[en] We have demonstrated probing single-molecule metal-to-ligand charge transfer (MLCT) dynamics at room temperature. Using photon antibunching measurements under CW laser excitation, non-classical photon statistics, and excitation power dependent measurements, we were able to selectively measure the single-molecule MLTC state lifetime. This work demonstrated the first single-molecule photon antibunching of triplet excited state and presents a step forward in studying single-molecule electron transfer in proteins using MLTC complex as an electron transfer donor or acceptor

[en] This paper presents a technique for predicting system performance reliability in real-time considering multiple failure modes. The technique includes on-line multivariate monitoring and forecasting of selected performance measures and conditional performance reliability estimates. The performance measures across time are treated as a multivariate time series. A state-space approach is used to model the multivariate time series. Recursive forecasting is performed by adopting Kalman filtering. The predicted mean vectors and covariance matrix of performance measures are used for the assessment of system survival/reliability with respect to the conditional performance reliability. The technique and modeling protocol discussed in this paper provide a means to forecast and evaluate the performance of an individual system in a dynamic environment in real-time. The paper also presents an example to demonstrate the technique

[en] A method has been developed to differentiate recrystallized from unrecrystallized grains in partially annealed samples based on the point-to-point misorientation within the grains. Recrystallized grains exhibit a low average point-to-point misorientation whereas the contrary is the case for deformed grains. The analysis for recrystallized fraction was calibrated based on this distinguishing feature, and it was found that the average point-to-point misorientation within a grain in a fully recrystallized sample was less than 0.7 deg. . Based on this calibration, partially recrystallized samples were analysed for their degree of recrystallization, and the technique was validated using microhardness measurements. The analysis of the misorientation data was in excellent agreement with the hardness data. There are three factors which distinguish the current method in comparison to the earlier work: a fixed limit is maintained on the minimum number of pixels which may constitute a grain; pattern quality is not considered; and the recrystallization criterion is calibrated to the experimental data. Nevertheless, in the early stages of annealing, where recovery is likely to have the most influence on the drop in hardness, the analysis of electron backscattered diffraction (EBSD) data underpredicts the recrystallized fraction. The analysis was also conducted on a cold-rolled, nonannealed sample, and from this, the error of the technique is estimated to be a maximum of 0.06 recrystallized volume fraction

[en] We review general domain-wall solutions supported by a delta-function source, together with a single pure exponential scalar potential in supergravity. These scalar potentials arise from a sphere reduction in M theory or string theory. There are several examples of flat (BPS) domain walls that lead to a localization of gravity on the brane, and for these we obtain the form of the corrections to Newtonian gravity. These solutions are lifted back on certain internal spheres to D=11 and D=10 as M-branes and D-branes. We find that the domain walls that can trap gravity yield M-branes or Dp-branes that have a natural decoupling limit, i.e., p≤5, with the delta-function source providing an ultraviolet cutoff in a dual quantum field theory. This suggests that the localization of gravity can generally be realized within a domain-wall/QFT correspondence, with the delta-function domain-wall source providing a cutoff from the space-time boundary for these domain-wall solutions. We also discuss the form of the one-loop corrections to the graviton propagator from the boundary QFT that would reproduce the corrections to the Newtonian gravity on the domain wall

[en] Near-field optical enhancement at metal surfaces and methods such as surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS), fluorescent quenching and enhancement, and various near-field scanning microscopies (NSOM) all depend on a metals surface properties, mainly on its morphology and SPR resonant frequency. We report on simulations of the influence of different surface morphologies on electromagnetic field enhancements at the rough surfaces of noble metals and also evaluate the optimal conditions for the generation of a surface-enhanced Raman signal of absorbed species on a metallic substrate. All simulations were performed with a classical electrodynamics approach using the full set of Maxwells equations, which were solved with the three-dimensional finite element method (FEM). Two different classes of surfaces where modeled using fractals, representing diffusion limited aggregation growth dendritic structures, such as one on the surface of electrodes, and second one representing the sponge-like structure used to model surfaces of particles with high porosity, such as metal coated catalyst supports. The simulations depict the high inhomogeneity of an enhanced electromagnetic field as both a field enhancement and field attenuation near the surface. While the diffusion limited aggregation dendritical fractals enhanced the near-field electromagnetic field, the sponge fractals significantly reduced the local electromagnetic field intensity. Moreover, the fractal orders of the fractal objects did not significantly alter the total enhancement, and the distribution of a near-field enhancement was essentially invariant to the changes in the angle of an incoming laser beam

