乙酰化值

This article introduces a simple method, which is acetylation method, to determinate the hydroxy content in petroleum oxidation products.

文章介绍了一种测定石油氧化物中羟值的简便方法——乙酰化法。

It is found that when the molar ratio of sulphoxide,pyridine and acetyl bromide is 1∶0.6∶0.4,the catalytic effect on the ring-enlargment is the best,and the yield and purity of the final product can reach 76% and 97% respectively at a pH of 1.8 in toluene under refluxing for about 3.5h.

通过正交实验可得出以下结论：当N，N′-双脲-亚砜为2.5∶1，乙酰溴-亚砜为0.4∶1，吡啶-乙酰溴为1.5∶1，回流时间为3.5h，酸化pH值为1.8时，扩环反应结果最好，总收率可达76%，纯度97%以上。

Then we compared cleavage rate and blastocyst rate among different groups. After that we evaluated the quality of blastocysts by using ICM/TE (Inner cell mass/Trophectoderm cells) ratio via staining with propidium iodide and Hoechest333258, and analyzed the level of genome methylation and histone acetylation by immunofluorescence.

比较各组受精卵的卵裂率和囊胚发育率；并应用碘化丙啶和Hoechest333258对囊胚进行染色，利用ICM/TE值评价各组胚胎体外发育的质量；同时将囊胚进行免疫荧光染色，观察其基因组甲基化和组蛋白乙酰化的水平。

acetyl chloride, a novel fluorescence derivatization reagent, has been developed for the determination of sterols and stanol .

采用荧光衍生化试剂2-(9-咔唑)乙酰氯，对天然产物谷甾醇、豆甾醇、菜油甾醇及谷甾烷醇的柱前衍生化条件，包括催化剂的种类、反应温度、衍生化时间等进行了考察，结果表明：催化剂选用三乙胺，反应温度80℃，时间20min，衍生产物具有恒定的最大检测响应值。

Three methods for the preparation of 1,2,4-trizolone~5 are provided. 22 compounds are prepared. 3, 4-disubstituted 1,2,4-trizolone-5 is prepared by reacting amide with ethyl hydrazine-fornate at 110癈 for 3h in the presence of phosphorus oxychloride, following neutralization and cyclization reaction, giving to 74.5 % yields,which is 30% more than the literature value.

以三氯氧磷为缩合剂，使酰胺和肼基甲酸乙酯在110℃反应3h，经碱中和、环化反应，合成3，4-二取代-1，2，4-三唑酮-5，两步反应总产率达74.5％，与文献报道值相比，高出了30％以上，在三唑酮类衍生物的合成方法中具有很大的突破性。

Then dendrimer-like polyamidoamine s based on the silica gel surface were prepared using Micheal addition of the amino and methyl acrylate,and ester-exchange of ethylene diamine and the ester group.

用硅烷偶联剂对硅胶表面进行氨基功能化，利用氨基与丙烯酸甲酯发生的Michael加成反应和乙二胺与酯进行的交换反应在硅胶表面合成了聚酰胺-胺树状大分子；利用红外光谱对PAMAM-SG的结构进行了表征，研究了溶液pH值、ρ(Ni2+)和温度对PAMAM-SG吸附Ni2+能力的影响。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。