Physical Review E

We present a detailed numerical study of dynamical heterogeneities in the aging regime of a simple binary Lennard-Jones glass former. For most waiting times t_w and final times t , both the dynamical susceptibility χ₄(t,t_w) and the dynamical correlation length ξ₄(t,t_w) can be approximated as...

For noisy self-sustained oscillators, both reliability, the stability of a response to a noisy driving, and coherence, understood in the sense of constancy of oscillation frequency, are important characteristics. Although both characteristics and techniques for controlling them have received great a...

Demographic noise causes unlimited population growth in a broad class of models which, without noise, would predict a stable finite population. We study this effect on the example of a stochastic birth-death model which includes immigration, binary reproduction, and death. The unlimited population g...

We formulate the generalized master equation for a class of continuous-time random walks in the presence of a prescribed deterministic evolution between successive transitions. This formulation is exemplified by means of an advection-diffusion and a jump-diffusion scheme. Based on this master equati...

We show, both heuristically and numerically, that three-dimensional periodic Lorentz gases—clouds of particles scattering off crystalline arrays of hard spheres—often exhibit normal diffusion, even when there are gaps through which particles can travel without ever colliding—i.e., when the sys...

We investigate the microscopic structure of strongly coupled ions in warm dense matter using ab initio simulations and hypernetted chain (HNC) equations. We demonstrate that an approximate treatment of quantum effects by weak pseudopotentials fails to describe the highly degenerate electrons in warm...

Telechelic star polymers are macromolecules with functionalized, mutually attractive end groups. We employ computer simulations on a lattice to investigate the phase behavior of trifunctional telechelic stars as a function of the fraction λ of attractive terminal monomers. We find macrophase sepa...

The high linear charge density of 20-base-pair oligomers of DNA is shown to lead to a striking nonmonotonic dependence of the long-time self-diffusion on the concentration of DNA in low-salt conditions. This generic nonmonotonic behavior results from the strong coupling between the electrostatic and...

We discuss elastic effects due to lattice strain which are a new key ingredient in the theory of dendritic growth for solid-solid transformations. Both thermal and elastic fields are eliminated by Green’s function techniques, and a closed nonlinear integro-differential equation for the evolution o...

The solvation force for two-dimensional Ising strips is calculated via exact diagonalization of the transfer matrix in two cases: the symmetric case corresponds to identical surface fields and the antisymmetric case to exactly opposite surface fields. In the symmetric case the solvation force is alw...

The ability to exert a significant degree of pore structure control in porous silicon materials has made them attractive materials for the experimental investigation of the relationship between pore structure, capillary condensation, and hysteresis phenomena. Using both experimental measurements and...

It is found that a micrometer-sized droplet in an aqueous solution of binary polymers [water/polyethylene-glycol (PEG)/dextran] disappears upon irradiation with a focused yttrium-aluminum-garnet laser. The interface of the dextran-rich droplet broadens and disappears, and it reappears upon turning t...

The dynamics of a network model of astrocytes coupled by gap junctions is investigated. Calcium dynamics of the single cell is described by the biophysical model comprising the set of three nonlinear differential equations. Intercellular dynamics is provided by the diffusion of inositol 1,4,5-trisph...

Telomeres are DNA repeats protecting chromosomal ends which shorten with each cell division, eventually leading to cessation of cell growth. We present a population mixture model that predicts an exponential decrease in telomere length with time. We analytically solve the dynamics of the telomere le...

We present an elastic model for B-form DNA with variable radius to study the elastic twist-stretch coupling of stretched DNA. In this model, only two strain variables as well as the changes in the energy of the hydrogen and covalent bonds of DNA during the deformation are considered. It is found tha...

We define a minimal model of traffic flows in complex networks in order to study the trade-off between topological-based and traffic-based routing strategies. The resulting collective behavior is obtained analytically for an ensemble of uncorrelated networks and summarized in a rich phase diagram pr...

We introduce the concept of entropy rate to characterize a diffusion process on a complex network. The entropy rate represents the minimal amount of information necessary to describe the diffusion on the network, and is a quantity extremely sensitive to the network topology and dynamics. By opportun...

