羟基

One of the two major products was characterized by single crystal X-ray diffraction.Here the rings configuration in the crystal structure is described clearly by semi-quantitative ring puckering analysis.

用硫酸亚铁引发青蒿素的自由基裂解反应，对主产物之一的3-羟基脱氧青蒿素进行了单晶培养和X射线的表征，运用环Puckering分析方法对结构中环的构象进行了半定量描述。

OBJECTIVE:To establish a quantitative HPLC method for the simultaneous determination of alizarin, purpurin and rubimaillin in herb Rubia cordifolia L.

目的：建立了高效液相色谱法同时测定茜草药材中茜草素、羟基茜草素和大叶茜草素含量的方法。

Firstly,starting from 2,2-dimethyl-1,3-propan-diol,synthesis of-pedamide was finished in 17 steps.The pyran ring was formed in a S_N2 substitution of hydroxyl and epoxide.

以新戊二醇为起始原料，通过基于分子内的羟基与环氧的S_N2亲核取代构筑吡喃环的方法，经过17步反应完成了外消旋的Pedamide的合成。

The formed dihydropyrazine can be further oxidized irreversibly to 2,5-dicarboxyethyl pyrazine in the presence of oxygen.

这种二羟基毗嗪还能被进一步不可逆氧化成2，5-吡嗪。

Ten kinds of metal and three kinds of organic templates, including ethylenediamine, 1,4-butylenediamine and pyrazine were used in the synthesis of metal phosphonate coordination polymers.

在所合成的16种金属有机膦酸盐配位聚合物中，有机配体为2-羟基乙酰基膦酸，用于配位的金属离子共10种，模板剂3种分别为乙二胺(en，1，4-丁二胺，哌嗪。

The results showed that the amorphous iron oxide has highly catalytic activity. The intermediate products are pyrocatechin, hydroquinone, benzoquinone and low-grade fatty acid. The mechanism of catalyst oxidation is assumed that the free radical OH attacks benzene cycle at the adjacent position and para-position of OH on phenol so that the benzene cycle is opened and low-grade fatty acid is produced and transformed into CO2 and H2O.

结果表明，非晶铁氧化物催化剂在催化氧化降解苯酚时具有较高的催化活性，苯酚降解的中间产物有：对苯二酚、邻苯二酚、苯醌和低级脂肪酸，其降解机理是羟基自由基攻击苯环上OH的部位或对位而使苯环开环，生成低级脂肪酸，并最终转化成二氧化碳和水，从而使苯酚得以降解。

According to the differences of the materials, there are many methods of synthesis for benzofuranol , such as the pyrocatechol method, the cyclohexanone method, the o-chlorophenol method, the nitrophenol method, the methoxy phenol method, and so on.

根据原料的不同，呋喃酚合成方法可分为邻苯二酚法、邻氯苯酚法、环己酮法、硝基苯酚法、愈创木酚法、邻异丙基酚法、羟基苯异酮法等，文章对前几种较常见的合成方法的原理及工艺进展进行了详细的综述，并展望了呋喃酚合成方法的发展趋势。

Catalysts in three synthesis routes,the hydroxylation of 4-tert-butyl-phenol,the alkylation of pyrocatechol by tert-butyl alcohol and the alkylation of pyrocatechol by isobutene,were discussed in detail in terms of reaction conditions,catalysts,temperature,reaction time etc.

论述了对叔丁基苯酚羟基化法、邻苯二酚与叔丁醇烷基化法和邻苯二酚与异丁烯烷基化法生产对叔丁基邻苯二酚的合成路线的催化剂。

By using a mixture of aromatic hydrocarbon and water as a binary solvent,reaction of pyrogallol with PhCCl 3 was carried out in the presence of a catalyst(ZnCl 2?AlCl 3 or SOCl 2).2,3,4-Trihydroxybenzophenone was obtained in yields of 80%-87% with the advantages of easy control,stable yield,high product quality and low cost.

以焦性没食子酸为起始原料，在惰性气体保护和催化剂(ZnCl2、AlCl3或SOCl2)的存在下，在芳香烃与水组成的二元混合溶剂中，与三氯甲苯反应，经过芳香烃溶剂的后处理，可以得到2，3，4-三羟基二苯酮，产率最高达87%。

OH was produced by Fenton reaction and super oxide radical (O-2.) was produced by the oxidation of pyrogallol.

羟基自由基由Fenton体系产生，超氧阴离子自由基(O-2·)由邻苯三酚自氧化体系产生。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。