二甲酸

After extraction by ethanol and purification by cationic ion-exchange column, a method of using reversed-phase high-performance liquid chromatography and precolumn derivatization with o-phthalaldehyde and 9-fiuorenylmethylchloroformate is employed for determination of free amino acids in tobacco . This method assures that amino acids with amino and imino groups can be determined simultaneously. The results of duplication experiment and recovery experiment are acceptable.

本试验用乙醇提取烟叶中的游离氨基酸，并用阳离子交换树脂纯化，再用邻苯二甲醛、氯甲酸芴甲酯联合柱前衍生、反相高效液相色谱分析测定了烟叶中的游离氨基酸，该方法能同时测定烟叶中的带氨基和亚氨基基团的氨基酸，并且分析方法的重现性和回收率均令人满意。

AIM: To study the effect of pyrrolidine dithiocarbamate, a potent inhibitor of NF2κB, proliferation and apop- tosis of human pterygium fibroblasts,inculture and search for a new method to prevent the recurrence after pterygium surgery.

目的：研究（nuclear factor，NF）2κB抑制剂吡咯烷二硫氨基甲酸(NF-B Inhibitor pyrrolidine dithiocarbamate，PDTC)对体外培养人翼状胬肉成纤维细胞（human pterygium fibroblast，HPF）增殖的影响，寻找辅助治疗和预防翼状胬肉复发的新方法。

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。

Only Cr reacts with DDTC to form a 1: 3 complex which is then extracted with methyl isobutyl ketone and determined by flame atomic absorption spectroscopy.

本文拟定的方法是在pH-4条件下，用二乙胺硫代甲酸钠与甲基异丁基甲酮络合萃取铬，用原子吸收光谱法测定。

Keywords: methyl carbamate, isocyanic acid ester, polyurethane, green chemical technology, dimethyl carbonate

中文关键词：氨基甲酸甲酯；异氰酸酯；聚氨酯；绿色化工；碳酸二甲酯

At first, urea decomposed into isocyanic acid, which interacted with ZnO to form a relatively steady isocyanate species. Then propylene glycol reacted with isocyanate species to form hydroxypropyl carbamate, and the HPC lost ammonia to form PC.

结果表明，该反应是分步进行的，首先尿素分解生成氨气和异氰酸，异氰酸与ZnO作用形成异氰酸物种，在丙二醇的作用下生成中间产物羟丙基氨基甲酸酯，然后由HPC脱氨气生成PC。

Also discussed is the research direction for development of new phosgenated products ,important among them being IPDI isophorone diiso.

简述了光气化产品开发研究方向，提出重点开发IPDI、NDI (1，5 萘二异氰酸酯)、氯磺酰异氰酸酯和较大分子量的氯代甲酸酯等光气化产品。

The results indicated isoprene was soon consumed under the condition of excess ozone. During the reaction, the major carbonyl products formed were methyl vinyl ketone, methacrolein, methylglyoxal, and formaldehyde. Formic acid, CO and CO2 were also among the products.

在反应温度(294±2)K，压力为1.01×10^5Pa空气，O3过量的条件下，异戊二烯很快反应完全，反应中生成的羰基产物主要包括甲基丙烯醛、甲基乙烯基酮、丙酮醛和甲醛；产物中还包括甲酸、一氧化碳和二氧化碳。

The concentration of glucose was detected by cyclic voltammetry via ferrocene monocarboxylic acid as mediator.

以甲酸二茂铁为电子媒介体，用循环伏安法检测GOD电极对葡萄糖的响应。

A new fluorescence quenched method has been found for determination of trace of gold based on the formation of nonfluorescent ternary complex Au- TBT -APDC.The composition ratio of Au to ligandi is 1:2:2.Under the optimum conditions,the linear range of the calibration curve is from 0 to 160ng Au/ml.

本文研究了在聚乙烯醇存在下，金与曙红、吡咯啶二硫代氨基甲酸形成三元络合物的合宜条件，并据此建立了水相荧光熄灭测定痕量金的新方法。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。