Critical phenomena in globally coupled excitable elements are studied by focusing on a saddle-node bifurcation at the collective level. Critical exponents that characterize divergent fluctuations of interspike intervals near the bifurcation are calculated theoretically. The calculated values appear ...

Frequency entrainment and nonlinear synchronization are commonly observed between simple oscillatory systems, but their occurrence and behavior in continuum fluid systems are much less well understood. Motivated by possible applications to geophysical fluid systems, such as in atmospheric circulatio...

It has recently been found in some dynamical systems in fluid dynamics that only a few unstable periodic orbits (UPOs) with low periods can give good approximations to the mean properties of turbulent (chaotic) solutions. By employing three chaotic systems described by ordinary differential equation...

We present a dynamical system that naturally exhibits two unstable attractors that are completely enclosed by each other’s basin volume. This counterintuitive phenomenon occurs in networks of pulse-coupled oscillators with delayed interactions. We analytically show that upon continuously removing ...

We measure the transmission and reflection amplitudes of microwaves in a resonator coupled to two antennas at room temperature in the regime of weakly overlapping resonances and in a frequency range of 3–16   GHz . Below 10.1   GHz the resonator simulates a chaotic quantum system. The...

It is shown that the pulses which develop in the NO+H₂ reaction on an alkali promoted Rh(110) surface reaction can transport alkali metal. This leads to the accumulation of a substantial alkali-metal concentration in the collision area of pulse trains. Realistic simulations revealed that the effec...

We consider evaporation of pure liquid drops on a thermally conductive substrate. Two commonly used evaporative models are considered: one that concentrates on the liquid phase in determining the evaporative flux and the other one that centers on the gas-vapor phase. A single governing equation for ...

A Hohlraum-like configuration is proposed for realizing a simple compact source for neutrons. A laser pulse enters a tiny thin-shelled hollow-sphere target through a small opening and is self-consistently trapped in the cavity. The electrons in the inner shell-wall region are expelled by the light p...

Modulational excitation of longitudinal photons and electron Langmuir waves, as well as ion sound waves by an incoherent strong and superstrong radiation (high-power short pulse lasers, nonthermal equilibrium cosmic field radiation, etc.), in plasmas, is investigated. A simultaneous generation of lo...

A class of nonautonomous nonlinear Schrödinger equations, claiming to be novel integrable systems with rich properties, continues to appear in the literature. All such equations are shown to be not new, but equivalent to the standard autonomous equation, which trivially explains their integrability...

The theory of linear mode conversion near evanescent layers is generalized for non-one-dimensionally inhomogeneous gyrotropic media. Effects are found that cannot be described within the standard one-dimensional paradigm of wave tunneling through the evanescent region when the mode coupling region a...

We solve analytically the multiple-scattering equations for two-dimensional photonic crystals in the long-wavelength limit. Different approximations of the electric and magnetic susceptibilities are presented from a unified pseudopotential point of view. The nature of the so-called plasmon-polariton...

The migration of a particle in a system of obstacles under the action of an external field is often modeled using lattice Monte Carlo algorithms. For example, such simulation methods have been used to study the electrophoresis of charged molecules in sieving gels and the separation of particles usin...

Telechelic star polymers are macromolecules with functionalized, mutually attractive end groups. We employ computer simulations on a lattice to investigate the phase behavior of trifunctional telechelic stars as a function of the fraction λ of attractive terminal monomers. We find macrophase sepa...

We consider coherent exciton transport modeled by continuous-time quantum walks on long-range interacting cycles (LRICs), which are constructed by connecting all the two nodes of distance m in the cycle graph. LRIC has a symmetric structure and can be regarded as the extensions of the cycle graph ...

We evaluate the azimuthal anchoring energy of a grooved surface by calculating numerically the Frank elastic energy of a nematic cell composed of the grooved surface and a flat one with rigid azimuthal anchoring, where the director is fixed along the ϕ direction. We pay attention to the surface a...

In this paper, the response of single three-dimensional phantom and self-avoiding polymers to localized step strains are studied for two cases in the absence of hydrodynamic interactions: (i) Polymers tethered at one end with the strain created at the point of tether, and (ii) free polymers with the...

