位阻

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 .

通过加入分子周边取代和中心取代，从而引入空间位阻效应使薄膜的结构变为非定形，表现在其吸收带的线宽变窄，红移变小。

By introducing the steric hindrance effects of peripheral and axial substitutions , the red-shift and broadening of the bands are weakened as the structure of the thin films become amorphous .

以聚合物甲基纤维素作空间位阻剂合成了X型分子筛。

X-type molecular sieves are synthesized by using polymer methylcellulose as a space-confined additive .

ASP良好的分散能力是静电斥力和空间位阻共同作用的结果。

Excellent dispersing performance of ASP is the result of co-action of electrostatic repulsion and steric hindrance .

CS结构修饰及其与AA相互作用的空间位阻效应

Structural modification of chondroitin sulfate and the spatial baffle effect of interaction with methylene blue

为了减小空间位阻效应，与中心Cu（Ⅱ）离子螯合配位的两个邻菲咯啉配体之间近似呈垂直排列。

The two phen ligands chelating to each Cu (ⅱ) center arrange in almost perpendicular orientation to avoid the severe steric hindrance .

BER还原芳醛的位阻效应和电子效应

The effect of steric hindrance and electron on aromatic aldehydes reduced by BER

表面活性剂PEG（600+20000）是利用胶粒的静电效应和对胶粒的空间位阻效应分散胶粒；

Surfactant PEG ( 600 + 20000 ) dispersed agglomeration colloids by electrostatic effect and space location-obstruct effect .

以B环经修饰的化合物61,63为底物，由于C（7）取代基的位阻而并未制得重排的中间体。

Due to the spatial resistance of substitute group in C ( 7 ), the key compound for rearrangement was not prepared by compounds 61 and 63 whose ring B were modified .

根据PEG分子的空间位阻、疏水性等解释了PEG分子量不同而获得不同粒径金纳米粒子的原因。

The cause of obtaining gold nanoparticle with different size is the different space effect and hydrophobic property of PEG .

影响~（11）C甲基化的因素有：甲基化试剂、进攻试剂碱性、溶剂极性和空间位阻等。

There are many influence factors for ~ ( 11 ) C methylation , such as methylation agents , the base of reagents , the polarity of solvent , the obstruct of space .

也简要地介绍了H2S、CO2在一种新型溶荆一位阻胺AMP（2氨基2甲基1丙醇）水溶液中的溶解度数据。

The author also briefly introduces the solubility data of H_2S and CO_2 in water solution of a new solvent-AMP ( 2-amino-2 methyl-1-propanol ) .

结果表明：增大激发光的光强与延长激发时间对促进MR分子光致异构具有等效作用，而且MR分子的光致异构过程对周围的空间位阻有很强的依赖性；

And it was found that the effect of strengthening laser energy is similar to that of prolonging the excitation time , and the photochromism process of MR strongly depends on steric hindrance around azobenzene molecule .

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。

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 .

结果表明，这类萃取剂对于Yb，Lu的萃取和分离能力随着其分子中取代基空间位阻的增大而降低。

The results show that the extraction and separation abilities for Yb and Lu decrease with increasing the steric hindrance of the substituents in extractant molecules .

结果：调节介质的pH值，使颗粒间处于较高的静电效应，在此条件下加入表面活性剂，使颗粒间又具有空间位阻稳定效应，空间位阻稳定效应可阻止颗粒间的团聚。

Results the particles may have higher electrostatic effect by adjusting the pH value of the medium and have steric hindrance effect by adding the surfactants on the previous condition , which prevent the particles from agglomeration .

随着AFP抗原浓度的增加，由于形成的免疫复合物的影响而导致的空间位阻和阻抗的增加，从而引起了DPV峰电流的降低。

The DPV peak currents decreased with the increased AFP concentration due to increasing spatial blocking and impedance from the formed immunoconjugates .

