it was found that the cations in the zeolite zsm-6 might exert steric hindrance on the adsorption of cyclohexane at room temperature (25℃).

发现室温下环己烷分子的吸附受到阳离子的空间障碍作用。

the large steric hindrance group avails to the enantioselectivity, but too much steric hindrance reduces the activity.

大位阻取代基有利于提高对映选择性，但位阻过大降低催化活性。

the results indicate that the larger steric hindrance in the amino alcohol unit of schiff base ligands leads to higher enantioselectivity.

结果表明，氨基醇部分的结构空间位阻越大，产物亚砜的对映选择性越高；

nevertheless, steric hindrance caused by chemical structure reduces the retention time.

药品化学结构引起之立体障碍会降低滞留时间。

their extraction ability markedly decreases with the increase of the steric hindrance from ester alkyl group.

萃取能力随着酯烷基空间位阻的增大而显着降低。

space steric hindrance resulted by length lateral chain and electrostatic repulsion of charged ion made the main contribution to water-reducing effect of paa.

自制paa系列的减水机理主要为其长侧链引起的空间位阻作用及其带电离子的静电斥力作用。

in addition, the molecule size and steric hindrance showed obvious effects on the interaction.

而氨基酸的手性对它们的相互作用在质谱条件下没有表现出影响。

and it was found that dioxo-methyl group was a key factor to determine the antioxidant activity of dcls, because its o and c had rather high net charge and its steric hindrance was rather low.

发现二氧甲基基团具有较大的o原子负电荷及c原子正电荷，且空间位阻较小，因此成为决定五味子素抗氧化活性的关键因素。

the results indicate that the zn2+-binding stability of carboxamidoquinoline could be decreased by the steric hindrance effect of 2-substituents.

光谱研究表明，喹啉2位取代基的空阻效应将降低酰胺基喹啉与锌离子络合的稳定性；

the dependence of chain scission and racemization on temperature results from molecular motion, 「cage effect」 and steric hindrance during recombination.

分子量降低和消旋作用对温度的依赖性，是由于分子运动和笼罩效应以及重合的空间位阻效应所致。

in the end, the steric hindrance of the acetyl group was discussed.

最后，本文讨论了空间位阻效应对反应性质的影响。

the size and steric hindrance of substituent of porphyrin is one of the crucial factors to affect the interaction between porphyrins and dna.

吡啶取代基的大小和空间位阻是影响相互作用方式的关键因素之一。

it was considered that steric hindrance and electrostatic repulsion were the main stabilizing mechanism.

空间位阻和静电排斥是其乳状液稳定的主要机理。

the dispersing ability of sshe as cement dispersant also came from steric hindrance effect and long side chain contributed to steric hindrance in a certain degree.

淀粉丁二酸单酯用作水泥分散剂时，其分散机理也主要来自空间位阻作用，且较长的极性侧链对空间位阻效应具有一定的贡献。

based on this, the selectivity and steric hindrance for the adsorption of bile acids are discussed.

对树脂吸附胆酸过程中的选择性和位阻作了讨论。

this approach covers the substrate range of aliphatic, aromatic, heterocyclic and steric hindrance ketones.

该催化剂适用于各种脂肪酮、芳香酮、杂环酮和位阻酮。

at the same time, we have also investigated the influence of the electric effect and steric hindrance effect of the substituents to the yields and regioselectivity.

同时，我们还研究了取代基团的电子效应和位阻效应对反应产率和区域选择性的影响。