乙酸乙酯

The wall-broken Cole bee pollen lOOg is extracted by 1:10 of anhydrous ethanol , continuously stirred in darkness for two hours. And then by means of centrifuge, cleaning, vacuum concentration, adjusting pH value, anion exchange resin chromatography, propanone extraction,being blown to dry and freeze-dried, we use HPLC to detect the content of the GA derivative of the freeze-dried powder.

将破壁油菜蜂花粉100g，在避光条件下用无水乙醇(料液比1：10)连续搅拌浸提2小时，浸提液经离心、洗涤、真空浓缩、pH值调节、阴阳离子树脂交换、乙酸乙酯萃取、吹干再冻干后用HPLC法分析，得冻干样品中赤霉素衍生物的含量为51.29％。

At the initial isolation to the extract from ethyl acetate, tow kinds of crystal a and b with higher purity were found, and the primary components were 98.45%. Quinic acid and 69.34% L-Proline, 5-oxo-, methyl ester.

在乙酸乙酯部分进行初次分离时，还得到了两种纯度较高的晶体a和b，经GC-MS分析可知其主要成份分别为98.45%奎宁酸和69.34%的5-脯氨酸甲酯。

The insecticidal activities of the ethanol extracts and 5 kinds of extracts with petroleum ether, chloroform, ethyl acetate, n-butanol, aqueous from Rubia cordifolia L. against wolfberry aphis was investigated.

采用点滴法，测定了茜草乙醇提取物和石油醚、氯仿、乙酸乙酯、正丁醇和水5种不同极性萃取物对枸杞蚜虫的触杀活性。

The antibacterial activity of acetate ethyl in the root bark of Chinese sapium was investigated.

［目的］研究乌桕根皮乙酸乙酯部位的抑菌活性。

Results The results showed that the material with the antibacterial activity in sapium root bark primarily was in the part of large polarity, but there was antibacterial activity in the material of the methanol elution with larger polarity; and the inhibitory components of the soluble material of ethyl acetate was complex and the different parts had the variable inhibition to different bacteria and in general these materials had a certain inhibition to Staphylococcus aureus and Escherichia coli.

结果］乌桕根抑菌活性物质主要存在极性较大的部分，但极性很大的甲醇洗脱部分也没有抑菌活性；乙酸乙酯可溶部抑菌成分较复杂，不同部分时不同细菌的抑制作用不同，总体来说对金黄色葡萄球菌和大肠杆菌有一定的抑制作用。

The repellent action and contact action of the extracts of 21 species of plants to adult maize weevil, Sitophilus zeamais Motschulsky were studied.

为了筛选对粮库安全的植物源杀虫剂，研究了21种植物的4种溶剂(无水乙醇、丙酮、乙酸乙酯和石油醚)提取物对玉米象Sitophilus zeamais Motschulsky的驱避和触杀作用。

In chapter 3, 83 volatile chemical constituents have been identified from the petroleum ether extracted part of ethanol extract of Debregeasia longifolia Wedd., and the relative percentages of the compounds are determined by GC method. From the extract of trichloromethane and ethyl acetate, 8 compounds have been isolated.

第三章首次对长叶水麻乙醇提取物的石油醚萃取部分分离并鉴定出83种成分，并用毛细管气相色谱面积归一化法测定了各组分的相对百分含量；从氯仿和乙酸乙酯萃取部分分离得到了8种化合物，用波谱学方法鉴定了其中2种成分。

Five species of solvents, namely, acetone, ethyl acetate, ether, trichloromethane and petroleum ether were selected to obtain extracts from Portulaca oleracea L. with microwave assistance and the biological activities of each extract was tested against Plutella xylostella L.

在微波加热条件下，以丙酮、乙酸乙酯、乙醚、三氯甲烷和石油醚为溶剂对马齿苋干粉进行提取，试验了各溶剂提取物对小菜蛾幼虫的触杀、胃毒及拒食活性，确定了石油醚提取物触杀作用的LD50。

Properlies It is yellow Powder with little osmyland taste bitter. The density is 1.42-1.52. Soluble in ethylacatate, ethanol,solution of NaOH and Na2co3, unsoluble in benzene, water and gasoline.Good storage stablility.

性状 淡黄色粉末，微臭，有苦味，无毒，比重1.42-1.52，熔点170以上，易溶于乙酸乙酯，丙酮，氢氧化钠及碳酸钠的稀溶液中，溶于乙醇，不易溶于苯，不溶于水和汽油，贮存稳定。

The inhibition effect of chloroform fraction was the most potent, with the inhibition rate about more than 83% to 5 plant pathogenic fungi under the concentration of 15mg/mL. Under the concentration of 15mg/mL, the ethyl acetate fraction and n-butanol fraction thoroughly inhibited the growth of Alternaria solani and Valsa mali, with the inhibition rate up to 100%. The n-butanol fraction showed the highest potent virulence, with EC50 to Alternaria solani and Valsa mali about 0.09 and 0.279 mg/mL respectively.

其中氯仿部分的抑菌效果较好，当质量浓度为15mg/mL时，其对5种植物病原菌的抑制率均在83%以上；15mg/mL乙酸乙酯部分和正丁醇部分分别对番茄早疫病菌和苹果腐烂病菌有强烈且稳定的抑制作用，抑制率达100.00%，正丁醇部分对这两种菌丝生长抑制毒力最好，EC50分别为0.090和0.279mg/mL。

If you are committed to an education career, then the Master of Arts in Education from Ashford University is for you.

如果你是致力于教育事业，那么，艺术教育硕士学位阿什福德大学是给你的。

objective:to explore the expression of survivin protein and its mrna in rectal cancer and their clinic significance.

目的：研究凋亡抑制因子survivin蛋白及其mrna在直肠癌组织中的表达及其与临床病理关系。