查询词典 catalyst

Under the catalyst, the polymerization retarder, the including water medicinal preparation existence condition, the methylacrylic acid and the polyethylene glycol single methyl ether (400) direct esterification synthesis methylacrylic acid polyethylene glycol single methyl ether (400) ester, and the influence factors of the catalyst, polymerization retarder, including water medicinal preparation has mellowly carried on the comparison.

摘要在催化剂、阻聚剂、带水剂存在的条件下，由甲基丙烯酸与聚乙二醇单甲醚(400)直接酯化合成甲基丙烯酸聚乙二醇单甲醚(400)酯，并对酸醇比、催化剂、阻聚剂、带水剂等影响因素进行了比较。

The experiment results indicate that: the increases of catalyst concentration, feed mole ratio of methanol to formaldehyde and the decrease of total feed flow can increase the yield of methylal; the concentration of methylal in distillate also increases with the increase of catalyst concentration; that the effects of reflux ratio on the yield and concentration of methylal in distillate are different from conventional distillation process, an optimal value of reflux ratio exists between 1 and 2 for this process.

实验结果表明：回流比对甲缩醛收率和塔顶甲缩醛纯度的影响不同于一般的精馏过程，存在一个最优回流比，本过程最佳回流比在1-2之间；提高催化剂浓度，甲缩醛收率和塔顶甲缩醛纯度均增加；提高进料醇醛摩尔比也会提高甲缩醛收率；进料总流量对甲缩醛的收率的影响十分明显，进料总流量减少可以使甲缩醛的收率得到明显提高。

The invention discloses a method for synthesizing acetyl tributyl citrate, which uses tributyl citrate and acetic anhydride as reaction articles, uses naphthalenesulfonic acid methylal as the catalyst during the ester synthesis process, filtering the catalyst from reacted articles after reaction, water-washing, alkaline-washing, distilling the filtrate to obatin acetyl tributyl citrate.

本发明公开了一种合成乙酰柠檬酸三丁酯的方法，它以柠檬酸三丁酯、乙酸酐为反应物，在酯合成过程中用萘磺酸甲缩醛作催化剂，反应结束后，将催化剂从反应后的物料中过滤出来，滤液经水洗、碱洗、蒸馏获得乙酰柠檬酸三丁酯。

One way is use of some co-catalyst and catalyst, the other is to revamp the present unit by carrying out MGD process.

在反应温度为5巧℃、RAG一8催化剂在系统藏量占25%时，汽油汽油烯烃含量可从39.2%降低到38.7%。

The different performance between HZSM-5 catalyst and HL catalyst is mainly due to the different acidity, specific surface and micropore volume which they have.

这种反应性能的差异主要是由于HZSM-5沸石和HL沸石的酸性特征、表面积和微孔体积不同所造成的。

The effects of reaction time and the amount of the catalyst on the ester yield were investigated with sodium bisulfate monohydrate green catalyst.

苯甲酸乙酯制备是典型的有机实验，本文采用自行设计的回流－吸水反应装置，一水硫酸氢钠为绿色催化剂，考察了反应时间、催化剂用量对酯化反应产率的影响。

It was found that the samples PVP-PdCl2-CdCl2 and PVP-PdCl2-HgCl2, compared with PVP-PdCl2, exhibited much higher catalytic activity and dechlorination selectivity, and the yields of the coupling by-products were obviously decreased. For example, when p-chloroaniline was used as substrate, the reaction time was shortened to 1/8, and the yield of dechlorination product was about 25 times as much as the original one, and when p-chlorotoluene was used as substrate, the yield of coupling by-product catalyzed by bimetallic catalyst was 1/390 of that catalyzed by monometallic catalyst.

与负载型单金属催化剂PVP-PdCl2相比， PVP-PdCl2-CdCl2和PVP-PdCl2-HgCl2对氯代芳烃脱氯有高得多的催化活性和脱氯选择性，且偶联副产物显著减少；以对氯苯胺为底物时，双金属催化下的反应时间缩短为单金属催化下的1/8，而脱氯产物收率提高25倍；底物为对氯甲苯时，双金属催化下的偶联副产物仅为单金属催化下的1/390。

The research results show for low Sn concentrations, for example 1wt%Sn with respect to Ni, the Ni/Sn surface alloy is energetically preferred. We have also used XPS to characterize the catalysts. The quantified Sn and Ni XP spectra for Ni/Sn/SLT catalysts show that Sn preferentially segregates to the surface of the Ni/Sn alloy. We demonstrate that supported Ni/Sn alloy catalyst provides significantly higher reforming reactivity and resistance to deactivation via carbon deposition than supported monometallic Ni catalyst both in steam reforming of CH4 and CO_2 dry reforming.

本文以SLT为支撑体，利用Sn对传统的Ni基催化剂进行表面合金化处理，成功制备了Ni/Sn表面合金重整催化剂，将该催化剂用于甲烷和丙烷的CO_2重整和水蒸汽重整反应，研究结果表明，在Sn浓度很低的情况下，例如1wt%Sn含量，从能量角度看更易于形成表面合金，XPS数据也显示Sn更易于富集在Ni/Sn合金催化剂表面。

The property of the monomolecular catalyst and the polymer effect can becombined via binding the monomolecular catalyst in the polymer.

以苯乙烯为底物，反应条件下环氧化ee值可达60％，这是迄今为止非酶催化剂得到的最好结果。

Naphthylamine is the intermediate of various dye products and the major raw materials of various rubber aging inhibitors,ɑ-naphthol produced with ɑ-naphthylamine is the major intermediate of pesticide carbaryl; KT-02 nickel catalyst is used to prepare naphthylamine by nitro-naphthalene catalytic hydrogenation, the product has high purity and high yield, and it's currently one of the best technological conditions, and the catalytic activity of the catalyst does not deteriorate after multiple times of recycle.

萘胺是多种染料产品的中间体，也是多种橡胶防老剂的主要原料，由ɑ-萘胺生产的ɑ-萘酚是农药西维因的重要中间体，KT-02型镍催化剂用于硝基萘催化加氢制备萘胺，产物纯度好、收率高，是目前最佳的工艺条件之一，且催化剂多次套用催化活性不减。

Who? I never heard of him, Paul said, before asking teammate James Posey if he had heard of him.

赛后，科比说，他一直都是一名非常出色的射手，今天他打得很棒。

When I joined the company, I rotated around the different sections.

我加入这个公司时，轮换过几个不同的部门。