查询词典 diazomethane

A new method of gas chromatographic analyses in the production of chloroacetic acid for process control using diazomethane as esterification agent is studied.

目前企业生产分析按照国家专业标准﹝1﹞进行，但分析周期长，不能对反应过程进行有效地实时控制，生产过程的实际中控方法为密度法。

By suing methanol to supersede diazomethane which is carcinogenic and easily explosive as the esterifying agent, the method to measure HAAs was improved.

由于采用甲醇为酯化剂，使测定过程更安全，因此本测定方法更适合我国国情，也更利于方法的推广。

Increasing the modified time from 0 day to 4 days, the surface contact angle indicated by glycerol increased from 88.7° to 99.0°, indicated by water from 54.2°to 69.1° and indicated by diazomethane declined hum 40.0° to 31.9°.

结果表明，改性0-10d的木材吸水率从138.4%下降到111.1%；木材分别经过1d、2d和4d的硅烷化改性，甘油表面接触角从未改性时的88.7°上升到99.0°，蒸馏水表面接触角从54.2°上升到69.1°，二碘甲烷则从40.0°下降到31.9°。

The recognition capability and adsorption rate of MIP can be significantly enhanced by selective modification.Separation factor could be increased from 1.60 to 3.06 after modification when naringenin was chosen as competitive molecules, and the time needed for adsorption equilibrium could be reduced from 100 min to 60 min.Within a certain range, increasing template molecule concentration or diazomethane dosage, or adopting solvent which had weaker hydrogen bond action with template molecules could all improve the modification effect.

结果表明，选择性修饰能明显提高MIP的识别能力与吸附速度，以柚皮素为竞争分子，分离因子可从修饰前的1.60提高到修饰后的3.06，吸附平衡时间从修饰前的100 min降低至修饰后的60 min；在一定范围内提高模板分子浓度，增大重氮甲烷用量，采用形成氢键能力较弱的溶剂，均能提高修饰效果。

Molecularly imprinted polymer using quercetin as template molecules, methacrylic acid as functional monomers, ethylene glycol dimethacrylate as crosslinking agent were prepared, and the binding sites of MIP were selectively modified with diazomethane.The effects of template molecule concentration, solvent and diazomethane usage on modification were discussed.

以槲皮素为模板分子，甲基丙烯酸为功能单体，乙二醇二甲基丙烯酸酯为交联剂，制备了分子印迹聚合物，并以重氮甲烷为修饰剂，对MIP的结合点进行了选择性修饰，探讨了模板分子浓度、溶剂及重氮甲烷用量等对修饰效果的影响。

The intermediate of flazasulfuron weedicide ,2-amino-4,6-dimethoxypyrimidineis conveniently obtained by treating 2-amino-4,6-dihydroxypyrimidinewith diazomethane at 20 °C for 24h.

本文利用硝酸胍和丙二酸二乙酯为起始原料，经环合及甲氧基化两步反应得到除草剂啶嘧磺隆的中间体：2-氨基-4，6-二甲氧基嘧啶。

Herein, we report the enantioselective total syntheses of slagenins A-C and their antipodes. Starting from readily available ethyl -4-chloro-3-hydroxy-butanonate, elongation of the carbon chain with diazomethane, followed by oxidation of the given α-diazoketone using distilled DMD, afforded a key intermediate α-ketoaldehyde .

本文从方便易得的-4-氯-3-羟基-丁酸乙酯出发，经重氮甲烷延伸碳连、DMD氧化相应的α-重氮酮，制得α-酮醛；该化合物与尿素在氢氟酸作用下，以协同方式非对映选择性的直接构建了cis-四氢呋喃并[2，3-d]咪唑啉-2-酮双环结构，进而合成了天然产物slagenins A、B、和C的对映体。

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。