Warping of triple line in the wetting of B4C by a Cu‐1 at.% Cr alloy

The wetting of polycrystalline B₄C by a molten Cu‐1 at.% Cr alloy was investigated at 1373 K using a modified sessile drop method. The triple line warped after the contact angle reached a certain degree. The mechanism for this unusual phenomenon was presumably ascribed to the large disparity in the wettability for the liquid on the CrB₂ reaction layer and the precipitated graphite phase, as well as to their formation kinetics, rather than to the capillary flow driven by the surface tension gradient, as observed in the Cu/Si system. Copyright © 2010 John Wiley & Sons, Ltd.     

A lattice-gas model for specific ion adsorption at liquid | liquid interfaces

A lattice-gas model is used to investigate the specific adsorption of ions at the interface between two immiscible electrolyte solutions. From Monte Carlo simulations, the profiles of particle densities and of the electrostatic potential are obtained. Specific adsorption is shown to affect the potential distribution markedly. In some cases an overshoot of the potential can be observed, an effect that is well known from specific adsorption at metal electrodes. This redistribution of charge and potential can increase the interfacial capacity, shift the potential of zero charge, and influence the rate of electron-transfer reactions.     

Large scale numerical simulations for multi-phase fluid dynamics with moving interfaces

This short communication presents our recent studies to implement numerical simulations for multi-phase flows on top-ranked supercomputer systems with distributed memory architecture. The numerical model is designed so as to make full use of the capacity of the hardware. Satisfactory scalability in terms of both the parallel speed-up rate and the size of the problem has been obtained on two high rank systems with massively parallel processors, the Earth Simulator (Earth simulator research center, Yokohama Kanagawa, Japan) and the TSUBAME (Tokyo Institute of Technology, Tokyo, Japan) supercomputers.     

Renormalized quantum tomography

Quantum tomography allows to expand operators over functions of a continuous set of spectral densities — the so-called quorum of observables. We present new nontrivial operator expansions for the quorum of quadratures of the harmonic oscillator, and introduce a general framework to generate new expansions based on the Kolmogorov construction.     

Dynamical behavior of a mesoscopic circuit in phonons bath derived by virtue of the IWOP technique

Taking into account the interactions between electrons and phonons, we study the dynamic behavior of a dissipative mesoscopic circuit for pure initial coherent state of phonon bath modes by virtue of the IWOP technique. It shows that if the bath modes are initially in coherent states, some phenomena like Brownian behavior will appear in mean charge and current of the mesoscopic circuit. The quantum fluctuations of charge and current are constant and irrelevant to the coupled coefficients between electrons and phonons.     

Theoretical consideration and modeling of self‐healing polymers

Bioinspired self‐healing polymers have attracted more and more interests. Imparting self‐healing ability to existing polymers or developing new polymeric materials capable of self‐healing is considered to be a solution for improving their long term stability and durability. This article reviews achievements in the field of theoretical researches on re‐establishment of bonding between broken surfaces of self‐healing polymers from microscopic and macroscopic point of view. Chains interaction, mechanical models related to healing procedures and effect of healing, design of novel self‐healing composite systems, and so forth are summarized and analyzed in detail. Both thermoplastics and thermosets are included to offer a comprehensive knowledge framework of the smart function. The scientific challenges are also highlighted, which are related to the production of more advanced self‐healing polymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

From Composites to Solid Solutions: Modeling of Ionic Conductivity in the CaF2–BaF2 System

By using calcium fluorite and barium fluorite as test materials, we demonstrated that homovalent “dopants” can greatly affect ionic conductivity through locally changing the defect density. Whilst this doping is a state‐of‐the‐art effect in the case of dopants that replace native ions of different charge (heterovalent dopants), it is a rather surprising effect at a first glance for substitutional dopants of the same charge; here, the phenomenon is not electrostatic, but elastic in nature. As a consequence of size mismatch, the smaller Ca atoms in the BaF₂ lattice favored the formation of interstitial sites that were located close to the Ca atoms, whilst doping larger Ba species into the CaF₂ phase favored vacancy formation. In terms of conductivity, and in agreement with the different mobilities, the first doping effect was favorable, whilst the other decreased conductivity. The concentration effects were formalized by a heterogeneous Frenkel reaction that was distinguished from the mean Frenkel reaction by additional (elastic) trapping that became more pronounced the lower the temperature. It was very revealing to relate this phenomenon to CaF₂–BaF₂ multilayers and composites. In very general terms, these effects in the solid solutions were understood as being the atomistic limit of the interfacial charge‐transfer that occurred at the hetero‐interface of the crystallites or films, and reflected the transition from heterogeneous doping (higher‐dimensional doping) to homogeneous doping (zero‐dimensional doping).