查询词典 mononitration

The para-selectivities of mononitration in aromatic compounds such as ethylbenzene, bromobenzene and iodobenzene increased by 18%, 15% and 16% respectively.

反应具有强对位选择硝化能力，乙苯、溴苯和碘苯的对位硝化比例分别提高18%、15%和16%。

Indicate the principal mononitration product from each of the following compound.

答：下列化合物中主要生成一硝化产物位置。

Mononitration, dinitration and trinitration of toluene are very important reactions. Products of these reactions are widely used in medicine, dyestuff, explosive, pesticide, etc.

甲苯的多段硝化是重要的化学反应过程，其各段硝化产物在医药、染料、炸药、农药等方面应用广泛。

Results indicate that the severity of a loss of control for mononitration of toluene by mixed acid can be reduced from medium to low by using semi-batch reactor, the reaction is 1.2 kinetic order in toluene, 1.3 order in nitric acid and 2.5 order in all. The MTSR_max under setting operating conditions are all in the range that can be accepted by the industrial nitration, so the reaction has less hazard potential by using those setting conditions.

分析结果表明：在设定的工艺条件下，反应过程中对甲苯的反应级数是1.2级反应，对硝酸是1.3级反应，采用半间歇反应可以使失控反应的严重度等级从中等降低到低等，在设定操作条件下假定反应失控所引发的MTSR_是在工艺条件允许的范围之内，不具有很大的危险性。

Effects of sonic factors, including dosage of catalyst, calcination temperature of catalyst, nitrated reaction time and recovered catalyst, on the selectivity of toluene in mononitration at the presence of silicotungstic acid catalyst were studied by gas chromatography.

通过气相色谱研究了诸如催化剂用量、催化剂焙烧温度、硝化反应时间、硝化反应温度及催化剂的重复使用等因素对甲苯硝酸硝化区域选择性的影响。

O-MNT、 p-MNT and m-MNT are got by mononitrating toluene, and the quantity of p-MNT and m-MNT that are needed is increased greatly, there is a great economic benefit to improve their ratioes , so the objective of this study is to improve the ratioes of p-MNT and m-MNT in the mononitration of toluene respectively through changing temperature and mixed acid composition in industrial way.

甲苯一硝化生成邻硝基甲苯、对硝基甲苯、间硝基甲苯，其中对硝基甲苯和间硝基甲苯的用量明显增加，提高它们在产物中比例的研究，具有十分可观的经济价值，所以本文从工业化的角度出发，通过改变温度和硝硫混酸的组成，分别对提高一硝基甲苯中对、间位异构体的比例进行研究。

To assess the thermal contribution from oxidation reaction, the standard formation enthalpes of all reactants and products were used to calculate the oxidation enthalpies. It could be found that all oxidation reactions were exothermic. And oxidation played a more important role during the toluene trinitration at high temperature, because the reaction temperature of toluene trinitration is the higher than mononitration and dinitration, and the temperature coefficient of oxidation is higher than that of trinitration too.

为了考察不同阶段氧化副反应对反应放热的贡献，用反应物和产物的标准生成焓推得氧化反应的理论反应热，计算结果表明，各段硝化的氧化副反应均为放热反应，其中三段硝化反应由于反应温度最高，氧化反应的温度系数比硝化反应高，故氧化副反应对三段硝化影响最大。

The optimum reaction conditions were: at present of acetic anhydride, a stoichiometric quantity of nitric acid, at room temperature for 40 minutes. Nitration of chlorobenzene gave a,50% yield of mononitro compounds, and an ortho-para isomer ratio 0.20 in product distribution of chlorobenzene mononitration.

结果表明：硅钨酸催化性能较好，催化剂载体以纳米二氧化硅最好，反应条件中醋酸酐用量是主要影响因素；SiW_(12)O_(40)~(4-)／纳米SiO_2催化剂具有强对位选择性：在醋酸酐存在下，氯苯与等当量的硝酸室温下反应40分钟，氯苯一硝化产物中邻／对硝基氯苯异构体的质量比达0.2，产率可达50％。

Five of their single crystals were obtained and their structures were determined by X-ray diffraction. By comparison, it was found that dithiocabamate complexes often formed an exactly planar MS4 unit, such as [Mo(R2dtc)2]; and also formed a special MS 5 unit, such as [Cu2(R2dtc)4], the copper atom lies in a distorted square-pyramidal environment.Four kinds of heteropoly acids were prepared and characterized; a series of solid superacid catalyst of supported heteropoly acid were prepared and characterized; regioselectivites of chlorobenzene mononitration with nitric acid with different heteropoly acid on different supports and reaction conditions have been investigated.

培养并解析了5个该类配合物的单晶结构，通过比较，发现二硫代氨基甲酸盐与过渡金属容易形成四配位结构，金属原子与4个硫原子共平面，比如二乙基二硫代氨基甲酸钼；也能形成比较特殊的五配位结构，比如二乙基二硫代氨基甲酸双核铜，Cu原子与5个S原子相连，处于一个变形的四方锥结构的配位环境。

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。