Little exchange at the liquid/solid interface: defect-mediated equilibration of physisorbed porphyrin monolayers

The transition from low to high density 2D surface structures of copper porphyrins at a liquid/solid interface requires specific defects at which nearly all exchange of physisorbed molecules with those dissolved in the supernatant occurs.     

Multiple photosynthetic reaction centres composed of supramolecular assemblies of zinc porphyrin dendrimers with a fullerene acceptor

Multiple photosynthetic reaction centres have successfully been constructed using supramolecular complexes of zinc porphyrin dendrimers [D(ZnP)(n): n = 4, 8, 16] with fulleropyrrolidine bearing a pyridine ligand (C(60)py). Efficient energy migration occurs completely between the ZnP units of dendrimers prior to the electron transfer with increasing the generation of dendrimers to attain an extremely long charge-separation lifetime.     

Fundamentals of designing cylindrical high-order transformation optics invisibility cloaks using silver–silica metamaterials

Metamaterials have effective properties that are distinct from their composites as they consist of engineered-designed properties that are not in nature. In order to be able to design a metamaterial, we should establish sufficient understanding of the properties of the constituents. This will enable us to engineer new effective parameters of the metamaterial. We shall perform a detailed analytical study for the effective parameters and the constituents’ parameters of silver–silica metamaterial. This will define the optical response of the mixture at different sizes of the inclusions’ and different volume fractions of the silver and silica. Also an optimum value of the volume fraction is proposed to achieve a broadened resonance optical response. Finally, we propose the design technique and constraints of a non-magnetic optical cloaking device, based on high-order transformation optics with different volume fractions of silver and silica.     

Ion and solvent transfer of polyaniline films electrodeposited from deep eutectic solvents via EQCM

Journal of Solid State Electrochemistry - We report herein the electrochemical polymerisation of aniline from a choline chloride (ChCl)-based deep eutectic solvent (DES) at room temperature in both...     

Autoparametric amplification of two nonlinear coupled mass–spring systems

The gearboxes of machines generally operate under a time-varying state rather than under steady-state conditions. However, it is difficult to investigate the nonlinear dynamics of a time-varying gear system. A gear system model of a railway vehicle was proposed in consideration of its time-varying mesh stiffness, nonlinear backlash, transmission error, time-varying external excitation, and rail irregularity. To obtain the nonlinear behaviors of a time-varying stochastic gear system, a quasi-static analysis was performed to observe its doubling-periodic bifurcation, chaotic motion, and transition from a lower to a higher power periodic motion. Based on the energy comparison results, the time-varying stochastic gear system was degraded to a time-varying system to simplify the calculation. Furthermore, the nonlinear response of the time-varying system was computed using the Runge–Kutta method and was compared with the results of a quasi-static analysis that employed a short-time Fourier transform method. The results of the quasi-static analysis were consistent with the results of the time–frequency analysis for the time-varying gear system except for the result at 3180 r/min, which represented a short period wherein the process transitioned to chaos. Hence, the comparison demonstrates the applicability of the quasi-static analysis for the nonlinear behavior analysis of a time-varying stochastic system.     

A heuristic for the Steiner problem in graphs

In this paper, we present a heuristic for the Steiner problem in graphs (SPG) along with some experimental results. The heuristic is based on an approach similar to Prim's algorithm for the minimum spanning tree. However, in this approach, arcs are associated with preference weights which are used to break ties among alternative choices of shortest paths occurring during the course of the algorithm. The preference weights are calculated according to a global view which takes into consideration the effect of all the regular nodes, nodes to be connected, on determining the choice of an arc in the solution tree.