羟基

The oxidationresistant experiments were studied by refined flavones, such as reducing power, antioxidation actions to axunge, scavenging action to superoxide anion, scavenging action to hydroxyl free radical. And the results showed total flavones of Hippophae had well oxidationresistant ability.

利用精制后的沙棘总黄酮进行了还原能力的测定、抗猪油氧化、清除超氧阴离子自由基和清除羟基自由基实验，实验结果表明沙棘黄酮有良好的抗氧化能力。

The result showed that every azeotrope was homogeneous and sensitive to pressure, which means a significant change in the azeotropic composition and allows the recovery of feed components without adding a separating agent.

结果显示：常压下，5个碳以下的某一腈类物质1与沸点在±1 t 20℃范围内的羟基在1号碳位上的直链醇类会形成均相共沸物，且其共沸组成随压力变化敏感，理论上可用变压精馏进行分离。

Eight methods for the recovery of polyhydroxyalkanoate from the Azotobacter chroococcum G-3 were used to optimize extraction and digestion conditions.

本论文对圆褐固氮菌G—3菌株聚羟基烷酸的八种提取方法进行了优化研究。

Effect of concentrations of coating agents on shelly bamboo shoot quality was studied and compared.

试验结果表明：1.5％壳聚糖混入1.0％对羟基苯甲酸乙酯制成的涂膜剂有较好的保鲜效果，抑制失重和纤维素含量增加有明显效果。

However, the presence of steric hindrance and electron-withdrawing groups on the benzene ring would decrease the activity of phenols.

苯环上有供电子基团的酚类化合物反应活性比较好，而钝化基团的存在，则会降低酚羟基的反应活性。

The new methods to synthesize 6-hydroxy-3, 8-dioxabicyclo[3.2.1]octane, dihydrobenzofuran and benzofuran derivatives are described in this thesis.

本文主要论述了(5R)-6-羟基-3，8-二氧二环[3.2.1]辛烷，苯并二氢呋喃和苯并呋喃类衍生物的合成新方法。

In the precence of the base catalyst KF/Al2O3, the one - pot reaction of 2 -hydroxybenzaldehyde or 2 - hydroxynaphthaldehyde with ethyl α- bromoacetate,α-bromoacetophenone , 1,4 - dichloromethylbenzene , 4,4'- dichloromethylbiphenyl and 1,5 -dichloromethylnaphthalene gave the benzofuran compounds in 38-89% yield.

本文报道用 KF/Al_2O_3作为碱催化剂，由水杨醛或2-羟基-1-萘醛分别和α-溴代乙酸酯、α-溴代苯乙酮、苄基氯、4，4'-二氯甲基联苯和1，5-二氯甲基萘等进行一锅化缩合反应，以38～89％的产率合成了14种芳并呋喃化合物。

Six novel dihydrobenzofuran and benzofuran neolignans compounds(1～6) were synthesized by knoevenagel reactiton,esterfication, biomimetic oxidative coupling ,DDQ dehydrogenation,reduction and hydrolysis with 4-hydroxybenzaldehyde and malonic acid as starting material.

以对羟基苯甲醛和丙二酸为原料，经Knoevenagel缩合反应，酯化、仿生氧化偶联、DDQ脱氢、还原和水解等反应步骤，合成了6种未见文献报道的苯并二氢呋喃新木脂素和苯并呋喃新木脂素类化合物(1~6)。

The optimal separating condition of chromatography analysis was: Shimadzu VP-ODS 150mm4.6mm as chromatographic column; acetonitrile/water (12/88,V/V, Contained 1.25mmol/l phosphoric acid) as mobile phase with flow rate of 1.0ml/min. Macroporous ion exchange resins and activated carbon were applied to enrich the trace level impurities and the main impurities was determined by LC-MS and GC-MS.They were : Benzonitrile , 2-Methyl-8-hydroxyquinoline, 2,6-Pyridinediamine , O-ethyloxime Cyclo-hexanone and compound with 220 molecular weight .

采用离子树脂和活性炭吸附富集这些微量的杂质，并通过液质联用和气质联用对杂质进行了定性分析，鉴定了影响290nm吸收的主要杂质为苯甲腈，2甲基-8羟基喹啉，2，6二氨基吡啶，O-乙基环己酮肟和分子量220的物质。

Three ways leads to the synthesis of fenclorin, one way discussed here has 3 steps. Stepl :benzonitrile using as raw material goes though dry hydrogen chloride and becomes a-imino phenylmethyl ether after meet carbinol.

解草啶的合成主要有三条路线，本文选取合成路线是以苯甲腈为原料，经三步反应而成：1、苯甲腈在干燥的氯化氢通入，与甲醇形成亚氨基苯甲醚，通入氨气后置换甲氧基得到苯基脒盐酸盐(收率76.18%)。2、苯基脒盐酸盐在碱性条件下与丙二酸二乙酯环合而得嘧啶醇(收率84.39%)。3、嘧啶醇在三氯氧磷中羟基被氯化得到产品解草啶(收率87.29%)。

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。