查询词典 alkenes

The results show that: 27 compounds were identified at 600℃, and most of them were alkenes, alkanes, acids, alcohols and phenolic substances; geraniol was identified, and its relative content was 3.6, which shows that geranyl 8-methoxycoumarin-3-carboxylic acid ester can release a certain amount of geraniol at smoke temperature; geranyl 8-methoxycoumarin-3-carboxylic acid ester can improve and modify the flavor, enhance the notes of sweet aroma and bean aroma, and reduce the biting taste of cigarette smoke.

结果表明，600℃时，8-甲氧基－香豆素－3-甲酸香叶酯的热解产物中共鉴定出27种成分，主要为烯类、烷类、酸类、醇类、酚类；鉴定出香叶醇，且相对峰面积3.6，说明8-甲氧基－香豆素－3-甲酸香叶酯能在卷烟燃吸温度下释放出一定量的香叶醇；8-甲氧基－香豆素－3-甲酸香叶酯具有改善和修饰卷烟香气，增加甜韵和豆香香韵，减轻刺激性的作用。

Difunctional group reagents, which have metal and heteroatom linked to the olefinic carbon atoms, play an important role in organic synthesis, especially in developing many convenient methods for the stereoselective synthesis of substituted alkenes.

含金属或杂原子的双官能团试剂为取代烯烃的立体选择合成提供了许多方便方法，在有机合成中具有重要作用。

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。

It was found that the introduction of Cr4 moiety did not remodel the mechanism of hydroformylation of simple alkenes.

计算结果表明Cr4片段的引入并没有改变简单烯烃氢甲酰化反应的机理。

Result The results showed that its components were quite complex, and 89 organic compounds were identified. There were 72 kinds of oxygen-containing organic compounds which included esters, phenols, aethers, ketones and alcohols in the depolymerization product, small amounts of alkanes, alkenes, arenes, thiophenol and nitrogen-containing organic compounds were also detected, which showed that characteristics of the product with high oxygen content, low nitrogen and sulphur content.

结果］超临界乙醇解聚产物成分十分复杂，GC/MS分析鉴定出89种有机化合物，其中72种为含氧化合物，主要有酯、酚、醚、酮和醇等，还检测出少量烷烃、烯烃、芳烃、苯硫酚和含氮化合物，反映了解聚产物的高含氧量和低含氮硫量的特性。

Seven major methods and their reaction characteristics for the synthesis of primary vicinal diamines starting from epoxides, and alkenes etc.

详细综述了从环氧化合物、烯烃等为起始原料合成一系列一级邻二胺的七条主要路线，并比较了各条反应路线的特点。

Organozinc reagents can react with a variety of α,β-acetylenic ketones and aldehydes in the absence of any catalyst. The one-pot reaction affords β-branched Baylis-Hillman type adducts, the multifunctionalized alkenes, in excellent yields with high stereoselectivity.

这种顺式亲核加成反应的发生是由于该类有机锌试剂既具有较强的亲核性，又具有Lewis酸的特性，使有机锌中R基团从同位进攻中心碳原子而形成新的碳碳键。

The combined TG-MS analysis showed that the gas products of the thermal decomposition of silver behenate were carbon dioxide,water,hydrogen,acetylene and some small molecule alkenes.

热重-差热分析-质镨联用的分析结果表明，山嵛酸银热分解的气态产物为二氧化碳，水，氢气，乙炔及一些小分子烯烃。

During the second transition about 231°C, a structural change took place, which corresponding to decomposition of silver behenate. The major thermal decomposition products are silver nanoparticles and behenic acid. The gas products from thermal decomposition of silver behenate were detected by MS. Carbon dioxide was first emerged, subsequently water, hydrogen, acetylene and some small molecule alkenes appeared.

采用MS对山嵛酸银在整个热分解过程中所释放出的气体产物的跟踪检测发现，首先是二氧化碳气体的放出，接着是氢气和水，随着温度的进一步升高，又伴随着乙炔和一些小分子的烯烃产生，当温度进一步升高到500℃左右时，被山嵛酸钝化的银纳米粒子逐渐失去了有机分子，最终的热分解产物为金属银。

In part three oxidation of bromide with an ion-supportedbenzene in ionic liquids afforded a clean path for bromination of alkenes. It was found that this reaction is highly stereoselective.

在离子液体中使用离子支持的二乙酸碘苯氧化溴离子，提供了一条清洁的烯烃加溴途径，发现反应具有高的立体选择性。4。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。