20,468 research outputs found

    Electron transfer theory revisit: Quantum solvation effect

    Get PDF
    The effect of solvation on the electron transfer (ET) rate processes is investigated on the basis of the exact theory constructed in J. Phys. Chem. B Vol. 110, (2006); quant-ph/0604071. The nature of solvation is studied in a close relation with the mechanism of ET processes. The resulting Kramers' turnover and Marcus' inversion characteristics are analyzed accordingly. The classical picture of solvation is found to be invalid when the solvent longitudinal relaxation time is short compared with the inverse temperature.Comment: 5 pages, 3 figures. J. Theo. & Comput. Chem., accepte

    Quantum molecular dynamics simulations of the thermophysical properties of shocked liquid ammonia for pressures up to 1.3 TPa

    Full text link
    We investigate via quantum molecular-dynamics simulations the thermophysical properties of shocked liquid ammonia up to the pressure 1.3 TPa and temperature 120000 K. The principal Hugoniot is predicted from wide-range equation of state, which agrees well with available experimental measurements up to 64 GPa. Our systematic study of the structural properties demonstrates that liquid ammonia undergoes a gradual phase transition along the Hugoniot. At about 4800 K, the system transforms into a metallic, complex mixture state consisting of NH3\textnormal{N}\textnormal{H}_{3}, N2\textnormal{N}_{2}, H2\textnormal{H}_{2}, N, and H. Furthermore, we discuss the implications for the interiors of Uranus and Neptune.Comment: 16 pages, 8 figures. arXiv admin note: text overlap with arXiv:1012.488

    Radially Excited States of ηc\eta_c

    Full text link
    In the framework of chiral quark model, the mass spectrum of ηc(ns)(n=1,...,6)\eta_c(ns) (n=1,...,6) is studied with Gaussian expansion method. With the wave functions obtained in the study of mass spectrum, the open flavor two-body strong decay widths are calculated by using 3P0^3P_0 model. The results show that the masses of ηc(1S)\eta_c(1S) and ηc(2S)\eta_c(2S) are consistent with the experimental data. The explanation of X(3940) as ηc(3S)\eta_c(3S) is disfavored for X(3940) is a narrow state, Γ=37−15+26±8\Gamma=37^{+26}_{-15} \pm 8 MeV, while the open flavor two-body strong decay width of ηc(3S)\eta_c(3S) is about 200 MeV in our calculation. Although the mass of X(4160) is about 100 MeV less than that of ηc(4S)\eta_c(4S), the assignment of X(4160) as ηc(4S)\eta_c(4S) can not be excluded because the open flavor two-body strong decay width of ηc(4S)\eta_c(4S) is consistent with the experimental value of X(4160) and the branching ratios of ηc(4S)\eta_c(4S) are compatible with that of X(4160), and the mass of ηc(4S)\eta_c(4S) can be shifted downwards by taking into account the coupling effect of the open charm channels. There are still no good candidates to ηc(5S)\eta_c(5S) and ηc(6S)\eta_c(6S).Comment: 5 page
    • …
    corecore