查询词典 carboxyl group

Then Doripenem came into the market in the July ,2005. We studied the synthesis of Doripemen.Firstly, we synthesized the chemical 2 from the starting material------o-hydroxylphenylacylamine through Reformastky reaction, alkylation, Diekmann reaction, enolization, esterification and etc. Secondly, we synthesized the chemical 3 from L — hydroxylproline through the protection of carboxyl, amidogen and hydroxyl group, reduction by NaBr, SN_2 substitution and Mitsumobu reaction.

我们以水杨酰胺为起始原料，经Reformatsky反应、烷基化、Diekmann环合、烯醇化、酯化等反应合成双环母核2；再从L-羟基脯氨酸出发，经酯化保护羧基、保护氨基、保护羟基、硼氢化还原酯得醇、Sn2取代和Mitsumobu反应等合成巯基侧链3；最后由化合物3经脱保护、水解得硫醇，和化合物2在二异丙基乙基胺的作用下缩合，最后Pd／C催化脱保护，历经16步反应最终得到产物多尼培南。

The reasons for the carboxyl end group fluctuation of bottle grade PET base chips were analysed.

对瓶用基片端羧基波动的原因进行了分析。

The carboxyl end group value control of Du pont's polyeser technology in direct spinning process is studied.

本文从工业生产的实践出发对杜邦聚酯技术直接纺工艺中端羧基控制进行了研究。

The measurement of carboxyl end group content in PBT was discussed with an automatic potentiometric titrator.

采用全自动电位滴定仪测定PBT切片的端羧基含量，对称样量、溶剂的配比、滴定剂的浓度等进行了正交优化。

In addition to the amino and carboxyl groups possessed by all amino acids, the R group of some amino acids can ionize.

另外，所有的氨基酸都拥有氨基和羧基，一些氨基酸的R基能电离

The present invention relates to a coating composition comprising; A at least one polyester oligomer prepared from reactants comprising a 20 60 wt.% of at least one polyol, b 5 30 wt.% of at least one polycarboxylic acid selected from the group of cyclic polycarboxylic acids, the esters or the anhydrides thereof, wherein the carboxyl groups are separated by 3 carbon atoms or less, and from the group of alpha , beta -saturated acyclic polycarboxylic acids, the esters or the anhydrides thereof, and c 20 60 wt % of at least one monocarboxylic acid, the sum of the wt.% indicated for the reactants,, and always being 100 wt.%, and the oligomer being a low-viscosity oligomer having a weight average molecular weight Mw of less than 5,000, and a hydroxyl number in the range of about 200 to about 400 mg KOH/g oligomer, and B at least one polyisocyanate.

本发明涉及一种包含如下组分的涂料组合物：A至少一种由包含如下成分的反应物制备的聚酯低聚物：a20-60wt％至少一种多元醇，b5-30wt％至少一种选自其中羧基被3个或更少碳原子隔开的环状多元羧酸、其酯或酸酐以及选自α，β-饱和的无环多元羧酸、其酯或酸酐的多元羧酸，以及c20-60wt％至少一种一元羧酸，其中反应物、和的wt％之和总是为100wt％，所述低聚物是重均分子量Mw低于5000且羟基值为约200-约400mg KOH/g低聚物的低粘度低聚物，以及B至少一种多异氰酸酯。

In addition to the am in o and carboxyl groups possessed by all am in o acids, the R group of some am in o acids can ionize.

另外，所有的氨基酸都拥有氨基和羧基，一些氨基酸的R基能电离

It is to say that the patch of RAFT agent on the hairy chains.PS particles with the shell of copolymer of styrene and vinylbenzyl chloride were prepared by similar seeded and starved addition processes. RAFT agent with carboxyl end-group attached on the shell surface of PS particles by group reaction. Adding NIPA and photo-initiator into the continuous phase of polymerization system, hairy PNIPA were obtained.

最后，以表面负载一层乙烯基苄氯的亚微米级单分散聚苯乙烯微球为基质，将水溶性RAFT试剂与聚苯乙烯微球表面的官能团反应以负载到其表面，再在连续相中直接引入NIPA和光引发剂，RAFT聚合得到PNIPA毛发。

The results of magnesium and calcium ions tolerance test indicated that the modified SPS, synthesized from the above two methods,has good chelation with magnesium and calcium ions for the crablike carboxyl and ester group and increase the reaction weight with magnesium and calcium ions for addition of hydrophilic group.Both of the two modified petroleum sulfonates could produce ultra-low interfacial tension at calcium and magnesium ions concentration lower than 600 mg/L,whereas the general petroleum sulfonates could only produce ultra-low value below 300 mg/L.

耐钙镁离子能力测试结果，以大庆炼化公司两种渣油为原料，采用上述两种合成方法制备的改性石油磺酸钠，由于产物中引入蟹爪状羧酯基，对钙镁离子有较强的螯合作用，同时增加了亲水基，增大了表面活性剂分子与钙镁离子的反应量，因而在600mg/L的钙镁离子溶液中获得10-3级的超低界面张力；而普通石油磺酸钠仅能在300mg/L的钙镁离子溶液中获得超低界面张力。

The carboxyl of the tripodal ligand is a goodbridging group. The building blocks are linked together by the bridging group andother weak interactions (hydrogen bond and π-π stacking interaction, etc), thusgenerating a one, two or three-dimensional metal complexes.2. Studies on the fluorescence properties of the lanthanide complexes indicated that:(1) The excitations in the ligand-based π-π〓 transitions cause the structuredemission of lanthanide complexes while the ligand luminescence is completelyquenched showing that ligand-to-metal energy transfer occurs.

三脚架配体所带的羧基是一个很好的桥联基团，配合物的结构基元通过这种基团的桥联作用及其它一些弱的作用力(如氢键、π-π堆积作用等)联系起来，构成了一维、二维或三维的超分子空间结构。2、稀土配合物的发光研究发现：(1)用配体的π-π〓跃迁波长进行激发，配合物均显示出稀土离子的特征发射峰，同时，配体的荧光峰没有出现，这说明在三脚架配体与稀土离子间进行了有效的能量传递。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。