相关论文: Can Small Free Methane Clusters Exhibit Phase-like…

By path integral Monte Carlo simulations we study the phase diagram of two - dimensional mesoscopic clusters formed by electrons in a semiconductor quantum dot or by indirect magnetoexcitons in double quantum dots. At zero (or sufficiently…

Molecular dynamics (MD) simulation is applied to the condensation process of supersaturated vapors of methane, ethane, and carbon dioxide. Simulations of systems with up to a million particles were conducted with a massively parallel MD…

The dynamics and thermodynamics of phase transition in hot nuclei are studied through experimental results on multifragmentation of heavy systems (A$geq$200) formed in central heavy ion collisions. Different signals indicative of a phase…

Co10Ge3O16 crystallizes in an intergrowth structure featuring alternating layers of spinel and rock salt. Variable-temperature powder synchrotron X-ray and neutron diffraction, magnetometry, and heat capacity experiments reveal a…

Using a coarse molecular-dynamics (CMD) approach with an appropriate choice of coarse variable (order parameter), we map the underlying effective free-energy landscape for the melting of a crystalline solid. Implementation of this approach…

Measurements of the sound velocities in a single crystal of MnSi were performed in the temperature range 4-150 K. Elastic constants, controlling propagation of longitudinal waves reveal significant softening at a temperature of about 29.6 K…

The structural phase transformations of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-30%PT) have been studied using x-ray diffraction (XRD) and neutron scattering as a function of temperature and electric field. We observe the phase transformational…

Using molecular dynamics simulation, we study structural and dynamical heterogeneities at melting in two-dimensional one-component systems with 36000 particles. Between crystal and liquid we find intermediate hexatic states, where the…

Hydrogen point defects in silicon still hold unsolved problems, whose disclosure is fundamental for future advances in Si technologies. Among the open issues is the mechanism for the condensation of atomic hydrogen into molecules in Si…

We investigate a new mechanism for the cosmological QCD phase transition: inhomogeneous nucleation. The primordial temperature fluctuations, measured to be $\delta T/T \sim 10^{-5}$, are larger than the tiny temperature interval, in which…

We present results predicting experimentally measurable structural quantities from molecular dynamics studies of hydrogen. In doing this, we propose a paradigm shift for experimentalists -- that the predictions from such calculations should…

We use molecular dynamics simulations to probe the rotational dynamics of the SPC/E model of water for a range of temperatures down to 200 K, 13 K above to the mode coupling temperature. We find that rotational dynamics is spatially…

We present 247-GHz molecular line observations of methanol (CH$_3$OH) toward sixteen massive star-forming regions, using the APEX telescope with an angular resolution of $25''$. The sample covers a range of evolutionary states, including…

Crystals form regular and robust structures that under extreme conditions can melt and recrystallize into different arrangements in a process that is called crystal metamorphism. While crystals exist due to the breaking of a continuous…

The evolution of the magnetic moment in iron clusters containing 20 to 400 atoms is investigated using first-principles numerical calculations based on density-functional theory and real-space pseudopotentials. Three families of clusters…

The dynamics of quantized vortices in rotating $^3$He-B is investigated in the low density (single-vortex) regime as a function of temperature. An abrupt transition is observed at $0.5 T_{\rm c}$. Above this temperature the number of vortex…

A wide variety of observables indicate that maximal fluctuations in the disassembly of hot nuclei with A ~ 36 occur at an excitation energy of 5.6 +- 0.5 MeV/u and temperature of 8.3 +- 0.5 MeV. Associated with this point of maximal…

Molecular dynamics simulation is used to study vacancy cluster formation in $\beta$- and $\alpha$-$Si_3N_4$ with varying vacancy contents (0 - 25.6 at%). Vacancies are randomly created in supercells, which were subsequently heat-treated for…

We study the effects of confinement between two parallel walls on a two dimensional fluid with competing interactions which lead to the formation of particle micro-domains at the thermodynamic equilibrium (microphases or microseparation).…

We present results of wavepacket simulations of scattering of an oriented methane molecule from a flat surface including all nine internal vibrations. At a translational energy up to 96 kJ/mol we find that the scattering is almost…