Showing papers in "Modern Physics Letters B in 2010"
TL;DR: In this paper, the controllability of nonlinear second-order stochastic infinite-dimensional dynamical systems with impulsive effects is considered. And the results are obtained under the assumption that the associated linear system is approximately controllable.
Abstract: Many practical systems in physical and biological sciences have impulsive dynamical behaviors during the evolution process which can be modeled by impulsive differential equations. In this paper, the approximate controllability of nonlinear second-order stochastic infinite-dimensional dynamical systems with impulsive effects is considered. By using the Holder's inequality, stochastic analysis and fixed point strategy, a new set of necessary and sufficient conditions are formulated which guarantees the approximate controllability of the nonlinear second-order stochastic system. The results are obtained under the assumption that the associated linear system is approximately controllable.
70 citations
TL;DR: In this article, the exponential stability of stochastic neural networks of neutral type with impulsive effects was investigated. And a new stability criterion was derived in terms of linear matrix inequality, which was used to show the effectiveness and applicability of the obtained result.
Abstract: This paper is concerned with the exponential stability of stochastic neural networks of neutral type with impulsive effects. By employing the Lyapunov functional and stochastic analysis, a new stability criterion for the stochastic neural network is derived in terms of linear matrix inequality. A numerical example is provided to show the effectiveness and applicability of the obtained result.
44 citations
TL;DR: In this article, a novel system of the dynamic potential well generation and control using light pulse control within an add/drop optical filter is proposed. But the system is not suitable for the use of optical tweezers.
Abstract: We propose a novel system of the dynamic potential well generation and control using light pulse control within an add/drop optical filter. The multiplexing signals of the dark solition with bright/Gaussian pulses are controlled, tuned and amplified within the system. The optical storage rings are embedded within the add/drop optical filter system, whereas the generated optical signals can be stored and amplified within the design system. In application, the storage signals can be configured to be an optical trapping tool which is known as optical tweezers, where the high field peak or well can be formed. The advantages are that the dynamic well can be stored and the array of well can be generated for multiple well applications. The difference in time of the first two dynamic wells of 1 ns is noted.
43 citations
TL;DR: In this paper, the influence of high pressure on the conductivity in the abplane of the oxygen deficient YBa2Cu3O7-δ single crystals is investigated.
Abstract: The influence of high pressure on the conductivity in the ab-plane of the oxygen deficient YBa2Cu3O7-δ single crystals is investigated. It is determined that excess conductivity Δσ(T) in the YBa2Cu3O7-δ single crystals in a wide temperature interval (Tc < T < T*, where Tc is the critical temperature and T* is the temperature that the PG regime begins) obeys an exponential temperature-dependence. The description of the excess conductivity with ) can be interpreted in terms of mean field theory. The temperature-dependence of the pseudo-gap is well described in the framework of the Bardeen–Cooper–Schrieffer (BCS) to the Bose–Einstein condensate (BEC) crossover theory. Increasing the applied pressure leads to the effect of narrowing the temperature range of implementation of the PG regime, thus extending the area of linear ρ(T) dependence in the ab-plane.
42 citations
TL;DR: In this paper, the exact traveling wave solutions of (4 + 1)-dimensional nonlinear Fokas equation are obtained by using three distinct methods with symbolic computation: modified tanh-coth method, extended Jacobi elliptic function method, and generalized wave solution with some free parameters.
Abstract: The exact traveling wave solutions of (4 + 1)-dimensional nonlinear Fokas equation is obtained by using three distinct methods with symbolic computation. The modified tanh–coth method is implemented to obtain single soliton solutions whereas the extended Jacobi elliptic function method is applied to derive doubly periodic wave solutions for this higher-dimensional integrable equation. The Exp-function method gives generalized wave solutions with some free parameters. It is shown that soliton solutions and triangular solutions can be established as the limits of the Jacobi doubly periodic wave solutions.
39 citations
TL;DR: In this article, the authors obtained an exact 1-soliton solution of the generalized Radhakrishnan, Kundu, Lakshmanan equation with nonlinear dispersion. And they proved that dark optical solitons can exist only when the power law nonlinearity reduces to Kerr law.
