酯化值

Methods: We divide the rats into 5 groups in random, with Morris method, detect the change of some active oxygen radicals such as super-oxide demitasse, Nitric Oxide Synthase, malondialdehyde etc. Also, we detect the change of cholinesterase, Monoamine Oxidize; using HE,PAS staining, immuno-histochemical technique, detect hippocampus CA1 cerebral pathology slices optical density value of NOS, CHE and lipofuscin of neural cell; detecting apoptosis rate and the expression of P53 , which are neuronal apoptosis related genes.

大鼠随机分为5组，采用"Morris水迷宫"法观察脑缺血性模型大鼠学习记忆功能，检测超氧化物歧化酶、一氧化氮合酶、丙二醛等自由基代谢异常的改变，检测胆碱酯酶、单胺氧化酶等老化相关酶的变化、脑组织神经细胞免疫组织化学技术、检查海马CA1区脑组织的病理切片，检测NOS、CHE光密度值；流式细胞技术：检测细胞凋亡率，及促细胞凋亡基因、P_(53)蛋白表达；病理切片采用HE染色、PAS染色及免疫组化法检查，检测对大鼠海马神经元细胞一般病理变化及脑细胞内脂褐含量。

The affections on the yield of DLLA caused by catalyst, temperature and time etc. were studied. By using ethylene glycol as diluent, the distillate temperature of DLLA was lowed and the carbonization phenomenon could be avoided, which caused the yield of DLLA increasing from 36.8% to 51.3%. The molecular weight of PDLLA prepared by this method could reach 184,000. DLLA and PDLLA was characterized and analyzed by DSC, XRD and IR.The key of direct method to synthesize PDLLA is the exclusion of H2O from reaction system.

丙交酯开环聚合制备PDLLA的关键在于中间体D，L-丙交酯的制备，研究了催化剂、反应温度、反应时间等因素对DLLA产率的影响，通过在反应体系中加入稀释剂乙二醇，DLLA的馏出温度明显降低，避免了DLLA在蒸馏过程中产生碳化现象，并使DLLA的平均产率由36.8％提高至51.3％，制备的PDLLA分子量最大值达18.4万。

In order to test the validity of this method, the saponification of methyl acetate, ethyl formate and methyl formate in aqueous solution at 25℃ has been studied.

研究了25℃下乙酸甲酯、甲酸乙酯和甲酸甲酯在水溶液中的皂化反应，其计算结果与文献值相吻合，从而验证了热弛豫法的正确性。

Compounds 3a-3d, 4a-4d, 5a-5d, 6a-6e and 7a-7e were prepared with a new efficient method, in which the aromatic amines were diazotized with isoamyl nitrite in EtONa/EtOH under refluxing condition, and mono -, bis -and tetrakis -substituted calix [4] arenes were obtained respectively as main product by diazo-coupling in different molar ratio to calix [4] arene.

一，提出了一个有效的新方法合成含有芳香偶氮基团的杯[4]芳烃衍生物3a-3d；4a-4d；5a-5d；6a-6e和7a-7e：即在非水溶剂乙醇中用亚硝酸异戊酯，在强碱乙醇钠存在下对芳香胺进行重氮化，得到芳香重氮酸盐沉淀，过滤，然后加入杯[4]芳烃的四氢呋喃溶液，通入CO〓气体调节溶液的pH值为7-9，使其发生偶联反应。

The stability of immobilized ECE on pH, temperature and operation were improved.

固定化酯酶的最佳pH值和温度分别为10.5和50℃。

Two-component waterborne polyurethane paint composed of acrylic dispersion and hydrophilically-modified polyisocyanate has fast dry time, good adhesion, flexibility, impact resistance, but poor water and chemical-resistance. The dry time becomes shorter with the increase of glass transition temperature and the decrease of acid value; the gloss of the film decreases with the increases of hydroxyl value, acid value and Tg of emulsion polymer; higher Tg polymer leads to harder film.

将制得的丙烯酸分散体与亲水改性多异氰酸酯组分配制水性双组分聚氨酯涂料，发现漆膜表干和实干比较快，干燥时间随玻璃化温度升高而缩短，随酸值的增加而增加；附着力、柔韧性和冲击强度比较好；光泽随分散体羟值、酸值的增加和玻璃化温度升高而降低；硬度随玻璃化温度升高而升高；较高的酸值使涂料的耐化学品性和耐水性较差，羟值在100mgKOH/g时较好，而酸值应尽可能低。

All process factors that influence the composite thermochomic materials including the molar ratio of ester to water, pH value, reaction temperature, aging temperature, the dosage of thermochomic materials were carefully researched to have successfully acquired the optimal formulation.

重点研究了制备工艺各因素如酯水摩尔比、pH值、反应温度、陈化温度和变色材料用量等对热敏变色复合材料的影响，得出最佳工艺。

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。

Technology of sulfuric acid catalyzed ethyl esterification of high acid value tuna oil was studied.

以浓硫酸为催化剂，对高酸值金枪鱼油进行了乙醇酯化工艺的研究。

In addition, 65% ee was obtained for 1, 3-dimethylprop-2-enyl acetate. Interestingly, the reactivities of these ligands are all very high.

对于1， 3-二苯基烯丙基醋酸酯的烷基化和胺化反应， ee 值最高分别为93%和98%，此外，在对1， 3-二甲基烯丙基醋酸酯的烷基化反应中 ee 值最高也可达65%。

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。