Explain the meaning of SI base units and SI derive

SI导出单位是由SI基本单位按定义式导出的,其数量很多,在这里列出其中三类：用SI基本单位表示的一部分SI导出单位；具有专门名称的SI导出单位；用SI辅助单位表示的一部分SI导出单位.其中,具有专门名称的SI导出单位总共有19个.有17个是以杰出科学家的名字命名的,如牛顿、帕斯卡、焦耳等,以纪念他们在本学科领域里作出的贡献.同时,为了表示方便,这些导出单位还可以与其他单位组合表示另一些更为复杂的导出单位.国际单位制是计量学研究的基础和核心.特别是七个基本单位的复现、保存和量值传递是计量学最根本的研究课题.SI derived unit is the basic unit SI derived by the definition of style,many of their number,three of which are listed here:The basic unit of that part of the SI derived units SI; with special names,SI derived units; use SI units,said auxiliary part of the SI derived unit.Among them,the SI with special names to export a total of 19 units.17 is named after outstanding scientists,such as Newton,Pascal,Joule,to mark the subject field in the contribution.Meanwhile,in order that convenience,these units can also be derived combination with other units in that other more complex derived unit.International System of Units is the basis for quantitative study and the core.Especially the reappearance of the seven basic units,storage and value transfer is the most fundamental metrology research topic.