烯酮

The 1,3-dipolar cycloaddition of nitrones with alkenes is one of the most studied reactions, among all the cycloadditions.

硝酮与烯烃的反应是环加成反应中研究最多的一种反应。

The results showed that SFE-CO_2 was the ideal method to extract volatile oils from lotus leaves. GC-MS was applied to isolate and analyze the components of extracted volatile oils. 76 components were detected, among which SD and SE detected 23 components respectively, while SFE-CO_2 detected 52 components. The main ingredients were terpenes, alcohols, esters, ketones and alkyls, etc.

并通过GC-MS联用技术，对提取得到的挥发油组分进行了分离分析，共检出76种成分，其中水蒸气蒸馏法和有机溶剂提取法分别检出23种成分，超临界萃取所得荷叶挥发油检出52种成分，主要为萜烯、醇、酯和酮、烷类化合物等。

A facile one-step method waspresented for the synthesis of N-fluoroalkanesulfonyl amidines 〓 inmoderate to good yield from the reaction of azides, ketones or aldehydes, andsecondary amines at room temperature.

在和无官能团取代的烯胺化合物的反应中，它发生了烷基迁移过程，而且利用该反应我们实现了由酮或醛，二级胺和叠氮一锅法合成脒类化合物〓。

Therefore, the research of synthetic method of flavonoids has the important value of scholarship and application.

因此，研究异戊烯基黄酮类化合物的合成方法具有重要的学术和应用价值。

Simultaneously, the activity and coding gene expression of ribulose 1, 5-bisphosphate carboxylase, phosphoenolpyruvate carboxylase, and glycollic oxidase all decrease in two rice accessions under low potassium supply while significant decrease in non-allelopathic rice "Lemont".

水稻光合作用相关酶的分析结果表明，低钾条件下核酮糖－1，5-二磷酸羧化酶、磷酸烯醇式丙酮酸羧化酶和乙醇酸氧化酶的活性及其基因表达强度均降低，但化感水稻&PI312777&的下降幅度显著小于非化感水稻&Lemont&。

In the fifth part, asymmetric synthesis of β,γ-trans-alkenyl α-amino esters was achieved by chiral phosphoric acid catalyzed transfer hydrogenation of β,γ-alkynyl α-imino esters. Utilizing Hantzsch ester as the hydrogen donor, both the alkyne and imine moieties of β,γ-alkynyl α-imino esters were reduced to yield β,γ-trans-alkenyl α-amino esters with up to 96% ee.

第五部分工作中，使用手性磷酸作为催化剂，Hantzsch酯作为氢源，β，γ-炔烃取代的α-酮酸酯亚胺中的炔键和亚胺官能团均被还原，以中等的收率和优秀的对映选择性（up to 96% ee）得到β，γ-反式烯烃取代的α-氨基酸衍生物。

The analysis on fatty acid,alcohol and ketone of oil with GC-MS method indicates that the alkyl acids,especially those with linear and saturated alkyl acids,are dominant in the newly generated acids.

采用气相色谱-质谱方法，对油样提取物中微生物产生的酸、醇、酮等物质进行了分析研究，两株菌产酸以饱和烷基酸为主，尤其以直链饱和烷基酸居多，同时也生成一定量的环烷、烯基酸和少量的芳基酸。

The trace amount of impurities,namely C5,tert-butyl alcohol,di-secondary butyl ether,methyl ethyl ketone and secondary butyl alcohol,in C4 hydrocarbon from butylene hydration tail gas were analysed by means of gas chromatograph with a column packed with sebaconitrile and polyethylene glycol-20M,and liquid-phase admission valve.

2m×4mm为填充柱，采用液相进样阀液态直接进样的填充柱气相色谱法分析了丁烯水合尾气C4烃中的C5、叔丁醇、二仲丁醚、甲乙酮及仲丁醇等微量杂质的含量。

The most prominent feature of Australian propolis is contained abundant flavonoid and terpenoid substances.

含有更丰富的黄酮类、萜烯类物质是澳洲蜂胶的最大特点。

There is a wealth of organic acids, terpenoid substances, vitamins, enzymes, polysaccharides, such as biological and pharmacological activity of natural ingredients.

澳洲蜂胶富含有20大类、380多种天然成分，包括30多种人体必需的微量元素、20多种氨基酸、数10种芳香化合物、30多种黄酮类物质，还有丰富的有机酸、萜烯类物质、维生素、酶类、多糖等具有生物学和药理学活性的天然成分。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。