甲基

The paint includes liquid A, which consists of acrylic resin, mixed solvent of xylene, acetone and isophorone, organic silicone solution, superfine silica powder, titanium dioxide powder, methyl-(N-beta-amino ethyl gamma-amino propyl)-dimethoxy siloxane solution, gamma-methyl acrylyloxy propyl tromethoxy siloxane solution and fluorocarbon modified siloxane; and liquid B, which consists of hexamethylene diisocyanate, polydiisocyanate, xylene, and methoxy propyl acetate. When the paint is used, two components are mixed together.

由丙烯酸树脂、二甲苯和丙酮及异佛尔酮混合溶剂、有机硅酮溶液、超细二氧化硅粉、钛白粉、甲基(N-β-氨乙基γ-氨丙基)二甲氧基硅烷溶液、γ-甲基丙烯酰氧基丙基三甲氧基硅烷溶液、氟碳改性硅氧烷溶液组成A液，由六亚甲基二异氰酸酯聚异氰酸酯、二甲苯和甲氧基乙酸丙酯混合溶液组成B液，使用时将两组分混合。

The diluent contain magnesium chloride, potassium citrate, sodium glutamate, dipotassium hydrogen phosphate, monopotassium phosphate and fructose, semen vitality is hightest after frozen.The average value is 0.52,highter than other 5 diluent significantly (P﹤0.01).So chose this diluent as semen cryopreservation diluent on chicken. Definite cryoprotectant, equilibrium time and thaw temperature:On the base of test one,research freeze sheltering effect about glycerin, DMSO ,DMA and DMF, each with 4 consistency.The result showed that 10%DMSO sheltering effect is the best, the next is 4%DMA,semen vitality are 0.58 and 0.55 after frozen.

冷冻保护剂、平衡时间和解冻温度的确定在试验一的基础上，研究甘油、二甲基亚砜、二甲基乙酰胺、二甲基甲酰胺4种冷冻保护剂在4种浓度下对鸡精子的冷冻保护作用，结果表明，10%DMSO保护效果最好，其次为4%浓度的DMA，精液冻后活力分别为0.58和0.55，两者之间差异不显著(P﹥0.05)。

Bis vinyl phenyl terminated polydimethylsiloxane was synthesized by the hydrosilylation of bis dimethylhydrogen siloxyl terminated PDMS with m divinyl benzene. The structure of the VTPDMS was characterized by 1H NMR.

通过双二甲基氢硅氧封端的聚二甲基硅氧烷与间二乙烯基苯的硅氢加成反应制备了双乙烯基苯封端的聚二甲基硅氧烷，用1H NMR对其结构进行了表征。

Other methyl nucleophiles includingMeMgBr, MeCeCl2, MeTiCl3, Me3Al, Me3ZnMgCl, MeMnClwere tried, but in all these cases no detectable amount of exo-C8-methylated product was obtained. Although protecting C3-carbonyl as 1,3-dioxolanes could be achieved, the serious enolization of C8-carbonyl was still problematic. Converting C9-furan ring to α,β-butenolide did depress the enolization, but desired C8-methylation was completely replaced by migration of the double bond of the butenolide.

在本论文的早期阶段，主要着眼于解决二环[3.2.1]-C8-羰基加成甲基所遇到的C9-呋喃环差向异构化和C3与C8两个羰基之间化学选择性的问题：通过引入不同金属降低甲基试剂的碱性并没有取得甲基化的成功；通过不同的方法将C3-羰基掩蔽，但是C8-羰基的烯醇化依然无法抑制；虽然通过将呋喃环转化为α，β-不饱和-γ-丁内酯可以抑制烯醇化，但内酯环上的双键迁移又成了新的竞争反应。

The article adopted the method of orthogonal design using Polyethylene Glycol and Methacrylic Acid to esterify Polythylene-glycol-mono Methacrylate, then using PMA, MAA and Methacrylic Acid Sulfonic Sodium as raw material to synthesize Polycarboxylic type water-reducer.

