乙酯

To minimize the contamination of detrimental elements such as sulfurand chlorine, a two-step sol-gel process was successfully developed to synthesize SiC precursors with oxalic acid and hexamethylenetetramine HMTA as the catalysts, which are free of sulfur and chlorine. Tetraethoxysilane TEOS and phenolic resin were used as the silicon source and carbon source, respectively.

为了尽量减少硫、氯等有害元素的含量，本文用不含有害元素的草酸和六次甲基四胺HMTA为催化剂，正硅酸乙酯TEOS为硅源，酚醛树脂为碳源，成功探索出了制备SiC前驱体的两步法溶胶-凝胶工艺。

Our company treasures technical innovation and development of new products. On the basis of stable food grade,pharmagrade glycine,we have also developed compound amino acid,4pyridone,hydantoin and Nbenzylglycine ethyl ester etc.

本公司十分注重技术创新和新产品开发，在稳定食品级，医药级甘氨酸等老产品生产的基础上，又开发了蚕蛹复合氨基酸，4羟基吡啶，海因，N苄基甘氨酸乙酯等产品。

In this paper,two dihydrazides were synthesized with hydrazine and diethy1 ester.

本文利用了戊二酸二乙酯在一定反应条件下合成戊二酰二肼。

The results show that the hydrofluoric acid is a effective catalyst for the gel formation.

以正硅酸乙酯为硅源，分别以HF和HF/氨水为催化剂，通过溶胶-凝胶法常压制备SiO2气凝胶。

We successfully improved the methods of departing O-methyl using boron tribromide, of isolating hydrogen bromide byα-chloro-ethyl chloroformate, and of related in synthesis of natrexone, new medicine, using boron tribromide. This resulted in generation of hydrogen cyanide becoming impossible.

改进了以氯甲酸-α-氯乙酯脱代替溴化氰以及改进的三溴化硼法作为新药纳曲酮合成中相应的方法，去除了合成过程中产生氰化氢气体的可能性。

MethodsSaccharide content was determined by anthracene ethyl ketone method;amino acid content was estimated by indene tri-ketone colorimetric method.

方法青蒿可溶性糖含量测定使用蒽酮醋酸乙酯法，青蒿游离氨基酸含量测定用茚三酮比色法。

Properties White powder, inodorous, non-toxic, soluble in dilute alkali solution, carbon disulfide, benzene, acetone, dichloromethane and a little soluble in chloroform, insoluble in alcohol, carbon tetrachloride and ethyl acetate.

性质 白色粉末。无毒、无味。溶于稀碱、二硫化碳、苯、丙酮和二氯甲烷，微溶于氯仿，难溶于乙醇、四氯化碳、醋酸乙酯。

As shown by the result, the biomass and astaxanthin content of oceanic red yeast was reduced due to the presence of β-ionone which inhibited the synthesis of carotenoids. The lethality rate of oceanic red yeast would attained 92.3% if 370 mg/L of the β-ionone concentration was contained in the plate medium. The oceanic red yeast mutated by ethyl methane sulfonate was cultured on plate medium containing 370 mg/L of the β-ionone. 200 mutants were randomly screened, positive mutants with increased the biomass, astaxanthin volumetric yield and astaxanthin specific yield accounted for 18% of the total strain, the mutants with higher biomass, astaxanthin volumetric yield and astaxanthin specific yield higher occupied 22.5%, 45% and 46%, respectively.

实验结果表明，在β-紫罗兰酮存在的情况下，由于类胡萝卜素合成受到抑制，海洋红酵母的生物量和虾青素合成量都减少；当平板培养基中β-紫罗兰酮浓度达到370 mg/L时，海洋红酵母的致死率为92.3%；在这种平板培养基上涂布经甲基磺酸乙酯诱变的海洋红酵母，随机筛选200个菌落，结果表明生物量、虾青素体积产率和细胞产率均有所提高的正突变株占18%，生物量、虾青素体积产率和细胞产率的单项指标有所提高的正突变株分别占22.5%、45%和46%。

The antibiotic substance was isolated and purified primary using the methods of solvent extraction and Thin Layer Chromatography. The results showed that the antibiotic substance contained four components, and the component Ⅰ and Ⅱ had bioactivity against Cmm.

通过乙酸乙酯抽提、旋转蒸发制备的活性物质粗提液经薄层层析分析后，共分离出四个组份，其中仅组份Ⅰ与组份Ⅱ对番茄溃疡病菌表现抑制作用；紫外及可见光区的吸收峰分别为：253 nm、424 nm和443 nm。

The control group were fed basal diet, group 1 to 3 were fed basal diet supplemented with 90,100,110 mg/kg of Lespedeza Bicolor crude extract, group 4 to 6 were fed basal diet supplemented with 60,70,80 mg/kg of ethyl acetate extract, group 7 to 9 were fed basal diet supplemented with 60,70,80 mg/kg of n-butanol extract.

试验期42 d。对照组饲喂基础日粮，1～3 组饲喂基础日粮加二色胡枝子粗提物90、100、110 mg/kg；4～6 组饲喂基础日粮加二色胡枝子乙酸乙酯萃取物60、70、80 mg/kg；7～9 组饲喂基础日粮加二色胡枝子正丁醇萃取物60、70、80 mg/kg。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。