羟基

As open-chain hydroxy aldehydes and hydroxyl ketenes, the monosaccharides are very reactive.

以开链的羟基醛和羟基酮形式存在的单糖非常活泼。

In order to investigate the effect of 2,4-Dihydroxylbenzoate on the combustion of double-base propellant, the combustion law of the propellants containing β-Bi was studied by means of the single frame amplification photography fl miniature thermocouple, the scanning electron microscopy and the LINK ISIS energy spectrum.

为了探索2，4-二羟基苯甲酸铋对双基推进剂燃烧的催化作用，采用单幅放大彩色摄影法、Ⅱ型微热电偶技术、扫描电镜和电子能谱研究了含2，4-二羟基苯甲酸铋双基推进剂的燃烧规律。

Vitamin D insufficiency is frequently defined as less than 30 nanograms per milliliter of blood of the 25-hydroxy form the major storage form - 25(OHD of the vitamin and deficiency as less than 20 nanograms per milliliter of 25-hydroxyvitamin D .

维生素D不足往往是界定为不超过30毫微克每毫升血液中的25羟基形式（主要的存储形式-2 5 d ）项和缺乏维生素的不到2 0毫微克每毫升2 5羟基维他命

A series of transition metals, transition metal oxides and composite metal oxides were investigated as catalysts for phenol hydroxylation. Twelve new types of phenol hydroxylation catalysts with good activity and application prospect were reported.

考察了一系列过渡金属氧化物、复合金属氧化物及金属作为苯酚羟基化作用催化剂的反应性能，筛选出12种具有良好活性与应用前景，尚未见文献报道的苯酚羟基化新型催化剂。

Furthermore, proton singlets of Fmoc group were treated as internal standard because of their station in both starting material and product.

用HR／MAS NMR分析技术不仅跟踪优化了固相羟基氨基酸的糖基化反应条件，而且选择固载在树脂上的糖基化Nα-Fmoc保护羟基氨基酸〓H NMR中最低场，且分辨好的Fmoc保护基信号做为内标，糖上乙酰基的积分面积为标准直接定量了键合在Tenta Gel S NH〓树脂上氨基酸甙化的产率。

In this dissertation, preparation of polysubstituted ethene and heterocyclic compounds based on 2-hydroxyalkyl phenyl selenides andα-phenylselenopropionic acid reagents were further investigated as follow: Firstly, O-ethyl-O-vinyl phosphonates were prepared in a one-pot, two-step transformation by Mitsunobu reaction of 2-hydroxyalkyl phenyl selenides with monoethyl esters of phosphonic acid in the presence of diethyl azodicarboxylate and triphenyl phosphine (PPh3) followed by oxidation-eliminatio...

中文摘要：本文主要进一步探索了2-羟基烷基苯基硒醚、α-苯硒基丙酸试剂在制备多取代乙烯和杂环化合物反应中的应用，具体研究内容和结果如下：一、在偶氮二羧酸乙酯和三苯膦(PPh3)存在下，苯基-2-羟基烷基硒醚和O-乙基膦酸单酯发生Mitsunobu反应，无需分离和纯化反应中间体，直接使用30 %的双氧水进行氧化-消除反应，提供了&两步、一锅&合成O-乙基-O-乙烯基膦酸酯的新方法，该方法反应条件温和，操作简便，产物收率良好(76-82 %)。

The structure composition adopted in the method are all established through experiments,including oxidant of ozone generated by ozone generator with electrolytic type, samplingmode by Flow Injection, Detecting System by Chemiluminescence. Based on the structurecomposition, the paper analyzed ozone generator with electrolytic type, includingthe method of generating steady concentration and raise oxidative degree.

在结构基础上分析了电解式臭氧发生器产生稳定浓度和提高氧化能力的方法，通过加入臭氧溶液平衡室，在动态平衡条件下，使臭氧溶液在UV灯条件下，产生稳定组成氧化剂—O_3和羟基自由基；分析了采样系统—流动注射的流动条件以及试剂浓度，包括羟基自由基消除试剂碳酸氢钠溶液、臭氧氧化发光试剂鲁米诺溶液、金属离子化学发光干扰屏蔽试剂钴离子溶液等；分析了化学发光检测与数据处理系统信号采集以及误差消除方法。

The cross-coupling reaction of DOPO with halogenated phenols were achieved for the first time, novel phenolic hydroxyl-containing reactive-type DOPO-based flame retardants used in epoxy resins were synthesized; the cross-coupling reactions of 2\'-hydroxybiphenyl-2-ylphosphinic acid or diphenyl phosphine oxide with halogenated phenols were studied according to the above result, new reactive-type flame retardants used in epoxy resins were synthesized.

采用Pd催化的方法首次实现了DOPO与卤代酚的交叉偶联，合成了新型含酚羟基的反应型DOPO基环氧树脂阻燃剂；在此基础上实现了2-(2-羟基苯基)苯基次磷酸和二苯基氧化膦与卤代酚的偶联，合成了新型反应型有机磷环氧树脂阻燃剂。

A reactive phosphorus-containing compound, bis-phenoxy (3-hydroxy) phenyl phosphine oxide was successfully synthesized to produce the phosphorus-containing flame retardant epoxy resin.

合成了一种含磷二羟基化合物双(3-羟基-苯氧基)苯基磷氧化物，并在此基础上合成了含磷环氧树脂BHPPO-EP。

In analysis by quintiles, MS risk was highest among indiiduals in the bottom quintile and lowest among those in the top quintile of 25-hydroxyitamin D leels.

通过五分位数分析，接受测试的个体中，25-羟基维生素D浓度最低的五分之一中多发性硬化的风险最高，25-羟基维生素D浓度最高的五分之一发病风险最低。

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。