国际单位制(SI)是以m,kg,s,A,K,mol,cd作为基本单位的。它的全部导出单位,包括现在称之为辅助单位的两个单位,均无例外地可以用这七个基本单位来组成而可以不需要另外的名称(见SI简介之二),例如体积V的SI单位为m~3,转动惯量J的SI单位为kg·m~2,磁场强度H的单位为A/m,表面张力 International System of Units (SI) is based on m, kg, s, A, K, mol, cd as the basic unit. All its export units, including the two units now called auxiliaries, can, without exception, be made up of these seven basic units without the need for additional names (see SI Profile 2), such as volume V The unit of SI is m ~ 3, the unit of SI of moment of inertia J is kg · m ~ 2, the unit of field strength H is A / m, the surface tension