查询词典 distilling tube

The preparation method comprises the following steps in sequence:(1) metric acetonitrile is added into a dual-bottleneck distilling flask that is provided with a refluxing and condensing tube, and simultaneously, long-chain dialkyl methyl tertiary amine and relevant saturated dihalide are added thereof;(2) nitrogen is pumped for 10 to 20 minutes for deoxidizing;(3) a magnetic mixing reaction is carried through for 10 to 15 hours under the condition of 78 to 83 DEG C.

其制备方法依次包括以下步骤：(1)在装有回流冷凝管的二颈蒸流烧瓶中，加入计量的乙腈，同时按一定比例加入二长链烷基甲基叔胺与相应的二卤代烷；(2)通氮气10-20分钟，排除氧气；(3)在78-83℃条件下磁力搅拌反应10～15h。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。