酯

People in natural Pyrethrum ester chemical structure on the basis of a variety of pyrethroid insecticides, but the validity of these pesticide residues are short and easy solutions for optical characteristics.

人们在天然除虫菊酯化学结构研究的基础上合成出了多种拟除虫菊酯杀虫剂，但这些杀虫剂均有残效期短和极易光解的特点。

On the other hand, 3(2)-fluoro-4-methoxyl methyl benzyl alcohol and 3(2)-fluoro-4-methyl benzyl alcohol are mixture and components of pyrethrum esters. Both of them have "mixture fluorine effect " and higher activity, lower drug resistance. As we know, the mixture benzyl alcohol containing fluorine is more easy to be synthesized than the single, so the cost of preparation is lower. We hope to apply it to molecule design of the new agriculture chemical. On the base of molecule design and structure-activity relationship research of pyrethric acid II and mixture of alcohol containing fluorine, we intend to get new pyrethrum ester that have higher activity and lower resistance.

另一方面，混合含氟对甲氧甲基苄醇和混合含氟对甲苄醇都是具有"混合氟效应"的高活性、低抗性的拟除虫菊酯醇组分，由于混合含氟醇的合成要比单一异构体的合成容易，成本较低，本文希望将其应用到新农药的分子设计中，用第二菊酸和一些含氟醇进行分子设计及进一步的构效关系的研究，筛选出一些高活性低抗性的拟除虫菊酯换代新品种。

Results Eleven compounds were isolated and identified as:quercetin(1),kaempferol(2),quercitrin(3),protocatechuic acid(4),gallic acid(5),protocatechuic acid ethyl ester(6),ethyl gallate(7),vanillic acid(8),1,5,7-trihydroxyl-3methylan...

结果得到11个化合物，分别鉴定为：槲皮素(1)、山柰酚(2)、槲皮苷(3)、原儿茶酸(4)、没食子酸(5)、原儿茶酸乙酯(6)、没食子酸乙酯(7)、香草酸(8)、1，5，7-三羟基-3-甲基蒽醌(9)、琥珀酸(10)、5-羟甲基糠醛(11)。结论化合物6、7、9、11为首次从该属植物中分离得到。

Presented in this article is a report of synchronous determination of acetylcholinesterase and butyrylcholinesterase in finger blood established on the basis of the regression equation (Y = 0.149 8X+22.483 5) where hemoglobin is highly correlated with hematocrit (r = 0.999 2, P.001), with quinidine sulphate as the specific inhibitor of BChE.

本文根据全血的血红蛋白含量与红细胞压积容量的高度相关性的回归方程式(Y=0.149 8X+22.4835)，以及用硫酸奎尼丁作为丁酰胆碱酯酶的特异性抑制剂，建立了指血乙酰胆碱酯酶和BChE活性的同步测定法。

Their infrared spectrum changes under UV-irradation and in the heating process have been monitored by ATR-FTIR. Then the aging mechanism has been induced by the infrared spectra before and after aging and their difference spectra. In the condition of UV-irradiation, the polyurethanes degrade to quinoid structures or azo-compounds, which is why polyurethanes' color can easily become yellow.

在紫外线照射下，聚氨酯类有机高分子涂料降解生成偶氮化合物或醌式结构，这也是聚氨酯老化颜色易变黄的原因；丙烯酸类有机高分子涂料降解机理为酯基断裂、形成稳定性较好的内酯，同时伴随侧链断裂的反应。

And Cucumis sativus L. were tested by bioassay-guided separation. The extracts from P. tomentosa flower with ethanol were extracted with petroleum ether, ethyl acetate and n-butanol. The inhibition rate of the ethyl acetate extract to growth of the 3 kinds of plant radicel were 99.89%, 63.53% and 32.74% respectively at 0.5 mg/mL concentration, and that of petroleum ether were 76.30%, 56.17% and 23.36%.

