查询词典 free radical

Used the PERCA method to carry on the determination to March campus environment atmosphere, had discovered the peroxy free radical signal had the obvious daily variation, the HO_2 free radical strongest about 14:00 appeared a peak value in the sunlight.

采用PERCA方法对三月份校园环境大气中的过氧自由基进行了测定，发现过氧自由基信号有明显的同变化，HO_2自由基在阳光最强的14：00左右出现一个峰值。

The experiment obtains the noon peroxy free radical density approximately 11 pptv, the observation had discovered the free radical the density has the direct ratio with the ozonedensity but to have the inverse ratio with the nitrogen dioxide density.

实验测得中午过氧自由基的浓度约11pptv，观测发现自由基的浓度同臭氧浓度成正比而与二氧化氮浓度成反比。

From the experiment discovered for the first time the dimethyl ether may substitute CO to take the chain-carrying agent of the peroxy free radical chemistry amplifier system, and optimized the CH_3OCH_3-NO-HO_2 chemistry amplifying system determination condition, the CH_3OCH_3 best density is 1.876 ppmv, the NO best density is 1.3ppmv, and obtained this method chain length CL=124, 5 parallel determinations densities of HO_2 are the 44.0pptv, the relatively standard deviation is smaller than 4%; Although chemistry box model computed result indicated the dimethyl ether, the ethene, the propene and the ethanol all can take the chain-carrying agent of the peroxy free radical chemistry amplifier system, and their simulation chain length all grows up compared to the CO-NO-HO_2 chemistry amplifying systems, but experiments proved the ethene, the propene and the ethanol have not suit the chain-carrying agents.

首次从实验上发现二甲醚可以替代CO作为过氧自由基化学放大系统的链传递试剂，并优化了CH_3OCH_3-NO-HO_2化学放大系统的测定条件，CH_3OCH_3的最佳浓度是1876ppmv，NO的最佳浓度为1.3ppmv，并得到了这一方法的链反应长度(CL=124)，5次平行测定浓度为44.0pptv的HO_2自由基，相对标准偏差＜4％；虽然化学盒子模式计算结果表明二甲醚、乙烯、丙烯和乙醇都能作为过氧自由基化学放大系统的链传递试剂，并且它们的模拟链长都比CO-NO-HO_2化学放大体系的链长大，但是实验证明乙烯、丙烯和乙醇不适合作为过氧自由基化学放大系统的链传递试剂。

The results of the ability of anti-oxidation scavenging DPPH free radical shows that polyhydroxy substituted N-benzoylserotonin derivatives (compound 1-10) have the generally better ability of anti-oxidation than control group, in which the IC50 of compound 1-10 ranges 8.75 to 18.02 μg/ml and the IC50 of trolox is 13.04 μg/ml. The abilities of anti-oxidation of compound 1, 4, 5, 7, and 10 are all better than the control group, trolox. Among all, compound 10 has the best ability of anti-oxidation (IC50 is 8.75 μg/ml). This study also discovers that the ability of scavenging DPPH free radical is strongly related to the number and the position of hydroxyl.

在清除DPPH自由基的抗氧化能力结果显示，相较於对照组水溶性维生素E之IC50值13.04 μg/ml，多羟基取代之N-色洛冬宁苯甲醯胺衍生物（化合物 1 ~ 10），皆具有相当不错的抗氧化能力，十种醯胺化合物的 IC50值介於8.75 ~ 18.02 μg/ml之间，化合物1、4、5、7、10的抗氧化能力效果皆优於对照组水溶性维生素E的IC50值，其中又以化合物10的效果最佳(IC50值8.75 μg/ml)，而清除DPPH自由基的能力发现与羟基的数量及其位置有关。

The free radical scavenging activity of four Lamiaceaeplants growing in Turkey, Stachys byzantina, Salviaviridis, S. multicaulis and Eremostachys laciniata wasdetermined using a stable DPPH free radical.

一 具去除自由基活性的4种唇形科植物生长在土耳其，绵羊水苏、丹参贻贝、长梗黄花稔和沙穗是确定可使用於稳定DPPH游离基。

A novel method combining a conventional free-radical solution polymerization with a chemical saponification was used to synthesize a, cu-dicarboxyl terminated oligo s with molecular weight below 1500. Here, cn-carboxyl terminated oligo s were firstly synthesized by the free-radical polymerization in THF, where 4,4'-azobis(4-cyanovaleric acid) was used as initiator, thioglycolic acid as chain transfer agent, then CTBMA were transformed into di-CTBMA via saponifying CTBMA in dioxane/H_2O/KOH solution.

利用传统自由基聚合法，在四氢呋喃溶液中自由基引发聚合甲基丙烯酸丁酯单体而得到w-羧基-甲基丙烯酸丁酯低聚物(分子量在1500左右)；利用CTBMA 末端酯基的反应特性，在二氧六环／水／KOH混合溶液中皂化CTBMA，使之转化为a ，w-羧基甲基丙烯酸丁酯低聚物；研究了溶剂的类别、反应时间等反应条件对皂化产物结构的影响；利用MALDI-TOF-MS及LSIMS对皂化各阶段产物进行了分析监测。

OBJECTIVE To study the effects of aloe-emodin and emodin on scavenging superoxide anion free radical O(superscript – subscript 2 and hydroxy free radical.

目的：研究芦荟大黄素和芦荟素对超氧阴离子自由基O(上标–下标 2、羟自由基的清除作用。

Methods The methods of DPPH , pyrograllol auto-oxidation and salicylicl acid were used in order to get the scavenging quality of DPPH free radical , superoxide free radical O2-.

方法采用DPPH法、邻苯三酚自氧化法、水杨酸法，分别测定缬草醚酯提取物清除DPPH自由基、超氧阴离子自由基和羟自由基的能力。

Fenton reaction was used to produce hydroxyl free radical, Rhodamine B was used as fluorescence indicator, and the detection solution is phosphate salt buffer. The measurement system was set up to measure the effects of nanose scavenging hydroxyl free radical.

Fenton反应产生稳定羟自由基，罗丹明B为荧光指示剂，磷酸盐缓冲液中检测了纳米硒清除羟自由基的效果。

In the previous studies the constituents from Cinnamomum philippinense reported to have the biological activities such as antiplatelet aggregation, vasorelaxation, cardiac muscle contraction, antioxidation and free radical scavenger activities etc. Furthermore, MA-1 a ligan isolated from Cinnamomum philippinense is considered to be an important prophylaxis to treat ischemic stroke due to its antioxidation and free-radical scavenger activities. The present project aims to develop MA-1 as a pre-medicine to treat ischemic stroke.

在过去的研究中，发现菲律宾樟树所含的成分对心脑血管相关的活性诸如抑制血小板凝集、血管松弛、影响心肌收缩、抗氧化、自由基清除等具有不错的活性作用，而由菲律宾樟树所分离得到的一种新木质酚MA-1，具有抗氧化作用且是自由基捕捉剂，获选为开发成缺血性中风之预防与治疗先导药物。

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。