共价键

The silanol groups of silica, is reacted with various silane reagents to produce covalently bound silyl derivatives covering a varying number of active sites on the surface of the support.

担体的表面，如，硅胶的硅烷醇基团，和不同的甲硅烷试剂反应制备共价键甲硅烷基衍生物，此衍生物在担体表面覆盖了许多不同的活性点。

The method by drying/adsorption was used to prepare DNA adsorptively modified electrodes, and thus-resulting DNA-modified electrodes were electrochemically and spectroscopically characterized, including cyclic voltammetry, scanning tunneling microscopy, Raman spectroscopy, in-situ UV/Vis reflection spectroscopy, X-ray photoelectron spectroscopy, and alternating current impedance. Some information about the state of DNA immobilized on electrode surfaces was obtained.

鉴于此，本论文工作首先利用简便的干燥吸附法制备获得DNA吸附修饰电极，采用电化学方法及多种谱学仪器方法如STM，XPS，Raman，交流阻抗，UV-Vis现场光谱等对DNA修饰电极进行了表征，获得了有关DNA在电极表面状态等有价值的信息；又采用自组装单分子层修饰技术，制备出DNA共价键合修饰SAM/电极，并对制备条件进行了优化，利用XPS及电化学方法对修饰电极进行了表征。

A major class of tautomeric reactions involves exchange of a hydrogen atom between two other atoms in the same molecule, in both cases forming a covalent bond.

一类主要的互变异构反应是氢原子在两个其它原子间交换，与任何一方都生成共价键。

A major class of tautomeric reactions involves exchange of a hydrogen atom between two other atom s in the same molecule, in both cases forming a covalent bond.

一类主要的互变异构反应是氢原子在两个其它原子间交换，与任何一方都生成共价键。

A major class of tautomeric reaction s involves exchange of a hydrogen atom between two other atoms in the same molecule, in both cases forming a covalent bond.

一类主要的互变异构反应是氢原子在两个其它原子间交换，与任何一方都生成共价键。

However, fully consideration of special structure and physiological function of CRP is critical to investigate whether CRP provide protect effect or pathogenic effect in the progression of atherosclerosis. CRP is a member of pentrxins family, which consists of five identical, noncovalently associated 23-kDa protomers arranged symmetrically around a central pore with a 102 A external diameter. Each protomer has a recognition face with a phosphocholine binding site consisting of two coordinated calcium ions adjacent to a hydrophobic pocket. The opposite face of the pentamer is the effector face, where complement Clq binds and Fc receptors are presumed to bind. A cleft extends from the center of the protomer to the central pore of the pentamer. Both faces ofpentamer form a special bi-phase structure: one face is the ligand recognition phase, which can recognize apoptosis cells and enzyme modified low density lipoprotein in which PCh is exposed.

CRP是一种五聚体蛋白，外径为102 A，由5个相同的单体以非共价键结合，形成双面的环形结构，每个单体的配体识别位点或受体结合位点分别位于五聚体两个平面上，分别组成配体识别相和效应器相，从而构成特殊的二相性结构：一面为配体识别相，含有磷酸胆碱(phosphorycholine，PCh)结合位点，能够使CRP识别在病理条件下暴露出PCh的凋亡细胞、酶修饰低密度脂蛋白(enzyme modified low density lipoprotein，E-LDL)等。E-LDL是天然低密度脂蛋白(native Low density lipoprotein，N-LDL)在多种蛋白酶，如胰蛋白酶、神经氨酸酶、胆固醇酯酶等作用下的代谢产物，其主要特点是结构发生改变(N-LDL大小均匀，平均直径250±30 A，E-LDL大小差异极大，直径为100-2000 A)，暴露磷酸胆碱位点，能够被CRP识别；另一面为效应器相，能够与巨噬细胞、单核细胞表面受体FcγRⅡa结合，介导巨噬细胞、单核细胞识别及吞噬凋亡、坏死细胞作用。

Fluorescing compounds were immobilized in PVC membrane and covalent binding to surface of glass, respectively. pH response characteristics were investigated under different conditions.

分别用PVC膜包埋法和玻璃表面共价键合法固定自行合成的荧光分子，测定了不同条件下的pH响应特性。

To create covalent bonds where the sticky ends have hybridized, an enzyme called ligase is required.

要在粘性末端已经发生杂交的地方形成共价键，还需要一种称为连接酶的酶。

To create covalent bonds where the sticky ends have hybridized, an enzyme called ligase is required.

要在粘性末端已经发生杂交的地方形成共价键，还需要一种称为连接酶连接酶的酶。

Step procedure. Firstly, glycidyl rnethacrylate was photo梘rafted onto the surface of PVC without degassing. An activated surface with active epoxy groups was formed. The grafted polymer can also act as the spacer between heparin and PVC; Secondly, heparin is attached to the grafted surface through its functional groups reacted with the epoxy groups.

第一步，通过紫外光接枝反应将甲基丙烯酸缩水甘油酯接枝到PVC材料表面，接枝链作为肝素和聚氯乙烯材料之间连接的间隔基，同时也得到了带有环氧基团的反应性表面；第二步，通过肝素分子所带功能基团与PVC材料接枝表面上的环氧基之间的反应将肝素共价键合到PVC材料表面。

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。