绒叶泡桐Paulownia tomentosa花乙醇提取物依次用石油醚、乙酸乙酯、正丁醇和水萃取后进行活性测定，结果表明，石油醚萃取物在浓度为0.5mg/mL时，对反枝苋、生菜和黄瓜种子胚根生长的抑制率分别为76.30%、56.17%和23.36%；乙酸乙酯萃取物在浓度为0.5mg/mL时，对反枝苋、生菜和黄瓜种子胚根生长的抑制率分别为99.89%、63.53%和32.74%。

The influence of the addition of element S of vulcanization reaction,the ester-exchange agent/rape seed oil of ester-exchange reaction and the R-OH/ P_2O_5 of phosphate re...

试验考察了硫化反应的硫化剂添加量、酯交换反应的交换剂与油的摩尔比以及磷酸酯化反应的R—OH与P2O5的摩尔比对产物结构和性能的影响。

Thus, in industry it is easy to determine the BA level in vaporized solvent through saponif ication and calculate the BA level in resins with the regression equation. Finally to obtain the residual monomer level simply through reduction formula.

这样，在工业生产中就可通过皂化法方便地测得蒸出少量溶剂中的丙烯酸丁酯的含量，再利用回归方程算得树脂中的丙烯酸丁酯含量，最后简单换算出丙烯酸-氨基漆中残余单体的含量。

The effects of molar ratio of linoleic acid and ethanol, temperature , and amount of ionic liquid on esterification reaction were studied and the optimal reaction conditions were obtained, that is, n :n = 4:1 , at refluence temperature, with the amount of ionic liquid equaling 42wt.

研究了环境友好的BF4离子液体催化亚油酸等高碳脂肪酸与无水乙醇酯化反应，考察了亚油酸与乙醇的摩尔比、反应温度、离子液体用量等条件对亚油酸酯化反应结果的影响，优化了反应的工艺条件。

By employing such a method, 5 series of elastomers, including natural rubbers, elastomeric polyester fibers and ethylene-octene, ethylene-methyl acrylate as well as SIS triblock copolymers, were investigated with the purpose of studying elongation induced phase structure and mobility changes of the samples. For NR samples, it was demonstrated that there exists a small amount of crystals at RT even for unelongated samples. For both NR and the soft segment of PEE, with the increase of elongation ratio, the elongation-induced crystallinity increases almost linearly in a certain region of R, in accord with the increase of the lamellar thickness of the crystals; The behavior of ethylene copolymers, in terms of elongation induced morphorpholgy changes, are quite different from NR and PEE. The crystals are found to be gradually destroyed with the increase of R, with accord with the decrease of the lamellar thickness; The motional behavior of the soft segment of SIS, changes from "liquid" to "solid", in terms of 13C NMR spin-lattice relaxation.For many of the aformented samples, the dependence of 13C spin-lattice relaxtion time T1 on R are different for different groups, indicating that the changes of mobility at MHz frequency region with elongation are different for different groups.

通过对天然橡胶、聚醚酯嵌段共聚物、乙烯-辛烯共聚物、乙烯-丙烯酸甲酯共聚物、SIS等高分子弹性体样品聚集态结构和分子运动的研究，获得了一些新的实验结果，如：给出了确切的实验证据，证明了室温下未拉伸的天然橡胶样品中存在着微量的结晶；发现随着拉伸比增加，天然橡胶及聚醚酯样品的软段部分会出现拉伸诱导的结晶，且结晶度在一定范围内呈现近似线性的增加，所形成晶片的厚度也随之逐渐增加；而乙烯共聚物随着拉伸比的增加，原有的结晶会被逐渐破坏，晶片厚度逐渐变薄，结晶中的缺陷逐渐增加；随着拉伸比的增加，SIS中PI软段部分的核磁共振弛豫行为会出现从液态到固态的转变等；在对上述多个体系的研究中，还发现不同基团的自旋-晶格弛豫时间随着拉伸比呈现不同的变化趋势，表明不同基团的高频运动随拉伸比增加有不同的变化规律。

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。