对树脂吸附胆酸过程中的选择性和位阻作了讨论。
Based on this, the selectivity and steric hindrance for the adsorption of bile acids are discussed.
综述了位阻型硅烷化试剂的特点、保护原理和应用。
The characteristics, protective principle and application of Sterically hindered silane blocking agents were reviewed.
该催化剂适用于各种脂肪酮、芳香酮、杂环酮和位阻酮。
This approach covers the substrate range of aliphatic, aromatic, heterocyclic and steric hindrance ketones.
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 large steric hindrance group avails to the enantioselectivity, but too much steric hindrance reduces the activity.
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。
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.
水凝胶中扩散理论模型主要有自由体积模型、流体力学模型、位阻效应模型三大类；
The theoretical models consist of three categories: free volume, hydrodynamic, and obstruction effect models.
简介了位阻胺光稳定剂(HALS)的作用原理及涂料工业中常用HALS的结构及性能。
HALS light stabilizer action and principle, together with conventional HALS structure and property in paint and coatings industry are briefly introduced.
油胺也存在于纳米颗粒的表面，表明它具有帽化试剂的作用，能通过提供位阻保护作用防止测试纳米颗粒发生凝聚。
Oleylamine was also found on the surface of nanoparticles, indicating its role as capping agent which provided steric protection of as-synthesized nanoparticles from agglomeration.
当腐蚀浸泡的时间大于120分钟后，腐蚀产物在铝合金表面产生了明显的位阻作用，从而使腐蚀速率逐渐下降，直至48小时后，腐蚀速率趋于一相对稳定的数值。
Because of the place obstruction of corrosion products in the surface of the alloys, while corrosion time is at 120 minutes above, the corrosion rate descends to the stable value in 48 hours.
阿吉和七位姑娘看见乡亲们为涵碧潭所阻，不能到对岸去赶场和耕种，便决心在涵碧潭上合力修建一座石桥。
Ji and the seven girls saw that villages were blocked by the Hanbi Pool and could not go to the other side for farming, so they decided to build a stone bridge over the pool together.
弗朗西斯·韦尔奇是一位退休牙医，以前是个烟民，现在是慢阻肺病患者。
Francis Welch is a retired dentist, former smoker and now a COPD patient.
弗朗西斯·韦尔奇是一位退休牙医，以前是个烟民，现在是慢阻肺病患者。
Francis Welch is a retired dentist, former smoker and now a COPD patient.
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