Abstract: This paper talks about obtaining an exact 1-soliton solution of the generalized Radhakrishnan, Kundu, Lakshmanan equation with nonlinear dispersion. The solitary wave ansatz will be used to carry out the integration. It will be proved that dark optical solitons can exist only when the power law nonlinearity reduces to Kerr law.
32 citations
TL;DR: In this paper, the authors proposed the necessary and sufficient conditions for turbulent transition in pressure-driven and shear-driven flow, respectively, based on the energy gradient method, and showed that turbulent transition can be effected via a singularity of the gradient function which may be associated with the chaotic attractor in dynamic system.
Abstract: Based on the energy gradient method, criteria for turbulent transition are proposed for pressure driven flow and shear driven flow, respectively. For pressure driven flow, the necessary and sufficient condition for turbulent transition is the presence of the velocity inflection point in the averaged flow. For shear driven flow, the necessary and sufficient condition for turbulent transition is the existence of zero velocity gradient in the averaged flow profile. It is shown that turbulent transition can be effected via a singularity of the energy gradient function which may be associated with the chaotic attractor in dynamic system. The role of disturbance in the transition is also clarified in causing the energy gradient function to approach the singularity. Finally, it is interesting that turbulence can be controlled by modulating the distribution of the energy gradient function.
30 citations
TL;DR: New delay-dependent criteria for checking the asymptotic stability of the neural networks are established in terms of linear matrix inequalities, which can be easily solved and checked by various convex optimization algorithms.
Abstract: In this paper, the problem of stability analysis of neural networks with discrete time-varying delays is considered. By constructing a new Lyapunov functional and some novel analysis techniques, new delay-dependent criteria for checking the asymptotic stability of the neural networks are established. The criteria are presented in terms of linear matrix inequalities, which can be easily solved and checked by various convex optimization algorithms. Three numerical examples are included to show the superiority of our results.
29 citations
TL;DR: In this article, the degree distribution of the Umpqua river series network, the Ocmlgee River series network and the subsequence of the Yangtze River series networks were analyzed from the view of complex networks.
Abstract: The daily streamflow series of three rivers are analyzed from the view of complex networks, i.e. the Yangtze River in China, the Umpqua River and the Ocmulgee River in the United States. We construct networks from these series by using the visibility graph algorithm respectively. The degree distribution and accumulative degree distribution are investigated. We find that the degree distribution of the Umpqua River series network, the Ocumlgee River series network and the subsequence of the Yangtze River series network can be better fitted by stretched exponential distribution (SED), although the degree distribution curves of these networks in a log–log plot have a linear part. Moreover, the slope α of the linear part and parameters μ in SED have significant meaning in the research of streamflow series properties.
29 citations
TL;DR: Based on the theory of interaction between high-intensity laser and materials, such as air and water, it is proved that transport in a water environment can be impulsed by laser as discussed by the authors.
Abstract: Problems that cumber the development of the laser propulsion in atmosphere and vacuum are discussed. Based on the theory of interaction between high-intensity laser and materials, such as air and water, it is proved that transport in a water environment can be impulsed by laser. The process of laser propulsion in water is investigated theoretically and numerically. It shows that not only the laser induced plasma shock wave can be used, but also the laser-induced bubble oscillation shock waves and the pressure induced by the collapsing bubble can be used. Many experimental results show that the theory and the numerical results are valid.
22 citations
TL;DR: In this paper, the resistance between two arbitrary lattice sites in an infinite square lattice of identical resistors is studied when the lattice is perturbed by substituting a single resistor using lattice Green's function.
Abstract: The resistance between two arbitrary lattice sites in an infinite square lattice of identical resistors is studied when the lattice is perturbed by substituting a single resistor using lattice Green's function. The relation between the resistance and the lattice Green's function for the perturbed lattice is derived. Solving Dyson's equation, the Green's function and the resistance of the perturbed lattice are expressed in terms of those of the perfect lattice. Numerical and experimental results are presented.
