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以下是小编为大家整理的relax名词，本文共6篇，欢迎阅读与收藏。

relax名词

篇1：Quantitative Structure-activity Rela

Quantitative Structure-activity Relationship Study on the Antioxidant Activity of Carotenoids

Carotenoids are a family of effective active oxygen scavengers, which can reduce the danger of occurrence of chronic diseases such as cardiovascular disease, cataract, cancer, and so on. The quantitative structure-activity relationship (QSAR) equation between carotenoids and antioxidant activity was established by quantum chemistry AMI, molecular mechanism (MM+) and stepwise regression analysis methods, and the model was evaluated by leave-one-out approach. The results showed that the significant molecular descriptors related to the antioxidant activity of carotenoids were the energy difference (EHL) between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) and ionization energy (Eiso). The model showed a good predictive ability (Q2 >0.5).

作者：SUN Yu-Jing PANG Jie YE Xing-Qian Lü Yuan LI Jun 作者单位：SUN Yu-Jing,YE Xing-Qian,Lü Yuan,LI Jun(College of Biosystem Engineering and Food Science,Zhefiang University,Hangzhou 310029,China)

PANG Jie(College of Food Science,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China)

刊名：结构化学 ISTIC SCI PKU英文刊名：CHINESE JOURNAL OF STRUCTURAL CHEMISTRY 年，卷(期)： 28(2) 分类号：O6 关键词：quantitative structure-activity relationship antioxidant activity carotenoids

篇2：Geochemical significance of the rela

Geochemical significance of the relative enrichment of pristane and the negative excursion of δ13CPr across the Permian-

Changes in the distribution of isoprenoid hydrocarbons and in δ13Ckero or δ13CPr across the section from the Changxing Formation to the lower Yinkeng Formation at Meishan (the GSSP of PTB) are studied, in which a relative enrichment of pristane and a sharp shift in both δ13Ckero and δ13Cmole near the boundary are revealed. A possible mechanism for the abnormal accumulation of pristane near PTB is suggested: Lipids in some marine animals and their metabolites, rich in pristane, can be preserved and accumulate in some suitable depositing facies under certain special conditions, such as the catastrophic death of animals and/or developing of an anoxic water column, and thus the pristane enrichment occurs in the sediment. The occurrences of isoprenoid enrichment and high Pr/Ph ratios have been found in other typical marine anoxic sediments accompanied by mass extinction in various extent during the most important geological periods, such as Late Ordovician, end of Devonian, Early Jurassic and Late Cretaceous. These occurrences support to a certain extent the above mechanism that interprets the genesis of a high Pr/Ph ratio in some typical marine anoxic sediments. The synchronous sharp negative shifts in δ13Cmole, δ13Ckero and δ13Ccarb from Beds 24 to 26 of the Meishan profile indicate that a sudden and strong variation of carbon source in the atmosphere-ocean system occurred during the quick but equable evolution from the end-Permian to Early Triassic, and the coupling between the pristane enrichment and negative shift in δ13Ckero and δ13CPr may well indicate the importance of the release of methane hydrates and marine anoxia in the end-Permian mass extinction.

作者：作者单位：刊名：科学通报（英文版） SCI英文刊名：CHINESE SCIENCE BULLETIN 年，卷(期)： 50(19) 分类号：P3 关键词：PTB pristane carbon isotope ratio animal lipids marine anoxia