二甲基甲烷

Based on the characteristic that boracic acid (H3BO3) has a condasation and complexation reaction with 3-MCPD forming a negative-charged adduct in aqueous phase, arapid method for the direct determination of 3-MCPD in HVP by capillary electrophoresis with conductivity detection was investigated.

利用硼酸能与3-氯-1，2-丙二醇(3-MCPD)上的2个邻位羟基进行键合生成配合阴离子、从而增加多羟基化合物的负电荷的特性，在15 mmol/L 三羟甲基氨基甲烷-10 mmol/L H3BO3(pH 8.3)介质中，采用毛细管电泳/电导检测法分离检测了3-MCPD，该方法的线性范围为0.5-20 mg/L，检出限为0.1 mg/L(S/N=3)。

The auxiliary can be recovered in high yield (81%) only by filtering and recrystallization. Besides, some other aldehydes have been chosen to test the enantioselectivity of N,N\'-dibenzyl tartamide, in comparison with two other allylaborates reagents developed previously by Roush and Brown, respectively. The results show that %e.e. of homoallylic alcohol is superior to that of the former, and approaches the Brown reagent.

产物经S_N2反应得瑞格列萘中间体-甲基烯丙基-2-氯苯基-叠氮甲烷(17)；同时，将筛选出的新型手性配体N-苄基酒石酸二酰胺用于其他几种醛(正丁醛，异戊醛和环己醛)的不对称烯丙基化反应，并与广泛应用的Roush配体(22)和Brown配体(27)相比较，发现其立体选择性优于Roush配体，并接近Brown配体，但明显具有可回收利用的优势。

Furthermore, benzoic acid, p-toluic acid and p-phthalic acid were transformed slowly in sediment slurries amended with BESA (20 mM) under the condition of 100% CO2 and H2/CO2 (20/80), respectively, and the sediment slurry was dominated by methanogene bacteria.

在底泥含有甲烷菌抑制剂及上层气体分别为100% CO2和H2/CO2 (20ml/80ml)时，苯甲酸、对位甲基苯甲酸及对位苯二酸之分解变慢，且此底泥菌群是以甲烷菌为主要优势菌。

Spiral Spirobifluorene acetylated is oxidated by m-chloroperoxybenzoic acid and hydrolyzed by sodium hydroxide ,obtaining 2,2 '- dihydroxy -9,9'- spiral Spirobifluorene .Through nitrification,Reduced by hydrazine hydrate, we may get the 2,2 '- diamino -9,9'- spiral Spirobifluorene which are characterizated by IR, 1H-NMR !

L-酒石酸和乙醇酯化得到酒石酸二乙酯，将保护羧基保护起来，然后用碘甲烷在2，3-位上两个甲基，得到2，3-二甲氧基-酒石酸二乙酯，再用氢氧化钠将其水解，得到2，3-二甲氧基-酒石酸，用五氯化磷将羧基酰化，得到2，3-二甲氧基- 1，4-丁二酰氯，经过与二环己胺反应，得到拆分配体2，3-二甲氧基–N，N，N'，N'-四环己丁二酰胺。

The castor oil based polyurethane potting materials were synthesized from castor oil,4,4 diphenylmethane diisocyanate,trimethylolpropane and 1,2 propanediol.

以蓖麻油，4，4' -二苯基甲烷二异氰酸酯、三羟甲基丙烷与 1，2 -丙二醇为原料合成了蓖麻油基聚氨酯灌封胶，研究了灌封胶的固化流变行为和凝胶化时间。

The aqueous polyurethane prepolymer was prepared through step-growth polymerization of diphenylmethane diisocyanate with polyester glycol and dimethylol propionic acid, which was then neutralized by triethylamine to form the stable transparent aqueous polyurethane dispersion.

以二苯基甲烷二异氰酸酯、聚酯二醇、二羟甲基丙酸等为原料合成了水性聚氨酯预聚体，用三乙胺中和制备了水性聚氨酯的透明乳液。

A series of polyether based polyurethaneurea aqueous dispersions with well-defined hard segment s were prepared by fractional steps with polyether polyol, 4,4′-diphenylmethane diisocyanate,dimethylolpropionic acid,1,4-butanediol,isophorone diisocyanate and ethylenediamine.

以二苯基甲烷二异氰酸酯、二羟甲基丙酸、1，4-丁二醇、异佛尔酮二异氰酸酯和乙二胺为硬段，聚醚多元醇为软段，通过分子设计采用分步合成法，制备了具有规整硬段和良好分散性能的聚醚型聚氨酯脲水分散液。

An unreported compound 2-cyclopropylbenzimidazolium salt was obtained from 2-cyclopropyl benzimidazole and iodomethane.

以邻苯二胺和环丙基甲酸为原料，以多聚磷酸为催化剂，在微波辐射下合成了环丙基苯并咪唑，用碘甲烷季胺化得到未见文献报道的环丙基苯并咪唑盐，通过苯并咪唑盐与Grignard试剂加成后水解反应制备环丙基甲基酮。

Result shows that the sulfur compounds in the diesel can react with iodomethane easily at room temperature, the most of sulfur compound derived into methylsulfonium salts; the homologue of benzothiophene get the higher conversion ratio and react selectivity than the homologue of dibenzothiophene. It is found that primarily sterically hindered alkylated DBT, for example, 4-or 4-, 6-DBT, is recalcitrant to be methylated.

结果表明：柴油中硫化物在室温条件下容易与碘甲烷发生甲基化反应，大部分硫化物转化为锍盐，总转化率超过80%，苯并噻吩类比二苯并噻吩类更易发生甲基衍生化反应，转化率也相应较高。

This thesis consists of four chapters:Chapter 1: Michael addition of chalcones with active methylene compounds such as diethyl malonate, ethyl acetoacetate and nitromethane catalyzed by potassium hydroxide in anhydrous ethanol results Michael adducts in 72-98% yield under ultrasound irradiation in 25-150min.

第一章：研究了超声辐射下，氢氧化钾催化的查耳酮与活泼亚甲基化合物如丙二酸二乙酯、乙酰乙酸乙酯和硝基甲烷的迈克尔反应。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。