“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	factor set factor space factors substitutability factor state factor structure factor synthesis law factor system factor theorem factor transformation factory act factory buildings factory-cultivated vegetable seedling factory farming factory law factory method pattern factory-oriented efficient agriculture demonstration zone factory production factory records factory to customer factory trawler FACTS Facts, Appraisal and Literary grace fact table factual action factual parameter

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。