The low-frequency limit of the electrical conductivity (dc conductivity) of differently flexible polyions in aqueous solutions has been measured over an extended polyion concentration range, covering both the dilute and semidilute (entangled and unentangled) regime, up to the concentrated regime. Th...

We present a thermodynamically guided, low-noise, time-scale-bridging, and pertinently efficient strategy for the dynamic simulation of microscopic models for complex fluids. The systematic coarse-graining method is exemplified for low-molecular polymeric systems subjected to homogeneous flow fields...

We study the effect of delay on the synchronization of two nerve impulses traveling along two ephaptically coupled, unmyelinated nerve fibers. The system is modeled as a pair of delay-coupled Fitzhugh-Nagumo equations. A multiple-scale perturbation approach is used for the analysis of these equation...

The doubly deprotonated [Asn,Val⁵] angiopeptide, in the gas phase, was irradiated with 266   nm photons. The time of flight (TOF) of the products formed following photoabsorption, namely, the monoanion and neutral fragments, was recorded with submicrosecond time resolution. Monte Carlo simu...

We propose a multiscale approach to understand the physics related to ion-beam cancer therapy. It allows the calculation of the probability of DNA damage as a result of irradiation of tissues with energetic ions, up to 430   MeV∕u . This approach covers different scales, starting from the la...

We use a long, all-atom molecular-dynamics (MD) simulation combined with theoretical modeling to investigate the dynamics of selected lipid atoms and lipid molecules in a hydrated diyristoyl-phosphatidylcholine lipid bilayer. From the analysis of a 0.1   μs MD trajectory, we find that the ti...

The dynamics of lines composed of two monatomic steps of opposite sign and periodically spaced on a crystal surface has been investigated under electromigration. It is found that, when adatoms have a diffusion bias parallel to the step edges, lines may become unstable with respect to shape fluctuati...

We define a minimal model of traffic flows in complex networks in order to study the trade-off between topological-based and traffic-based routing strategies. The resulting collective behavior is obtained analytically for an ensemble of uncorrelated networks and summarized in a rich phase diagram pr...

We study a spatial two-strategy (cooperation and defection) prisoner’s dilemma game with two types ( A and B ) of players located on the sites of a square lattice. The evolution of strategy distribution is governed by iterated strategy adoption from a randomly selected neighbor with a probabilit...

Frequency entrainment and nonlinear synchronization are commonly observed between simple oscillatory systems, but their occurrence and behavior in continuum fluid systems are much less well understood. Motivated by possible applications to geophysical fluid systems, such as in atmospheric circulatio...

In order to simulate observational and experimental situations, we consider a leak in the phase space of a chaotic dynamical system. We obtain an expression for the escape rate of the survival probability by applying the theory of transient chaos. This expression improves previous estimates based on...

We study synchronization of unidirectionally coupled optical bistable systems. In particular, we consider two semiconductor lasers with an external cavity, which exhibit, when isolated, coexistence of two different attractors: fixed point and chaos, fixed point and one periodic orbit, and two period...

We present microwave measurements for the density and spatial correlation of current critical points in an open billiard system and compare them with new and previous predictions of the random-wave model (RWM). In particular, due to an improvement of the experimental setup, we determine experimental...

We employ the Los Alamos suite of atomic physics codes to model the inner-shell x-ray emission spectrum of xenon and compare results with those obtained via high-resolution x-ray spectroscopy of xenon clusters irradiated by 30   fs Ti:Sapphire laser pulses. We find that the commonly employed ...

We introduce a system of linearly coupled parametrically driven damped nonlinear Schrödinger equations, which models a laser based on a nonlinear dual-core waveguide with parametric amplification symmetrically applied to both cores. The model may also be realized in terms of parallel ferromagnetic ...

A single-sided structure left-handed metamaterial (LHM), of which the symmetric paired split-ring resonators are connected directly through cut wires, is discussed in this paper. This connected single-sided LHM can exhibit a low loss and broad negative refraction passband. Good agreement of the retr...

A noninvasive optical technique combining digital interferometry in transmission and transparency measurement of concentration is developed to analyze spatiotemporal dynamics of physicochemical systems. This technique allows one to measure simultaneously the two-dimensional (2D) dynamics of concentr...

