三键

Human beta-defensin-2 (HBD-2) is a cysteine-rich cationic 41 amino acid antimicrobial peptide with three disulphide bonds.

人β防御素-2(HBD-2)是一种由41个氨基酸组成并富含半胱氨酸残基的阳离子抗菌短肽，内有三个二硫键。

As for XYN-OU, it could retain over 50% activity from the pH value 4.0 to 9.0 at 50°C in 30 min. The result of the mutated xylanase indicated that constructed disulphide bridge could improve its thermostability at relatively higher temperature.

对木聚糖酶分子改良的结果反映出在β片层间添加二硫键可以有效改善酶在较高温度下三维结构的刚性，提高热稳定性。

The extraction equilibrium constants of Nd , Eu , Am in the system of seven monoacidic organophosphorus compounds dodecane 1. 0mol/l NO〓are reported. The dependency of the extractability on the PO〓function group、bonding charactor、metallic ion species and the structure of substitute has been examined.

给出了七个烷基磷酸的正十二烷熔液从1.0mol／lNO〓水溶液中萃取Nd、Eu、Am的平衡分配常数Kex，考察了萃取剂PO〓官能团、萃合物成键特性、金属离子及取代基结构与萃取性能间的关系，发现了：（1）可运用取代基自由能加和模型预测辛基膦酸辛基酯对La、Eu、Nd、Am等三价离子的平衡分配数据。

Three new fulvene polymeric compounds, namely 1[Ag (L3]CH2C12 , 2[Ag2(L25(H2O)(S03CF3)2]0.5C6H6 and 3 Mn(L42(C2H5OH)2 , were synthesized, respectively. Compounds 1 and 2 reported herein represent the organometallic polymers based on both Ag-N and Ag-C coordination interactions. In the solid state, compound 3 are bound together by strong intermolecular N H-O hydrogen bonding system into a supramolecular one-dimensional H-bonded chain.B.

一、富烯有机配体的合成及与金属离子的反应化学利用富烯负离子的芳酰化反应和Heck-偶联反应合成了富烯配体L1-L18，并合成了三个基于富烯配体的金属有机配位聚合物1[Ag(L3]·CH_2Cl_2、2[Ag_2(L25(H_2O)(SO_3CF_3)_2]·0.5C_6H_6和氢键驱动的超分子聚集体3Mn(L4_2(C_2H_5OH)_2。

In the forth part, the heterotactic enthalpic pairwise interaction coefficients between amino acids and butanediol isomers (1,3-butanediol, 1,4-butanediol and 2,3-butanediol) at 298.15K and 310.15K are discussed.

第五部分：采用密度泛函理论等方法研究了甘氨酸分子分别与丁二醇的三种异构体分子以1：1的比例形成的氢键络合物，从B3LYP6-31G到6-31 G基组水平进行了优化，利用结合能数据讨论了焓对作用系数的差别。

In this thesis, a series of complexes based on aromatic multicarboxylic acids have been successfully synthesized in solutions or under hydrothermal conditions. Their structure and properties are investigated.(1) Eight complex compounds have been synthesized and characterized by X-ray single crystal diffractive technology: The eight complexes are listed as following: [Cu242] complex 1 [Cd22(H2O)4]·4H2O complex 2 [Co(H2btc)(H2O)3] complex 3 [Co2(H2O)2]·H2O complex 4 [Ni22(H2O)4] complex 5 [Cu22(H2O)4] complex 6 [Co(H2biim)2(H2O)2](H2btc) complex 7 [Zn(H2biim)2(H2O)2](H2btc) complex 8 The structure of complex 1 is dinuclear complex resulted from weak interactions（0-D chain）; complex 2 is 1-D chain stucture result from interactions of water molecules; complex 3、4、5、6 are coordination polymers using hydrothermal synthses, where the first kind ligand is H4btc, the second kind ligand is phen and Co2+、Ni2+、Cu2+ as center ions, respectively. While the coordination enviroment of Co2+ is the same in complex 3, the coordination geometries around the Co atoms in complex 4 are obviously different because of the different reaction conditions. In complex 4, the 1-D chains are connected into 2-D layer through carboxy groups of ligand H4btc. The structures of complex 5、6 are 1-D chain stucture result from interactions of carboxy groups in ligand H4btc. Complex 7、8 are homeomorphy compounds. Either of them are linked to the 3-D chains through intermolecular hydrogen bonds. Each H4btc lose two protons and H2btc2- acts as negative electron balance.

