选择性的

In this thesis, we did modifications of alkyl groups upon benzyl fluorophosphonate. In order to study the influence of alkyl length and steric effect on activity and selectivity of probes, we synthesized benzyl fluorophosphonate recognition heads with modifications including ethyl, butyl, octyl and cyclohexyl. By way of connecting different kinds of tag like azido group, biotin and rhodamine with recognition heads separately through a higher hydrophilic ethylene glycol derived linker, a series of benzyl fluorophosphonate probes were made up. And they will apply to various biological testing strategies.

在本论文中，我们以苯甲基氟化磷酸酯为基础，於其上进行一系列烷基之修饰，为了探讨烷基长度与空间立体性质对於探针活性及选择性的影响，我们合成了包含乙烷基、丁烷基、辛烷基以及环己烷基修饰的苯甲基氟化磷酸酯辨识端，并藉由具较高亲水性的聚乙二醇衍生连接桥结合三种不同的发报端，分别有叠氮基团、生物素及萤光基团来构成不同的化学探针组合，这一系列苯甲基氟化磷酸酯类化学探针将可被应用於不同的生物测试策略。

The fluorescence images that RhoCr1 coordinated with Cr~(3+)in PC12 cells showed RhoCr1 to be capable of penetrating into living cells and imaging intracellular Cr~(3+)changesFive probes have been designed and synthesized,where different aldehydes were covalently linked to rhodamine B dyes with diethylamine flexible chains.

吸收和荧光光谱的测试结果表明，探针RhoCr1在Tris-HCI中性缓冲溶液中能高选择性的识别Cr~(3+)并产生了荧光增强，通过对探针光谱性能的测试和TEPN滴定实验表明，探针RhoCr1与Cr~(3+)的络合是一个可逆的过程。

In conclusion, a catechol moiety is presumably to be essential for its activity and substitution of the p-hydroxybenzyl group at C-1 position with correct stereochemistry in the isoquinoline molecule makes a great contribution to the activation of beta adrenergic receptors.

本实验初步结果发现，对於去甲基乌药碱分子之药效，catechol基是必备无疑；而异喹啉环的碳－1位置上取代的p-hydroxybenzyl基对於药效有非常大的影响；至於其立体化学的配位是有立体选择性的。

The recent advancement of the asymmetric addition of organozinc reagent s to ketones and α-ketoesters is reviewed according to the type of the chiral ligands, with an emphasis on the introduction of the ligands with high efficiency and high selectivity.

按照手性配体的结构类型分类，综述了近年来有机锌试剂对酮、α-酮酯等化合物的不对称加成反应的研究进展，对高效、高选择性的手性配体在该类反应中的应用进行了重点评述。

The researching content was as follows: 1. When AlClx/HY zeolite be used as catalyst, the effects of the ratio of 2-methylnaphthalene to tetramethyl benzene, catalyst concentration, reaction temperature and reaction time on the conversion (based on 2-methylnaphthalene), yield and selectivity (both based on 2,6-DMN) were discussed. In addition, by orthogonal experiment, the optimum reaction conditions were determined at the same time. The optimum reaction conditions : the molar ratio of 2-methylnaphthalene and tetramethyl benzene =1:1, reaction temperature was 400℃.

具体研究如下： 1、以AlClx/HY型分子筛为催化剂，研究原料配比(2-甲基萘与均四甲苯的摩尔比)、反应温度和反应时间对2-甲基萘的转化率、目的产物2，6-DMN的收率和选择性的影响，并通过正交实验确定了该催化剂体系下的最佳反应条件为：原料的摩尔比为(2-甲基萘：均四甲苯)=1：1，反应质量空速为6h-1，反应温度为400℃。

The selectively etching on germanium-on-glass structure can achieve visible light and infrared detection on the same chip with the unetched part for infrared detection and the etched part for visible light detection.

若在玻璃上覆锗的结构上做选择性的蚀刻，便可达到在同一晶片上在未蚀刻的部分来侦测红外光而蚀刻的部分侦测可见光的好处。

This would lead to a selective pressure on men to take the task of propositioning very seriously indeed. Making a bad mistake would be almost as deleterious to the potential for reproduction, as forgetting to bring a dagger to a knife fight.

这就导致选择性的压力，当一个男人必须相当严肃的对待他试图接近的异性时，一个的错误都可能导致这个男人传宗接代的可能性成为泡影，而这无异于自杀，就像拼刺刀时不带刺刀一般。

Next, Dr LaVan and his colleagues installed a protein called alpha-hemolysin into the protocell membrane. This functioned as a selective bridge, permitting the passage of positively charged sodium ions, but not negatively charged chloride ions.

接下来，拉文和他的同事们在原细胞的细胞膜中加入了一种叫阿尔法溶血素的蛋白质，这样就建立了一个选择性的通道——允许正极的钠离子通过，却阻止负极的氯离子。

Then we completed the first total synthesis of-Plakoridine A using Eschenmoser couping reaction as akey step. During the synthesis we found the choice of protecting groups and the configuration of the chiralcenter of the substrate play an important role to the key Eschenmoser reaction,so we think our successwould be of guide for synthesizing other polysubstituted pyrrolidines or piperidines.

在论文的第一章中，我们先以易得的对羟基苯乙酸乙酯为原料经多步反应制得了所需的β氨基酸酯，然后利用立体选择性的Aldol缩合反应和内酰胺化反应制得了Plakoridine Alactam，随后，以Eshenmoser缩合反应为关键步骤完成了生物碱-Plakoridine A的首次不对称全合成。

Macrocyclic supramolecular drugs forming by macrocycle s with special structure and high selectivity according to their different purpose could play important parts in the drug-controlled releasing, chiral recognition, mimic enzyme, molecular switch, and so on, especially supramolecular drugs can help to improve solubility, bioavailability of drugs and realize targeting when it encapsulates drugs.

具有独特的结构和高选择性的大环化合物所形成的大环类超分子药物可根据其目的不同在药物控制释放、手性识别、模拟酶、分子开关等方面起着重要作用，能大大改善药物的溶解度、生物利用度及实现靶向作用等，因此大环超分子药物为化学药物治疗提供了新的推动力。

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。