查询词典 esters

Optically active β,δ-dihydroxy esters have been widely used in the synthesis of natural products, polyol fragments, and chiral drugs.

具有光学活性的β，δ-二羟基酯已经在天然产品、多羟基化合物以及手性药物的合成中得到了广泛的运用。

According to the structure and synthesis character of the geminal dinitro energetic plasticizers,the current situation about the synthesis,the property and application of geminal dinitro aldehyde acetals,esters and ether energetic plasticizers is summarized with 21 references.

从偕二硝基含能增塑剂的结构和合成特点出发，综述了偕二硝基缩醛类、酯类及醚类等含能增塑剂的合成、性能及应用研究现状。

When the resulting nitro compounds was reduced over 5% Pd/C catalyst, the nitro phosphinic acids required more catalyst that the esters nitro phosphinic acid, and dinitro compounds required more catalyst than mono-nitro compounds in the case of all nitro groups completely changed into amino groups.

用5％Pd/C作催化剂，将上述硝基物还原时发现，次膦酸形成的硝基物比次膦酸酯形成的硝基物需要更多催化剂才能使硝基全部还原成氨基；二硝基化合物比单硝基化合物需要更多的催化剂。

The fish samples were cleaned up by Florisil, then analyzed by GC-EI-MS to determine eight phthalic acid esters, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, butyl benzyl phthalate, dipentyl phthalate, dicyclohexyl phthalate, dihexyl phthalate and diethyl hexyl phthalate.

鱼肉样品以Florisil硅藻土层析柱净化后，经气相色谱-电子轰击离子源-质谱法分析其中8种邻苯二甲酸酯含量：邻苯二甲酸二乙酯、邻苯二甲酸二丙酯、邻苯二甲酸二丁酯、邻苯二甲酸丁基苄基酯、邻苯二甲酸二戊酯、邻苯二甲酸二环己基酯、邻苯二甲酸二己酯、邻苯二甲酸二(2-乙基己基)酯。

Some non-coded a , a -disubstituted amino acids could be obtained with up to 75.3% ee by using ketone imino esters as nueclophilles in the allylic alkylation reaction.

当利用亚胺的氨基酸酯衍生物时，可以得到一些非天然的季碳氨基酸衍生物， ee 值最高可以达到75.3%。

In this thesis, standard fingerprint of daphne diterpene esters from the root extract was first established by HPLC-UV, which can be used for D. genkwa identification and quality control. The major peaks in the standard fingerprint were identified by LC-MS.Quantitative analysis methods of yuanhuacine and yuanhuadine were established herein.

本文建立了芫花根中瑞香烷型二萜原酸酯类组分HPLC-UV标准指纹图谱，对主要色谱峰用LC-MS进行了归属，并对其中主要成分建立了定量分析方法，为不同产地、采收季节和人工栽培等原料药材的质量控制提供了科学依据。

Daphne diterpene esters are principal activitive components of Daphne genkwa, which is an endemic traditional Chinese medicine. Yuanhuacine has potent inhibition against several cancer cell lines. Inhibition against DNA topoisomerase I is probably its anticancer mechanism.

芫花为中国特有的瑞香科植物，主要有效成分为植物中罕见的瑞香烷型二萜原酸酯类化合物，其中芫花酯甲对多种癌细胞系有较强的抑制活性，对DNA拓扑异构酶I的抑制作用是其抗癌的可能机理。

The organoboron compounds in this paper are based on triarylboranes, boronic acids and boronic esters. The structure-property relationship and sensing mechanism are elucidated. Organoboron compounds as Lewis acid can be used as fluoride probe with high sensitivity and selectivity because they have a unique LUMO in which the π-conjugation is divergently extended through the vacant p-orbital of the boron atom. The complexation of the boron π-electron systems with fluoride ion would interrupt the π-conjugation extended through the boron atom, causing the change of photophysical properties.

介绍了基于三芳基硼化合物、硼酸和硼酸酯的有机硼化合物在氟离子检测中的应用，评述了这些化合物的结构和检测性能之间的关系，讨论了检测机理，即有机硼化合物中硼原子空的p轨道使其作为路易斯酸能够选择性地结合氟离子，硼原子与氟离子的结合破坏了硼中心与芳香取代基的p-π共轭，引起有机硼化合物光物理性质的变化，从而实现对氟离子的高选择性检测。

To evaluate the potential of several biodiesels, which had different content of fatty acid methyl ester, as substitute solvent for quizalofop-p-ethyl emulsifiable concentrate, the type and content of fatty acid methyl esters in tested biodiesels were analyzed by gas chromatography, and 5% quizalofop-p-ethyl ECs were prepared with different biodiesels, respectively. The control test against gramineous weeds by the 5% quizalofop-p-ethyl ECs were carried out in greenhouse.

为评价不同来源生物柴油作为溶剂配制精喹禾灵乳油的效果，采用气相色谱法测定了几种生物柴油中脂肪酸甲酯的种类及含量，利用相应制备的5%精喹禾灵乳油进行了防治禾本科杂草的盆栽试验，同时比较了不同生物柴油对药剂稀释液表面张力、干燥时间和在叶片表面沉积量等药液物理性状的影响。

We studied DBU-mediated Ireland-Claisen rearrangement. Using DBU as the base for enolization of allylic esters of unsaturated acids 9-16, we found a novel DBU-mediated tandem Ireland-Claisen rearrangement /isomerization reactions and established a consecutive Ireland-Claisen rearrangement /Cope rearrangement.

利用DBU作为烯醇化碱，对含有活泼质子的烯酸烯丙酯类化合物9-16的Ireland-Claisen重排进行了系统的研究，创建了一条新颖的DBU-促进的Ireland-Claisen重排/异构化串联反应及Ireland-Claisen重排/Cope重排的串联反应路线。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。