羧基的

The amino and carboxyl groups themselves are basic and acidic, respectively; the amino group of one amino acid really combines with the carboxyl group of another.

氨基和羧基分别具有碱性和酸性，氨基酸的氨基易于和另一个氨基酸的羧基相结合，结果是消去一分子水和形成一个肽键。

Objective To express the functional domain at C-terminus of Clostridium difficile cytotoxin B and lay a foundation of developing effective vaccine against infection with Clostridium dificile and diagnostic antigen.

目的 表达并纯化艰难羧菌细胞毒素B羧基末端功能区片段，为制备高效防治艰难羧菌感染的疫苗和诊断抗原奠定基础。

The neighbor-ing two Gd3+ ions are connected by two simple bridged carboxyl groups and a μ2-bridging carboxylgroup. Each G-d3+ ion is simuetaneosly coordinated by two water molecules. So the coordination num-ber of Gd3+ is nine, forming a coordination polyhedron of distorted mono capped square antiprism.

相邻Gd3+离子通过2个简单羧基桥和1个μ2羧基桥联结起来，还有2个水分子配位于每个Gd3+离子，所以Gd3+的配位数为9，形成变形的单帽四方反棱柱体。

In all those complexes, no matter which conformation IDA assumes (mer- or fac-style), the two 0 atoms of 1N2O are both from carboxylic hydroxyl. However, by comparing the bond length, we can find that O(4) and O(2) atom is from different group in this complex, 0(4) atom from carboxylic hydroxyl, whereas, 0(2) from carboxylic carboxide.

值得注意的是：在这个双核配合物中，我们首次发现一种新颖的配位方式：IDA上与金属离子配位的三齿螯合原子是亚氨N原子、一个羧基上的羟基O原子和另外一个羧基上的羰基O原子。

All the complex series based on 4',4''-dicarboxy-1,6-diphenoxyhex- ane (C6-2COOH) and 4',4''-dicarboxy-1,10-diphenoxydecane (C10-2COOH) possessed higher melting and clearing points, usually showed soft crystal or crystalline smectic phases and crystal polymorphs except C10-2COOH/ p -PhBPy complex displaying also an enantiotropic nematic phase, while the complexes based on 4,4'-dicarboxy-α,ω-diphenoxy tetraethyleneglycol ether (C8O4-2COOH) with a longer flexible spacer exhibited monotropic fluidic smectic SmA and/or nematic phases.

研究表明，分别具有较短的6或10个亚甲基的烷烃间隔基的双苯甲酸衍生物4'，4''-二羧酸-1，6-二酚氧基己烷(C6-2COOH)和4'，4''-二羧酸-1，10-二酚氧基癸烷(C10-2COOH)的系列复合物具有较高的熔点和清亮点，一般都只出现结晶近晶相和多晶型转变现象。

From the structural analysis of three praseodymium complexes, we could draw a conclusion that as the dentate arms of carboxyl group on ligands elongating, the coordination numbers of Pr and the coordination modes of ligands increase, and the mean distances between metallic atoms of metallic helices existing in these complexes augment.2. By altering 5-substituting group of isophthalic acid three series of lanthanide complexes 8～19 with 5-methylisophthalic acid and 5-nitroisophthalic acid have been prepared.

从得到的三个配体的镨配合物的结构分析可以看出，随配体的羧基齿臂的增长，Pr的配位数逐渐增大，配体的配位模式增多，配合物中存在的螺旋金属链中的金属间平均距离增大。2、通过改变间苯二甲酸配体的5位取代基，制备了5-甲基间苯二甲酸和5-硝基间苯二甲酸的三个系列稀土羧酸配合物8～19。

In this article, high-pure lactic acid and ethanol acid were used to synthesized PLGA by direct condensation polymerization, and zinc octanoate of low nocuity was used as katalyst, instead of stannous octanoate to synthesize PLGA by the way of opening ring.

