查询词典 phenols

The catalytic esterification of acetic anhydride and nine phenols were investigated in the presence of complex resin catalyst at 20 ℃,and its mechanismes were discussed.

研究了 2 0℃时，醋酸酐与九种酚在复合树脂催化剂下的催化酯化反应，并探索了其反应的机理。

As a comparison,the amination of phenols turn out to be unsuccessful under various conditions tested.

同时我们也开展对苯酚类化合物氨基化的反应研究，使用多种策略，均未成功。

The content of total anthocyanin, total flavonoids and total phenols of arbutus juices were measured by spectrophotometry.

结果如下：对杨梅进行榨汁，并测定其花色苷、总黄酮、总酚含量。

And 100%, respectively, under optimized reaction conditions. The existence of electron-donating groups on the benzene ring would enhance the activity of phenols.

使用苯酚作反应底物考察了各因素的影响，在优化的反应条件下，苯酚的转化率可达到99.8％，产物苯甲醚的收率高达99.8％。

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。

Results show that the antibacterial component belongs to volatile oil、sesquiterpene、phenols and organic acids. The antibacterial part of the broth was isolated by silica gel column and 6 fractions of obviously antibacterial activity were obtained .By further study Fractions 1、2、3 contain sesquiterpene and fractions 8、9 contain phenols and fraction 10 contains phenolic organic acid.

对发酵液抑菌成分的研究表明，抑菌活性成分组成为挥发油倍半萜、酚和有机酸等类化合物，采用硅胶柱层析对发酵液抑菌活性部位进行分离实验，得到了6个具有明显抑菌活性的粗组分（组分1、2、3、8、9、10），其中组分1、2、3含有倍半萜类物质，组分8、9含有酚类物质，组分10中有含酚羟基的羧酸类物质。

OrthoSubstituted phenols gave the para-para-coupling products and para-substituted phenols gave the ortho-ortho-coupling ones, while hindered phenol gave the corresponding oxidative coupling product.

该氧化偶联反应的反应条件温和、产物易于分离、收率高，可作为有机合成中某些碳-碳键形成的新方法加以应用。

The main structure of Phenolic resin curing is a three-dimensional network linked by methylene between phenols.It is shown in the process of thermal degradation that the thermal degradation of phenols and methylenes,and degradation product of gas small-molecule is a little;While the character of the epoxy resin molecule structure is that the milecule chains contain lively epoxy group,which can be at the end ,middle of the molecule or forms rings structure.

酚醛树脂固化物的主要结构为苯酚之间通过亚甲基连结的一种三维体型网络，因此在热降解过程中主要表现为酚基和亚甲基的热降解，降解后气态小分子产物很少；而环氧树脂的分子结构是以分子链中含有活泼的环氧基团为其特征，环氧基团可以位于分子链的末端、中间或成环状结构。

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。

But some academician considers that phenols are not the cause of soil degradation, in contrast, some of phenols afford protection to the growth of plants.

而一些学者认为，酚类物质并不是引起地力衰退的主要原因，相反，某些酚类物质对植物的生长具有保护作用。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。