four-membered
英
美
[网络] 四元
双语例句
- A Study of Bonding on Four-Membered Boron-Nitrogen Rings
四元硼氮环成键的研究 - In EIMS there are many frame-rearrangement ion peaks. The cleavage of C-O, C-F. C-CF3 bonds and the formation of five-or four-membered heterocyclic ring ions containing nitrogen by losing CO are major mass spectrometric characters.
在EIMS中，均存在较多的骨架重排离子峰，其中CO，CF，CCF3，键断裂及失去CO形成的五元，四元含氮杂环离子是重要质谱特征。 - This reaction includes the intermediates of the four-membered ring and the six-membered ring. And it indicated from the calculations that the step of β-H reductive elimination was the rate-determinating step.
具有四元环和六元环中间体，β&H（10）的还原消去反应是整个反应的速率决定步骤。 - This paper designed and synthesized several chiral nitrogen-containing heterocyclic four-membered ring amide of chiral catalysts, studies its application in catalytic asymmetric Aldol reaction, and acquired better catalytic effect. 1.
本文设计合成了几种手性氮杂四元环酰胺类手性催化剂，研究了其在催化不对称Aldol反应中的应用，取得了较好的催化效果。 - Four-membered heterocycles can often significantly improve the solubility of drug molecules, regulate the pKa, and at the same time remain membrane permeability and metabolic stability. It is also possible to adjust the toxicity of the drug molecules.
小分子四元杂环往往能显著改善药物分子的水溶性，调节pKa，同时可能保持良好的透膜性和代谢稳定性，也有可能调节药物分子的毒性。