Herr Ran Jia

Physik

Biografie

Kurzbiographie

• Geboren 09. July 1979 in VR China, männlich, ledig.
• 1998-2002: Bachelor, Harbin Institute of Technology, VR China;
• 2002-2007: Diplom, Fachbreich Physik, Universität Osnabrück, Deutschland;
• seit 2008: Doktorand, Fachrichtung theoretische Physik, Bergische Universität Wuppertal

Titel und Abstract des Dissertationsprojektes

Titel: Computer Simulation of the Stockmayer Fluid in an applied electric field

Abstract: Using Molecular Dynamics computer simulation we compute gas--liquid phase coexistence curves for the Stockmayer fluid (and polarizable Stockmayer fluid) in an external electric field. We observe a field induced shift of the critical temperature, $\Delta T_c$. The sign of $\Delta T_c$ depends on whether the potential or the surface charge density is held constant, assuming that the dielectric material fills the space between capacitor plates. Our own as well as previous literature data for $\Delta T_c$ are compared to and interpreted in terms of a simple mean field theory. Despite considerable errors in the simulation results, we find consistency between the simulation results obtained by different groups including our own and the mean field description. The latter ties the sign of $\Delta T_c$ to the outside constraints via the electric field dependence of the orientation part of the mean field free energy.

Neuigkeiten

Vortragstätigkeit

1. Anwendung der linearisierten Boltzmanngleichung auf wellenartigen Anregungen in Gasen, Universität Osnabrück, am 19.12.2006
2. Defektstruktur in SrF2 , Universität Wuppertal, am 25.10.2007
3. Defektstruktur in SrF2 , Universität Braunschweig, am 07.01.2008

Publikationen

1. Ab-initio calculations for SrF2 with F and M centers.
   Computational Materials Science 43, 980-988 (2008)
   R. Jia, H. Shi and G. Borstel
2. First principles calculations of oxygen-vacancy dipoles and hydrogen impurities in SrF2 .
   Physical Review B 78, 224101 (2008)
   R. Jia, H. Shi and G. Borstel
3. Dipolar particles in an external field: Molecular dynamics simulation and mean field theory.
   Physical Review E 80, 051502 (2009)
   R. Jia and R. Hentschke
4. Atomic and electronic structure of CaF2 and BaF2 crystals with H centers: A hybrid DFT calculation study.
   Journal of Physics: Condensed Matter 22, 055501 (2010)
   R. Jia, H. Shi and G. Borstel
5. First-principles calculations of surface H centers in BaF2 .
   Physical Review B 81, 195101 (2010)
   H. Shi, R. Jia and R. I. Eglitis
6. Ab initio calculations for the H-center in SrF2 crystal.
   Journal of physical Chemistry A 114, 8444-8449 (2010)
   L. Yue, R. Jia, H. Shi, X. He and R. I. Eglitis
7. First-principles simulations on the aggregation of F centers in CaF2 : M and R centers.
   Journal of physical Chemistry A (submitted)
   H. Shi, R. Jia, A. Istrate and R. I. Eglitis
8. Gas-liquid coexistence in a system of dipolar soft spheres.
   Physical Review E (submitted)
   R. Jia, H. Braun and R. Hentschke
9. First-principles calculations of surface H centers in CaF2.
   Journal of physical Chemistry A (submitted)
   H. Shi, R. Jia, L Yue and R. I. Eglitis
10. First-principles calculations of surface H centers in SrF2. (in preparing)
    R. Jia, H. Shi, J. Reckfort and R. I. Eglitis
11. Phase behavior of the polarizable dipolar particles in an external field via molecular dynamics simulation and mean field theory. (in preparing)
    R. Jia and R. Hentschke
12. First-principles simulations on the aggregation of F centers in BaF2 : R centers
    Solid State Ionics (submitted)
    H. Shi, R. Jia, W. Ouyang and R. I. Eglitis

Sonstige wissenschaftliche Aktivitäten/Mitgliedschaften

In Bearbeitung

Sonstiges

Diplom-Physiker