硝饼

The synthesis method comprises the following steps: adding 2-( 5-(dimethylamino methyl- 2- furyl methyl sulpho ethylamine and 1- methylthio- 1- methylamino- 2- nitro ethylene with a molar ratio of 1.04: 1 into water, heating to 48- 52 Deg. C, reacting 4.5 hours with a vacuum degree of 0.02- 0.05 MPa, cooling, adding sodium-hydroxide of concentration of 10% to regulate the PH value to 11.0- 11.4, filtrating and cooling the filtrate to 0- 2 Deg. C, crystallizing for 12 hours, centrifugally filtrating, and rinsing filter cake with purity water to prepare wet ranitidine alkali; dissolving ranitidine alkali in alcohol and reacting with chlorhydric acid to prepare ranitidine hydrochloride.

合成方法包括：将摩尔比为1.04∶1的2-(5-(二甲氨基甲基-2-呋喃基甲基硫代乙胺与1-甲硫基-1-甲胺基-2-硝基乙烯加入水中，升温至48-52℃，于真空度0.02～0.05MPa反应4.5小时，反应完毕降温，用10％氢氧化钠溶液调pH＝11.0-11.4，抽滤，滤液降温至0～2℃，结晶12小时，离心甩滤，用纯化水漂洗滤饼，得雷尼替丁碱湿品；将雷尼替丁碱溶于乙醇中与盐酸反应，制备得到盐酸雷尼替丁，产品符合欧洲药典标准。

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。