碳环的

All compounds are synthesized starting from the acylation reaction of gallic acid with L-glutamine to form the basic scaffold, followed by the cyclic reaction in acetic anhydride and the key intermediate cyclic anhydride (compound 4) was obtained. The intermediate compound is condensed with different amino acids or primary amines, and produces the target compounds.

本研究以L－谷氨酸为基本骨架，与甲醚化保护的没食子酸缩合后，经过酰化、环合反应得到关键中间体环状酸酐（化合物4），再经胺解反应合成目标化合物，其化学结构经过红外光谱、电喷雾质谱和核磁共振谱（氢谱、碳谱、碳氢异核多键相关谱）确证。

Especially, furyl-, cyclopropane- and several odd and branched chain fatty acids were found in Gymnocypris przewalskii oil.

青海湖裸鲤鱼油中还存在不常见的环丙烷基和呋喃基脂肪酸及多种奇数碳链和支链脂肪酸。

The Catalyst used for preparation of carbodiimide from condensation of isocyanate were reviewed in this paper, including phosphorus-containing heterocycle compounds, phosphonate,organic metal compounds and polymer-grafting solid catalysts.

综述了异氰酸酯缩合生成碳化二亚胺催化剂的开发现状，包括磷杂环化合物、磷酸酯类化合物、金属有机化合物、聚合物接枝固相催化剂4大类。

Artificial mechanical cardiac valve was produced by Lanzhou Flight Control Instrument Factory. Prosthetic valve frame was acid-resisting chrome-nickel alloy of high intensity, valve ring was polyester filament fabric, valve was consisted of graphite matrix in interior and deposited hydrolytic carbon on surface.

人工机械心脏瓣膜由兰州飞控医疗仪器厂生产，为C-LⅠ型短柱人工机械心脏瓣膜，瓣架为高强度耐酸铬镍合金，瓣片的内部为石墨基体，表面为沉积热解碳，瓣环为涤纶长丝织物。

Only the major Isomers be displayed in the attacks of propylene oxide was replaced by the less carbon.

只有主要位置异构体被显示攻击在环氧丙烷较少被取代的碳。

Pyrimidine: Any of a class of heterocyclic compounds with a ring structure of four carbon and two nitrogen atoms .

嘧啶：具有环状结构(由4个碳原子和2个氮原子组成)的一类杂环化合物。

Pyrimidine: Any of a class of heterocyclic compound s with a ring structure of four carbon and two nitrogen atoms.

嘧啶：具有环状结构(由4个碳原子和2个氮原子组成)的一类杂环化合物。

High efficiency, no rubbing mechanical wastage between exciting power and carbon brush, slip ring, an energy saving product

制动特性良好；效率高，没有励磁功率和碳刷、滑环之间摩擦的机械损耗，是节能产品

Silica has a brush type surfacewith the stationary phase and silanol groups, whereas PGC has aflat surface composed of sheets of hexagonally arranged carbonatoms, where the spacing between sheets is similar to that in alarge polycyclic aromatic molecule.

硅胶表面就像一个刷子，布满了硅醇基和固定相，而 PGC 是由碳原子排布成6角形的平整表面，就像芳环一样。

Annonaceous acetogenins are natural compoundsisolated so far only from Annonaceae and showed potential as anticancer,immunosuppressive, and pesticidal agents.

Tonkinecin是一个具C5羟基37个碳的单四氢呋喃环番荔枝内酯化合物，它对人类肿瘤细胞如肝细胞瘤、胃癌等强烈细胞毒性。

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。