stereospecificity

In order to improve the stereospecificity of DQ spherical catalyst , the synthetic process and recipe of the catalyst had been studied .

为了解决DQ催化剂立体定向性方面存在的问题，对DQ催化剂的合成工艺及配方进行了研究。

Effects of mole ratio of Al to Ti , polymerization temperature , time and solvent type on catalyst activity and catalytic stereospecificity were studied .

考察了n（Al）∶n（Ti）、聚合温度、聚合时间及溶剂种类对复合催化剂的活性及定向催化能力的影响。

The stereospecificity of the thermal cleavage of pyrazolines is lacking although stereoselectivity does exist .

二氢吡唑热解虽然有立体选择性，但没有立体定向性。

Activity , hydrogen response , stereospecificity and kinetic behavior of catalysts with 1,3-diol dibenzoate as internal donor for propylene polymerization were studied .

研究了1,3-二醇酯为内给电子体的丙烯聚合ND-01系列催化剂的活性、氢调敏感性、定向性及动力学行为。

MgCl as a supporting material can greatly improve the activity and stereospecificity of heterogeneous Ziegler-Natta catalysts , leading to significant simplifications in polyolefin production processes .

氯化镁作为一种非常重要的载体材料，可以极大地提高非均相Ziegler-Natta（Z-N）催化剂的聚合活性和定向能力，极大地推动了聚烯烃工业的发展。

The activity and stereospecificity of the catalyst were so high that the very small amount of catalyst residues and atactic polypropylene possibly formed during the polymerization process might be left in the product without any further treatment .

由于该催化剂具有高活性和高定向能力，催化剂的残渣和无规物的含最很低，因而可以不经处理而残留在产品中。

The experimental results showed that the activity and stereospecificity of the catalyst were dependent on the polymerization temperature , the composition and concentration of the activator , and the quantity of poisonous impurities in the propylene monomer .

用络合Ⅱ型催化剂对丙烯液相本体聚合进行系统研究。发现聚合温度、活化剂成份和浓度以及丙烯中的有害杂质数量均对催化剂活性和定向能力有显著影响。

Except menthyl formate , they all preferentially hydrolyzed short-chain fatty acid esters of menthol with high stereospecificity , which indicated that the two purified enzymes were short-chain fatty acid esters hydrolase .

除甲酸薄荷酯外，均优选短链l-型脂肪酸薄荷酯进行水解。因此，两目的酶都属于短链酯酶。