RANDOM SAMPLES

摘要

Diamonds may set the standard for beauty in jewelry. But another crystal structure is mathematically as exquisite as diamond's, says mathematician Toshikazu Sunada of Meiji University in Kawasaki, Japan. Diamond and the other structure, which he dubs K_4, are the only ones that possess both of two key symmetries, Sunada reports in the February issue of the Notices of the American Mathematical Society.