共价键

These two series of probes differ in their mechanism of action. The first series exploits the concept of suicide substrate. When the probe is hydrolyzed by the target sulfatase, it will release an intermediate that undergoes elimination to form a reactive quinone methide which in turn reacts with nearby nucleophiles. The second series belongs to an electrophilic reagent which utilizes a cyclic sulfamate moiety serving both as the recognition unit and the trapping device.

这二系列标示分子的主要差异在於其标示机制，第一系列是源自於自杀性受质的概念，利用水解后的中间体会生成高反应性的quinone methide，来达到标示的效果；第二系列则是属於亲核性试剂型，采用环状胺基磺酸衍生物做为辨识端及捕捉机制，预期在其进入酵素的受质结合区后能与酵素催化中心形成共价键结。

Disulfide bridge In PROTEINS, a covalent bond formed between the sulfhydryl groups of different cysteine molecules.

二硫桥：在蛋白质中两个半胱氨酸残基的两个巯基之间形成的共价键。

The assembled tweezer has been successfully utilized to direct the self-assembly of a series of dynamic [2]catenanes from three components via three different non-covalent interactions.

通过三种不同的非共价键作用力，这种分子镊通过超分子识别和组装的原理被成功地用于构建一系列新颖的三组分动态[2]索烃。

In such structure, each In atom is bonded with two Si substrate atoms and one neighboring In atom, thus all three valency of In are saturated.

在这种再构结构中，每个 In 原子与两个衬底 Si 原子及一个相邻的 In 原子形成共价键。

It is the fluorosilicic ion that exsits in the slurry and plays an important role in flotation, fluorosilicic ion not only reacted with Fe〓 on the surface of aegirine to form ionic compound, but also formed stable Si-F bond in Si-O etching reaction. Only ionic compound was obtained when it was attached to hematite surface according to the theories of coordination chemistry, Compared with SiF〓, Fatty acid ion preferentially acts with Fe〓 on the minerals surface, therefore, SiF〓 Can't obstruct the adsorption of collector on the surface of hematite completly, but can reduce the flotation recovery of aegirine selectively.

运用FTIR、XPS等测试方法仔细研究了氟硅酸盐抑制剂对含铁硅酸盐钠辉石的选择性抑制作用机理，氟硅酸盐在弱酸性条件下对赤铁矿浮选的抑制作用很微弱，而对含铁硅酸盐钠辉石强烈抑制，从而扩大了两者之间的浮选差异；SiF〓是矿浆中起抑制作用的主要成分，SiF〓不仅与钠辉石表面的Fe〓形成离子型配合物，而且还与Si-O键形成稳定的Si-F共价键，而与赤铁矿表面只能形成离子型配合物，根据晶体配位场理论，与SiF〓相比较羧酸根离子将优先与矿物表面Fe〓发生配位作用，因此SiF〓的存在并不能完全阻碍捕收剂在赤铁矿表面的吸附作用，却能够选择性地抑制钠辉石的上浮。

Also, we investigate another self-assembly which is formed through noncovalent bond interactions of a novel kind of dimelamine and barbituric moleclus.

同时还进行了互补的另一类自组装研究，即巴比妥酸与一类新型的双密胺分子间通过非共价键相互作用的自组装。

In this thesis, a reductive amination was used to prepare compound 16 with the boronic acid moiety. The moiety can provide covalent interaction with sugars.

本论文中，合成化合物16，是将化合物15与2-甲醯苯硼酸用还原胺化法而得到；其含有硼酸部分，可以与醣类分子以共价键键结。

The tryptophan residues play important roles in DNA photoreactivation catalyzed by CPD photolyases. We have investigated the action mechanism concerning Trp in DNA photoreactivation, and obtained the results as follows: 1 We proposed a mechanism of photosensitized splitting of CPDs by Trp and Trp-containing peptides. 2 Quantum yields of splitting of the model compounds that a Trp linked covalently a CPD were obtained under 290 nm light in various solvents, these values changing with solvent, range from 0.01 to 0.5. 3 Utilizing pulse radiolysis technique, splitting processes were observed in aqueous solution of the CPDs with hydrated electron and some oxidative species (such as hydroxyl radical, bromic radical and azide radical), and obtained their rate constants. In the case of interaction between CPD and hydrated electron, splitting of the CPD anion, and pyrimidine anion transfer an electron to FAD or Rf, were observed. The process rate was slower one order more than that in photolyase. Minor, but highly mutagenic UV-light-induced lesions are (6-4) photoproducts, which are repaired by (6-4) photolyases. These enzymes, discovered in 1993, are not well characterized and their mechanism is still under investigation.

我们研究它的作用机理，获得以下结果：1）建立了色氨酸及其肽对嘧啶二聚体光敏化裂解的直接修复作用机理模型；2）获得了色氨酸共价键连接于嘧啶二聚体的化合物在多种溶剂中290nm光辐照裂解的量子效率，其值随溶剂而变化，范围在0.01-0.5；3）运用脉冲辐解观察到嘧啶二聚体与水合电子和一些氧化性的自由基作用裂解过程，得到相应速率常数；对二聚体与水合电子作用发生裂解以及向FAD返还电子的过程进行了体外模拟；4）（6-4）光解酶的作用机理中一个关键假定是氧杂环丁烷中间体在接受电子后能自发裂解，恢复二嘧啶的结构。

By means of covalent coupling with the activation of 1-ethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride and N-hydroxysulfosuccinimide.

利用自组装技术将三巯基丙酸固定在金电极上，以1-乙基-3-（3-二甲氨基）碳二亚胺盐酸盐和N-羟基硫代琥珀亚胺作为活化剂，将甲基对硫磷抗体以共价键形式固定在三巯基丙酸自组装单分子膜修饰的金电极上，制备了一种免疫传感器。

Ferrocenecarboxylic-ssdeoxyribonucleic acid probe was made by chemically bounding FCA to terminal 5'-amino of oligonucleotide in the presence of a water-soluble carbodiimide. The hybridization reaction was conducted by immersing the immobilized-ssDNA electrode in FCA-ssDNA probe solution.

在偶联活化剂碳二亚胺的存在下，通过羧基二茂铁上的羧基与DNA分子上的氨基共价键合，将FCA标记在氨基修饰的寡聚核苷酸片段上，制备成FCA-ssDNA探针。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。