TL;DR: In this paper, the authors derived a mathematical model based on statistical treatment using the probability density function of the cavity mouth radius and existing correlation for active nucleation site density, the volume of single bubble at departure, the bubble departure diameter and bubble departure frequency.
Abstract: In this paper, dependence of active nucleation site density on boiling surfaces are developed. For pool boiling heat transfer, a mathematical model is derived based on statistical treatment using the probability density function of the cavity mouth radius and existing correlation for active nucleation site density, the volume of single bubble at departure, the bubble departure diameter and the bubble departure frequency. The proposed model is expressed as a function of wall superheat, the contact angle, maximum and minimum active cavities, and physical properties of fluid. It is shown that the wall heat flux can be determined by the consideration of the variation of the cavity mouth radius. A good agreement between the proposed model predictions and experimental data is found for different contact angles. It also turns out that the present model explains well the mechanism on how wettability affects the pool boiling.
TL;DR: A fuzzy logic system is employed to describe the unknown nonlinear function yielded by Ito's lemma due to the unknown diffusion matrices, and the response system is synchronized with the drive system within an arbitrarily small error bound.
Abstract: In this paper, we present a method for synchronizing two different chaotic systems that have unknown parameters that are affected by stochastic variations generated by the Wiener process. The parameters are expressed by the sum of their mean values and the white Gaussian noise multiplied by the diffusion matrices. To describe the unknown nonlinear function yielded by Ito's lemma due to the unknown diffusion matrices, a fuzzy logic system is employed. Using adaptive fuzzy control, the response system is synchronized with the drive system within an arbitrarily small error bound. Numerical simulations show the effectiveness of the proposed method.
TL;DR: In this article, a simple analytic tool, namely the general series expansion method, is proposed to find the solutions for nonlinear differential equations, where a set of suitable basis functions is chosen such that the solution to the equation can be expressed by.
Abstract: A simple analytic tool, namely the general series expansion method, is proposed to find the solutions for nonlinear differential equations. A set of suitable basis functions is chosen such that the solution to the equation can be expressed by . In general, t0 can control and adjust the convergence region of the series solution such that our method has the same effect as the homotopy analysis method proposed by Liao, but our method is simpler and clearer. As a result, we show that the secret parameter h in the homotopy analysis methods can be explained by using our parameter t0. Therefore, our method reveals a key secret in the homotopy analysis method. For the purpose of comparison with the homotopy analysis method, a typical example is studied in detail.
TL;DR: In this article, the influence of annealing temperature on the structural, morphological and optical properties of the as-deposited and annealed TiO2 thin films has been examined.
Abstract: TiO2 thin films have been deposited on glass and indium tin oxide (ITO) coated glass substrates by sol–gel technique. The influence of annealing temperature on the structural, morphological and optical properties has been examined. X-ray diffraction (XRD) results reveal the amorphous nature of the as-deposited film whereas the annealed films are found to be in the crystalline anatase phase. The surface morphology of the films at different annealing temperatures has been examined by atomic force microscopy (AFM). The in situ surface morphology of the as-deposited and annealed TiO2 films has also been examined by optical polaromicrograph (OPM). TiO2 films infatuated different structural and surface features with variation of annealing temperature. The optical studies on these films suggest their possible usage in sun-shielding applications.
TL;DR: In this article, the complementary roles that 119Sn Mossbauer spectroscopy and neutron diffraction are playing in developing a complete description of magnetic ordering in the R3 Cu4Sn4 and R3Ag4sn4 intermetallic compound series are reviewed.
Abstract: We review the complementary roles that 119Sn Mossbauer spectroscopy and neutron diffraction are playing in developing a complete description of magnetic ordering in the R3 Cu4Sn4 and R3Ag4Sn4 intermetallic compound series. We show that the two techniques yield consistent pictures of the order, and in many cases both are essential to obtaining a complete description. The recent neutron diffraction work on Sm3Cu4Sn4, Sm3Ag4Sn4 and Gd3Ag4Sn4 is highlighted.
