查询词典 selectivity

In recent papers [14,15] good activity and selectivity in the epoxidation of limonene, cyclohexene, 1-octene and pinene by anhydrous and aqueous H2O2 catalyzed by alumina were reported.

近年来，用氧化铝催化的，用无水的和含水的H2O2将莱烯、环己烯、1－辛烷和蒎烯环氧化中良好的活性和选择性已有报道。

The way of synthesis of piperazine using the industrial ethylenediamine as rawmaterial is applicable, the Higher activity and selectivity of K-ZSM-5 catalyst prepared by the method of ion-exchange was obtained.

离子交换法制备的K-ZSM-5分子筛作为脱氨环化反应的催化剂具有较好的活性和选择性。

This paper pointed out that the complex sentence of selective default and its closely related,"would rather" sentence, and "even if" the sentence is similar to selective, concessions are in the lower body show the premise of selective, and selective concessions are inseparable ; However, the two sentences in selective areas there are also many different and specific expression: the different levels of concessions, the focus of different default, choose different context, the choice of the situation is different and selectivity Weak, such as different levels of five.

本文指出，复句的选择性与其预设密切相关，"宁可"句和"即使"句的选择性具有相同之处，都是在让步的前提下体现出选择性，让步性与选择性是密不可分的；但是，两个句式在选择性方面也存在很多不同之处，具体体现为：让步的程度不同、预设的重点不同、选择语境有所不同、选择项的情况不同以及选择性强弱程度不同等五个方面。关键词：让步复句；预设；选择性

In the current study, a series of cationic α-helical peptides of 20 a.a. were designed and synthesized based on four structural parameters, including charge, polar angle, hydrophobicity, and hydrophobic moment. Several methods were performed to describe the influence of these parameters on the antimicrobial and hemolytic activity, and on the permeabilizing effect on model membranes. The potential of these parameters to increase the antibacterial activity and to improve the prokaryotic selectivity is assessed.

本实验利用自行设计合成的人工抗菌胜肽当模型，固定长度为 20 个胺基酸，改变其电荷、极性角度、疏水性及疏水性矩等四种结构特性，并利用其对各种不同病原菌之抗菌活性及对兔子红血球细胞的溶血活性来研究其结构特性的改变对其抗菌活性、选择性及微脂体膜的渗透性之影响，以期望改变结构参数能增加抗菌活性及对原核的选择性。

For a peptide to act as part of the host defense system or to be of pharmaceutical interest, high antimicrobial activity must be combined by low hemolytic activity. Our results indicated that the antimicrobial activity increased with increasing charge and polar angle, with charge of ＋4 and polar angle of 140° exhibiting the highest antibacterial and membrane permeabilizing activity. Higher hydrophobicity and hydrophobic moment correlated with increased hemolytic activity, thus decreasing selectivity dramatically.

胜肽要扮演宿主免疫机制的一部分或要成为新型态的抗生素不仅要有强大的抗菌活性还需要有高度的选择性，由本实验的结果发现，当抗菌胜肽的正电荷及极性角度增加时，胜肽之抗菌活性会随之增加，当抗菌胜肽的电荷为＋4而极性角度为 140°时，胜肽有最强之抗菌能力及膜渗透活性；而随著胜肽疏水性以及疏水性矩的增加，会增加溶血活性，结果反而降低了抗菌胜肽的选择性。

For the determination of polarizable anions, a pulsed amperometric detector has higher selectivity, precision and sensitivity.

在测定上述易极化阴离子时，脉冲安培检测器具有选择性强、精密度好和灵敏度高等优点。

Electroannalytical methods are characterized by cheap, high sensitivity and selectivity,especially the stripping voltammetry and catalytic polarography.

电化学分析一直是十分活跃的领域，其中的极谱法以其灵敏度高、选择性好及设备简单、价格低廉而倍受广大电化学分析工作者的关注和重视。

With the characterization of NMR and IR, combining with the synthesis of active species and studies of their structures, it is suggested that the hydride [RuHCl(PPh3)3], being favorably formed in the acid media, exhibited higher activity in the reduction of the C=C bond, while the hydride [RuH4(PPh3)3], being preponderantly formed in the basic media, showed activity and higher selectivity towards the C=O reduction.

通过核磁、红外等表征手段，并结合可能催化活性配合物的合成和结构研究，推测了在非水介质中对C=C和C=O双键起到活化作用的催化剂活性物种和可能的选择加氢反应机理，即，催化剂[RuCl2(PPh3)3]在酸性环境下倾向于生成[RuHCl(PPh3)3]物种，该Ru-H物种对C=C双键加氢反应表现出较高的活性；而碱性环境下则易于生成[RuH4(PPh3)3]物种，该Ru-H物种对C=O双键加氢具有较高的催化活性。

Influence of pretreatment of the catalyst, reaction temperature on the yield and selectivity was investigated.

考察了催化剂预处理、反应温度等对脱氢过程产物收率和选择性的影响。

Since its initial publication at the end of 2004, Mr Taruskin's five-volume survey of 1,200 years of musical tradition has come in for many criticisms—selectivity, subjectivity, riding roughshod over contemporary intellectual orthodoxy—but prolixity and over-comprehensiveness have not been among them.

初版自2004年末面世之后，塔鲁斯金这套纵览上下1200年音乐传统的丛书便遭到了诸多批评—包括筛选、主观、藐视当代正统学说—但还无人指责它的篇幅长度和广度。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。