Two approaches for closing the turbulence subgrid-scale stress tensor in terms of matrix exponentials are introduced and compared. The first approach is based on a formal solution of the stress transport equation in which the production terms can be integrated exactly in terms of matrix exponentials...

We studied the dynamics of a single sonoluminescing bubble (SBSL) in a liquid hammer device. In particular, we investigated the phosphoric acid–xenon system, in which pulses up to four orders of magnitude brighter than SBSL in water systems (about 10¹² photons per pulse) have been previously rep...

The interaction between microbubbles through pressure pulses has been studied to show that it can be a source of cavitation noise. A recent report demonstrated that the acoustic noise generated by a shrimp originates from the collapse of a cavitation bubble produced when the shrimp closes its snappe...

We introduce a new family of molecular rotors that may convert light or chemical energy into directed translational motion along surfaces. The dependencies of diffusion coefficient and drift velocity of the rotating molecule on the magnitude of external torque, symmetry of surface potential and temperature have been investigated. Our simulations show that, for the optimal choice of system parameters, the rotation-translation coupling could be very efficient, and the molecule may move by approximately one surface lattice spacing per complete rotation. We have found that the unidirectionality of the rotary motion is not required to produce efficient directed sliding; this effect can be achieved by applying an oscillatory torque which induces alternating molecular reorientations but does not generate complete rotations.

The ferromagnetic phase of an Ising model in d=3, with any amount of q uenchedantiferromagnetic bond randomness, is shown to undergo a transition to a spin-glass phase under sufficient quenched bond dilution. This general result, demonstrated here with the numerically exact global renormalization-group solution of a d=3 hierarchical lattice, is expected to hold true generally, for the cubic lattice and for quenched site dilution. Conversely, in the ferromagnetic-spinglass-antiferromagnetic phase diagram, the spin-glass phase expands under quenched dilution at the expense of the ferromagnetic and antiferromagnetic phases. In the ferro-spinglass phase transition induced by quenched dilution reentrance as a function of temperature is seen, as previously found for the ferro-spinglass transition induced by increasing the antiferromagnetic bond concentration. PACS numbers: 75.10.Nr, 64.60.ah, 75.50.Lk, 05.10.Cc

We perform molecular dynamics simulation of a small number of particles in a box with periodic boundary conditions from a view point of chaotic dynamical systems. There is a transition at a critical energy Ec that each particle is confined in each unit cell for E < Ec, and the chaotic diffusion occurs for E > Ec. We find an anomalous behavior of the jump frequency above the critical energy in a two-particle system, which is related with the infinitely alternating stability change of the straight motion passing through a saddle point. We find simultaneous jump motions just above the critical energy in a four-particle system and sixteen-particle system, which is also related with the motion passing through the saddle point.

We study the Bose-Hubbard model with an external harmonic field, which is effective for modeling a cold atomic Bose gas trapped in an optical lattice. We modify the directed-loop algorithm (DLA) to simulate large systems efficiently. As a demonstration we carry out the simulation of a system consisting of 1.8 ×105 particles on a 643 lattice. These numbers are comparable to those in the pioneering experimental work by Greiner et al. [Nature 415, 39 (2002)]. Furthermore, we observe coherence between two superfluid spheres separated by a Mott insulator region in a `wedding-cake' structure.

Nonzero currents characterize the nonequilibrium state in stochastic dynamics (or master equation) models of natural systems. In such models there is a matrix, R, of transition probabilities connecting the states of the system. We show that if the strength of a transition increases, so does the current along the corresponding bond. We also address the inverse problem: given a set of observed currents, we show the extent to which the original "R" can be recovered. These considerations lead to a general discussion of time scales and substance flows.

With Monte Carlo simulations, we investigate the relaxation dynamics of domain walls at the Kosterlitz-Thouless phase transition, taking the two-dimensional XY model as an example. The dynamic scaling behavior is carefully analyzed, and a domain-wall roughening process is observed. Two-time correlation functions are calculated and ageing phenomena are investigated. Inside the domain interface, a strong logarithmic correction to scaling is detected.

