查询词典 catalytic

For the α-arylation of ethyl acetoacetate, the product was α-aryl ethyl acetoacetates, rather than ethyl a-arylacetates which are the major products in other catalytic systems.

较为惰性的氯代芳烃在Pd2/L1的催化下，也能够跟1，3-二羰基化合物发生α-芳基化反应。

Yields from chiral bisoxazolines (5a) with diethyl oxalate using NaOCH〓 as base for the first time. The structures of chiral multioxazolines and their intermediates, multi (β-hydroxylamide) s, were characterized by 〓H NMR, IR, mass spectra and elemental analysis. The catalytic activities and enantioselectivities of chiral multi (β-hydroxylamide) s (4) and chiral multioxazolines (5～8) were investigated by using acetophenone and β-acetonaphthone as former chiral ketone, KBH〓 or NaBH〓 as reductive reagent in chapter three.

在此基础上，对合成方法作了创新，以羧酸或酯为原料，在无催化剂的条件下与手性α-氨基醇反应，通过回流分水或脱醇的方法，一步反应合成了手性多噁唑啉（5～8），产率为89.2%～98.4%；以手性双噁唑啉（5a）为原料，在NaOCH〓的作用下，与草酸二乙酯反应，首次合成了呋喃类双嗯唑啉（6a），产率为72.9%～75.6%。

Basing on above researches, we designed a series of ionic liquid supported acetylacetone metal catalysts and non ionic liquid supported acetylacetone metal catalysts. The catalytic abilities of these catalysts were evaluated by using them to catalyze the methane oxidation reaction.

在以上研究的基础上，本论文设计了系列离子液体支载的乙酰丙酮金属催化剂及非离子液体支载的乙酰丙酮金属催化剂，并通过这些催化剂对甲烷氧化反应的催化效果来预测它们的活性。

Instructed by this method, the structure-reactivity relation of the oxidation reaction catalysts was found and a way was proposed to enhance the catalytic ability of traditional acetylacetone catalysts by supporting them on ionic liquid.

在该方法的指导下，发现了氧化催化剂结构活性关系，提出了一套用离子液体支载来提高乙酰丙酮金属催化剂催化氧化活性的方案。

Supporting the acetylacetone on ionic liquid was established for the purpose of catalyst recycling. The following works focused on what kind of supporting methods can enhance the catalytic ability of acetylacetone.

从提高催化剂可回收性方面考虑，论文计划将乙酰丙酮支载在离子液体上，接下来研究采用怎样的离子液体如何支载能够提高催化剂的催化氧化活性。

The E-TOF will also be feasible and practical to assist chemists in screening the optimal reaction condition or evaluating the overall efficiency of different catalytic systems for a specific asymmetric reaction.4.For the first time,we explored chiralγ-hydroxy-α,β-acetylenic esters,which were prepared via asymmetric alkynylation,as key intermediates to the synthesis of chiralγ-butyrolactones. This convergent and enantioselective approach to chiralγ-butyrolactones is practical and easily handled with protecting group free.

这一概念包括反应产率、对映选择性、配体用量以及反应时间四个重要反应参数，不仅适用同一反应不同催化体系的横向综合性评价，而且适用于某一特定反应催化体系的优化过程，有助于研究人员选择最佳的反应条件。4、我们发展了以手性γ-羟基-α，β-炔酸酯为关键中间体完成了手性γ-丁内酯类天然产物的对映立体选择性全合成，该关键中间体能够以我们的催化体系方便的对映选择性合成，之后的官能团转换方法成熟，易于操作，无需进行繁琐的官能团保护和脱保护过程，绿色经济。

The catalytic system composed of NHPI and transition metal ion can catalyze effectively ethane into acetic acid,cyclane into dicarboxylic acid,toluene into benzoic acid,alkene into epoxide,alkyne into acetylenic ketone,and amide into imide;NHPI used alone can catalyze adamantane to be carbonylated,hydrogen peroxide prepared by oxidization alcohol;NHPI combined with as...

NHPI与过渡金属离子组成的催化体系能高效地催化乙烷氧化为乙酸、环烷烃氧化为二元羧酸、甲苯氧化为苯甲酸、烯烃氧化为环氧化物、炔烃氧化为炔酮、酰胺氧化为酰亚胺；NHPI单独使用能催化金刚烷发生氧化羰基化反应、催化氧化醇制取过氧化氢；NHPI与有机助催化剂如偶氮二异丁腈、溴化季铵盐、蒽醌和醇等也能催化分子氧氧化反应。

Portable camp heaters of other than the catalytic type for use with liquefied petroleum gases; Addenda

ANSI Z21.63b-1984 用液化石油气的非催化型便携式露营加热器。

Zeolite is a kind of cellular material, which has good ion-exchanging, catalytic and adsorptive capacity.

沸石是一种微孔材料，具有优良的离子交换、催化和吸附性能。

Adsorptive catalytic voltammetry plays an important role in both improving analysis sensitivity and studying kinetic of electrode process.

本文还在该电极上进行了大黄酸与DNA相互作用电化学及DNA测定的研究，获得了很好的线性关系和检测限。

You can do some assertiveness training.

你可以进行一些自信训练。

We were well on the path to making a rear-wheel-drive global platform," says Mays."

我们正致力于建立一个后轮驱动的平台，"Mays这样说道。"