International Journal of Modern Physics B

We show theoretically that the optical properties of one-dimensional metallic photonic crystals can be enhanced considerably over the corresponding constituent metal. By properly choosing the structural and material parameters, the optical properties of one-dimensional metallic-dielectric photonic crystals can be enhanced by one order of magnitude in the visible and in the THz regions.

The dynamic features of soliton transporting the bio-energy in the α-helix protein molecules with three channels under influences of temperature of systems and chain–chain interaction among these channels have been numerically studied by using the dynamic equations in a new model and the fourth-order Runge–Kutta method. This result obtained shows that the chain–chain interaction depresses the stability of the soliton due to the dispersed effect, but the stability of the soliton in the case of simultaneous motivation of three channels by an initial conditions is better than that in another initial condition. We also find from this investigation that the new soliton can transport steadily over 1000 amino acid residues in the cases of motion of long time of 120 ps, and retain their shapes and energies to travel towards the protein molecules after mutual collision of the solitons at the biological temperatures of 300 K. Therefore the soliton is very robust against the thermal perturbation of the α-helix protein molecules at 300 K. From the investigation of changes of features of the soliton with increasing temperature, we find that the amplitudes and velocities of the solitons decrease with increasing temperature of proteins, but the soliton disperses in the cases of higher temperature of 325 K and larger structure disorders. Thus we find that the critical temperature of the soliton occurring in the α-helix protein molecules is about 320 K. Therefore we can conclude that the soliton in the new model can play an important role in the bio-energy transport in the α-helix protein molecules with three channels at biological temperature, and the new model is possibly a candidate for the mechanism of this transport.

A soft approach has been described for the formation of α–Fe₂O₃ nanorods by simple reaction of iron with water at a very low temperature range of 100–300°C. It is shown that the nanorods have diameters ranging from 50–80 nm, and their typical lengths are in the range of 5–10 μm. The chemical composition and crystalline structure of nanorods were investigated by various characterization techniques. The initial formation and subsequent growth of α–Fe₂O₃ nanostructures may be explained by the iron metal corrosion mechanism.

In this paper, we study Susskind–Glogower phase distribution of entangled state in the framework of interactions involving two modes of interacting Fock space which in its turn provides an interesting insigth into the structure of entangled state.

In this paper, we mainly investigate the character of consensus convergence speed of Multi-Agent Systems (MAS) with small-world communication network and the method of devising a speed-optimized small-world communication network in consensus problem based on genetic-algorithm (GA). It is found that, for a small-world communication network, the time to reach a consensus changes rapidly with the change of the number of long-range communication links and the agents which the long-range links connect. The convergence speed of consensus of MAS increases rapidly with the number of long-range links increasing. As we construct a small-world communication network for MAS with a smaller network size and fixed long-range links, we can optimize the long-range link configuration using GA methodology to obtain a small-world communication network with faster consensus speed for MAS.

In this study, a fiber Bragg grating sensor for temperature measurement is proposed and experimentally demonstrated. In particular, we point out that the method is well-suited for monitoring temperature because they are able to withstand a high temperature environment, where standard thermocouple methods fail. The interrogation technologies of the sensor systems are all simple, low cost and effective as well. In the sensor system, fiber grating was dipped into a water beaker that was placed on a hotplate to control the temperature of water. The temperature was raised in equal increments. The sensing principle is based on tracking of Bragg wavelength shifts caused by the temperature change. So the temperature is measured based on the wavelength-shifts of the FBG induced by the heating water. The fiber grating is high temperature stable excimer-laser-induced grating and has a linear function of wavelength-temperature in the range of 0–285°C. A dynamic range of 0–285°C and a sensitivity of 0.0131 nm/°C almost equal to that of general FBG have been obtained by this sensor system. Furthermore, the correlation of theoretical analysis and experimental results show the capability and feasibility of the purposed technique.

We investigate dynamics properties of proton transfer in hydrogen-bonded ferroelectrics with asymmetric double-well potential, in an externally applied field, based on a two-component model. We obtain the equations of motion and their soliton solution. The soliton velocity and conductivity are found; this expression shows that the phase-transition critical index is equal to unity, and this value coincides quite well with the experimental result.

The effects of vacancies on the strength and elastic constants of silicon, such as Young's modulus and Poisson's ratio are investigated using the molecular dynamics simulations with the Stillinger–Weber potential. The defected crystalline cells contain randomly generated defect distributions in the simulation models. The ideal strength is found to be 33.6 GPa at the strain 0.26. The Young's modulus and Poisson's ratio is 148 GPa and 0.252, respectively. It is found that the strength decreases as the point defect fraction increases, and the variation of the strength versus the point defect fraction coincides with a decaying exponential function. In addition, vacancies are shown to reduce the elastic constants. In general, the elastic constants of silicon vary linearly versus the defect fraction.

We have used the lowest order constrained variational (LOCV) method to calculate some ground-state properties of polarized liquid ³ He at zero temperature with the spin-dependent correlation function employing the Lennard–Jones and Aziz pair potentials. We have seen that the total energy of polarized liquid ³He increases with increasing polarization. For all polarizations, it is shown that the total energy in the spin-dependent case is lower than the spin-independent case. We have seen that the difference between the energies of spin-dependent and spin-independent cases decreases by increasing the polarization. We have shown that the main contribution of the potential energy comes from the spin-triplet state.

In this paper, a nonisospectral and variable-coefficient Korteweg-de Vries equation is investigated based on the ideas of the variable-coefficient balancing-act method and Hirota method. Via symbolic computation, we obtain the analytic N-soliton solutions, variable-coefficient bilinear form, auto-Bäcklund transformations (in both the bilinear form and Lax pair form), Lax pair and nonlinear superposition formula for such an equation in explicit form. Moreover, some figures are plotted to analyze the effects of the variable coefficients on the stabilities and propagation characteristics of the solitonic waves.

In this study, titanium dioxide (TiO₂) thin films were deposited on unheated glass substrates using an unbalanced magnetron sputtering system with different deposition times of 25, 35 and 45 min, respectively. The structure and surface morphology of TiO₂ thin films were characterized by atomic force microscopy (AFM) and transmission electron microscopy (TEM) with selected-area electron diffraction (SAED). It was found that the crystallite size of TiO₂ thin films was in the range of 10–20 nm, and the surface roughness was 1–3 nm. The SAED patterns show that the phase of TiO₂ thin films obtained in this study is anatase phase.

The electronic band structure and optical properties of the ferroelectric single crystal KIO₃ have been investigated using the density functional methods. The calculated band structure for KIO₃ evidences that the crystal has a direct band gap with a value of 2.83 eV. The structural optimization has been performed. The real and imaginary parts of dielectric function, energy-loss function for volume and surface, and refractive index are calculated along the crystallographic axes.