Narrow Results

We consider a ferromagnetic Ising spin system, consisting of m+1, d-dimensional, layers with “–” boundary condition on the bottom layer and “+” on the top layer. When β is larger than β_cr, the inverse critical temperature for the d-dimensional Ising model, the interface generated by the boundary conditions is expected to be halfway between bottom and top, for m odd, and just above or below the middle layer, for m even (each possibility with probability ). In this paper, we prove the above assertion under the condition that β≥const . m and partly for β>β_cr.

We find the probe D5-brane solution on the black hole space–time which is asymptomatically ${\mathrm{\text{AdS}}}_5\times S^5$. These black holes have spherical, hyperbolic and toroidal structures. Depending on the gauge flux on the D5-brane, the D5-brane behaves differently. By adding the fundamental string, the potential energy of the interface solution and the Wilson loop is given in the case of nonzero gauge flux.

We develop a class of Hamiltonian-preserving numerical schemes for high frequency elastic waves in heterogeneous media. The approach is based on the high frequency approximation governed by the Liouville equations with singular coefficients due to material interfaces. As previously done by Jin and Wen [10, 12], we build into the numerical flux the wave scattering information at the interface, and use the Hamiltonian preserving principle to couple the wave numbers at both sides of the interface. This gives a class of numerical schemes that allows a hyperbolic CFL condition, is positive and l^∞ stable, and captures correctly wave scattering at the interface with a sharp numerical resolution. We also extend the method to curved interfaces. Numerical experiments are carried out to study the numerical convergence and accuracy.

Foam–metal composites are being increasingly used in a variety of applications. One important aspect in the structural integrity of foam–metal interface is the ability to resist failure around the interface whilst ensuring required load bearing capacity. This study investigated the mechanical and failure behavior at the interface region at micro-scale. The foam–metal composite consisted of polyurethane (PU) foam directly adhered to a galvanized steel face sheet. Optical, scanning electron and atomic force microscopies were used to examine the interface geometry and to obtain a realistic surface profile for use in a finite element (FE) model. Finite element analysis (FEA) was used to study the effects of different interfacial roughness profiles on the mechanical interlocking and modes of failure, which are directly related to the interfacial strength. A set of FE models of idealized surface pairs of different geometries and dimensions were developed based on the microscopic observations at the foam–metal interface. The FE modeling results show that the micro-scale roughness profile at the foam–metal interface causes mechanical interlocking and affects the stress field at the scale of the interface surface roughness, which consequently governs the specific failure mode and the relative proportion of the cohesive to adhesive failure in the interface region for a given foam–metal interface. It was found that the aspect ratio (relative width and height) and width ratio (relative spacing) of roughness elements have a significant effect on the stresses and deformations produced at the interface and consequently influence the modes (cohesive or adhesive) of failure.

We investigate the cohesive response of biointerfaces mediated by noncovalent receptor–ligand bonding under monotonic, cyclic or other types of loading. By examining the spatiotemporal evolution of the state probability distribution that describes the collective association and dissociation kinetics of interfacial bonds, we show that such interfaces resist the imposed surface separation in a strongly rate-dependent manner. Remarkable hysteresis is exhibited when the interfaces are exposed to single stretching and relaxation cycles at high loading rates, and this hysteretic response shifts in consecutive multiple cycles. There generally exists an optimal ramping velocity that gives rise to the maximum energy dissipation at the interfaces. These results should be useful in understanding the cell-matrix adhesion and de-adhesion phenomena under dynamic and repetitive forces, as well as the adhesion-mediated cellular behaviors such as migration and reorientation.

Interface is an important element for the interaction problem of soil masses and object. This paper proposes an interface layer method to treat the interface of saturated soil medium and rigid object (solid). In the domain, the radial point interpolation method (radial PIM) with compact support is applied. An interface layer is proposed to treat the compression, opening and shear friction of the interface. This method has following advantages over traditional interface element (Goodman, 1968). First, the node distribution on both sides of interface is not required to be the same. Such a scheme is special helpful to the meshless methods for both side domains. Second, water flow in the interface can be considered if the interface is open. Third, the accuracy for interface interpolation is adjustable according to the node distribution. Numerical examples are studied to demonstrate the capability of the current interface layer method.