查询词典 methyl salicylate

Chloro-2-methyl-4-acetoxy-2-butene was treated with hexamethylenetetramine, followed by hydrolysis to yield 4-acetoxy-2-methyl-2-butenal, a key intermediate for vitamin A .

1-氯-2-甲基-4-乙酰氧基-2-丁烯与乌洛托品成盐后水解，得到合成维生素 A的重要中间体4-乙酰氧基-2-甲基-2-丁烯-1-醛，用微波辐射可促进水解，反应0.5h收率可达77%。

The formed long and linear chain alkyl benzene changes into benzene methyl and alkene through β-scission and monomolecular homolysis, and then benzene methyl shifts to the position of α-Carbon in the long chain alkyl benzene through H-transfers.

已形成的长直链烷基苯通过β分裂、单分子均裂形成苯甲基、烯烃，苯甲基通过氢转移到长链烷基苯的α碳上，烯烃再与α碳结合形成带支链的烷基苯。

Methyl hydrazine and hydrazine hydrate in reaction mixtures from the preparation of methyl hydrazine were determined by Gas Chromatography.

建立了甲基肼合成液中甲基肼、水合肼含量的气相色谱分析方法。

Adding Cr in the catalyst enhances the selectivity to benzaldehyde (from 85.6 to 91.2％ at 400℃). Cu or Ti is very beneficial for the hydrogenation of methyl benzoate to toluene or the hydrogenolysis of methyl benzoate.

Cr调变的催化剂提高了甲醛选择性(在400℃，从85.6提高到为91.2％)，Cu和Ti调变的催化剂则显示较高的苯甲酸甲酯深度加氢活性，即氢解活性。

An alternative way of the synthesis of methanol from syngas is low-temperature methanol synthesis via methyl formate in liquid phase, namely, carbonylation of methanol in the first step, and hydrogenolysis of methyl formate in the second step.

低温液相甲醇合成是指在（80-160℃）范围内，甲醇首先与合成气中的CO发生羰基化反应生成甲酸甲酯，甲酸甲酯再氢解生成甲醇的两个反应在一个反应器内串联进行的方法。

The most preferable substituents are methyl groups for positions R1 and/or R2, due to the existence of a hyperconjugation effect between the p z orbital of the central carbon atom and one of the C—H bond orbitals in methyl group.

当R1， R2位置是甲基时，由于碳原子的p z 轨道与甲基的一个C—H键轨道间存在强的超共轭效应，从而可以较大程度地降低α-氢转移反应的势垒。

Meanwhile,the factors which affected the drying were also analyzed including the flow rate of methyl chloride ,the content of isobutylene,the amount of regenerated nitrogen,the regeneration time,the discharging condition of methyl chloride remaining in tower before regeneration,the using time of Al_2O_3,and so on.

研究了丁基橡胶装置干燥塔的干燥、再生过程，对影响干燥效果的主要因素如氯甲烷流量、异丁烯含量、再生氮气量、再生时间、再生前塔内残留氯甲烷的排放程度、干燥剂Al_2O_3的使用时间等进行了分析。

The concentrations of isopentane, 2-methyl-pentane, pentane and 3-methyl-pentane which are from automobile exhaust and gasoline evaporation were highest in alkanes. Benzene/toluene ratio was close to 0.5 which is the characteristic value of automobile exhaust. The concentrations of pinene and isoprene were highest in alkenes.

烷烃类物质中异戊烷、2-甲基戊烷、正戊烷和3-甲基戊烷等机动车尾气或汽油挥发特征性物质浓度最高；芳香烃类物质中苯／甲苯的特征比值略高于机动车尾气排放特征比值0.5；烯烃类物质以植物排放的蒎烯、异戊二烯为主。

Under the catalyst, the polymerization retarder, the including water medicinal preparation existence condition, the methylacrylic acid and the polyethylene glycol single methyl ether (400) direct esterification synthesis methylacrylic acid polyethylene glycol single methyl ether (400) ester, and the influence factors of the catalyst, polymerization retarder, including water medicinal preparation has mellowly carried on the comparison.

摘要在催化剂、阻聚剂、带水剂存在的条件下，由甲基丙烯酸与聚乙二醇单甲醚(400)直接酯化合成甲基丙烯酸聚乙二醇单甲醚(400)酯，并对酸醇比、催化剂、阻聚剂、带水剂等影响因素进行了比较。

The objective of this article was to review the production of methyl mercaptan and the relationship of methyl mercaptan and periodontitis.

本文就甲基硫醇的生成机制及其对牙周组织的破坏机制进行综述。

This immediately brings us to the next part of this article: creating an output "replace function".

下面进入文章的第二部分：建立一个"缓存处理函数"。

He was elected as an International Ornithological Committee member in 2002 during the 24th IOC held in Beijing.

现为中国鸟类学会理事和WPA 专家组成员。2002年被推选为国际鸟类委员会委员。