TL;DR: A unified, information theoretic interpretation of the number-phase complementarity that is applicable both to finite-dimensional and infinite-dimensional systems is developed, with number treated as a discrete Hermitian observable and phase as a continuous positive operator valued measure (POVM).
Abstract: We develop a unified, information theoretic interpretation of the number-phase complementarity that is applicable both to finite-dimensional (atomic) and infinite-dimensional (oscillator) systems, with number treated as a discrete Hermitian observable and phase as a continuous positive operator valued measure (POVM). The relevant uncertainty principle is obtained as a lower bound on entropy excess, X, the difference between the entropy of one variable, typically the number, and the knowledge of its complementary variable, typically the phase, where knowledge of a variable is defined as its relative entropy with respect to the uniform distribution. In the case of finite-dimensional systems, a weighting of phase knowledge by a factor μ (> 1) is necessary in order to make the bound tight, essentially on account of the POVM nature of phase as defined here. Numerical and analytical evidence suggests that μ tends to 1 as the system dimension becomes infinite. We study the effect of non-dissipative and dissipative noise on these complementary variables for an oscillator as well as atomic systems.
TL;DR: Based on the field enhancement principle of trapped modes, two new asymmetric metamaterial resonators are presented in this article, which can be flexibly tailored to design requirement by varying the asymmetry parameter or the topological structure of the resonator.
Abstract: Based on the field enhancement principle of trapped modes, two new asymmetric metamaterial resonators are presented. Transmission response (S21) of the rectangular wave-guide filled with an asymmetric metamaterial resonator is simulated. Results show that the asymmetric resonator possesses high Q-factor and improved sensitivity. The microwave sensor based on the asymmetric resonator can be flexibly tailored to design requirement by varying the asymmetry parameter or the topological structure of the resonator. The asymmetric metamaterial resonator-assisted microwave sensor will have potential applications in biosensor and chemosensor fields for sensing minute amounts of dielectric sample substance.
TL;DR: In this paper, the multisoliton solutions in Hirota's forms for isospectral and non-ispectral modified Kadomtsev-Petviashvili equation (mKP) were studied.
Abstract: The phenomena of soliton resonance can occur in (2+1)-dimensional modified Kadomtsev–Petviashvili equation (mKP). In this paper, we study the multisoliton solutions in Hirota's forms for isospectral and non-isospectral mKP. We take two-soliton solutions as examples to investigate soliton resonances occurring in uniform and non-uniform media according to different values of the phase shift parameter.
TL;DR: In this article, the electrical and optical properties of a new material containing polymer-clay nano-composite dispersed in a nematic liquid were examined, which was modified by copolymerization of maleic anhydride and divinyl benzene using azobisisobutytironitrile as the initiator.
Abstract: We examined the electrical and optical properties of a new material containing polymer–clay nano-composite dispersed in a nematic liquid. The clay (Cloisite-type) was modified by copolymerization of maleic anhydride and divinyl benzene, using azobisisobutytironitrile as the initiator. The final polymer–clay nano-composite has an intercalated structure according to XRD patterns. We measured the thermally stimulated depolarization currents and determined the activation energies. Simultaneously we measured the optical transmission and we studied the influence of the previously applied polarizing electric fields.
TL;DR: In this paper, the influence of spontaneously generated coherence on the linear absorption and Kerr nonlinearity in a three-level atomic system was investigated. And the authors showed that the effect of spontaneous coherence can be dramatically affected by the effect on the absorption.
Abstract: In a three-level atomic system, the influences of spontaneously generated coherence on the linear absorption and the Kerr nonlinearity are investigated. Our studies show that properties of linear absorption can be dramatically affected by the effect of spontaneously generated coherence. With increase of intensities of spontaneously generated coherence, absorption inhibition will occur, and finally the atomic medium becomes transparent. Furthermore, we find that the Kerr nonlinearity can be obviously enhanced under the action of effects of spontaneously generated coherence. Comparing with traditional scheme of the electromagnetically induced transparency, absorption and Kerr nonlinearity can be controlled without need another driving field in our scheme.
