Using first-principles calculations, we systematically study the dissociations of 02 molecules on different ultrathin Pb（lll） films. According to our previous work revealing the molecular adsorption precursor states...Using first-principles calculations, we systematically study the dissociations of 02 molecules on different ultrathin Pb（lll） films. According to our previous work revealing the molecular adsorption precursor states for O2, we further explore why there are two nearly degenerate adsorption states on Pb（lll） ultrathin films, but no precursor adsorption states existing at all on Mg（0001） and Al（lll） surfaces. The reason is concluded to be the different surface electronic structures. For the O2 dissociation, we consider both the reaction channels from gas-like and molecularly adsorbed O2 molecules. We find that the energy barrier for O2 dissociation from the molecular adsorption precursor states is always smaller than that from O2 gas. The most energetically favorable dissociation process is found to be the same on different Pb（lll） fihns, and the energy barriers are found to be influenced by the quantum size effects of Pb（lll） films.展开更多
A two parameters equation of state (EOS) for nonaqueous electrolyte solutions system has been developed. The equation is in terms of Helmholtz free energy and incorporated with results of low density expansion of non-...A two parameters equation of state (EOS) for nonaqueous electrolyte solutions system has been developed. The equation is in terms of Helmholtz free energy and incorporated with results of low density expansion of non-primitive mean spherical approximation. The EOS was tested for experimental data reported in literatures of 9 nonaqueous single electrolyte solutions of which the temperature was 298.15 K, and it also has a good predictive capability for nonaqueous electrolyte solutions at different temperature in this work. The comparisons with EOSs published earlier by other researchers in literatures are carried out in detail.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.90921003,10904004 and 60776063)the Fundamental Research Funds for the Central Universities,China(Grant No.JD1109)
文摘Using first-principles calculations, we systematically study the dissociations of 02 molecules on different ultrathin Pb（lll） films. According to our previous work revealing the molecular adsorption precursor states for O2, we further explore why there are two nearly degenerate adsorption states on Pb（lll） ultrathin films, but no precursor adsorption states existing at all on Mg（0001） and Al（lll） surfaces. The reason is concluded to be the different surface electronic structures. For the O2 dissociation, we consider both the reaction channels from gas-like and molecularly adsorbed O2 molecules. We find that the energy barrier for O2 dissociation from the molecular adsorption precursor states is always smaller than that from O2 gas. The most energetically favorable dissociation process is found to be the same on different Pb（lll） fihns, and the energy barriers are found to be influenced by the quantum size effects of Pb（lll） films.
文摘A two parameters equation of state (EOS) for nonaqueous electrolyte solutions system has been developed. The equation is in terms of Helmholtz free energy and incorporated with results of low density expansion of non-primitive mean spherical approximation. The EOS was tested for experimental data reported in literatures of 9 nonaqueous single electrolyte solutions of which the temperature was 298.15 K, and it also has a good predictive capability for nonaqueous electrolyte solutions at different temperature in this work. The comparisons with EOSs published earlier by other researchers in literatures are carried out in detail.
