Polarographic study of the acid hydrolysis of ketoximes

Kinetics of the acid hydrolysis of acetophenone exime and its substituted compounds have been investigated polarographically. A detailed study of the hydrolysis of acetophenone oxime in 0·05–1·0 M HCl indicated that the rate determining step varied with acid concentration. The reaction in acid concentrations below 0·3M is catalysed by hydrogen ions while general base catalysis by water is predominant in high acid concentrations. Addition of methanol is found to decrease the rate of hydrolysis predominantly.     

Solvent influences in the alkaline hydrolysis of esters in aqueous ethanol

The rate data for the alkaline hydrolysis of a number of monoesters, diesters and lactones have been obtained in varying compositions of aqueous ethanol. The application of the Amis and Laidler-Landskroener equations to the data yields reasonable values for the parameters representing the radius of the transition state for the hydrolysis confirming the ion-dipole nature of the reaction. An attempt to explain the rate data on the basis of the solvation requirements of the transition state has been made.     

Search for physiologically active compounds

A number of 3-(3-pyridyl) coumarins with and without 4-methyl substituent have been prepared following Oglialoro and modified Perkin reactions. These compounds have been tested against fish and bacteria. Of all the compounds tested, 7-bromo-4-methyl-3-(3-pyridyl) coumarin exhibited maximum activity. A few have also shown bacteriostatic activity.     

Phonon dispersion relations,effective interionic potential and liquid resistivity of Al

Phonon dispersion relations and effective interionic potential for solid Al are calculated using the nonlocal optimized model potential of Shaw screened with the improved self-consistent dielectric function of Vashishta and Singwi. A very good agreement is obtained between the calculated and experimental phonon frequencies. Comparison is made using three other dielectric functions. It turns out that in Al the interionic potential is very sensitive to the screening function. Also electrical resistivity of liquid Al has been calculated using the model potential when screened with the four different dielectric functions. Influence of the spatial distribution of depletion charge at the ion site is discussed. A comparative study of nonlocal and local potentials by taking two local potentials: (1) modified point-ion, and (2) empty core, screened with the self-consistent dielectric function, is also presented.     

醛类分子的拉曼光谱研究

应用便携式拉曼光谱仪,采集了四种醛类分子(GnH2nO,n=1,2,3,4)的拉曼光谱,并通过量子化学中密度泛函理论(DFT)对四种醛类分子进行了分子模型构建和理论拉曼光谱模拟计算.通过实验拉曼光谱和DFT模拟计算结果的对比,对四种醛类分子的特征振动峰进行了指认.同时对四种醛类分子的实验光谱进行了分析比较.应用便携式拉...     

农产品外部品质无损检测中高光谱成像技术的应用研究进展

高光谱成像技术是一种传统图像及光谱的融合技术,可以同时获取研究对象的空间及光谱信息.由于图像数据能反映农产品的外部特征、表面缺陷及污斑情况,而光谱数据又可以对物体内部物理结构及化学成分进行分析.因此,近几年在农产品品质无损检测中引起越来越多的关注,成为一个研究热点.为了跟踪国内外的最新研究成果,对高光谱反射及荧光成像技术应用于农产品(水果、蔬菜、肉类、谷物等)的外部品质检测进行了分类综述,以期为高光谱技术在农业方面更广阔的应用提供参考.