铁与水蒸气反应的实验改进

新人教版必修1中“铁与水蒸气反应”的实验,该实验装置虽简单易操作,但实验成功率很低,故笔者对该实验装置进行了小改进,设计了一种实验装置同样简单易操作,但实验现象更明显,实验成功率更高的实验装置。     

浓硫酸性质实验的整合创新设计

对浓硫酸的几个性质(吸水性、脱水性、强氧化性、遇水放热性、催化性)实验进行了整合创新设计, 解决了教材实验中的药品耗量大、不易操作、药品易撒落、易污染水源、耗时长、不适合学生分组实验等缺点。整合创新后设计的实验不仅操作简便、体现绿色实验理念, 而且操作安全, 适合中小学生开展课外活动。     

乙酸乙酯制备实验的微型化改进

针对教材中乙酸乙酯制备实验的不足,结合自身实践,使用真空采血管设计微型减压蒸馏装置用于制备乙酸乙酯。通过实验证明,该装置安全高效、实验效果好、简便易携。     

凝固点降低法测定摩尔质量实验的改进

针对过冷程度控制,对搅拌装置作了改进:上端带鼓气球(捆紧)的玻璃弯管通过鼓气搅拌。改进后,搅拌方便简单、速度易控制、过冷现象明显、最高温度易观察、数据准确、满足了实验的要求。     

溴乙烷消去反应不宜采用演示实验进行教学

针对中学化学溴乙烷消去反应演示实验教学存在实验条件下反应复杂、演示实验反应方程式的表达与事实不符、实验现象易误导学生3个方面的问题,阐述了由于中学生思维方式和知识水平的局限,中学化学中溴乙烷消去反应内容的教学不宜采用演示实验。     

基于可见光催化分解水制氢的物理化学综合实验设计

将可见光催化分解水制氢引入物理化学综合实验,系统介绍了催化剂制备、表征及光催化反应性能评价等实验内容.以无毒、易制备的g-C3N4作为实验用可见光催化剂,考查了制备温度对催化剂的结构及光催化性能的影响.     

氨气的制取和性质实验的绿色化研究

用氧化钙与氯化铵反应制取氨气,并将氨气的制备、收集和性质实验组合设计,形成半封闭装置,有效防止了传统方法中试管易炸裂、污染环境和危害人体健康等弊端。该实验方法操作简便、时间短、成功率高,是一种无污染、经济易行的绿色化学实验。     

新课标中钠在空气中燃烧实验的探究与改进

为解决新课标《化学1(必修)》和普通中学化学教科书中钠燃烧实验存在的玻璃管易破裂、现象不易观察以及空气污染等问题,对该实验的装置、材料和演示方法进行了探讨,设计了在封闭的装置里进行钠燃烧实验的新方案,取得了良好的实验效果.     

无溶剂条件下研磨促进的Michael加成反应——推荐一个新的半微量有机化学实验

采用研磨促进环己酮与查尔酮Michael加成反应的手段新颖,实验时间短,产率高,使用的反应容器简单,操作方便易实现,试剂用量少,是一个半微量有机实验,便于实现实验的系列化,节约实验开支。     

粉尘爆炸实验的简单易行的2种改进

用简便易寻的生活废品,组成了简单的装置,简化了人教版初中化学教材的疑难实验粉尘爆炸的操作,进行的2种对于粉尘爆炸实验的改进达到了目前此实验的最佳效果。     

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。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。