查询词典 hindered

The sterically hindered Organosilane protective agents have some special advantages.

位阻型有机硅保护剂具有一些特殊的优点。

However,for the catalytic pyrolysis of sterically hindered PP,the effect of mesoporous molecular sieve sructure on pyrolysis results of PP is more important than that of mesoporous molecular sieve acidity.

而对于具有较大空间位阻的PP的催化裂解反应，催化剂酸性在一定范围内对PP的裂解结果影响不明显，表明催化剂孔结构的作用更重要，较大的孔径有利于PP的催化裂解。

Ethoxyberberine and 9-isopropanoxyberberine bearing with different sterically hindered groups were synthesized from beberrubine material.

以小檗碱为原料，合成了小檗碱C-9位不同空间位阻取代的9-乙氧基小檗碱、9-异丙氧基小檗碱，通过MS、1H NMR确认其结构。

Under the optimum conditions of n: n=40, mass percentage of ZrO2 18%, temperature 400℃, m m=0.02 and reaction time 0.5 h, the conversion was 91.2% and the yield of liquid products was 83.6%. Compared with the results obtained by thermal pyrolysis and catalytic pyrolysis on HZSM-5, ZrO2/Ti-MCM-41 was of better catalytic activity and higher yield of liquid products, and was especially suitable for the pyrolysis of sterically hindered polymers such as PP.

结果表明，n：n=40，ZrO2负载质量分数为18%的ZrO2/Ti-MCM-41，在反应温度400℃，m(ZrO2/Ti-MCM-41)：m=0.02，反应时间30min的条件下，PP的转化率可达91.2%，液体产物的收率为83.6%，该结果优于热裂解及传统的HZSM-5小孔分子筛催化剂的催化裂解结果。

However, when trans-4-aryl-3-buten-2-ones were taken as the substrates, the electron-rich but less sterically hindered ligand 9c gives the best results (up to 96.4 % ee) with highly catalytic activity.

而富电子但空间位阻小的配体9c对亚节基丙酮类底物获得最好的结果(%。4%ee)，同时还表现了最好的化学活性。

There are more and more acid gas components,〓 and 〓, from petroleum refinery gasesbecause China will import mass sour crude oil in the near future. In order to improve theselective absorption behavior of desulfurizer, new sterically hindered amine desulfurizers aredeveloped.

本论文以处理炼油厂加工进口含硫原油产生的大量含〓和〓的酸性炼厂气为背景，开发新型位阻胺脱硫剂以达到选择性脱除炼厂气中〓的目的。

LY series desulfurizers are synthesized by sterically hindered fatty amine, ethylene oxide andpropylene oxide, which is a ring-splitting polymerization reaction at the catalysts.

采用带有空间位阻基团的脂肪胺在催化剂的作用下与环氧丙烷和环氧乙烷开环聚合，合成LY系列脱硫剂。

In the presence of DMSO as co-solvent and under vigorous agitation, baker\'s yeast in water was found to reduce substituted fluorenones to the corresponding fluorenols in good to excellent enantioselectivies (52%~ 100% ee). The experimental results clearly revealed that when mass transfer limitations are overcome, baker\'s yeast is able to reduce even highly sterically hindered ketones, such as substituted fluorenones.

在强烈的搅拌、并使用DMSO作为底物助溶剂的反应条件下，面包酵母对取代芴酮显示出较高得还原活性，得到立体选择性很高的相应的芴醇(52%～100%ee)。

So, there is an especial significance in the case of energy sources shortage and huge energy consumption nowadays. Based on reaction mechanism of alkanolamines with acid gases in this work, selective absorption of H_2S from mixed-gas streams into the aqueous solution of blended amines of MDEA-TBEE has been studied using a static and a dynamic evaluation setup, respectively. TBEE, a severe sterically hindered amine, was added into MDEA to form the blended amines.

开发高效活化剂是酸性气体吸收领域重要的研究方向之一，研究工作采用一乙醇胺为原料，氢气为反应氛围，低压下有机气相通过管式催化反应器合成活化剂哌嗪，考察合成催化剂组成和操作参数对合成反应的影响；将合成产物应用于膜吸收装置和再生装置上考察其吸收和解吸CO_2的性能。

Continuous determination of a polymer chain end group(initiating and chain growth species) at various times by electrospray ionization mass spectrometry indicates that the sterically hindered strong organic base predominately plays an initiator of polymer-chain growth in the copolymerization process.

利用飞行时间质谱对聚合物链端进行了跟踪检测，直接观察到了聚合反应的引发及链增长过程，证明大位阻有机碱在共聚反应过程中对聚合物的链增长起着重要的引发作用。

The most precious possession that ever comes to a man in this world is a womans heart.

在这个世界上，男人最可贵的财产就是一个女人的心。

Some 4 years above company and divisional management experience, 6 year foreign enterprises work experience.

有4年以上的公司及部门管理经验，6年外企工作经验。