【简答题】过共析钢液 η=0.0049Pa . S ,钢液的密度为 7000kg/m 3 ,表面张力为 1500mN/m ,加铝脱氧,生成密度为 5400 kg/m 3 的 Al 2 O 3 ,如能使 Al 2 O 3 颗粒上浮到钢液表面就能获得质量较好的钢。假如脱氧产物在 1524mm 深处生成,试确定钢液脱氧后 2min 上浮到钢液表面的 Al 2 O 3 最小颗粒的尺寸。
【简答题】There are many problems between parents and their children. Some parents don’t understand their , and many of them even argue with each other. If I am a parent, how will I my child? Well, I think ther...
【简答题】Many Chinese high school students are tired of their parents’ nagging(唠叨). They think their parents’ high expectations are burdens (负担). But a recent survey found that they are much luckier than a...
【简答题】在下面的空里填上合适的代词或介词: Donc, nous lisons, en partie, pour dépasser notre vie et comprendre _____ des autres. Mais ce n’est pas la seule raison du plaisir _____ donnent les livres. Par l’existence quotidie...