TL;DR: In this paper, the authors presented new empirical relations to evaluate opto-electronic properties such as refractive index (n), band gap (Eg) and optical electronegativity (Δχ) in terms of electronic structure of atoms and crystal structure of materials.
Abstract: In this paper, we present new empirical relations to evaluate opto-electronic properties such as refractive index (n), band gap (Eg) and optical electronegativity (Δχ) in terms of electronic structure of atoms (i.e. valence electrons) and crystal structure of materials (i.e. nearest-neighbor distance, d) for zinc blende (AIIBVI and AIIIBV) and chalcopyrites ( and ) structured solids. The refractive index (n), band gap (Eg) and optical electronegativity (Δχ) of these solids exhibit a linear relationship when plotted against the nearest-neighbor distance d (A), but fall on different straight lines according to the product of the valence electron of the compounds. We have applied the proposed relation on these solids and found a better agreement with the experimental data as compared to the values evaluated by earlier researchers.
TL;DR: In this paper, the dielectric properties and electrical conductivity of different concentrations of poly methylmethacrylate (PMMA)/fullerene C60 composites have been reported at room temperature in the frequency range from 1 kHz to 5 MHz.
Abstract: Dielectric properties and electrical conductivity of different concentrations of Poly methylmethacrylate (PMMA)/fullerene C60 composites have been reported at room temperature in the frequency range from 1 kHz to 5 MHz. The frequency dependence of complex permittivity, e*, and complex electrical modulus, M*, have been measured. Frequency dependence of dielectric constant, follows Cole–Cole dielectric relaxation equations, was investigated diagrammatically. Moreover, equations of Tsangaris et al. have been tested for our case to describe the dielectric behavior of particulate polymeric composite containing fillers which give a satisfactory agreement taking into account the variation of the aspect ratio with the volume fraction of fullerene C60 doped in the PMMA matrix.
TL;DR: Using the complete discrimination system for polynomial method, this article studied the (2+1)-dimensional Davey-Stewartson equation and obtained the classifications of all envelope traveling wave solutions.
Abstract: Using the complete discrimination system for polynomial method, we study the (2+1)-dimensional Davey–Stewartson equation and obtain the classifications of all its envelope traveling wave solutions This is very convenient in practice to give the corresponding solutions for the concrete parameters
TL;DR: In this article, the long-range interaction in nano-grain BaTiO3 nanocrystals with 180 degree nano-domains was calculated and the relationship between grain size and domain size was analyzed.
Abstract: The size effect of nano-grain BaTiO3 ceramics has been studied in this paper. We assume that the surface charge does not fully compensate long-range Coulomb interaction, so that 180 degree nano-domains still exists in small BaTiO3 particles. We have calculated the long-range interaction in BaTiO3 nanocrystals with 180 degree nano-domains, and obtained the relationship between grain size and domain size. The relation between transition temperature and grain size is also obtained by incorporating the domain-wall energy into the Landau–Ginzburg free-energy density. The results show that with decreasing grain size the transition temperature of cubic-tetragonal phase decreases, while those of tetragonal-orthorhombic and orthorhombic-rhombohedral phases increase. Our model predicts that with further reduction of grain size, the structures of ferroelectric phase becomes unstable and gradually disappears, leaving only one stable structure of cubic phase. In addition, an interesting conclusion is that a quadruple ...
TL;DR: In this article, the authors investigated the dynamic responses of the metal core piezoelectric fibers to unsteady airflow and found that the maximum voltage and the steady-state velocity were also related.
Abstract: In the previous study, possible applications of metal core piezoelectric fibers with a diameter of 200 to 250 µm as bionic airflow sensors mimicking the flow sensitive receptor hairs of crickets have been proposed. This study aims to investigate the dynamic responses of the metal core piezoelectric fibers to unsteady airflow. The metal core piezoelectric fiber is half coated on the outer surface and is used in the bending mode. Wind tunnel tests were carried out and the output voltage of the fiber under the excitation of the unsteady aerodynamic force during flow acceleration and deceleration was measured when the wind tunnel was suddenly closed or opened by a shutter. The relationship between the maximum voltage and the steady-state velocity and that between the voltage and the acceleration of flow were also obtained.