We present new results of the collision process of a bead onto a static granular packing. We provide in particular a 3D extensive characterization of this process from a model experiment that allows to propel a spherical bead onto a granular packing with a well-controlled velocity and impact angle. A collision typically produces a high-energy particle (rebound particle) and several low-energy grains (ejected particles). The collision process is recorded by means of two fast video cameras. The sequence of images from both cameras are then analyzed via image processing and the trajectories of all particles are reconstructed in the 3D space. We show that the incident particle does not remain in the vertical incident plane after the rebound and that the deviation angle increases with increasing impact angle. Concerning the ejected particles, we evidenced that the ejection angle (measured with respect to the horizontal plane) is surprisingly independent on both the impact angle and velocity of the incident particle, and is very close to 60. The horizontal component of the ejection speed of the splashed particles is found to be weakly dependent on the incident speed and impact angle, and is relatively isotropic (no particular horizontal direction is favored). This last feature suggests that the bead packing acts as a perfect diffusive medium with respect to energy propagation.

The condensation-driven aggregation (CDA) model which we recently proposed is revisited with special emphasis on its geometric aspects and it is solved using scaling theory. It is shown that the particle size spectra exhibit transition to scaling c(x,t) ~ t-bf(x/tz) accompanied by the emergence of fractal of dimension df < 1. A remarkable feature of this model is that it is governed by a non-trivial conservation law, namely, the dfth moment of c(x,t) is time invariant. The reason why it remains conserved is explained. Exact values for the exponents b, z and df are obtained and are shown that they obey a generalized scaling relation b = (1+df)z.

We report on the dynamical behaviour of paramagnetic ellipsoidal particles dispersed in water and floating above a flat plane when subjected to an external precessing magnetic field. When the magnetic field and the long axis of the particles are on the same plane, two clear regimes are distinguished in which the particles follow synchronously or asynchronously the magnetic modulation. Both regimes are also observed when the field precesses at an angle J < 90 degree with respect to the normal to the confining plane, while the transition frequency increases with decreasing the precession angle. We combine experimental observations with a theoretical model to characterize the particle dynamics. The possibility to control and/or reorient microscopic elongated particles by changing the frequency/strength of the applied field makes them suitable in microfluidic devices such as microgates for microchannels or active fluid mixers when placed close to channels junctions.

We formulate a phase-field description of step dynamics on vicinal surfaces that makes use of a single dynamical field, at variance with previous analogous works in which two coupled fields are employed, namely, a phase field proper plus the physical adatom concentration. Within an asymptotic sharp interface limit, our formulation is shown to retrieve the standard Burton-Cabrera-Frank model in the general case of asymmetric attachment coefficients (Ehrlich-Schwoebel effect). We confirm our analytical results by means of numerical simulations of our phase-field model. Our present formulation seems particularly well adapted to generalization when additional physical fields are required.

Phase diagram, structural evolution and kinetics of temperature-induced protein gelation have been studied as a function of solution pH and protein concentration. The protein gelation temperature represents the onset of turbidity in the protein solution, which increases significantly with increase in pH beyond isoelectric pH of the protein molecule. On the other hand, the gelation temperature decreases with increase in protein concentration only at low protein concentration regime, and shows a small increasing trend at higher protein concentrations. Structural evolution and kinetics of protein gelation have been studies using small-angle neutron scattering (SANS). The structure of the protein molecule remains stable up to temperatures very close to gelation temperature. On increasing the temperature above gelation temperature, the protein solution exhibits a fractal structure, an indication of gel formation due to aggregation. The fractal dimension of the gel increases with increasing temperature, suggesting increase in branching between the aggregates, which leads to stronger gels. The increase in both solution pH and protein concentration is found to delay the growth in the fractal structure and its saturation. The kinetics of gelation has been studied using temperature jump process of heating. It is found that the structure of the protein gels remains invariant after the heating time (~ 1 min), indicating a rapid formation of gel structure within this time. The protein gels prepared through gradual and temperature jump heating routes always do not show the same structure. In particular, at higher temperatures (e.g. 85 ºC) while gradual heating shows a fractal structure there is collapse of such fractal structure during temperature jump heating.

