: whether it can be written as a fraction. A ...

Dear reader, at the risk of being considered politically biased or “in” on any number of drone-related conspiracy theories, it’s our duty to inform you that trying to shoot down one of these ...

Kevin Lamarque/Reuters With his “four red lines,” Chinese leader Xi Jinping ... “Washington should not fear the end state desired by a growing number of Chinese: a China that is able to ...

College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, P. R. China College of Chemistry, Sichuan University, Chengdu 610065, P. R. China ...