查询词典 carboxylate

The parity-violating energy difference of D- and L-alanine was undertaken as a function of the dihedral angle θ of the carboxylate plane with respect to the Cα-Hα plane.

自然界的力只有弱力是宇称不守恒的。在分子物理中，电弱力宇称不守恒是导致D-和L-丙氨酸能差的根源。

Methyl 3,6,8-trihydroxy-7-methoxy-1-methylanthraquinone-2-carboxylate is a new COX-2 selective inhibitor isolated from Gladiolus gandavensis.

1-甲基-2-甲氧羰基-3， 6， 8-三羟基-7-甲氧基蒽醌是从唐菖蒲干球茎中分离到的具有环氧化酶-2选择性抑制活性的多取代蒽醌类化合物。

Surface modified nano-sized mgnesium hydroxide was prepared by direct precipitation method with magnesium nitrate hexahydrate and sodium hydroxide as raw materials,and sodium fatty alcohol polyoxyethylene ether carboxylate as modifying agent.The optimum dosage of modifying agent was 0.2% of the mass of magnesium hydroxide,which was confirmed by sediment volume experiment.Modified and unmodified samples were characterized by fourier transform infrared spectroscopy,X-ray diffraction,transmission electron microscope,and tap density test.

以六水硝酸镁、氢氧化钠为原料，脂肪醇聚氧乙烯醚羧酸钠为改性剂，采用直接沉淀法一步合成改性纳米氢氧化镁，用沉降体积实验确定改性剂的最佳用量为氢氧化镁质量的0.2%，通过红外光谱、X射线衍射、透射电镜、表观密度对改性前后的样品进行表征。

WithinPMAO LB films,because the distance between the metal ions is no morethan 0.3nm,the carboxylate groups of a molecule form a nanoparticle(the size is less than 0.2nm)by the hydrogen bond or metal ion asthe bridges.

实验表明，在这种高羧基密度的聚合物中，由于羧基距离较近(＜0.3nm)，羧基通过氢键或金属离了为桥在分子内聚集成纳米团簇(＜2nm)。

During the manufacturing of the critical intermediate cephalosporin nucleus --7-amino-3-chloro-cephalosporanic acid diphenylmethyl ester hydrochloride salt, first the feasibility of the one-pot synthetic route of open loop, closed loop and ozonization when chlorine is passed over is qualified by experiments. Then the critical factors that will influence this reaction are studied as follows: the mol ratio of triphenyl phosphite and Diphenylmethyl 3-hydroxy-7-phenylacetaminoceph-3-em-4-carboxylate-l-oxide is four to one; the quantity of the stablizer should be at least more than two to one. The temperature of the system must be 25℃ when chlorine is passed over so that the hydrochloride can be precipitated to obtain cephalosporin nucleus of cefaclor--7-amino-3-chloro-cephalosporanic acid diphenylmethyl ester hydrochloride salt.

在制备关键中间体头孢母核7-氨基-3-氯头孢烷酸二苯甲酯盐酸盐时，先通过实验验证把开环、闭环、臭氧化三步在通入氯气时并为一锅煮的合成路线的可行性之外，又研究了影响该反应的几个重要因素：亚磷酸三苯酯与3-羟基-7-头孢烷-5-亚砜-2-甲酸二苯甲酯的摩尔比为4：1；稳定剂2-甲基-2-丁烯的用量至少大于2：1，通入氯化氢气体时体系温度在25℃时盐酸盐则能够顺利析出，获得头孢克洛的头孢母核—7-氨基-3-氯头孢烷酸二苯甲酯盐酸盐。

The ammonia was evaporated under decreasing pressure, and the precipitate was filtered off and the liquid was poured into hot saturated picric acid solution to get picrate with a yield of 85.0%. The optimum process starting from imidazole-4,5-dicarboxylic acid was: imidazole-4,5-dicarboxylic acid in acetic anhydride was refluxed to get imidazole-4-carboxylic acid, and the product was esterification in ethanol with a catalyzer of concentrated sulfuric acid to get ethyl imidazole-4-carboxylate, at last the compound above was reduced by LiAlH4 in ether at room temperature to get the target compound, the total yield of this route was 49.6%.

