“commemorative stamp”的概念、定义、翻译、参考文献-科学参考

单词	commemorative stamp
释义	commemorative stamp Encyclopedia 工学邮资凭证释 commemorative stamp纪念邮票邮政部门为纪念重大事件、重要活动或人物而专门发行的邮票。是邮票票种之一，图案多以与事件、活动或人物有关的内容为题材，并有特定的纪念文字或徽志及年代，发行数量有一定限制，出售时间较短，一般不再重印。
随便看	nonnative Chinese speakers profiling non-native fishery species Nonna Victorovna Mordyukova nonnegative non negative characteristic form non-negative characteristic form nonnegative characteristic form nonnegative combination nonnegative definite nonnegative definite kernel nonnegative definite matrix nonnegative definiteness nonnegative definite quadratic estimate non-negative definite quadratic estimator nonnegative divisor nonnegative element nonnegative function nonnegative integer nonnegative integral kernel nonnegative manifold nonnegative matrix non-negative matrix factorization nonnegative measure nonnegative number nonnegative operator

科学参考收录了854744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。