TL;DR: In this article, the perturbation formulas of the spin Hamiltonian parameters for a 4f9 ion in tetragonal symmetry were derived from the ZrSiO4 crystal, and the contributions to g factors due to the J-mixing among the ground 6H15/2, the first excited 6H13/2 and second excited 6h11/2 states via crystal-field interaction, the admixtures among the states with the same J value via spin-orbit coupling interaction and the interactions between the lowest Kramers doublet Γγ and other
Abstract: The electronic paramagnetic resonance g factors g‖, g⊥ of Dy3+ centers and the hyperfine structure constants A‖ and A⊥ of 161Dy3+ and 163Dy3+ isotopes in ZrSiO4 crystal are theoretically studied from the perturbation formulas of the spin Hamiltonian parameters for a 4f9 ion in tetragonal symmetry. In these formulas, the contributions to g factors due to the J-mixing among the ground 6H15/2, the first excited 6H13/2 and second excited 6H11/2 states via crystal-field interaction, the admixtures among the states with the same J value via spin-orbit coupling interaction and the interactions between the lowest Kramers doublet Γγ and other 20 Kramers doublets ΓX within the states 6HJ (J=15/2, 13/2 and 11/2) via crystal-field and orbital angular momentum interactions are considered. The calculated EPR parameters show reasonable agreement with the observed values. The results are discussed.
TL;DR: In this paper, the authors construct two sets of symmetries for the isospectral differential differential difference Kadomstev-Petviashvili hierarchy, which form an infinite dimensional Lie algebra.
Abstract: By introducing suitable non-isospectral flows, we construct two sets of symmetries for the isospectral differential–difference Kadomstev–Petviashvili hierarchy. The symmetries form an infinite dimensional Lie algebra.
TL;DR: In this paper, two different approaches to study thermal expansion and compression of nanosystems are unified, which have been treated quite independently by earlier workers, by providing the simple theoretical analysis, which demonstrates that these two approaches may be unified into a single theory, viz.
Abstract: Two different approaches to study thermal expansion and compression of nanosystems are unified, which have been treated quite independently by earlier workers. We provide the simple theoretical analysis, which demonstrates that these two approaches may be unified into a single theory, viz. one can be derived from other. It is concluded that there is a single theory in the place of two different approaches. To show the real connection with the nanomaterials, we study the effect of temperature (at constant pressure), the effect of pressure (at constant temperature) as well as the combined effect of pressure and temperature. We have considered different nanomaterials viz. carbon nanotube, AlN, Ni, 80Ni–20Fe, Fe–Cu, MgO, CeO2, CuO and TiO2. The results obtained are compared with the available experimental data. A good agreement between theory and experiment demonstrates the validity of the present approach.
TL;DR: In this paper, the grand potentials of ideal quantum gases, the number of particles, internal energy, three diagonal components of the pressure tensor, and other thermodynamic quantities of the ideal quantum gas systems confined in a rectangular box are analytically derived.
Abstract: Based on the grand potentials of ideal quantum gases, the number of particles, internal energy, three diagonal components of the pressure tensor, and other thermodynamic quantities of the ideal quantum gas systems confined in a rectangular box are analytically derived. It is found that the internal energy of the systems is non-extensive and that the other thermodynamic quantities, which are extensive under the thermodynamic limit condition, are also non-extensive. It is also found that the pressure tensor of the quantum gas systems in a confined space is, in general, no longer isotropic because of the geometric effect of the boundary. Moreover, the influence of the size effect of the containers on the properties of the systems and the thermosize effects in the confined quantum gas systems such as the Seebeck-like, Peltier-like and Thomson-like thermosize effects are discussed with the help of the assumption of local equilibrium. It is very significant to note that the new concept of the "mix" heat capacity, which is neither the heat capacity at constant pressure nor the heat capacity at constant volume, must be introduced in the investigation of Thomson-like thermosize effect. The results obtained may be directly used to analyze the thermodynamic properties and thermosize effects of the confined classical gas.