用正交实验法研究了聚乙二醇和甲基丙烯酸酯化合成聚乙二醇单甲基丙烯酸酯的合成工艺，以该酯化物与MAA和甲基丙烯酸磺酸钠为原料，在引发剂的作用下合成聚羧酸系减水剂。

Then sodium ethoxide was used as base,the nucleophilic substitution of 2-pyrrolidone with the intermediate provided nefiracetam.

以碳酸钠为缚酸剂，摩尔比为1︰1的2，6-二甲基苯胺与氯乙酰氯反应合成了中间体2-氯-N-(2，6-二甲基苯基)乙酰胺；在强碱乙醇钠作用下，2-吡咯烷酮再与2-氯-N-(2，6-二甲基苯基)乙酰胺经亲核取代合成了目标化合物奈非西坦。

Ib was synthesized by condensation of phthalic anhydride with 2-methylresorcinol in fused AlCl〓/NaCl (5∶1), followed by selective acetylation, methylation, NBS bromination and condensation with sodium ethoxide.

邻苯二甲酸酐在熔融的三氯化铝-氯化钠(5：1)中和-2，6-二羟基甲苯环合得1，3-二羟基-2-甲基蒽醌〓后经选择性乙酰化、甲基化、NBS溴化、乙醇钠缩合得1-甲氧基-2-乙氧甲基-3-羟基蒽醌。

Ethylation specific PCR analysis also revealed that the BLU promoter was highlymethylated in 74％(17 of 23) of primary tumors where the gene was downregulated,whereas only 2 of 9 non-neoplastic nasopharyngeal epithelia exhibitedhypermethylation in the BLU promoter region.

SP分析的结果表明，在23例表达下调的鼻咽癌组织中，17例(74％，17／23)标本的BLU基因发生了异常甲基化，而9例非癌对照中仅有2例甲基化，说明启动子甲基化在BLU基因的转录失活中具有重要作用。

The formation of microemulsion system containing emulsifier,acrylamide,2-ethyltrimethyl ammonium chloride,sodium-2-acrylamido-2-methyl-propane-sulfonate and hexamethylene was studied.

对复配乳化剂(span+tw een)、丙烯酰胺、(2-甲基丙烯酰氧乙基)三甲基氯化铵、2-丙烯酰胺基-2-甲基丙磺酸钠和环己烷组成的微乳液体系进行了研究，研究了单体总质量浓度、AM摩尔含量和阴阳离子单体配比改变对形成微乳液需要的适宜H LB值和最小乳化剂用量的影响。

Tetrachloroterephthalic acid was prepared by chlorinating terephthalic acid, oleumsolvent and iodine catalyst. Tetrachloroterephthalic acid was acylated by sulphurous oxychloride in the presence of DMF to form tetrachloroterephthaloyl chloride. The acyl chloride product was fluorinated by potassium fluoride and esterified by methanol to synthesize dimethyl tetrafluoroterephthalate. The ester was reduced with potassium borohydride and lithium chloride to give tetrafluoroterephthalyl alcohol. The above product was bromated in the hydrobromic acid to obtain 4-bromomethyl-2,3,5,6-tetrafluoro-benzene methanol. 4-Methyl-2,3,5,-6-tetrafluorobenzene ethanol was obtained by reducing the bromide with magnesium. In the exist of DCC and DMAP, tefluthrin was got by the condensation reaction between 4-methyl-2,3,5,6-tetrafluoro-benzene methanol and-(1RS,3RS)- 3-(2- chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cycolpropanecar-boxylate acid.

对苯二甲酸与氯气在碘存在下以发烟硫酸为溶剂进行氯化制备四氯对苯二甲酸；再以DMF为催化剂与二氯亚砜反应生成四氯对苯二甲酰氯；以氟化钾为氟化剂，环丁砜为溶剂置换氟化，再与甲醇酯化得到四氟对苯二甲酸甲酯；以KBH4-LiCl为还原剂二甲醚为溶剂反应制得四氟对苯二甲基苄醇；以氯苯为溶剂在溴化氢溶液中溴化得到溴化产物；在乙醇溶液中经镁粉还原得到4-甲基-2，3，5，6-四氟苄醇；甲基苄醇与功夫酸在催化剂二环己基碳二亚胺和4-二甲氨基吡啶作用下缩合得到七氟菊酯，总收率达43.6%。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。