On the Strategy of NMR Spectral Analysis. The 1H-NMR Spectrum of Amphetamine

The successive steps of the computer analysis of a NMR spectrum are examined. Better results can be obtained by direct simulation of tentative model spectra. As an example the ¹H-NMR spectrum of amphetamine is analysed.     

Nanoindentation Experimental Approach and Numerical Simulation of Al/Cr Bilayer Films

The Al/Cr double-layer film structure samples (thickness, 1200 nm) were prepared by the magnetron sputtering method. To investigate the mechanical properties, the samples were measured by using a nanoindentation instrument. The test results showed the nonlinearity and different modes of the main mechanical properties by comparing the macro-scale structure samples with other samples of similar materials. Based on the test, the elastic modulus and hardness of thin film structures can be calculated by considering different loads to conduct multi-point indentations. Meanwhile, the relationships between the mechanical parameters can be investigated based on these Al/Cr double-layer film structure samples. To validate the test, numerical analysis was developed using a finite element method to simulate the loading and unloading process of indentation. The simulation results were compared with the results of experiments to illustrate the validity of both the test and simulation to a certain extent. The investigation builds not only an experimental basis for practical applications for future study, but also supplies a complementary means of verification for theoretical analysis.     

双－苯并噻唑非环冠醚的合成与表征

2-巯基苯并噻唑(MBT)与二溴缩甘醇在碳酸钾存在下发生S-烷基化反应生成双－苯并噻唑非环冠醚化合物1～4,并通过元素分析、IR、NMR(^1H,^13C)、MS波谱进行结构表征。     

P[(NH3)5CoimM(tren)](ClO4)4·2H2O[M=Cu(II), Zn(II)]的合成、表征及咪唑桥的断裂

本文合成了两个新的异双核咪唑桥联配合物[(NH3)5CoimM(tren)](ClO4)4·2H2O[M=Cu(II), Zn(II); im=咪唑基], 用热重差热、反射光谱、ESR等手段进行表征, 证实咪唑桥的存在, 用PH法结合计算机拟合, 定量地模拟了异双核配合物中咪唑桥的断裂过程, 表明在水溶液中, 金属-咪唑键首先从非钴(III)端断裂。     

超氧化物岐化酶的模拟: 大环双核铜(II)配合物中咪唑桥的稳定性

以2,6-二乙酰基吡啶与3-氧杂戊烷-1,5-二胺缩合而成的二四元环配体, 合成了以咪唑为桥基的双核铜(II)配合物。用EPR和pH滴定分别研究了在50%DMSO和水溶液中桥基稳定性。实验结果表明: 在混合溶液中桥基稳定的pH范围为5.6-10.3, 在水溶液中pH范围为7.5-10.5, 当pH>10时, 羟基取代了咪唑桥。由于大环效应使配合物的咪唑桥能在较宽的pH范围内稳定存在。     

LiF-KF熔盐溶液局部结构的计算机模拟研究

本文用Monte Carlo法对同离子系LiF-KF熔盐溶液的局部结构进行了计算机模拟,介绍了计算方法和模型。计算了LiF, KF及Lif-KF混合前后正-正离子, 正-负离子, 负-负离子间位能变化, 各类离子的近邻离子排布规律, 以及各种形式离子团的组成比例。本文还讨论了在熔盐瞬时结构中存在的静电场的微区涨落。     

ZnCI~2-KCI系溶液的分子动力学模拟

用Busing离子间势,对ZnCI~2-KCI 系熔盐液的结构作分子动力学计算机模拟研究,模拟结果与中子衍射,X射线衍射,Raman光谱和红外光谱的若干结构相符.     

不同温度下熔融NaCl的分子动态学计算机模拟

用分子动态学方法对不同温度下的熔融NaCl进行了模拟计算, 得到了被模拟系统的偏径向分布函数、结构因子、配位数、马德隆常数以及Na^+和Cl^-的自扩散系数等。计算值与实验值大体符合。据此,还讨论了熔体的结构。     

Numerical simulation of micro-scratch tests for coating/substrate composites

In this paper the micro-scratch test is simulated by ANSYS finite element code for thin hard coating on substrate composite material system. Coulomb friction between indenter and material surface is considered. The material elastic-plastic properties are taken into account. Contact elements are used to simulate the frictional contact between indenter and material surfaces, as well as the frictional contact after the detachment of coating/substrate interfaces has taken place. In the case of coating/substrate interfaces being perfectly bonded, the distributions of interfacial normal stress and shear stress are obtained for the material system subjected to normal and tangential loading. In the case of considering the detachment of interfaces, the length of interfacial detachment and the redistribution of stresses because of interfacial detachments are obtained. The influences of different frictional coefficients and different indenter moving distances on the distributions of stresses and displacements are studied. In the simulation, the interfacial adhesion shear strength is considered as a main adhesion parameter of coating/substrate interfaces. The critical normal loading from scratch tests are directly related to interfacial adhesion shear strengths. Using the critical normal loading known from experiments, the interfacial adhesion shear strength is obtained from the calculation. When the interfacial adhesion shear strength is known, the critical normal loading is obtained for different coating thicknesses. The numerical results are compared with the experimental values for composite materials of thin TiN coating on stainless steel substrate.     

Investigation of the electro-oxidation and oxidation of catechol in the presence of sulfanilic acid

The electrochemical oxidation of catechol (1) in the presence of sulfanilic acid (2) was investigated. Some electrochemical (EC) techniques such as cyclic voltammetry and controlled-potential coulometry were used. The oxidation reaction of catechol (1) with periodate in the presence of sulfanilic acid (2) was also investigated spectrophotometrically. The results indicate that the o-quinone derived from catechol participate in Michael addition reaction with sulfanilic acid (2). In addition, according to the ECE mechanism, the observed homogeneous rate constant (k_obs) for the reaction of o-quinone derived from catechol (1) with sulfanilic acid (2) has been estimated by digital simulation of cyclic voltammograms.