基于正交实验的实验室脱水制乙烯实验改进

设计装置简单、操作简便、安全性高、现象明显、高效高产的实验室脱水制乙烯实验。并以乙醇的用量、反应火候、乙醇与火焰的距离为变量,设计正交实验,在保障产率的同时,探究实验室脱水制乙烯新方案的最佳演示实验效果。     

TiCl4溶胶凝胶法制备TiO2纳米粉体

利用TiCl4的乙醇溶液作为前驱体 ,运用溶胶凝胶法制备了TiO2 纳米粉体 .研究结果表明 ,在TiCl4与乙醇混合成溶液的过程中 ,TiCl4即与乙醇及乙醇中的微量水发生醇解和部分水解脱氯反应形成钛酸酯 .在随后的成胶化过程中 ,则主要是钛酸酯吸收气氛中的水气 ,脱去乙醇基形成Ti-OH键并发生缩脱水聚合形成无机聚合物溶胶 .增加成胶化时间 ,可以促进乙醇基的脱去和无机聚合物的形成 ,促进锐钛矿TiO2 纳米颗粒的形成     

HZSM-5催化乙醇脱水停料效应的研究

在HZSM-5分子筛催化乙醇脱水反应中观察到了停料效应：即当停止乙醇-水进料一定时间,恢复进料后乙烯选择性明显提高。通过考察不同反应条件下的停料效应,发现乙醇质量分数控制在55%附近、延长停料时间、升高反应温度和降低乙醇进料空速会提高停料效应强度,并较长时间维持高乙烯选择性。500 h的催化剂稳定性测试表明,停料效应可有效延长催化剂的使用寿命。结合含水乙醇脱水反应机理和实验结果,推测HZSM-5催化乙醇脱水停料效应产生的原因是停料时乙氧基中间体的积累和催化活性空位的再生。     

乙醇氧化脱氢实验的深度研究

通过实验验证和理论分析,说明教材乙醇脱氢反应的实验设计存在不足。分析研究乙醇的2种脱氢方式,认为使用氧化铜欠妥,在此基础上提出了较为科学、合理的实验设计。     

乙醇脱水演示实验问题的教学探究

对苏教版中乙醇脱水制取乙烯的演示实验中存在的问题进行了研究,改进了实验条件,提出了更合理的实验方案:采用磨口有机玻璃仪器,调整反应物之间的投料比,使用气压差方式等进行有害气体的吸收,体现绿色化学的实验理念,使课堂教学焕发出新的生机和活力。     

乙醇脱水制备乙烯综合性实验设计

从实验设计的思路、实验目的、实验设备、实验操作流程、实验思考题、实验数据记录和实验结果的处理等方面介绍乙醇脱水制备乙烯综合性实验的设计与实现过程.     

聚酰亚胺中空纤维膜的脱湿性能以及在乙醇气相脱水过程中的应 …

采用聚酰亚胺和碘化聚芳醚砜共混改性的中空纤维膜,研究了在不同操作条件下对压缩空气的脱湿性能,并以此作为吹扫气源,研究了在气流吹扫操作方式下蒸汽渗透法乙醇气相脱水过程,实验结果表明,膜的脱水性能与膜材料的亲水性有关,控制共混比例可以得到综合性能优良的气体脱湿膜。     

五氧化二磷使乙醇脱水的实证探索与反思

通过实验探究和文献分析,说明五氧化二磷具有强脱水性,它与乙醇反应生成磷酸氢乙酯和磷酸二乙酯,不是乙醇脱水的催化剂,分析了造成人们错误认识的原因。     

对五氧化二磷催化乙醇脱水反应的研究

研究了不同反应条件下用P2O5催化乙醇脱水反应的情况,并用GC和GC-MS方法检测反应产物。为苏教版《有机化学基础》教材中“认识乙醇的脱水反应”提供教学参考。     

对测定乙醇分子结构实验的改进

高二课本测定乙醇分子结构的实验,我们按照课本、作了多次实验,结果所产生的H2体积都比理论量少,难以说明乙醇分子仅有一个与众不同的活泼氢原子。以下把我们几次实验的记录列下:为什么产生H2体积都偏低呢?     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...