空间位阻效应

由于空间位阻效应，长链脂肪醇与短链脂肪醇可能存在不同的毒性作用机理。

Due to the steric effect , there may be different toxicity mechanisms between long-chain and short-chain aliphatic alcohols .

红外图谱证明了分散剂在纳米二氧化钛表面形成了牢固的化学吸附，以此产生电斥力和空间位阻效应，使纳米二氧化钛在分散体系中处于稳定的悬浮状态。

FTIR proved that the dispersant tightly adsorbed at the surface of nano-TiO_2 by chemisorption , and induced the nano-particle to keep stable in the aqueous dispersion due to the electric repulsion force and steric effect .

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 .

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 .

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 .

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 .

本论文合成了新型分子内电荷转移（ICT）荧光体-苯甲酰苯胺衍生物并研究了其吸收光谱、荧光光谱、电子效应、空间位阻效应及分子内电荷转移。

This dissertation describes the synthesis of a new type of ICT fluorophors , benzanilides , and the study of their absorption spectra , fluorescence spectra , electronic effect , steric effect and intramolecular charge transfer ( ICT ) .

空间位阻效应及电子效应的协同作用使HTMA与环氧树脂的固化反应速度降低，固化过程中放热量小，放热平缓。

HTMA cured with epoxy resin gently and slowly , owing to the synergistic effect of steric hindrance effect and stereo-electronic effect .

最后，讨论了清除过程中取代基的空间位阻效应。

In the end , the steric hindrance of the substitute was discussed .

研究结果表明随着苯氧基取代程度的增加，苯环的空间位阻效应逐渐显现。

The results showed that with the increasing of substitute degree , the steric effects of benzene ring appear gradually .

并对其作用机制进行了分析，认为是由于极压抗磨添加剂分子中带负电性的双键和带正诱导效应及空间位阻效应的支链共同作用的结果。

It is the interactional result of electronegative double bond and branched chain with positive induction effect and space steric effect .

聚乙二醇的大分子结构通过空间位阻效应将沉淀粒子分隔防止团聚，而柠檬酸则是通过静电排斥作用使颗粒分散。

As the modified agents , polyethylene glycol dispersed the precipitated particles by space steric effect , but citric acid worked by electrostatic repulsion .

主要研究结果：①苯乙酰胺类凝血酶抑制剂与凝血酶活性位点的相互作用主要有氢键相互作用，疏水作用，静电相互作用以及空间位阻效应。

The research results are as follows : ① The main interactions between phenyl acetamides derivatives and thrombin activity sites are hydrogen bonds , hydrophobic interactions and electrostatic interactions .

为20种有机溶剂制定了供电子效应常数，首次将空间位阻效应定量地应用于溶剂效应，并为这些溶剂确定了供电子位阻效应常数。

The stereo-hindrance effect was first quantitatively applied in the study on solvent effects . Electron donor effect constants and electron donor hindrance constants were proposed for 20 solvents .

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 .

总的来说，缓蚀剂的静电吸附作用越强，空间位阻效应越小，中心吸附原子的电子云密度越大，缓蚀剂的抗硫效果越好。

In general , corrosion inhibitors , which have stronger electrostatic adsorption , smaller the steric effect , and larger the electron density of central adatom , would have better corrosion resistance to sulfur .

结果表明，在胶体溶液中加入混合表面活性剂后可以提高胶体的ζ电位绝对值，使静电效应和空间位阻效应同时增强。

The results indicated that , by using mixed surfactant , the absolute value of ζ potential was enhanced and the static effect and steric hindrance effect of colloidal solution were strengthened as well .

反应速度随酯基基团空间位阻效应呈线性下降，说明稀土离子与水杨酸酯之间环状配位化合物的形成在亚硝基化反应中起着重要作用。

The fact of reaction rate decreasing linear with the steric hindrance of ester groups shows that the formation of ring coordination compound between rare earth ions and salicylate ester takes an important role in the nitrosation reaction .

之前有研究发现渗透剂对蛋白质的稳定能力与它的分子表面的极性基团表面积比例呈反比关系，但忽略了分子体积所代表的空间位阻效应的影响，因此存在一定误差。

There was a research before which found that the osmolyte stabilizing effect have negative correlations with the ratio of polar group surface area of their molecules . However , it failed to consider the molecular volume which could represent the steric exclusion effect , therefore had some deviations .

通过对钛白粉的无机包覆和有机改性，可利用钛白粉表面较多有机官能团的空间位阻效应改善粉体的团聚情况，同时有机官能团改善了它与锦纶界面的相容性。

Through inorganic coating and organic modification of titanium dioxide respectively , we can improve powder reunion by using organic functional groups steric of titanium dioxide surface . At the same time , the coating of titania with organic functional groups improves the compatibility between the particles and nylon matrix .

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 .

我们从空间位阻和溶剂效应讨论了这些结果。

These results are discussed in terms of steric effect and solvent effect .