用计算机模拟得到了交联剂分子的最低能量构象图，提出了封闭型TDI交联剂由于空间位阻效应而发生了三官能团式的交联固化反应。

We discover that the NH CO space hindered effect in themolecule that causes the type of three group crosslinking curing in blocked TDI crosslinker .

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。

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

认为MB与CS相互作用具有空间位阻效应，CS的抗凝血功能与磺酸基有关。

It is considered that the interaction between Methylene Blue and Chondroitin Sulfate has an effect on spatial locality interference and Interference Unit of CS is related to its sulfonic group .

此处使用Span-80为分散剂，是利用其空间位阻作用。

In the synthesis , Span-80 was used as surfactant , due to its steric hindrance effect .

降冰片烯及其衍生物是进行ROMP反应的常用单体，降冰片烯基单体的构型、空间位阻及极性都是影响ROMP反应的重要因素。

The configuration , steric exclusion and polarity of the norbornene-based monomers are important factors to affect the ROMP reaction .

其支化程度与离子对的结构，即炔酰胺上N原子相连取代基和路易斯碱的位阻大小有关，可通过对链转移反应的抑制控制支化程度。

The degree of branch structure is related to the ion-pair , which is the substituent group connected to N atom in alkyne , and the steric effect of the Lewis Base . The branch structure can be restrained by controlling the chain transfer reaction .

与CMC类似，当体系的pH小于5.2时，CMc也开始吸附在酪蛋白胶粒表面，提供空间位阻作用和静电排斥作用从而稳定酪蛋白胶粒。

CMc can also adsorb on the surface of casein particles and provide steric repulsion and electrostatic repulsion to stabilize the casein particles when pH of CMc / casein micelle mixture is at and below 5.2 .

蛋白质空间构型模拟分析发现，Thr359Met导致蛋白质空间构型发生改变，有较大侧链的Met置换了Thr后引起空间位阻，同时氢键数目也发生改变。

It is found by computer simulated molecular model that the replacement of Thr by Met which has a larger and longer side chain might cause steric hindrance , and change the number of H bonds .

文中在PU弹性体体系中添加了一种含有位阻性液体二胺类扩链剂和经过处理的特种填料，制备了新型阻尼聚氨酯（PU）阻尼材料。

In this paper , the system of the PU elastomer adde a liquid containing sterically hindered diamine chain extender and processed specialty fillers , prepared a new type of damping polyurethane ( PU ) damping materials .

结果表明，MS的双重荧光与所处微环境的氢键性质密切相关，β-CD取代基的大小会导致空腔口处的极性和空间位阻不同，相应改变了分子间氢键相互作用。

It was found that dual fluorescence of MS closely correlate with the hydrogen bonding property of its surrounding microenvironment . The sizes of substituents at the rim of β - CD result in different polarity and steric hindrance at the cavity opening .

逐步回归分析表明，表征位阻效应的参数MW与表征电性效应的参数pKa相结合，能够较好地拟合取代苯甲酸的生物降解速率常数。

Stepwise regression analysis shows that combination of MW , which represents the steric effect , and pK a , which represents the electric effect , can fit biodegradation rate constants of substituted benzoic acids well .

在纳米Al2O3表面接枝聚缩醛可在粒子表面建立起空间位阻稳定层，不但提高了纳米粒子的分散稳定性，还可以增强纳米粒子与树脂基体的相容性。

Steric hindrance layer can be established when the surfaces of nano-Al_2O_3 were grafted with polyacetal , which ( increased ) the dispersibility of the nano-particles as well as the compatibility between the particles and the resin matrix .

此外，CFG也不像CMC和CMc一样能吸附在酪蛋白胶粒上提供静电排斥效应和空间位阻效应，其不能作为酸性乳饮料的稳定剂。

In addition , CFG can not adsorb on the casein particles and provide steric repulsion and electrostatic repulsion as CMC and CMc . CFG can not be used as a stabilizer of acidified milk drinks .