The African shield-backed bug Calidea panaethiopica is a very colorful insect which produces a range of iridescent yellow, green and blue reflections. The cuticle of the dorsal side of the insect, on the shield, the prothorax and part of the head, is pricked of uniformly distributed hemispherical hollow cavities, a few tens micrometers deep. Under normal illumination and viewing, the insect's muffin-tin shaped surface gives rise to two distinct colors: a yellow spot arising from the bottom of the well and a blue annular cloud that appears to float around the yellow spot. This effect is explained by multiple reflections on an hemispherical Bragg mirror, with a mesoscopic curvature. A multi-scale computing methodology was found to be needed to evaluate the reflection spectrum for such a curved multilayer. This multiscale approach is very general and should be useful for dealing with visual effects in many natural and artificial systems.

Complex networks have acquired a great popularity in recent years, since the graph representation of many natural, social and technological systems is often very helpful to characterize and model their phenomenology. Additionally, the mathematical tools of statistical physics have proven to be particularly suitable for studying and understanding complex networks. Nevertheless, an important obstacle to this theoretical approach is still represented by the difficulties to draw parallelisms between network science and more traditional aspects of statistical physics. In this paper, we explore the relation between complex networks and a well known topic of statistical physics: renormalization. A general method to analyze renormalization flows of complex networks is introduced. The method can be applied to study any suitable renormalization transformation. Finite-size scaling can be performed on computer-generated networks in order to classify them in universality classes. We also present applications of the method on real networks.

In this paper, a complex anisotropy is derived heuristically and incorporated to the two-dimensional bistable system described by FitzHugh-Nagumo reaction diffusion model. The effects of such anisotropy on pattern formation are studied by deriving the relation between the normal velocity of wave front and its curvature. It is indicated that complex anisotropy plays an important role on the wave propagation, which would induce various complex patterns often encountered in nature. The sufficiently strong diffusion anisotropy can lead to the wave breakup. Some of these phenomena can only possibly be observed in the complex anisotropic bistable media. Numerical simulation identifies several new patterns, such as polygon shaped target structures and spiral waves etc.

We experimentally observe synchronization of chaos in two mutually-coupled vertical-cavity surface-emitting lasers (VCSELs). We observe in-phase and anti-phase synchronization of polarization-resolved chaotic temporal waveforms under the condition of injection locking. We investigate leader-laggard relationship between two chaotic waveforms of mutually coupled VCSELs and find that the laser with longer wavelength becomes the leader. The leader-laggard relationship is related to the characteristics of injection locking in optically coupled VCSELs.

In this paper we make a thorough exploration of the technique of partial control of chaotic systems. This control technique allows one to keep the trajectories of a dynamical system close to a chaotic saddle even if the control applied is smaller than the effects of environmental noise in the system, provided that the chaotic saddle is due to the existence of a horseshoe-like mapping in phase space. We state this here in a mathematically precise way using the Conley-Moser conditions, and we prove that they imply that our partial control strategy can be applied. We also give an upper bound of the control-noise ratio needed to achieve this goal, and we describe how this technique can be applied for large noise values. Finally, we study in detail the effect of imperfect targeting in our control technique. All these results are illustrated numerically with the paradigmatic Hénon map.

Random networks of coupled phase oscillators with phase shifts in the interaction functions are considered. In such systems, extensive chaos (turbulence) is observed in a wide range of parameters. We show that, by introducing global feedback, the turbulence can be suppressed and a transition to synchronous oscillations can be induced. Our attention is focused on the transition scenario and the properties of patterns, including intermittent turbulence, which are found at the edge of chaos. The emerging coherent patterns represent various self-organized active (sub)networks whose size and behavior can be controlled.

The effect of helicity (velocity-vorticity correlations) is studied in direct numerical simulations of rotating turbulence down to Rossby numbers of 0.02. The results suggest that the presence of net helicity plays an important role in the dynamics of the flow. In particular, at small Rossby number, the energy cascades to large scales, as expected, but helicity then can dominate the cascade to small scales. A novel phenomenological interpretation in terms of a direct cascade of helicity slowed down by wave-eddy interactions leads to the prediction of new non-kolmogorovian inertial indices for the small-scale energy and helicity spectra.

