查询词典 selectivity

New methods for asymmetric synthesis of pinacol are reviewed, the catalytic effects and stereo- selectivity with various catalytic systems are discussed in this paper.

综述了近年来不同催化体系的不对称合成呐醇的方法，并总结了不同的催化效率和对映选择性的差异

Separation/preconcentration is always necessary for improving sensitivity and selectivity of analyt...

在分析科学中，为提高分析方法的灵敏度与选择性，分离与富集是必不可少的，其中柱材料分离富集占有十分重要的位置。

Separation/preconcentration is always necessary for improving sensitivity and selectivity of analytical method.

在分析科学中，为提高分析方法的灵敏度与选择性，分离与富集是必不可少的，其中柱材料分离富集占有十分重要的位置。

The best catalytic activity and selectivity could be found in the prepared catalyst system with the optimum combination of the ionic liquid, nano-Pd, and support. The stabilizer is also used to prevent the aggregation of nano-Pd particles. One of the advantages of this approach is that the prereduction of catalyst is not required.

其中离子液体、奈米钯金属及担体皆有其功能，三者之组合才能达到良好之效果，同时，在合成奈米钯过程中，必须使用稳定剂以避免奈米钯金属之聚集此触媒系统之另一优点为不需先加氢还原处理，耐水性强且可重覆使用，是一种颇具潜力之选择性氢化触媒。

The magazine merit depends on the pertinency is strong , selectivity is good , confidence is tall , reads rates height again and again , summons the strong point reading rates height , preserving scheduled time , has intact preservability , advertisement life to grow have certain authority together.

杂志的优点在于针对性强，选择性好，可信度高，并有一定的权威性，反复阅读率高，传读率高，保存期长，有完好的保存性，广告生命长。

The main objective of this research project is to modify the Methyl-Acetylene/propadiene selective hydrogenation reaction system of the No.3 Naphtha Cracker in CPC. The original gas phase reaction system was redesigned to a liquid phase reaction so that higher propylene selectivity was achieved and lower rates of propane and green oil were produced. To recover effectively the higher production of valuable propylene from the reaction system, the following fractionator was also redesigned.

本研究之目的在於修改中油公司三轻工场老旧的甲基乙炔／丙二烯选择性氢化气相反应系统，使成为液相反应系统，藉由液相反应的优异性，提高由MAPD氢化得到丙烯之选择率，同时降低丙烷及绿油产率，以增加丙烯产率，另亦修改丙烯精馏系统，以提升蒸馏塔提纯之效率。

This paper reports the experimental equipment and technology parameter for the synthesis of diisopropylbenzene and triisopropylbenzene by catalytic alkylation between benzene and propene, the conversion of benzene is more than 98%,the selectivity of diisopropylbenzene and triisopropylbenzene is more than 40% and 36% respectively.

报道了苯与丙烯催化烷基化合成二异丙苯和三异丙苯的实验装置与工艺条件，苯的转化率达98%以上，二异丙苯的选择性≥40%，三异丙苯的选择性≥36%，经分离后可获得纯度≥95%的二异丙苯和三异丙苯产品，所提供的合成工艺基本上无污染，在国内外具有先进的技术。

The total selectivity of propionic acid and propionate is 85.51%,and ethanol conversion is 95.30%.

在试验条件下Ni-Cu/C催化剂对乙醇转化率为95.3％，丙酸＋丙酸乙酯的选择性为85.51％。

The main conclusions are: Mexican hat wavelet is anisotropic one, and it could detect pointlike singularities very efficiently. Morlet and Cauchy wavelet could be used to detect specific directions, and Cauchy wavelet has better direction selectivity than Morlet one. And it has been used to separate the wave field of Ricker. Its results are basically accurate and computation is more efficient.

主要结论有：Mexcian帽小波是各向同性的，主要用来检测点状信号分量，Morlet小波和Cauchy小波主要用来检测方向信号分量，并且Cauchy小波比Morlet小波的方向性要好，检测结果的分辨率要高；利用二维连续小波反变换，以合成的Ricker子波为模拟信号为例进行波场分离，提高了运算效率，实验结果基本上比较准确，还需要实际地震信号的进一步验证。

Compared with flunarizine and nimodipine, in addition the Chinese herb tetramethylpyrazine has the beneficial effects on the antagonism of brain Post-ischemic hypertension or increase of PAP and PCWP, while tetrand- rine showed weak amelioration effects on brain resusci- tation, which may be due to its no selectivity on brain or brain vesseles.

与氟苯桂嗪和尼莫地平相比，中药川芎嗪还具有对抗脑缺血后继发性外周血压和肺血管压升高的独特效应。而汉防己甲素的抗脑缺血损害效应微弱，可能与此药对脑血管、脑细胞选择性作用较低有关。

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。