“national primary frequency standard”的概念、定义、翻译、参考文献-科学参考

单词	national primary frequency standard
释义	national primary frequency standard Encyclopedia 工学频率标准释 national primary frequency standard秒长国家计量基准直接复现秒定义的实验装置。输出的标准频率具有最高计量学特性，作为统一全国秒长量值（频率量值）最高依据的计量器具，全国只有一套。
随便看	uncertainty management uncertainty measure uncertainty principle uncertainty problem uncertainty quantification uncertainty reasoning uncertainty reduction theory uncertainty relation uncertainty-sensitive planning uncertainty treatment of experimental data uncharged particle uncharmed unchecked unchirped UNCHR uncia unciform bone uncinate fasciculus uncinate process unciniger uncinus UNCITRAL UNCITRAL Model Law on Electronic Commerce UNCITRAL Model Law on Electronic Signature uncivil individuals

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。