[en] The process of grain boundary migration involves moving interfaces and topological changes of grain boundary geometry. This can not be effectively modeled by Lagrangian, Eulerian, or arbitrary Lagrangian Eulerian finite element formulation when stress effect is considered. A coupled finite element and meshfree approach is proposed for modeling of grain boundary migration under stress. In this formulation, the material grid carries material kinematic and kinetic variables, whereas the grain boundary grid carries grain boundary kinematic variables. The material domain is discretized by a reproducing kernel partition of unity with built-in strain discontinuity across the grain boundaries. The grain boundaries, on the other hand, are discretized by the standard finite elements. This approach allows an arbitrary evolution of grain boundaries without continuous remeshing

[en] We show that rotating p-brane solutions admit an analytical continuation to become twisted Sp-branes. Although a rotating p-brane has a naked singularity for large angular momenta, the corresponding S-brane configuration is regular everywhere and exhibits a smooth bounce between two phases of Minkowski spacetime. If the foliating hyperbolic space of the transverse space is of even dimension, such as for the twisted SM5-brane, then for an appropriate choice of parameters the solution smoothly flows from a warped product of two-dimensional de Sitter spacetime, five-dimensional Euclidean space and a hyperbolic 4-space in the infinite past to Minkowski spacetime in the infinite future. We also show that non-singular S-Kerr solutions can arise from higher-dimensional Kerr black holes, so long as all (all but one) angular momenta are non-vanishing for even (odd) dimensions. (author)

[en] The microstructure of materials, i.e. the size, shape and arrangement of grains, determines essentially the material properties such as mechanical strength, toughness, electrical conductivity and magnetic susceptibility. In general the desirable property of materials can be controlled and improved by understanding of microstructure evolution processes in grain growth controlled by grain boundary migration, and grain boundary diffusion. The process of grain growth involves both grain boundary migration (moving interfaces) and topological changes of grain boundary geometry, and it can not be effectively modeled by Lagrangian, Eulerian, or Arbitrary Lagrangian Eulerian finite element method when in addition the stress effect is considered. A double-grid method is proposed for modeling grain boundary migration under stress. In this approach, the material grid carries kinematic and kinetic material variables, whereas the grain boundary grid carries only grain boundary kinematic variables. The material domain is discretized by a reproducing kernel approximation with strain discontinuity enrichment across the grain boundaries. The grain boundaries, on the other hand, are discretized by the standard finite elements. This approach allows modeling of arbitrary evolution of grain boundaries without remeshing

[en] At the leading order, the low-energy effective field equations in string theory admit solutions of the form of products of Minkowski spacetime and a Ricci-flat Calabi-Yau space. The equations of motion receive corrections at higher orders in α', which imply that the Ricci-flat Calabi-Yau space is modified. In an appropriate choice of scheme, the Calabi-Yau space remains Kaehler, but is no longer Ricci-flat. We discuss the nature of these corrections at order {α'}³, and consider the deformations of all the known cohomogeneity one non-compact Kaehler metrics in six and eight dimensions. We do this by deriving the first-order equations associated with the modified Killing-spinor conditions, and we thereby obtain the modified supersymmetric solutions. We also give a detailed discussion of the boundary terms for the Euler complex in six and eight dimensions, and apply the results to all the cohomogeneity one examples. (author)

[en] The electrode potential or galvanic series is usually used to reflect the nobility of metals and semi-metals. However, this potential is environment-dependent and the intrinsic nobility of a metal is ultimately governed by its electron stability, which can be represented by the electron work function (EWF). This article reports our studies on the corrosion behavior of isomorphous Cu–Ni alloy in HCl and NaCl solutions, respectively. It was demonstrated that the EWF of the alloy increased as the Ni concentration was increased, so did the corrosion resistance in the acidic solution. In the sodium chloride solution, however, the trend was reversed due to adsorption, hydrolysis and the formation of oxide scale on Cu-rich samples, which more or less prevented them from further corrosion in this solution. In order to confirm this, corrosive wear tests were performed to analyze the performance of the alloy when the effect of oxide scale was eliminated or minimized by the mechanical action. - Highlights: • Increasing %Ni resulted in higher overall electron work function of Cu–Ni alloy. • Higher EWF corresponded to higher resistance to corrosion in a HCl solution. • Trend was reversed in a NaCl solution due to the formation of oxide scale. • During slurry-jet tests, alloys with higher EWFs performed better.