“sigma ring”的概念、定义、翻译、参考文献-科学参考

单词	sigma ring
释义	sigma ring [`sig·mǝ ´riŋ] ^MATHEMATICS A ring of sets where any countable union of its members is also a member.
随便看	friction gear friction head friction horsepower friction layer frictionless flow friction loss friction pile friction ridge friction saw friction sawing friction shoe friction tape friction torque friction-tube viscometer friction velocity friction welding friction yielding prop Friedel-Crafts reaction Jupiter XII Jupiter XIII Jupiter XIV Jupiter XV Jupiter XVI Jura juran

科学参考收录了103327条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。