本文首次采用高纯度乳酸、乙醇酸直接缩聚合成无催化剂的端羧基PLGA，并分别采用了低毒性辛酸锌代替辛酸亚锡为催化剂通过开环聚合法合成端羧基／酯封端PLGA。

The present invention concerns the compounds having the formula N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs, esters and metabolites thereof, wherein R1 and R8 each are H, optionally substituted C1-6alkyl, C2-6alkenyl, C3-7cycloalkyl, aryl, Het1, Het2; R1 may also be a radical of formula (R11aR11b)NC(R10aR10b)CR9-; t is 0, 1 or 2; R2 is H or C1-6alkyl; L is -C-,-O-C-,-NR8-C-,-O-C1-6alkanediyl-C-,-NR8-C1-6alkanediyl-C-,-S2-,-O-S2-,-NR8-S2 ; R3 is C1-6alkyl, aryl, C3-7cycloalkyl, C3-7cycloalkylC1-4alkyl, or arylC1-4alkyl; R4 is H, C1-4alkylOC, carboxyl, aminoC, mono- or di(C1-4alkyl)aminoC, C3-7cycloalkyl, C2-6alkenyl, C2-6alkynyl or optionally substituted C1-6alkyl; R5 and R6 are H or C1-6alkyl.

本发明涉及右式化合物其N-氧化物、盐、立体异构形式、外消旋混合物、前药、酯及代谢物，其中R 1 及R 8 各是氢、C 1-6 烷基、C 2-6 烯基、C 3-7 环烷基、芳基、Het 1 、Het 2 ；R 1 也可以是式(R 11a R 11b )NC(R 10A R 10b )CR 9 -之基；t是0、1或2；R 2 是氢或C 1-6 烷基；L是-C-、-O-C-、-NR 8 -C-、-O-C 1-6 烷二基-C-、-NR 8 -C 1-6 烷二基-C-、-S 2 -，-O-S 2 -、-NR 8 -S 2 -；R 3 是C 1-6 烷基、芳基、C 3-7 环烷基、C 3-7 环烷基C 1-4 烷基或芳基C 1-4 烷基；R 4 是氢、C 1-4 烷基OC、羧基、氨基C、一-或二(C 1-4 烷基)氨基C、C 3-7 环烷基、C 2-6 烯基、C 2-6 炔基或任选被取代的C 1-6 烷基；R 5 及R 6 是氢或C 1-6 烷基。

When the concentration of zinc nitrite is lower than 0.1 M,(002) is the prior face for zinc oxide. As the concentration raise, the other kinds of crystal face would appear. Among those data,(002) grows the best when the concentration of zinc nitrite is 0.06 M. We add lactic acid and citric acid respectively; there is an carboxyl group on the lactic acid and three carboxyl groups on the citric acid. The monodentate of lactic acid helps the growth of zinc oxide, compared to the tridentate of citric acid which can only produce zinc oxide film under very low concentration, but the growth of (002) face is not that stable as adding the lactic acid and zinc will electrodeposit to substrate.

实验中，当硝酸锌浓度低於0.1 M 时，氧化锌以(002)面为优选位相，当浓度提高，其他晶面将会出现，当硝酸锌为0.06 M，(002)晶面成长最佳，分别加入乳酸和柠檬酸，乳酸结构上有一羧基团而柠檬酸有三个羧基团，单芽基的乳酸有助於氧化锌成长，对照於三芽基的柠檬酸，则必须在极低的浓度下才能制备氧化锌薄膜，但(002)面成长却没有添加乳酸来的稳定而金属锌也会电沉积到基板上。

The result indicated that MgO and α- methacrylic acid can together thicken epoxy, and the speed of thickening epoxy become quickly with the increasing content of MgO; when the ratio of MgO and α- methacrylic acid is 3:1, thickening epoxy have a better effect; the thickening mechanism: the terminal corboxyl group of α- methacrylic acid react with MgO, and it accompany with large numbers of heat, the heat can accelerate the reaction between the terminal corboxyl group with the secondary hydroxyl groups of epoxy, intermolecular hydrogen bonding which the water of above-mentioned formation result in and complex compound which format the metal atoms and carbonyl group complexing collective increase the viscosity of epoxy resin.

结果表明：MgO和α－甲基丙烯酸配合可增稠环氧树脂，随着MgO加入量的增加，环氧树脂增稠的速度加快；MgO与α－甲基丙烯酸为3：1时，增稠环氧树脂的效果较好；推测环氧树脂的增稠机理是α－甲基丙烯酸中的端羧基与氧化镁反应，放出热量促使其端羧基与环氧树脂中的仲羟基反应，上述反应生成水产生的氢键和羰基与氧化镁中的金属原子形成络合物共同导致环氧树脂的粘度增加。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。