羟基

In chapter four molecular modeling method is employed to comparatively study five S-allyl γ-hydroxy ketene dithioacetals reactions of Thio-Claisen rearrangement with and without zeolite catalysts.

第四章用分子模拟途径研究了在有、无分子筛催化条件下五种丙烯基羟基乙烯酮二硫代乙缩醛Thio-Claisen重排反应。

With and without the assistance of one water, ammonia, and methanol molecule, the proton-transfer tautomerisms of 2-hydroxylpyridine are investigated systematically employing the B3LYP/6-311++G** level of theory. Both the keto and hydroxyl form of 2-hydroxylpyridine can exist stably though the keto form is slightly more stable than that of hydroxyl form.

采用量子化学中的密度泛函理论，在B3LYP/6-311++G**计算水平上，系统考察了在水、氨和甲醇分子辅助下，2-羟基吡啶醇式和酮式结构的质子转移异构化行为。

The comparisons of biochemistry between OP and OR rats The differences between OP and OR rats included not only body weight, but lipids metabolism and insulin sensitivity as well, characterized with insulin resistance, increasing in serum free fatty acids and ketone body, and hepatic TC and TG in OP rats. However, no significant differences were observed in serum TG, TC, LDL, HDL and fasting glucose between OP and OR rats.⑶Comparisons of metabolites in serum, urine and liver tissue between OP and OR rats①There were significant differences in amino acids concentration between OP and OR rats,especially in liver tissue, such as high concentrations in ketogenic and glucogenic amino acids in OP rats, suggesting differences in amino acids metabolism;② The different metabolites between OP and OR rats included increasing of various saturated fatty acids and decreasing of polyunsaturated fatty acids in OP rats;③The urinary metabolites analysis indicated that different structure or metabolism of gut microflora might exist between the two phenotypes, which probably influenced the regulation of body weight gain;④The end-products of catecholamines in urine and intermediates of krebs cycle in serum in OP rats were all up-regulated, suggesting that the activity of sympatheic nervous system and energy metabolism was higher in OP rats than OR rats.

胰岛素耐受实验和胰岛素敏感指数表明OP动物的胰岛素敏感性较OR动物下降，而OP大鼠血清中游离脂肪酸、酮体、肝脏总胆固醇和甘油三酯水平显著升高；但是，OP与OR大鼠血清中总胆固醇、甘油三酯、低密度脂蛋白、高密度脂蛋白和空腹血糖等的水平并无显著性差异；⑶肥胖易感与肥胖抵抗大鼠血清、尿液和肝脏组织提取物中代谢物的比较研究表明：①OP与OR大鼠的血清、尿液和肝组织提取物中多种氨基酸的含量存在显著差异，并以肝组织中的差异氨基酸数量为最多，包括各种生酮和生糖氨基酸水平在OP组的升高，说明氨基酸代谢的差异是两种体重表型大鼠之间存在的重要差异特征之一；②OP与OR动物肝脏和血清差异代谢物中包含多种饱和长链脂肪酸的升高如十四烷酸、十六烷酸、硬脂酸等和多不饱和脂肪酸的下降如亚油酸和花生四烯酸，说明两种体重表型动物的肝脏脂肪酸代谢存在明显差异；③长期高脂饮食喂养后，动物的尿液代谢物分析表明OP与OR动物体内的肠道菌群结构存在差异，这些菌群上的差别可能在动物体重增长的调节上产生影响；④与OR动物相比，OP动物尿液代谢物中儿茶酚胺类递质的代谢终产物如高香草酸、扁桃酸和4-羟基苯乙酸明显升高。

They can exist in a chain form or in a ring formed by reaction of the ketone or aldehyde group with an – OH group on one of the carbons at the other end of the chain.

它们有链式和环式。环式结构的形成是酮基或醛基与碳链另一端的羟基发生反应而相结合。

Sugar molecules consist of linked carbon atoms with – OH groups attached, and either an aldehyde or ketone group.

由携带羟基的一系列碳原子连接而成为骨架，再加上醛基或酮基构成了糖。

By this reaction, an aldose is converted into another aldose and the corresponding ketose, and a ketose is converted into the corresponding two aldoses.

单糖的异构化涉及羰基和相邻近的羟基，通过这个反应，一种醛糖转化为另一种醛糖，和相对应的酮糖，一种酮糖转化为相对应的两种醛糖。

On the basis of the chemical topological theory, Kier's molecule shape index (superscript mK of 25 chlorinated hydroxyl-phenylaldehydes were calculated in this paper.

基于化学拓扑理论，计算了25种氯代羟基苯甲醛衍生物的分子形状指数

As one of the most urgently needed medical intermediates, D-p-hydroxyphenylglycine is used mainly to produce β-lactam antibiotics.

D-对羟基苯甘氨酸主要用于合成β-内酰胺类半合成抗生素，是国内最紧缺的医药中间体之一。

Hydroxyapatite/poly lactide biomaterial has become one of the most important and potential bone graft substitutes because of its favorable biocompatibility and bioactivity.

羟基磷灰石/聚乳酸复合材料以其良好的生物相容性和生物活性成为骨替代材料中较重要、较有潜力的一部分。

Its molecular structure is made up of a five member, unsaturated lactone ring with two hydroxyl groups.

其分子结构是由五个成员国，不饱和内酯环两个羟基。

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。