Coupled Variational Inequalities: Existence,Stability and Optimal Control

Journal of Optimization Theory and Applications - In this paper, we introduce and investigate a new kind of coupled systems, called coupled variational inequalities, which consist of two elliptic...     

The binding of CO molecule with small Wn(n = 2−9) clusters: a DFT investigation

The effect of water conductivity on electrospraying of water was studied in combination with positive DC corona discharge generated in air. We used a point-to-plane geometry of electrodes with a hollow syringe needle anode opposite to the metal mesh cathode. We employed total average current measurements and high-speed camera fast time-resolved imaging. We visualized the formation of a water jet (filament) and investigated corona discharge behavior for various water conductivities. Depending on the conductivity, various jet properties were observed: pointy, prolonged, and fast spreading water filaments for lower conductivity; in contrast to rounder, broader, and shorter quickly disintegrating filaments for higher conductivity. The large acceleration values (4060 m/s² and 520 m/s² for 2 μS/cm and 400 μS/cm, respectively) indicate that the process is mainly governed by the electrostatic force. In addition, with increasing conductivity, the breakdown voltage for corona-to-spark transition was decreasing.     

Wander of a Gaussian-Beam Wave Propagated Through a Non-Kolmogorov Turbulent Atmosphere

Both increasing experimental evidence and some results of theoretical investigation have shown that there exist two kinds of turbulence in the aerosphere, Kolmogorov and non-Kolmogorov turbulence. Thus, it is necessary to improve the theory of optical wave propagation through atmospheric turbulence, namely, study the laser-beam propagation in non-Kolmogorov turbulence, before analyzing the joint influence of the Kolmogorov turbulence and non-Kolmogorov one on satellite laser communication. The beam wander will lead to the performance degradation of satellite laser communication systems and exert an influence on the achievement and stability of its links. In this paper, we consider a theoretical power spectrum of refractive-index fluctuations with a generalized power law in order to derive the variance of Gaussian-beam wave wander in weak turbulence for a horizonal path and analyze the influence of spectral power-law variations on the beam wander. We show that the expression for the beam-wander variance is of concise closed form and independent of the optical wavelength.     

Moments for Tempered Fractional Advection-Diffusion Equations

This paper develops moment formulas for exponentially tempered, fractional advection-diffusion equations (TFADEs) that transition from anomalous to asymptotic diffusion limits over time. Exact analytical expressions or series representations for spatial moments up to the fourth order are derived by integral transform or asymptotic expansion approach. A fully Lagrangian solver, cross verified by an implicit Eulerian approach, is also developed to calculate numerically the complete evolution of moments for the TFADEs with complex initial and boundary conditions. Moment analysis identifies the diffusion equation that attracts the tempered anomalous diffusion in the long time limit. Fitting of moments measured at two end members of alluvial systems checks the applicability of moment analysis in understanding real diffusion.     

Schemes to generate and distinguish a type of genuine four-qubit entangled states in a cavity QED system

We propose a scheme to generate a type of genuine four-qubit entangled states, which were firstly introduced by Yeo et al. [Y. Yeo, W. K. Chua, Phys. Rev. Lett. 96 (2006) 060502]. These states have many interesting entanglement properties and possess possible applications in quantum information processing and in fundamental tests of quantum physics. We show that such a type of 16 orthonormal basis states can be deterministically distinguished by a cavity QED system.     

Facile approach to prepare PIPD nano-spheres

Poly(2,6-diimidazo [4,5-b:4′5′-e]pyridinylene-1,4(2,5-dihydroxy) phenylene) (PIPD) was synthesized via polycondensation in phosphorus acid and separated as nano-spheres about 50 nm in diameter. When a heterogeneous additive, acid-treated carbon nanotubes, or calcium carbonate nanoparticles were present during polycondensation, nano-spheres near or larger than 100 nm could be obtained. The morphology of PIPD nano-spheres was observed using transmission and scanning electron microscopy. The thermal behavior and the relative composition of the nano-spheres were characterized using thermal gravimetric analysis. The function of the additives was explored in terms of heterogeneous nucleation. The effect of the solvents used for sphere separation was also considered.     

The Structural Fate of Individual Multicomponent Metal‐Oxide Nanoparticles in Polymer Nanoreactors

Multicomponent nanoparticles can be synthesized with either homogeneous or phase‐segregated architectures depending on the synthesis conditions and elements incorporated. To understand the parameters that determine their structural fate, multicomponent metal‐oxide nanoparticles consisting of combinations of Co, Ni, and Cu were synthesized by using scanning probe block copolymer lithography and characterized using correlated electron microscopy. These studies revealed that the miscibility, ratio of the metallic components, and the synthesis temperature determine the crystal structure and architecture of the nanoparticles. A Co‐Ni‐O system forms a rock salt structure largely owing to the miscibility of CoO and NiO, while Cu‐Ni‐O, which has large miscibility gaps, forms either homogeneous oxides, heterojunctions, or alloys depending on the annealing temperature and composition. Moreover, a higher‐ordered structure, Co‐Ni‐Cu‐O, was found to follow the behavior of lower ordered systems.