The excess Helmholtz free energy functional for nonpolar chain-like molecules is formulated in terms of a weighted density approximation （WDA） for short-range interactions and a Weaks Chandler Andersen （WCA） appro...The excess Helmholtz free energy functional for nonpolar chain-like molecules is formulated in terms of a weighted density approximation （WDA） for short-range interactions and a Weaks Chandler Andersen （WCA） approximation and a Barker Henderson （BH） theory for long-range attraction. Within the framework of density functional theory （DFT）, vapour liquid interracial properties including density profile and surface tension, and vapour-liquid nucleation properties including density profile, work of formation and number of particles are investigated for spherical and chain- like molecules. The obtained vapour liquid surface tension and the number of particles in critical nucleus for Lennard- Jones （L J） fluids are consistent with the simulation results. The influences of supersaturation, temperature and chain length on vapour liquid nucleation properties are discussed.展开更多
Freezing processes of several liquids under static magnetic field(SMF) less than 50 mT were investigated. Central temperature of liquid samples held in glass test tubes immersed in a liquid bath was measured and colle...Freezing processes of several liquids under static magnetic field(SMF) less than 50 mT were investigated. Central temperature of liquid samples held in glass test tubes immersed in a liquid bath was measured and collected. Nucleation temperature and phase transition time were obtained from freezing curves. Normality tests were performed for nucleation temperature of these liquids with/without magnetic field and normality distributions were justified. Analysis of variances was carried out for nucleation temperature of these liquids with magnetic field flux density as the influencing factor. Results showed that no significant difference was found for deionized water with or without SMF. However, differences exist in 0.9% NaCl solution and 5% ethylene glycol solution with and without SMF. Nucleation temperature of 0.9% NaCl with SMF is lower than that without SMF, while its phase transition time is shorter than that without SMF. Nucleation temperature of 5% ethylene glycol with SMF is higher than that without SMF, while its phase transition time is not modified with SMF.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 20576030 and 20606009）, the Program for New Century Excellent Talents of China （Grant No 06-0206）, and the Research Fund of Key Laboratory for Nanomaterials, Ministry of Education of China （Grant No 2006-2）.
文摘The excess Helmholtz free energy functional for nonpolar chain-like molecules is formulated in terms of a weighted density approximation （WDA） for short-range interactions and a Weaks Chandler Andersen （WCA） approximation and a Barker Henderson （BH） theory for long-range attraction. Within the framework of density functional theory （DFT）, vapour liquid interracial properties including density profile and surface tension, and vapour-liquid nucleation properties including density profile, work of formation and number of particles are investigated for spherical and chain- like molecules. The obtained vapour liquid surface tension and the number of particles in critical nucleus for Lennard- Jones （L J） fluids are consistent with the simulation results. The influences of supersaturation, temperature and chain length on vapour liquid nucleation properties are discussed.
基金Supported by the National Natural Science Foundation of China(51306104)
文摘Freezing processes of several liquids under static magnetic field(SMF) less than 50 mT were investigated. Central temperature of liquid samples held in glass test tubes immersed in a liquid bath was measured and collected. Nucleation temperature and phase transition time were obtained from freezing curves. Normality tests were performed for nucleation temperature of these liquids with/without magnetic field and normality distributions were justified. Analysis of variances was carried out for nucleation temperature of these liquids with magnetic field flux density as the influencing factor. Results showed that no significant difference was found for deionized water with or without SMF. However, differences exist in 0.9% NaCl solution and 5% ethylene glycol solution with and without SMF. Nucleation temperature of 0.9% NaCl with SMF is lower than that without SMF, while its phase transition time is shorter than that without SMF. Nucleation temperature of 5% ethylene glycol with SMF is higher than that without SMF, while its phase transition time is not modified with SMF.
