反应物

In this paper, 2,2-dimethylolbutyraldehyde was synthesized through the acetal reaction of formaldehyde and butyraldehyde, using silicotungstic acid as catalyst.

通过实验研究了硅钨酸对此羟醛缩合反应的催化效果，研究探讨了硅钨酸对此缩醛反应的催化反应活性，以及催化剂的的用量，反应物配比，反应时间等因素对反应产品收率的影响，确定了最佳催化条件。

The action spectrum analysis shows that the structure of daidzein-phospholipid complex is different from the reactant monomers and their physical mixture.The complex is a new product that is significantly different from those of daidzein.

对制备出的复合物进行紫外光谱、红外光谱、差热和X-衍射等光谱学分析，结果表明，大豆黄素与磷脂形成了复合物，且复合物是不同于反应物单体及单体物理混合物的新物相。

The capacity is even more prominent in anode of cell.

而反应物到达反应区的质量传递率主要是由反应物在介质中的传递机理决定的[1]。

And the optimum pH was 4-6 for the dechlorination reaction of 2,4-D, and pH between 2 and 8 were all suited for the reaction in Pd/Fe systems. Intermediate and final products of 2,4-D, HCH and chlordane with Pd/Fe were determined by GC/MS, and the possible dechlorination pathways were concluded: 2,4-D can be converted to phenoxyacetic acid through gradual hydrogenolysis, and HCH can be transformed to cyclohexatriene through dichloroelimination or dehydrochlorination.

通过GC/MS定性定量分析了三种目标污染物在Pd/Fe体系中发生还原脱氯反应过程中的反应物及最终产物，并根据反应产物推测分析了这三种有机污染物在催化还原反应体系中可能的反应途径：2，4-D主要通过逐级氢解最终生成彻底脱氯产物苯氧乙酸；而六六六则可能通过逐步双氯消除反应或脱氯化氢反应，最后生成环己三烯。

Study on the synthesis of ultrafine powder of lead carbonate.

采用均匀沉淀法合成碳酸铅，研究反应温度、时间、反应物浓度、反应物配比对碳酸铅收率的影响。

The results show that smaller height of reaction channel can shorten the time which reactants diffuse from channel to reaction surface, longer length of micro-channel can extend residence time of reactants on the catalyst surface, and consequently increase the methane conversion and hydrogen production. The pressure drop between inlet and outlet increases lineally with the increasing of length, while the height influences the pressure drop significantly when the height is less than 0.4 mm. Based on the overall consideration for the methane conversion and resistance characteristic generally, the suitable height of channel should be between 0.4 mm and 0.6 mm.

结果表明：较小的通道高度能够减小反应物在通道中的扩散时间，较长的反应通道长度能够增加反应物与催化剂的接触时间，甲烷转化率和产氢率提高；通道长度线性地影响微通道进出口压降的大小，而在通道高度小于0.4mm时，通道高度显著地影响进出口压降的大小；综合考虑微通道的重整性能和进出口压降等因素，通道高度在0.4~0.6mm之间较为合适。

The change of average size of products along the radius at the exist of reactor has also been calculated. The calculated results indicate that the residence time is longer, the average size of products is larger, but the distribution of size is narrower, tending to self-preserving distribution; when the concentrations of reactants increase, the average size of products becomes larger, but the distribution of size becomes narrower; the gradients of reactants are greater, the average size is larger; the increasing of reacting temperature will cause the size of product to be larger under same residence time. The average size of product at the exist of reactor varies along the radius, has a maxim value.

模型计算结果表明，产物粒度随停留时间的增加而增大，但粒度分布变窄，趋向自保分布；产物粒度随反应物进料浓度的增加而增大，粒度分布随进料浓度的增大而减小；反应器中反应物浓度梯度较大（相当于化学反应为快反应）时，相同停留时间下所得到的产物平均粒度增加；反应温度的增加，粒子平均粒径增加，粒度分布变窄；反应器出口处粒子平均粒径，随着与对称轴的距离的增加，有一极大值，先增加，后减小。

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。

From the potential energy profile, it can be predicted that, the dominant channel of this reaction consists of three steps: the two reactants first form a three-membered ring intermediate (INT1) through a barrier-free exothermic reaction of 19.2 kJ/mol; three-membered ring intermediate (INT1) isomerizes to a four-membered ring silylene(P2) via the transition state (TS2) with an energy barrier of 22.8 kJ/mol; four-membered ring silylene(P2) further reacts with ethene(R2) to form a silicic bis-heterocyclic compound (P3), which is also a barrier-free exothermic reaction of 132.2 kJ/mol.

用CCSD//MP2/6-31G*方法研究了单重态二甲基亚烷基硅烯与乙烯生成硅杂双环化合物环加成反应的机理，根据该反应的势能面可以预言，该反应的主反应通道有三步组成：第一步是两反应物（R1， R2）首先生成了一三元环中间体（INT1），它是一无势垒的放热反应，放出的能量为19.2 kJ/mol；第二步是三元环中间体(INT1)经过渡态TS2异构化为了四元环硅烯（P2），其势垒为22.8 kJ/mol；第三步是四元环硅烯（P2）进一步与乙烯(R2)反应生成了硅杂双环化合物（P3），该反应也是一无势垒的放热反应，放出的能量为132.2 kJ/mol。

A numerical model was designed to describe kinetics for a reactant to diffuse with a second-order reaction with another reactant in a gelatin layer.

设计一个数值模型用来描述反应物在明胶层中边扩散边与另一种反应物发生二级反应的动力学过程。

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。