查询词典 selectivity

Properties of frontier orbital of xanthogen formates and ethoxycarbonyl thionocarbamates, including HOMO energy, shape of HOMO and atomic HOMO density, were calculated with quantum chemistry programs GW03 and FUJISTU CAChe. According to the results, the relationship between selectivity of such two kinds of collectors and their quantum chemical indices was investigated to discuss the feasibility of applying them in screening chalcopyrite collectors.

摘 要：利用量子化学软件GW03和FUJISTU CAChe计算黄原酸甲酸酯类、乙氧羰基硫氨酯类黄铜矿捕收剂的前线轨道的性质—HOMO能量、HOMO形状以及药剂组成原子的HOMO密度，并结合这两类药剂的浮选结果研究这些量化参数与药剂选择性之间的联系，探讨这些参数作为选择黄铜矿捕收剂判据的可行性。

Histograms can be used to estimate the selectivity of queries in query optimization.

直方图在查询优化过程中起着重要作用。

In the presence of hydrogen, the effects of electrode material and structure, peak voltage input of the electric fields and feed flow rate on methane conversion, single pass yield and selectivity of C2 hydrocarbons were investigated.

采用新型的旋转电极辉光放电反应器，在常温常压下对辉光等离子体作用下的甲烷转化制C2烃进行了研究。

As expected, TS-1 exhibited high catalytic activity as well as perfect selectivity in the reduction of nitric oxide by excess hydrogen.

如我们所预料，TS-1在用过量氢气催化还原NO的反应中表现出高的催化活性和很好的选择性。

Catalysts of this invention, applied in the reaction of selective oxidation of carbon monoxide to carbon oxide from hydrogen－rich gas mixtures, exhibited highly catalytic activity and excellent selectivity.

本发明之触媒应用在由富氢气体混合物中将一氧化碳选择性氧化成为二氧化碳反应中，显现出高催化活性及优越的选择率。

To design a good lanthanide luminescent sensor, a unique combination of features must be realized: high selectivity and recognition to lanthanide ions; presence of multiple absorbing groups suitable for energy-transfer ; high thermodynamic stability and kinetic internees.

一个优良的发光器件必须具备以下几个条件：配体对金属离子有较高的选择识别性能；配体含有共轭发色团有利于能量从配体向中心离子转移；配合物具有相对较高的动力学和热力学稳定性。

It was also found that thecross-linking degree, the micro structure and the surface morphology of the IPN membranes was more important to proton selectivity than the amount of ionomer.

同时发现，相对于离子聚合物中离子交换位的多少，膜的交联程度、微观结构及表面形貌对质子交换膜的性能影响更大。

With the improvement of Si/Al ratio, total BET surface area decreased and mesopore volume increased, which favored the diffusion of feed/isomerized products, avoided too much secondary reaction and improved the selectivity of isomers.

磷钨酸可以使得分子筛的孔道阻塞，使其内部的酸中心和金属中心无法得到体现，因此，催化剂的金属功能受到限制，烷烃的氢解反应减少，产物中的甲烷和庚烷量下降。

A novel method to determine isoniazid with high sensitivity and good selectivity has been established by using Cu as a spectroscopic probe ion.

以Cu为光谱探针建立了一种高选择性、高灵敏度测定异烟肼的新方法。

According to the results of the examination, the stronger the electron-withdrawing protective group of imines, the better the cis-selectivity of the reaction, 68% yield, trans:cis is 99:1 diastereoselectivity could be leaded by Ts-imines (4-methyl-N-methylene-benzenesulfonaides) with a substituent [2,4-(CH3O)2C6H3], Substrate scope investigation revealed that a wide variety of ketenes and imines could react smoothly to afford corresponding,β-lactams.

实验结果表明，亚胺的保护基团吸电子能力越强，越有利于顺式产物的生成。对甲苯磺酰基保护的取代基为2，4-二甲氧苯基的亚胺参与的该反应可得到68%的产率，反式：顺式=99：1的非对映选择性。底物拓展过程中发现Staudinger反应适用于多种不同的亚胺与烯酮。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