甲烷

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。

Ethylene dibromide and methyl bromide,liquid mixture, see

二溴化乙烯和溴甲烷的液态混合物，见

It indicates that the Ethanol and Methylerie dichloride can extract more active components from P.

在4种溶剂中，乙醇和二氯甲烷两种溶剂更适合于提取侧柏植物中的挥发性活性成分。

Bifasciatus to extracts of Ethanol and Methylene dichloride were much stronger than those of Petroleum and Hexane, and 20μl of extracts could bring the biggest EAG response.

这表明乙醇和二氯甲烷提取的植物气味中含有较多的对双条杉天牛成虫具有生理活性的化学成分。

The results showed recovery of spiked sample and RSD from method of ultrasonic extraction with methylene dichloride met timeliness and accuracy requirements of SVOCs monitoring in soil.

结果表明，二氯甲烷超声萃取法提取土壤中的半挥发性有机物的时效性，准确性能够满足监测分析的要求。

Key words 〗 Ultrasonic extraction; Semi volatile organic compounds ; Soil; Methylene dichloride; Soxhlet extraction

关键词〗超声波萃取；半挥发性有机物；土壤；二氯甲烷；索氏提取

To study the mechanism of DNA damage induced by dichloromethane.

［目的］探讨二氯甲烷对DNA的损伤作用。

Therefore, these two companies may represent the domestic dichloromethane industry.

因此，这两个公司可以代表国内二氯甲烷产业。

Meanwhile, the increase of domestic investment of dichloromethane was also lower than that of the quantity under domestic demands.

同时，国内对二氯甲烷的投资增长也低于国内需求量的增长。

Influence of metabolite accumulation on degradation rate of dichloromethane was studied.

研究了代谢调节产物浓度积累对生物法降解二氯甲烷效率的影响。

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。