Haldane gap in the S = 1 Haldane-Shastry model

We present evidence that the S = 1 Haldane- Shastry model has a gap in the energy spectrum, extending to the case of a model with long-range interactions results previously obtained by Haldane and, numerically, by other authors for the case of short-range interactions. We studied the groundstate and first excited state using a modified Lanczos algorithm and obtained the low temperature behavior diagonalizing exactly small chains. The correlation functions decay exponentially with distance and the low-T susceptibility decays exponentially to zero. The gap is larger than for the Heisenberg model and the correlation functions decay faster indicating a smaller correlation length.     

Chemistry and anti-herpes simplex virus type 1 evaluation of 4-substituted-1H-1,2,3-triazole-nitroxyl-linked hybrids

Molecular Diversity - HSV disease is distributed worldwide. Anti-herpesvirus drugs are a problem in clinical settings, particularly in immunocompromised individuals undergoing herpes simplex virus...     

Quantitative determination of the hubbard model phase diagram from optical lattice experiments by two-parameter scaling

We propose an experiment to obtain the phase diagram of the fermionic Hubbard model, for any dimensionality, using cold atoms in optical lattices. It is based on measuring the total energy for a sequence of trap profiles. It combines finite-size scaling with an additional "finite-curvature scaling" necessary to reach the homogeneous limit. We illustrate its viability in the 1D case, simulating experimental data in the Bethe-ansatz local-density approximation. Including experimental errors, the filling corresponding to the Mott transition can be determined with better than 3% accuracy.     

Nanoporosity,Inclusion Chemistry,and Spin Crossover in Orthogonally Interlocked Two‐Dimensional Metal–Organic Frameworks

[Fe(tvp)₂(NCS)₂] ( 1 ) (tvp=trans‐(4,4′‐vinylenedipyridine)) consists of two independent perpendicular stacks of mutually interpenetrated two‐dimensional grids. This uncommon supramolecular conformation defines square‐sectional nanochannels (diagonal≈2.2 nm) in which inclusion molecules are located. The guest‐loaded framework 1@guest displays complete thermal spin‐crossover (SCO) behavior with the characteristic temperature T_1/2 dependent on the guest molecule, whereas the guest‐free species 1 is paramagnetic whatever the temperature. For the benzene–guest derivatives, the characteristic SCO temperature T_1/2 decreases as the Hammet σ_p parameter increases. In general, the 1@guest series shows large entropy variations associated with the SCO and conformational changes of the interpenetrated grids that leads to a crystallographic‐phase transition when the guest is benzonitrile or acetonitrile/H₂O.     

On the rate of decay in interacting continua with memory

This paper is concerning the linear theory of isothermal interacting continua with memory. We consider anti-plane shear deformations in a mixture of two elastic solids where the dissipation mechanisms can be the viscosity in one of the components and the viscosity with respect to the relative displacement. We have seen that when the only dissipation mechanism applies on the relative displacement we cannot expect the exponential decay for the solutions. We have also analyzed the case when the viscosity mechanism applies on a constituent. We have seen that generically the decay is of exponential type. However if the coupling constitutive parameter vanishes the decay is slow.     

Further mathematical results concerning Burgers fluids and their generalizations

In this paper, we extend the earlier work by Quintanilla and Rajagopal (Math Methods Appl Sci 29: 2133?C2147, 2006) and establish qualitative new results for a proper generalization of Burgers?? original work that stems form a general thermodynamic framework. Such fluids have been used to describe the behavior of several geological materials such as asphalt and the earth??s mantle as well as polymeric fluids. We study questions concerning stability, uniqueness and continuous dependence on initial data for the solutions of the flows of these fluids. We show that if certain conditions are not satisfied by the material moduli, the solutions could be unstable. The spatial behavior of the solutions is also analyzed.     

Spin torque on magnetic domain walls exerted by supercurrents

We calculate the spin density, spin currents and spin torque due to a spin polarized current on a magnetic domain wall juxtaposed to or inserted in a conventional superconductor. The superconductor is part of a heterostructure of the type NSN or FSF. In general, the spin torque exerted on the domain wall is weaker with respect to a normal metal. However, there are regimes where the torque is enhanced with respect to the normal metal. In these regimes the motion of the domain wall is therefore more efficient. A notable case is the passing of an unpolarized current which leads to a finite torque in the case of the superconductor.     

Infrared energy transfer in Tm3+:LiNbO3

The infrared optical properties of LiNbO₃ crystals doped with variable thulium concentrations have been studied. In particular, the infrared emissions that appear after direct pumping to the ³H₄ multiplet (795 nm) have been analyzed. The emission spectra, as well as the lifetimes, show that an efficient energy transfer between ³F₄ and ³H₄ levels takes place. The concentration dependence of the lifetimes has been studied and the transfer probability has been characterized.     

Exponential decay in a thermoelastic mixture of solids

In this paper, we investigate the asymptotic behaviour of solutions to the initial boundary value problem for a one-dimensional mixture of thermoelastic solids. Our main result is to establish a necessary and sufficient condition over the coefficients of the system to get the exponential stability of the corresponding semigroup. We also prove the impossibility of time localization of solutions.     

Flash DSC crystallization study of blown film grade bimodal high density polyethylene (HDPE) resins. Part 2. Non‐isothermal kinetics

Non‐isothermal ultra‐fast cooling crystallization tests were conducted on three blown film grade bimodal high density polyethylene (HDPE) resins using a fast differential scanning calorimeter, the Flash DSC. Non‐isothermal tests were performed at cooling rates between 50 and 4000°K/s, and the data were analyzed using the modified Avrami model by Jeziorny (Polymer, 1978 , 19, 1142). Non‐isothermal data were used to propose a new method named crystallization–time–temperature–superposition, and the two activation energies were obtained for each of the resins. This is very useful for obtaining theoretical crystallization kinetics data at different cooling rates, allowing its use in ultra‐fast cooling polymer processes such as blown film. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1822–1827