以4，5-二羧酸咪唑为原料的较佳工艺：1 脱羧反应：4，5-二羧酸咪唑40g，醋酐1200ml，回流10h，过滤并将滤液浓缩至干，所得固体加至50%的乙醇溶液回流，过滤并将滤液自然冷却过夜，过滤得固体；2 酯化反应：4(5)-羧酸咪唑50g，乙醇1000ml和浓硫酸60ml，加热回流2h，5%浓度NaOH溶液调节至pH＝8，减压浓缩至干，加入少量水回流，自然冷却过夜并过滤得固体；3 还原反应：LiAlH410g，乙醚300ml和4(5)-羧酸咪唑乙酯28g，常温反应1.5h，小心滴加25ml水后过滤，滤渣溶于300ml甲醇中并过滤，收集所得乙醚和甲醇滤液浓缩至干，将所得固体溶于300ml乙醇中加热回流，后将溶液浓缩至约30ml，冷却并过滤得固体，该路线总收率为49.6%。

Purified protein samples were separated by 2-DE with 17 cm IPG strips, and the protein spots were detected by fast silver staining. Six protein spots were randomly excised from the silver stained gel for primary analysis by MALDI-TOF MS. Four proteins were identified, and they were 1-aminocyclopropane-1-carboxylate synthase 2, ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit, F11O4.2 and Rubisco small subunit.

根据预实验结果，选用17 cm IPG预制干胶条对纯化的蛋白样品进行2-DE实验，采用快速银染法进行染色，随机挖取银染胶上6个蛋白点进行MALDI-TOF MS分析和数据库检索，鉴定了3个蛋白，它们是：1-氨基环丙烷-1羧酸合酶2，核酮糖-1，5-二磷酸羧化酶/加氧酶大亚基和F11O4.2。

In order to improve their water solubility, 4"-fatty amido-3"-sodium carboxylate azobenzene-4-sodium sulfonates were synthesized. They are azo compounds with two hydrophilic groups of carboxyl and sulfonyl. They decrease the surface tension in dilute solution slowly, and show some surfactivity, but are not surfactants. The probable reason is their relative strong hydrophile. Furthermore, their colors are not fresh and far from our destination.

为了改善其水溶性，改用对氨基苯甲酸为原料合成了4′-脂肪酰氨基-3′-羧酸钠偶氮苯-4-磺酸钠盐，以偶氮结构为主的亲水基团上连有羧酸基和磺酸基两个亲水性较强的基团，但可能由于其亲水性太强，在稀溶液中只能缓慢地降低溶液的表面张力，具有一定的表面活性，但不是表面活性剂，而且颜色不鲜艳，距离我们的目标较远。

Methacryloyloxydecyl-2-thiouracil-5-carboxylate was synthesized from the reaction of thiouracil with diethyl ethoxymethylene malonate and ω-hydroxy-decyl-methacrylate.

以硫脲、乙氧基次甲基丙二酸二乙酯和甲基丙烯酸ω-羟癸酯为主要原料合成了一种新的粘接性单体10-甲基丙烯酰氧癸基－2-硫脲嘧啶－5-羧酸酯。

AOX is a member of di-iron carboxylate proteins. Two structural models exist for AOX and the latest one is a monotopic protein instead of span membrane. Relatively little is known about its 3-dimensional structure. Main reason is that the sufficient quantities of AOX suitable fur crystallogram structural studies is unavailable because of its unstableness.

AOX是首次发现的双铁羧酸蛋白质成员中的膜蛋白质，AOX与膜分离后容易失活，至今尚未有三级结构的报导，只有二级结构的2种假设模式，最新的模式AOX为膜界面蛋白质而不是跨膜蛋白。

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。