查询词典 acid radical

The mechanism was supposed as follows: polyfluoroalkyl iodides were initiated by sodium dithionite to give R〓 which was added to one double bond of diallylacetic acid, after the sequential radical cyclization and nucleophilic substitution to form bicyclo-lactones.

这是因为：多氟烷基碘化物在连二亚硫酸钠的引发下，得到自由基R〓，后者加成到二烯丙基乙酸中的一个—C=C—双键上，然后在碱性介质中进行分子内亲核反应得到双环内酯类产物。

The trial model with chicken encephalomalacia was set up by using the feed of low congtent of V〓 and supplying excessive unsaturated fatty acid in feed for studying the molecular mechanism of chicken encephalomalacia in the study. On the basis of observing the symptom and postmortem examination in clinic and determining the content of V〓, the bodyweight, the weight of cerebrum and cerebellum, the focus of the study was on follows which were relative to neuropathic injury. The concentration of free radical and the function of antioxidant defense system of chicken with encephalomalacia were determined systematically.

中文题名雏鸡脑软化症的分子机理副题名外文题名 The molecular mechanism of chicken encephalomalacia 论文作者王振勇导师石发庆教授学科专业临床兽医学研究领域\研究方向动物营养代谢病学位级别博士学位授予单位东北农业大学学位授予日期2002 论文页码总数110页关键词雏鸡脑软化鸡馆藏号BSLW /2003 /S858 /7 为了深入探讨雏鸡脑软化症发病的分子机理，本课题通过在采用低V〓饲料和添加过量UFA建立了雏鸡脑软化症实验模型。

On the base of molecular structure design, the mechanism and technique of the synthesis of 2-(acryloyloxy ethyl trimethyl-ammonium chloride/2-acrylamido-2methylpropane sulfonic acid/acrylamide (AETMAC/AMPS/AM) amphoteric terpolymers by radical co-polymerization in aqueous solution was studied systematically.

依据分子结构设计理论，将2—丙烯酰氧乙基—三甲基氯化铵/2—丙烯酰胺基—2—甲基丙烷磺酸/丙烯酰胺(AETMAC/AMPS/AM)三种单体进行水溶液自由基共聚，合成了AP系列两性离子聚合物。

A series of reactions may occur when the nitrous acid and naphthalene inside the atmospheric aqueous phases is exposed to sunlight. This article devotes to investigating from a microscopic angle the reaction mechanism and kinetics of this system using laser flash photolysis technique with an excitation wavelength of 355nm. The main research results are listed as below:(1) The OH quantum yield FOH for the photolysis of HNO2 in the aqueous phase was determined to be 0.234 and the absorption spectrum of OH radical was recorded as well.

本文以激光闪光光解为主要研究手段，考察了大气液滴中的HNO2及HNO2+萘体系经355nm紫外光照射后发生的微观反应及其机理，结果表明：(1)液滴中的HNO2经355nm光照产生OH自由基的量子产额为FOH=0.234；以瞬态技术记录了水相中的OH自由基的吸收光谱。

Using the MP2 method at the 6-311G level, the geometries of the reactants, transition state and products of the hydrogen abstraction reaction of isocyanic acid with formyl radical have been optimized. Changes of bond lengths of interacting molecules and the stationary point structures were discussed along the minimum energy paths.

在 UMP2/6-311G计算水平上，优化了标题反应的反应物、过渡态、产物的几何结构，沿最小能量途径讨论了异氰酸和甲酰自由基发生氢转移反应位能面上驻点的结构以及相互作用分子结构变化。

Isocyanic acid ; Hydrogen abstraction reaction ; ab initio ; Formyl radical ; Rate constant

异氰酸；氢转移反应； abinitio ；甲酰基自由基；速率常数

The method was based on the aromatic hydroxylation of terephthalate by hydroxyl radical, produced from the homolysis of peroxynitrite in weak acid media, to yield a highly fluorescent product, 2-hydroxy-terephthalate, which was then detected fluorimetrically.

具体做法是将ONOO〓在pH 5.0的缓冲液中转化为其共轭酸ONOOH，而ONOOH本身不稳定，均裂生成·OH，·OH进攻对苯二甲酸生成强荧光产物2-羟基对苯二甲酸，利用荧光分析法测定2-羟基对苯二甲酸，从而间接确定ONOO〓的含量。

The results show that all the fucoidan fractions had scavenging effects on superoxide, hydroxyl radical and hypochlorous acid, except that the high sulfated fractions F-B1 and F-B2 with low molecular weight had little scavenging activities on the three oxygen free radicals.

因低硫组分F一AZ(分子量8.7KD)在体外具有很好的抗氧化活性，因此选用四氯化碳(ee一4)和脂多糖+D一氨基半乳糖造成的急性肝损伤小鼠为模型，研究了F一AZ组分在这两种肝损伤小鼠体内的抗氧化活性和肝损伤的保护之间的关系。

Based on IR spectrum and HPLC chromatography, four polysacchharides had β-indican and characteristic absorbance of glucide without vitriol radical, galacturonic acid and acetyl.

红外光谱和其完全水解的高效液相色谱分析表明，4种多糖不含硫酸基团和乙酰基，具备β-糖苷键以及糖类特征吸收峰。

Objective To develop an OA kneepad and explore its mechanism and efficacy on the prevention and treatment of osteoarthritis of the knee through observing the effects of OA kneepad on cytokines, matrix-dissolution, hyaluronic acid, oxygen free radical metabolism, articular cartilage micro-structural changes, cell proliferation and apoptosis.

目的 研制OA护膝，并通过观察OA护膝对骨性关节炎细胞因子、基质溶解素、透明质酸、氧自由基代谢、关节软骨宏微观结构变化和细胞增殖、凋亡的影响，探讨其防治膝骨性关节炎的机制及疗效。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。