查询词典 benzaldehyde

The selectivity of phenylacetaldehyde is increased when Br〓nsted acidity is getting stronger. The selectivity of benzaldehyde can be increased by increasing the amount of extraframework titanium species.

分子筛的B酸中心强度对产物分布有着显著的影响，B酸越强，苯乙醛的选择性越高，B酸位是催化环氧苯乙烷定向重排生成苯乙醛的催化活性中心；非骨架钛物种的增加有利于苯甲醛的生成。

When using urea-hydroperoxide as oxygent, just the trimethylphosphine adsorbed on the Lewis acid sites in TS-1 zeolite was oxidized. It further confirmed that the hydroperoxo-titanium species formed by the interaction between the titanium in Lewis acid sites and urea-hydroperoxide are the active oxidation center, and the titanium in the framework as Lewis acid sites enhances the oxidation ability of hydroperoxide. 3. Phenylacetaldehyde and benzaldehyde are found to be the major products in the catalytic oxidation of styrene over TS-1 zeolite, and styrene epoxide is not as speculated detected.

当以过氧化氢尿素为氧化剂时，室温条件下吸附在TS-1分子筛Lewis酸性位的三甲基膦即能被氧化，由此进一步证明，TS-1分子筛中由Lewis酸性位的骨架钛与过氧化氢相互作用形成的过氧化钛物种是三甲基膦氧化反应的活性中心，骨架钛作为Lewis酸中心提高了过氧化氢的氧化能力。

The volatile components were separated and identified using GC-MS technique. RESULTS Seven ingredients were. isolated: 2-ethyl-hexyl-adipate (66.5%), 1-methoxy-4-(1-propenyl)benzene (12.5%), isopropyl isothiocyanate (6%), isobutylisothiocyanate (6%), 6-methyl-5-heptene-2-one (3.5%), benzaldehyde (1.4%), phenylacetaldehyde (0.8%).

结果 分离出7个成分，采用峰面积归一化法确定了各成分的相对含量，分别为66.5%双－2-乙基己基－己二酸、12.5%1-甲氧基－4-（1-丙烯基）苯、6%异硫氰酸异丙酯6%、6%异硫氰酸异丁酯、3.5%6-甲基－5-庚烯－2-酮、1.4%苯甲醛、0.8%苯乙醛。

Results Six compounds were isolated and identified as:5α,8α-epidioxy-(22E,24R)-ergosta-6,22-dien-3β-ol,scopoletin,isofraxidin,p-hydroxy benzaldehyde,3,4,5-trimethoxy benzoic acid,protocatechuic acid ethyl ester...

结果得到6个化合物，分别鉴定为：5α，8α表二氧(22E，24R)麦角甾6，22二烯3β醇、东莨菪素、异秦皮啶、对羟基苯甲醛、3，4，5三甲氧基苯甲酸、原儿茶酸乙酯。结论化合物Ⅰ～Ⅵ均为首次从该属植物中分离得到。

Thiobarbituric acid was synthesized by sulfourea and diethyl malonate in sodium alcohol and 5-Arylidene thiobarbituric acid was prepared by the Knoevenagel condensation reaction from benzaldehyde and thiobarbituric acid.

采用丙二酸二乙酯和硫脲在乙醇钠存在下合成了硫代巴比妥酸，再分别采用固相反应和水相反应，由硫代巴比妥酸和苯甲醛经Knoevenagel缩合反应，制备了5-亚苄基硫代巴比妥酸。

Bis (P—bromobenzylamino) ethane and 1,2—bis (m—Iodobenzylamino) ethane may be prepared by condensation of the corresponding halo benzaldehyde with ethylenediamine and followed by catalytic hydrogenation of the Schiff's bases over Pto_2 in glacial acetic acid solutions: Both Ⅱa and Ⅱb may react in neutral mediam with aldehydes to form well—defined crystalline tetrahydro—imidazole, which may be served as derivatives of identification for aldehydes: Under the same condition, however,Ⅱb may ...

用1，2-二乙烷与二十余种醛类作用，得到有固定熔点的晶体衍生物，它们的熔点分布在85—210℃之间，产率为40—96％，这试剂与甲基酮类在相同条件下无反应，因此，它可作为鉴定醛类的专属试剂。 2。上述衍生物用稀盐酸在室溫处理，能发生水解，可以定量地收回原来的醛，因此这试剂又可作为分离醛类的试剂。 3。上述衍生物可以用非水滴定法半微量地测定其分子量可作为鉴定醛类的另一项参考数据。 4.1，2-二乙烷与醛类能生成晶体衍生物，但这试剂也与甲基酮在同样条件下发生反应，所以不适合作为鉴定醛类的专属试剂。

Therefore, with integrated consideration of the situations mentioned above, if the cathode reaction could be sufficiently utilized, preparation of benzaldehyde and tolualdehyde from toluene and xylene by electrooxidation with Ce /Ce as oxidative media would be more advantageous.

因此，综合考虑上述情况，若能充分利用阴极反应，选择Ce／Ce为氧化媒质，间接电氧化甲苯或二甲苯制备苯甲醛和甲基苯甲醛将更加有利。

Comparing Ce /Ce with Mn/Mn oxidative medias, we learned that:①A better results could be achieved using Ce than using Mn as oxidant to prepare benzaldehyde and tolualdehyde from toluene or xylene with the product\'s yield 10%～15% higher;②Mechanisms of the two electrooxidation reaction were different from each other.

二者的电解氧化反应机理有所不同，Ce由Ce直接电氧化得到，而Mn则是由Mn间接电氧化获得，且前者电解氧化所需的硫酸浓度仅为后者的十分之一。

Under the optimum conditions (i.e., reaction at 40℃ using hyperthermophilice esterase APE1547, 4-Cl-benzaldehyde substrate, and trichloromethane solvent), this reaction provided optically active secondary alcohol with an enantiomeric excess up to 56% and a yield up to 78%.

在最适条件（嗜热酯酶APE1547为酶源，反应温度40℃，氯仿为溶剂，4-Cl-苯甲醛为底物）下，加成反应生成的光学活性醇产率最高达78%，ee值最高可达56%。

The results showed that the suitable condition for the reaction are as follows: benzaldehyde/1, 2-propylene molar ratio is 1:1.4, the mount of potassium dodecatungstocobaltate trihydrate (K5CoW12O403H2O) is 0.5g, the volume of cyclohexane is 9 mL, and reaction time is 70 min.

实验结果表明，杂多化合物K5CoW12O403H2O是合成环己酮l， 2-丙二醇缩酮的良好催化剂，在酮醇物质的量比为l：1.4、催化剂质量为0.5g、带水剂环己烷体积为9mL、反应时间为70min的最佳条件下，环己酮l， 2-丙二醇缩酮的收率最高可达94.2%。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