查询词典 selectivity

The catalyst has high catalytic activity and excellent stability, both the conversion rate of TAME and the selectivity of isoamylene can be over 99%.

该催化剂具有良好的活性和稳定性，TAME转化率和异戊烯的选择性均超过99%。

The yield of product was 56.1% when rare-earth composite solid superacid SO(superscript 2- subscript 4)/ZrO2-CeO2 was used as catalyst at dosage of 3 % of the mass of β-pinene, while mass ratio of borneol to isoborneol in the product reached 46.0:23.2, showing higher borneol selectivity than other catalysts.

当用稀土复合固体超强酸SO(上标 2-下标 4)/ZrO2-CeO2为催化剂，用量3%时，粗龙脑产率为56.1%，但对正龙脑的选择性高于其他催化剂，正、异龙脑比为

When the amount of SO(superscript 2- subscript 4)/ZrO2 catalyst was 7% of the mass of β-pinene, the yield of product was 62.0%, and the mass ratio of borneol to isoborneol in the product was 13.6:48.7. When the amount of S2O(superscript 2- subscript 8)/ZrO2 catalyst was 7% of the mass of β-pinene, the yield of product was 66.7%, the mass ratio of borneol to isoborneol in the product was 11.5:49.5. Both two catalysts were poor for borneol selectivity.

在上述反应条件下，当催化剂SO(上标 2-下标 4)/ZrO2用量为7%时（以β-蒎烯质量计，下同），粗龙脑产率为62.0%，产品中正、异龙脑比为13.6：48.7；当催化剂S2O(上标 2-下标 8)/ZrO2用量为7%时，粗龙脑产率为66.7%，正、异龙脑比为11.5：49.5；这两种催化剂对正龙脑选择性比较差。

The conversion of isobutyraldehyde and the selectivity to 2,4,6-triisopropyl-1,3,5-trioxane were 91.1% and 99.8% respectively under optimum reaction condition isobutyraldehyde 25.0 g, [Et3NH]Cl/FeCl3 ( x (FeCl3)＝0.62 1.0 g, 25 ℃ for 1 h .

在最佳的反应条件下（异丁醛25.0 g， [Et3NH]Cl/FeCl3 x (FeCl3=0.62 1.0 g， 25 °C，N2保护下反应1 h，异丁醛的转化率为91.1%，对2，4，6-三异丙基-1，3，5-三氧噁烷的选择性达99.8%。

The results indicated that the total surface basic sites was in favor of increasing catalytic activity, while the higher ratio of medium-strength basic sites was good for improving the selectivity of isophorone.

经过镧改性催化剂的表面总碱量增加，可提高催化剂的活性，但增加的碱量主要位于弱碱性位，因而不利于提高催化剂对于异佛尔酮的选择性。

The experimental results show that this new kind of chitosan derivative has the characters of both chitosan and dithiocarbamate.This compound has much better selectivity and capability for heavy metals.Meanwhile,it is convenient,safe and more jarless in acid solution.All results above show that this chitosan derivative has a good application foreground.

本文合成的二硫代氨基甲酸改性壳聚糖兼具天然高分子壳聚糖与二硫代氨基甲酸基的结构与特性，对重金属离子具有良好的选择性和优异的捕集效果，能同时去除多种重金属离子，而且具有使用方便、毒性小、抗干扰能力强、性能稳定等优点，具有良好的应用前景。

Sometimes there is some selectivity in who is laid off,' says Jerald Jellison, a psychologist and professor of social psychology at the University of Southern California who specializes in the workplace.

南加州大学(University of Southern California)的社会心理学教授杰利森是专门研究职场的心理学家，他说，有时候谁会被裁还是有一定的选择性。

The effects of reaction time, mole ratio of reactants and amount of catalyst on yield of ketal were investigated by using the [SO3H-bPy] [H2PO4] ionic liquid as catalyst. Results show that the ionic liquid was an efficient catalyst for the ketalization with high conversion and selectivity in mild conditions.

以磺酸基功能化的吡啶磷酸类离子液体[SO3H-bPy][H2PO4]为催化剂，系统考察了反应时间、酮与醇的配比、催化剂的用量及催化剂重复使用、不同阴离子、阳离子等因素对反应的影响，优化了反应条件。

Before impregnating nickel, the addition of 3wt% lanthana into Ni/SiO2 could enhance the activity, selectivity and stability of catalyst apparently.

采用先浸渍方式向催化剂中引入含量为3wt%的镧助剂后，镍基催化剂的催化加氢活性、选择性和稳定性得到了很大幅度的提高。

The results indicated that the selectivity of levulinic acid could be improved at a lower reaction temperature and a higher sulfuric acid concentration.

研究结果表明，降低温度和提高硫酸浓度有利于提高生成乙酰丙酸的选择性。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。