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steric adj.【化學】(原子的)空間(排列)的;位的。adv....

steric hindrance

Monodisperse ( coefficient of variation 5 % ) polystyrene microspheres in the size range of 1 . 0 ~ 10 m are prepared by dispersion polymerization in ethyl alcohol reaction media using polyvinylpyrrolidone ( pvp ) as a steric stabilizer and 2 , 2 ' - azobisizobutyronitrile ( aibn ) as an initiator in suitable condition 摘要以聚乙烯吡咯烷酮為分散劑、無水乙醇為反應介質、偶氮二異丁腈為引發劑,采用分散聚合的方法,通過優化反應條件,成功制備出了粒徑范圍為1 ~ 10 m不同粒徑級別的單分散(分散系數5 % )聚苯乙烯微球。

The interactions between particles were discussed based on dlvo and edlvo theories . experiment results show the effect of the ph on the dispersion is due to the repulsion interactions of electrical double layer ; and addition suitable inorganic dispersant or organic macromolecule dispersant results in improvement the stabilization of the dispersion . the main action of the inorganic dispersants is to increase the repulsion interactions of electrical double layer and the main action of organic macromolecule dispersant is to increase hydration shell and steric hindrance 研究表明: ph對顆粒分散的影響主要體現在對顆粒間雙電層靜電排斥力的改變;添加合適分散劑可以改變顆粒在水中的分散性;無機電解質的分散機制主要是增加顆粒表面的雙電層靜電排斥作用能,而高分子分散劑的分散機制主要是增加顆粒的水化膜排斥能和位阻排斥能;復合分散劑的分散效果要優于單一分散劑;提出了用經時損失性來評價分散穩定性。

Some special surface treatment methods were adopted to improve the interface interaction between the polymer and magnetic particles in order to increase the encapsulation efficiency . the ultrasonic technique , some organic solvents and several functional steric stabilizers were applied to improve the quality of final magnetic particles . ps / iron oxides magnetic composite microspheres with the size 80 - 210nm were prepared via improved emulsion polymerization 三種方法可以制備具有不同粒徑和磁性能的磁性fe _ 3o _ 4納米粒子,其中,共沉淀法制備的磁性微粒粒徑大小穩定,比較容易控制在10nm左右,且所得磁性微粒的磁響應性強,具有超順磁性,利于制備高性能的磁性復合微球。

Syntheses of ? ? diimine and 2 - aminopyridine transiting metal complexes bearing 2 , 6 - unsym - substituents on the aryl , and investigation on the steric and electronic effects of the unsym - subatituents on the catalytic property 以2 , 6位不同基團取代的苯胺與相應的二酮反應合成系列的? ?二亞胺和吡啶胺基過渡金屬配合物。主要考察芳環2 , 6位基團立體位阻對催化性能的影響,同時也考慮基團的推拉電子效應。

Using the data of gravity field parameter variations observed by grace , and mean sea level variations observed by satellite altimetry removed steric sea level changes calculated from the numerical ocean models , global ocean mass change is studied 利用grace衛星觀測得到的重力場系數變化資料及重力衛星測高得到的海平面變化扣除由模式得到的熱容海平面變化,研究了海水的質量變化。

In another way , they prevented ion exchange process in some degree because of space steric hindrance . in short , this paper will make a good foundation for further application research about urushiol hybrid material and electropolymerization in future 綜上所述,本文用兩種不同方法制備了不同聚合漆酚納米無機物雜化材料,研究了合成方法,結構特征及性能等。

This enzyme is industrially important and useful for the clinical determination of total or free serum cholesterol by coupling with related enzymes , the determination of the steric configuration of 3 3 - hydroxysteroids and the preparation of hormone 膽固醇氧化酶是膽固醇代謝的關鍵酶之一,它催化膽固醇氧化及異構反應,生成膽甾- 4 -烯- 3 -酮和過氧化氫。

Moreover , template can be pre - designed according to the size and shape of objective materials . microgels are cross - linked latex particles with narrow size distribution and the inherent steric stability 微凝膠是一種交聯型的膠乳粒子,它具有較窄的尺寸分布和空間位阻作用。

The three - dimensional “ functional shape ” formed by the steric ( physical ) and electric fields of a drug molecule that cause the molecule ' s pharmacological activity 一個藥物分子經過物理或電場作用形成三維功能結構從而引起分子的藥理活動。

. . aerospace series . non - metallic materials . liquid chromatography characterization high performance liquid chromatography . steric exclusion chromatography . general methodology 航空航天系列.非金屬材料.液相色譜法特性

Some albumin molecules may hae undergone steric modification or ligand binding such that the immunoreactie sites hae become obscured 某些白蛋白分子也許經歷了空間修飾或配體結合上的改變以至于其免疫反應位點被湮沒。

Determination of molecular weight averages and molecular weight distribution of polystyrene standards by steric exclusion chromatography 體積排斥色譜法測定聚苯乙烯標準樣品的平均分子量及分子量分布

Chinese herbs combined with steric and dynamic interference current therapy on 60 patietns with hemiparalysis after stroke 中藥內服配合立體動態干擾電療儀治療腦卒中偏癱60側

Steric effects in 126 may also be responsible for its inertness to the grignard reagent ( 126 )的空間效應也是它對格氏試劑反應遲鈍的原因

Steric exclusion chromatography , sec 空間排阻色譜法

Steric effects in rate constants for bimolecular dissociation 離解反應速率常數中的方位因素

It follow therefore that the steric blocking effects of substituents are reflected in adverse kinetic, rather than thermodynamic factors . 由此可以看出,取代基的主本阻礙反應,是反映在違背動力學因素而不是熱力學因素。

Macromolecules cannot approach the ligand owing to steric hindrance of the matrix . 由于載體的立體位阻的關系,大分子化合物不能接觸到配基。

Steric effects in 126 may also be responsible for its inertness to the grignard reagent . (126)的空間效應也是它對格氏試劑反應遲鈍的原因