A subset A of a vector space where for each element x in A, tx belongs to A if |t| < 1. For example, a sphere centred at the origin in Cartesian space is a balanced set.
科学参考收录了60776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。