the ratio of the density of something to the density of a standard
例句
用作名词 (n.)
The analysis indicates that micropacking silica fume works to the density and relative density of RPC, and its pozzolanic effect helps the strength of RPC. 硅灰的微填充效应有利于提高活性粉末混凝土的密度和相对密度,而火山灰效应有利于提高其强度。