The non-random two liquids （NRTL） equation together with the Pitzer/Curl Virial equation of state are used to investigate the simultaneous representation of excess enthalpies （h^E） and vapour-liquid equilibria （...The non-random two liquids （NRTL） equation together with the Pitzer/Curl Virial equation of state are used to investigate the simultaneous representation of excess enthalpies （h^E） and vapour-liquid equilibria （VLE） and the VLE prediction from h^E data. The calculation strategy for properly determining NRTL parameters and the effect of their temperature dependence on the simultaneous correlation of h^E and VLE data and the VLE extrapolation are analysed in detail.展开更多
The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） wit...The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.展开更多
Some thermodynamic properties of NHk fixation by loess soil in plowing and clay layers are discussed.The. results indicate that the four ion adsorption equations commonly used can describe the properties of NHk fixati...Some thermodynamic properties of NHk fixation by loess soil in plowing and clay layers are discussed.The. results indicate that the four ion adsorption equations commonly used can describe the properties of NHk fixation in these soils under constant temperature. Among the four adsorption equations, the singlesurface Langmuir equation is the best. When the concentration of NH4Cl solution is 10-1 mol below, the Freundlich equation can be used.The changes of apparent standard free energy (△Go), enthalpy (△Ho) and entropy (△So) illustrate that NHk fixation in soil is an endothermic adsorption and spontaneous reaction, and the process can be enhanced by a higher temperature and clay content in soil.The "proper value of NHk fixation by soil (K1×qm) increased with increasing clay content and temperature. The heat of NHk fixation in soil (Qm) confirms the conclusions made in this paper.展开更多
基金Supported by Deutsche Forschungsgemeinschaft(DFG) (LE 886/4-1)
文摘The non-random two liquids （NRTL） equation together with the Pitzer/Curl Virial equation of state are used to investigate the simultaneous representation of excess enthalpies （h^E） and vapour-liquid equilibria （VLE） and the VLE prediction from h^E data. The calculation strategy for properly determining NRTL parameters and the effect of their temperature dependence on the simultaneous correlation of h^E and VLE data and the VLE extrapolation are analysed in detail.
基金Supported by the National Natural Science Foundation of China （20737001）.
文摘The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.
文摘Some thermodynamic properties of NHk fixation by loess soil in plowing and clay layers are discussed.The. results indicate that the four ion adsorption equations commonly used can describe the properties of NHk fixation in these soils under constant temperature. Among the four adsorption equations, the singlesurface Langmuir equation is the best. When the concentration of NH4Cl solution is 10-1 mol below, the Freundlich equation can be used.The changes of apparent standard free energy (△Go), enthalpy (△Ho) and entropy (△So) illustrate that NHk fixation in soil is an endothermic adsorption and spontaneous reaction, and the process can be enhanced by a higher temperature and clay content in soil.The "proper value of NHk fixation by soil (K1×qm) increased with increasing clay content and temperature. The heat of NHk fixation in soil (Qm) confirms the conclusions made in this paper.
