硝酸

The low-grade phosphate ores with high impurities of sesquioxide were digested in phosphoric acid and nitric acid.

采用正交实验，研究了高倍半氧化物含量的中低品位磷矿在磷酸与硝酸混酸中的酸解行为，并确定了实验室最佳工艺条件：反应温度65℃，液固比14∶1，磷酸浓度(P2O5)20%，硝酸浓度9.50g/L，添加物KDD浓度5.50g/L，反应时1h。

The results show that the optimum preparation conditions of CuO/AC catalyst are as follows:the concentration of Cu（NO3）2 is 3%,soakage temperature 30 ℃,soaking time 6 h,calcinating temperature 300 ℃,and calcinating time 3 h.

研究结果表明，硝酸铜-AC制备CuO/AC催化剂的最佳条件为：硝酸铜质量分数为3%，浸渍温度为30 ℃，浸渍时间为6 h，焙烧温度为300 ℃，焙烧时间为3 h。

Determination of nitrite nitrogen and nitrate nitrogen and the sum of both by flow analysis and spectrometric detection.

用流量分析法和光谱检出法测定亚硝酸氮和硝酸氮及两者的总含量CFA和

Products available:strontium chloride,strontium nitrate,high purity strontium carbonate,strontium hydroxide,strENDS UNION ENTERPRISE LTD.

提供产品：氯化锶，硝酸锶，高纯碳酸锶，氢氧化锶，半水醋酸锶，高纯氯化钡，氢氧化钡，高纯碳酸钡，醋酸钡，氯化锰，硝酸锰，醋酸锰，碱式碳酸铅，硫磺。

The product of high-purity strontium oxide can be acquired after stoving and burning the precipitate of high-purity strontium oxalate,which is formed by means of adding high-purity oxalic acid under the condition of appropriate pH range.

以分析纯硝酸锶为原料，采用硝酸锶分次重结晶同时加入适量的硫酸除去钡及其它杂质，加入适量草酸除去钙杂质，然后选择合适的pH值加入高纯草酸制得高纯草酸锶沉淀，经烘干灼烧后得到高纯氧化锶产品。

Nitro-4-methylsulfonylbenzoic acid was prepared from 4-toluene sulfonyl chloride by the reaction of Alkylation (in the condition of sodium sulfite and baking soda), Nitrification (in the condition of nitric acid and vitriol) and Oxidation reaction (in the condition of nitric acid and catalyzer).

研究了以对甲苯磺酰氯为起始原料，首先通过亚硫酸钠和碳酸氢钠的水溶液进行烷基化、其次在浓硝酸和浓硫酸加热回流的条件下峭化、最后在浓硝酸和催化剂的条件下进行氧化，3步反应合成了玉米田高效除草剂甲基磺草酮的重要中间体2-硝基－4-甲磺酰基苯甲酸。

The effect of reagents, reaction temperature, dinitrogen tetroxide and nitric acid on the yield and purity of 1,2-propanediol dinitrate were also investigated.

结果表明，N_2O_5和环氧丙烷硝化的主产物是1，2-丙二醇二硝酸酯，副产物是1，2-丙二醇单硝酸酯。

The results indicated that CHCl3 was optimum reagent and the reaction temperature was better controlled at 10~15℃. Dinitrogen tetraoxide and nitric acidhad a detrimental effect on the yield and purity of 1,2-propanediol dinitrate. When the concentrations of dinitrogen tetroxide and nitric acid were below 1.00% and 5.53% respectively, these detrimental effects could be neglected. Under the optimum conditions, the yields and the purity of 1,2-propanediol dinitrate were 99.01% and 95.89%, respectively.

同时考察了反应溶剂、反应温度、N_2O_5中N_2O_4和HNO_3杂质对1，2-丙二醇二硝酸酯收率和纯度的影响，结果表明，适宜的溶剂是CHCl3；适宜的反应温度为10～15℃；在适宜条件下，1，2-丙二醇二硝酸酯的收率和纯度可分别达到99.01%和95.89%；N_2O_4和HNO_3对产物的收率和纯度均有不利影响，但当N_2O_5中N_2O_4含量小于1.00%，HNO_3含量小于5.53%时，对产物收率和纯度的影响不大。

Exploratory study was made on the Guanting reservoir influent treatment by using two-stage BAF at extreme low temperature.The results show that the removal of organics and ammonia nitrogen is seriously inhibited due to low temperature,and the conversion of nitrite into nitrate is no longer a limiting factor of complete nitrification.One possible hypothesis is that the activity of nitrobacter is hi gher than that of nitrosomonas at extreme low temperature.

摘 要：两级曝气生物滤池在极低温度下(1℃以下)处理官厅水库入库水的探索性研究试验结果表明，有机物和氨氮的去除受到了低温的严重抑制，亚硝酸盐转化成硝酸盐不再是完全硝化反应的限制步骤，这可能是在极低温度条件下硝酸菌的活性高于亚硝酸菌活性的缘故。

Nitratomethyl-3-ethyloxetane was synthesized by the process of cyclization, nitation from trimethlolpropane and diethyl carbonate, and the homopolymer of 3-nitratomethyl-3-ethyloxetane was synthesized with 1,4-butanediol as initator and boron trifluoride etherate as an catalyst by cationic ring-opening polymerization.

以三羟-甲基丙烷和碳酸二乙酯为原料经环化、硝化两步反应合成了化合物3-硝酸酯甲基－3-乙基氧丁环；采用1，4-丁二醇为引发剂，三氟化硼乙醚(BF3Et2O)为催化剂，NIMEO发生阳离子开环聚合得到一种端羟硝酸酯均聚醚PNIMEO。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。