合成了8个结构新颖的配合物，并用X-射线单晶结构分析方法确定了晶体结构，分别为： [Cu242] 配合物1 [Cd22(H2O)4]·4H2O 配合物2 [Co(H2btc)(H2O)3] 配合物3 [Co2(H2O)2]·H2O 配合物4 [Ni22(H2O)4] 配合物5 [Cu22(H2O)4] 配合物6 [Co(H2biim)2(H2O)2](H2btc)配合物7 [Zn(H2biim)2(H2O)2](H2btc)配合物8 配合物1是一个依靠弱作用连接的双核铜结构；配合物2借助水分子形成一维链状结构；配合物3、4、5、6是以H4btc为第一配体、phen为第二配体，通过水热法合成的配合物，其中，Co2+、Ni2+、Cu2+为中心离子；配合物3中的二价钴离子具有相同的配位环境，不同反应条件下得到的配合物4中的二价钴离子存在不同的配位环境，在配合物4中，一维链通过H4btc上的羧基形成一个二维层结构；配合物5、6是借助H4btc上的羧基形成的一维链状结构；配合物7、8属于异质同晶结构，它们的分子通过分子间氢键形成三维网状结构，H4btc上的羧基失去2个质子，作为一个二价负离子起到电荷平衡作用。

The amphiphiles, 4-8, can not form reverse bilayers in organic solvent, which result in that the molecular interactions unable to meet the need for hydrophile-lypophile balance, so that they crystallize and exhibit no gelling abilities. The mono-chained L-alanine derivatives, 1-3, can self-assemble into bilayer aggregates, through intermolecular hydrogen bonding and homochiral effect in a number of organic liquids, which are juxtaposed and interlocked by van der Waals interaction, and finally gelate the organic liquids.

单链酰基化L-丙胺酸两亲物1-3在一些低极性的有机溶剂可以通过分子间氢键相互作用及同手性聚集作用形成有序的反双分子膜结构，这些有序反双分子膜结构单元依靠vander Waals力相互作用可以平行排列且相互之间进行连结形成长纤维状的聚集体，纤维状聚集体在有机介质中可以进一步相互连结形成三维网状结构，进而胶凝有机溶剂。

The complex formed inerratic octahedron configuration, and H bonds,π-π stacking were observed between the molecules.

配合物分子之间通过氢键和π-π堆积等弱相互作用构筑成三维超分子结构。

The initial three chapters of this dissertation aim to improve the regularity of ladderlike polysiloxane through strong H-bonding template and slowly dropping half water for hydrolysis and condensation.

本论文前三章旨在利用强氢键模板作用和半水量水解同步缩合脱氯化氢的改进方法首次合成了(1)高规整性、可溶的反应性含对苯二胺有机桥基的聚氢基硅氧烷高分子，29Si-NMR 图中显示梯形主链上硅原子-Si(HO2/2峰的基线宽度△1.0 ppm，这是至今文献报道的所有梯形聚硅氧烷规整性最好的数据；采用分段去撑法成功的合成了纯无机梯形聚氢基硅氧(来源：1bABC论文网www.abclunwen.com)烷。

Finally the application of the homemade ODS for MSPD and the economical availability of the product was evaluated. Results show as the following: 1. It is a simple method for the preparation of a bonded octadecyl phase which has large particle and high extent of coverage of the bonded phase.

研究结果表明：①采用大粒径无定形硅胶为基质，选择十八烷基三氯硅烷为硅烷化试剂，完整地合成了一种大颗粒、高表面积的ODS键合相，合成的ODS可作为基质固相分散MSPD的固相分散剂，用于样品的前处理。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。