排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
B. Prathab T. M. Aminabhavi R. Parthasarathi V. Subramanian 《Theoretical chemistry accounts》2007,117(1):167-169
Molecular dynamics simulations have been carried out on different perfluoroalkyl methacrylates to predict their densities. Density calculations on selected perfluoroalkyl methacrylates have been performed using molecular dynamics in the NPT ensemble by employing COMPASS force field. The calculated density values compared quite well with the experimental data reported in the literature. 相似文献
2.
Monte Carlo NPT系综法模拟考察几种水模型 总被引:3,自引:0,他引:3
应用NPT系综法模拟考察了五种水的势能模型 .模拟中采用周期边界条件、Metropolis抽样方法 ,并用Ewald方法对水分子间电荷作用进行长程校正 .模拟计算了内能 ,密度 ,压力及恒压热容等性质 .同时 ,还对这五种模型模拟得到的径向分布函数作了分析 .结果与文献及实验测定相比符合较好 相似文献
3.
To demonstrate the nature of the interaction of optical isomers of propranolol with the surface of the graphitic electrode modified with melamine, uracil, cyanuric, and isocyanuric acids, we have performed molecular dynamics simulations of the four‐component systems with variable modifier's molecules. We have considered the possible formation of complexes between the propranolol and modifier's molecules, covering the electrode approximated as the graphene surface. Our simulations demonstrate that the l ‐isomer in aqueous solutions is bonded to the electrode surface stronger than its d ‐counterpart; hence, the difference in analytical signals arises. Different strengths of bonding of the propranolol enantiomers to the surface modifiers are caused by the different intramolecular interactions taking place in the molecules of d ‐ and l ‐isomers. Thus, we have computationally shown that the modification of the graphite surface with melamine, uracil, cyanuric, and isocyanuric acids allows for increasing the sensitivity of the electrode toward the propranolol enantiomers and using the modified graphitic electrodes for the detection of its d ‐ and l ‐forms. 相似文献
4.
In this work, a short time test method to determine the slow crack growth behaviour of samples made out of pipes was evaluated. The cracked round bar (CRB) method used provides results below 48 h with brittle fracture surfaces, which indicates the type of slow crack growth failure. To evaluate the usability of the method, the results were compared with well-known tests such as notch pipe test, 2 notch creep test and instrumented Charpy impact tests. The results indicate that the CRB test can be used to predict long term slow crack growth behaviour of PE pipes. 相似文献
5.
6.
7.
A kinetic Monte Carlo (kMC) scheme in the NPT ensemble (constant number of molecules, pressure and temperature) has been developed to determine accurate chemical potentials for all components in a homogeneous mixture. The simulation requires two moves: (1) a displacement move and (2) a volume change move. In the former, the mobility rate of a selected molecule is determined by its interaction with all the other molecules in the system and is moved to a random position within the simulation box, according to the Rosenbluth algorithm, without any rejections (entropic sampling). The volume change move is decided by a comparison between either the instant pressure or the partial average pressure (with long-range correction) and the specified pressure and is carried out much less frequently than the displacement move. We applied this NPT scheme to a number of mixtures in both the gaseous and liquid phases, and show that the derived chemical potentials are accurate and reproducible. The method is recommended for obtaining chemical potentials in mixtures that are required as input in a grand canonical ensemble simulation. 相似文献
8.
Margarita G. Ilyina Edward M. Khamitov Rail N. Galiakhmetov Ildar A. Mustafin Arslan F. Akhmetov Regina Kh. Shayakhmetova Akhat G. Mustafin 《中国化学会会志》2020,67(1):33-40
In the present work, the composition and relative density of light gasoil of catalytic cracking (LGCC) were studied using chromato-mass-spectrometry and its key physical properties were numerically simulated using molecular dynamics. We have studied the distribution of hydrocarbon compounds over narrow fractions of LGCC. We have applied the ASTM D2892-11a standard distillation to find the component composition of LGCC and its narrow fractions obtained from a mixture of West Siberian oils. Molecular dynamics simulations were performed using the GROMOS96 54a7 force field for the ensemble of constant number of particles (N), pressure (P) and temperature (T) (NPT) ensemble under the constant temperature and constant pressure conditions. The topologies of the structures under study were generated by the automated topology builder (ATB) service. Both the chromatographic mass spectrometry experiments and molecular dynamics simulations indicate the contents of aromatic hydrocarbons in LGCC from the mixture of West Siberian oils up to 80 wt%. 相似文献
9.
Ikeguchi M 《Journal of computational chemistry》2004,25(4):529-541
A partial rigid-body method of molecular dynamics simulations for proteins and membranes is presented. In this method, the symplectic integrator for rigid bodies is combined with the equations of motion for the NPT ensemble. The standard NPT ensemble is extended to the membrane-specific ensembles, the NPAT (constant normal pressure and lateral surface area of membranes and constant temperature) and NPgammaT (constant normal pressure and lateral surface tension of membranes and constant temperature) ensembles. By more than 30-ns simulations of aqueous proteins and hydrated lipid bilayers, the results of the partial rigid-body method demonstrated excellent conservation of total energy and consistent behavior with the traditional constraint method in terms of structural distribution and fluctuation of proteins and lipids. The efficient implementation of the partial rigid-body method in parallel computation is presented, which is shown to work well in large-scale molecular dynamics simulations. 相似文献
1