For a nonrelativistic classical particle undergoing arbitrary oscillations in external fields, the generalized effective potential Y is derived through calculating the nonlinear eigenfrequencies of the particle-field system. Specifically, the ponderomotive potential is extended to a nonlinear oscillator, resulting in multiple branches near the primary resonance. For a pair of particle natural frequencies in a beat resonance, Y scales linearly with the internal actions and is analogous to the dipole potential for a two-level quantum system. Thus cold quantum particles and highly-excited quasiclassical objects permit uniform manipulation tools, particularly, one-way walls.

Random phase approximation (RPA) has become one of the most used methods to describe the energy loss of charged particles in plasmas. The RPA is usually valid for high-velocity projectiles and in the weak coupling limit of the electron gas. However, for partially coupled plasmas RPA it is not sufficient and the electronic coupling has to be taken into account. This coupling can be considered through local field corrections (LFCs). In this work, we have constructed a dynamical local field correction (DLFC) function from Mermin dielectric function. This DLFC function has the advantage to describe plasmas at any degeneracy. Mermin DLFC function is compared with other DLFC functions from the bibliography in the energy loss calculation. We see important differences between them; they are significant at low velocities and very relevant around the maximum, almost 30%.

In our previous paper, we developed an optical measurement for absolute densities of fast (tens of keV) H ions in an abnormal hollow cathode discharge of hydrogen in the units to tens of mTorr pressure range. We apply this method to a cylindrically symmetric, Inertial Electrostatic Confinement (IEC) discharge of hydrogen using the Doppler spectrum of Ha. We predict neutron production rates for an equivalent discharge of deuterium and compare these with experimental values under the separate conditions of constant deuterium gas pressure ( ~ 6 mTorr) and voltage (30 kV). Our predictions capture the variation of production rates with DC current (10-50 mA) and agree with experiment to within an order of magnitude. The applicability of this diagnostic to the cylindrical IEC discharge is thus demonstrated, with our results supporting the theory that the discharge is dominated by energetic neutrals emerging from the cathode apertures.

This work deals with soliton solutions of the nonlinear Schroedinger equation with cubic and quintic nonlinearities. We extend the procedure put forward in a recent Letter and we solve the equation in the presence of linear background, and cubic and quintic interactions which are modulated in space and time. As a result, we show how a simple parameter can be used to generate brightlike or darklike localized nonlinear waves which oscillate in several distinct ways, driven by the space and time dependence of the parameters that control the trapping potential, and the cubic and quintic nonlinearities.

A collective variable approach is used to map domains of existence for (3+1)D spatio-temporal soliton solutions of a complex cubic-quintic Ginzburg-Landau equation. A rich variety of evolution behaviors, which include stationary and pulsating dissipative soliton dynamics, is revealed. Comparisons between the results obtained by the semi-analytical approach of collective variables and those obtained by a purely numerical approach show a good agreement for a wide range of the equation parameters. This also demonstrates the relevance of the semi-analytical method for a systematic search of stability domains for spatio-temporal solitons, leading to a dramatic reduction of the computation time.

It is shown that cascade quasi-synchronous frequency conversion on quadratic nonlinearity can be described in terms of an effective cubic nonlinearity. This enables one to reduce four-mode interaction problem to solving a system of two coupled nonlinear Schrdinger equations (NLSEs) for the amplitudes of waves participating in both nonlinear processes. Exact analytic solutions of corresponding system are found in a form of multi-component cnoidal waves with components expressed through a sum and a difference of two same fundamental solutions of Lame equation with shifted arguments. It is shown that solutions obtained by such a way enable one to optimize the conversion efficiency because full covering the range of possible boundary conditions.

Modeling and simulating gas flows in/around micro-devices are a challenging task in both science and engineering. In practical applications, a gas is usually a mixture made of different components. In this paper we propose a lattice Boltzmann equation (LBE) model for microscale flows of binary mixture based on a recently developed LBE model for continuum mixtures [P. Asinari and L.-S. Luo, J. Comput. Phys. 227, 3878 (2008)]. A consistent boundary condition for gas-solid interactions is proposed and analyzed. The LBE is validated and compared with theoretical results or other reported data. The results show that the model can serve as a potential method for flows of binary mixture in the microscale.