酸基

After the supplement of L-Leu, extracellular isovaleric acid was accumulated in vitro and then reabsorbed for eutilization, the ultimate relative content of isovalerylspiramycin II, isovalerylspiramycin III was increased by 41% and 50% respectively, and the relative content of total isovalerylspiramycins increased by 41.9% with the biological titer of biotechspiramycin being equal to that of the control group.

添加Leu对初级代谢影响不大，异戊酸在胞外积累，随后被重新吸收利用，最终异戊酰基螺旋霉素II和异戊酰基螺旋霉素III组分分别提高了41%和50%。同时总异戊酰基螺旋霉素相对含量也比对照提高了41.9%，效价和对照基本一致。

Amino-monomethoxypoly(ethy1ene glycol)(mPEG-NH2) was synthesized based on the principle of Gabriel synthesis.Monomethoxypoly(ethy1ene glycol) tosylate was prepared at first,and then reaction with potassium salt of phthalimide as nucleophile to produce the monomethoxypoly(ethy1ene glycol)phthalimide derivative.

摘 要：首先合成了单甲氧基聚乙二醇对甲苯磺酸酯，然后根据盖布瑞尔合成法原理，以邻苯二甲酰亚胺钾盐为亲核试剂与mPEG-OTs反应，生成单甲氧基聚乙二醇的邻苯二甲酰亚胺衍生物，mPEG-PI与水合肼反应肼解生成伯胺，合成了一端为氨基的单甲氧基聚乙二醇(mPEG-NH2)。

Ti-PILCs were also obtained with pillaring agent prepared from Ti(n-C4H9O)4 and HC1 by Sol-Gel, using purified Na-montmorillonite in Hubei as the starting clay.

以鄂东钙基膨润土经提纯钠化后所得的精制钠基蒙脱石d_(001=1.28nm为基质粘土，以钛酸正丁酯[Ti(n-C_4H_9O)_4]为钛源，采用溶胶—凝胶法制备了一系列钛交联蒙脱石纳米复合材料；并对Ti／土比、H／Ti摩尔比和盐酸浓度等主要合成条件进行了讨论。

In this study, the cDNA fragments encoding α subunit of nicotinic acetylcholine receptor was cloned from the diamond back moth, Plutella xylostella with RT-PCR techniques. The amplified fragments are 425 nucleotides in length, from which 141 amino acids were deduced.

测序结果显示，扩增的目的基因片段包含了nAChRα亚基的三种亚型，分别命名为Pxal、Pxa2、Pxa3，都具有典型的α亚基的结构：两个相邻的半胱氨酸；形成胞外环的15个氨基酸；与烟碱和α银环蛇毒素结合有关的氨基酸残基。

The fluorescence spectra of 4- 5 '-p-biphenylyloxadiazolyl-2' benzyl ω-p-biphenylyl polymethylene car-boxylate have been determined. The results of experi-ment show that they can form not only intramolecularexciplex but also intermolecular excimer and triplex.

测定了ω-对联苯基多亚甲基羧酸4-[5'-对联苯基〓二唑-2']苄酯的荧光发射光谱，从实验结果得到，它们不但可以形成分子内激基复合物，而且可以形成分子间激基缔合物和三分子激基复合物。

In this paper,pyromellitic dianhydride,1,2,3,4-cyclobutanetetracarboxylic dianhydride,4[(4-aminophenyl)-bis(4-methoxyphenyl)methyl]benzeneamine,4-hexyloxy-biphenyl-3′,5′-diaminobenzoate,and additive ADD-34 were used to synthesize four PIs.

文章用均苯四甲酸二酐，4[(4-氨基苯基)-二(4-甲氧基苯基)甲基]苯胺，1，2，3，4-环丁烷四羧酸二酐，4-己烷氧基联苯酚-3′，5′-二胺基苯甲酸酯和不同含量的添加剂制备了聚酰亚胺液晶取向剂。

Preliminary experiments show that the rate of condensation of sulfanilic acid with 4-[4-(4-Ni-tro-2-sulfostyryl)-3-sulfophenyl-azo]-3-methyl-1-phenyl-5-pyrazolol is slower than those of p-phenylene diamine a...

对氨基苯磺酸和4-[4-(4-硝基-2磺基苯乙烯)-3-磺基苯偶氮]-1-苯-3-甲-5-羟吡唑在稀的氢氧化钠溶液中缩合的速度，较对苯二胺及对氨基苯甲酸为慢。

Disclosed is a polyimide resin having a glass transition temperature of 200-320 DEG C and containing a siloxane diamine residue, a fluorene diamine residue and a specific tetracarboxylic acid dianhydride residue at certain ratios.

本发明提供玻璃化转变温度为200～320℃，以特定比例含有硅氧烷系二胺残基、芴系二胺残基和特定四羧酸二酐残基的聚酰亚胺树脂。

Following resolution, the following steps are performed: reduce the isomer to an alcohol, react the alcohol with triphenylmethyl chloride, ozonalyze the resulting reaction product, reduce the ozonalyzed product to yield a diol and react the diol with a methane sulfonyl compound to form-3-2-{(methylsulfonyloxy}ethoxy-4--1-butanol methane sulfonate.

拆分后，进行下一步：将异构体还原为醇，使醇与三苯基甲基氯反应，臭氧化所得反应产物，还原臭氧化产物以得到一种二醇并使所述二醇与甲烷磺酰基化合物反应以形成-3-2-{(甲基磺酰基氧}乙氧基-4--1-丁醇甲烷磺酸酯。

Several methods applied widely for synthesizing uronic acid are introduced, such as methods of one-step process and two-step process.

分别就糖醛酸的几种常用合成方法进行了介绍，即直接将羟甲基氧化成羧基的一步法和先将羟甲基氧化成甲酰基、再氧化成羧基的两步法。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。