This paper investigated expansion property that common Portland cement was as basic body and cement Q phase - C2S - C4AF - C12A7 as expansionage nt with a little addition of gypsum.
采用普通硅酸盐水泥作为基体、Q相- C2S - C4AF - C 12a7水泥作为膨胀剂、加入少量石膏的条件下进行试验研究。
2
Note that the present age of the universe follows from the expansion history and present expansion rate.
请注意,目前的宇宙年龄是由宇宙当前的膨胀速率所估计的。
3
Keck is helping astronomers determine the age of the universe and its expansion rate as well as allowing them to watch the birth of stars in other galaxies.