Influence Of Higher-order Effects Research Articles

Higher-Order Effects in Biaxial Flexure of GFRP I-Section Beams

A theoretical study of Glass Fiber Reinforced Polymer (GFRP) beams subjected to biaxial bending moments is presented with a focus on the influence of higher-order effects on maximum normal stresses. It is shown that the biaxial bending type of loading causes a dramatic increase in the maximum normal stress for a GFRP beam when induced torsional effects are included. The study demonstrates that the traditional first-order theory can grossly underestimate the maximum normal stress in a GFRP beam. Based on the numerical results presented using a higher-order theory which also accounts for induced warping normal stresses, the maximum normal stress is found to be about two to three times larger than that determined using the first-order theory.

Propagation Characteristics of Airy Pulses in the Dissipative System under the Influence of Higher-order Effects

Propagation Characteristics of Airy Pulses in the Dissipative System under the Influence of Higher-order Effects

Influence of Higher-order Effects on N-soliton Solution of the Coupled Nonlinear Schrdinger Equation

Influence of Higher-order Effects on N-soliton Solution of the Coupled Nonlinear Schrdinger Equation

超材料中高阶效应影响下飞秒准亮孤子解及其特性

超材料中高阶效应影响下飞秒准亮孤子解及其特性

Influence of higher-order effects on pulsating solutions, stationary solutions and moving fronts in the presence of linear and nonlinear gain/loss and spectral filtering

We have studied the impact of the higher-order effects: intrapulse Raman scattering (IRS), third-order of dispersion (TOD) and self-steepening (SS) on pulsating solutions, moving fronts and stationary solutions of the complex cubic–quintic Ginzburg–Landau equation (CCQGLE) found in Tsoy and Akhmediev (2005) as well as on the solutions presented in Uzunov et al. (2014). The applied basic equation generalizes the CCQGLE with the IRS, TOD and SS effects. A finite-dimensional dynamical system has been derived using the method of moments. Applying the derived dynamical system alongside with the numerical solution of the generalized CCQGLE performed by means of the fourth-order Runge–Kutta interaction picture method we have found that the influence of IRS and SS is stronger than the impact of TOD for the solutions of Tsoy and Akhmediev (2005). Perturbed pulsating solutions, moving fronts and stationary solutions in the presence of IRS, SS and TOD have been numerically observed. They exist up to some critical values of the parameters of perturbations. For the values of parameters larger than the critical ones the pulsating solutions are transformed into stable stationary solutions or unstable solutions. New localized fluctuating and stationary solutions have been obtained for fairly large values of parameters of IRS and TOD, respectively. The transformation of the stable stationary solution of Uzunov et al. (2014) under the influence of SS into pulsating solution has been numerically observed.

Propagation properties of soliton solutions under the influence of higher order effects in erbium doped fibers

Under investigation in this paper is the Hirota–Maxwell–Bloch system which governs the propagation of optical solitons in nonlinear erbium doped fibers with higher order effects. By virtue of the Darboux transformation, the Akhmediev breathers, Ma-breathers, localized solitons, bound solitons, two-breathers and localized solutions are generated for the Hirota–Maxwell–Bloch system. Considering the influences of higher order effects, propagation properties of the breathers, modulation instability conditions for the Akhmediev breathers and interaction scenarios between bound solitons and two-breather solutions are discussed.

Breathers and localized solitons for the Hirota–Maxwell–Bloch system on constant backgrounds in erbium doped fibers

In nonlinear erbium doped fibers, the Hirota–Maxwell–Bloch system with higher order effects usually governs the propagation of ultrashort pulses. New soliton solutions for this system are constructed on the constant backgrounds including one and two breathers and first and higher order localized soliton solutions. Considering the influence of higher order effects, propagation properties of those soliton solutions are discussed.

The influence of higher-order effects on the transmission performances of the ultra-short soliton pulses and its suppression method

Under the condition of the higher order effects, a propagation equation is established to investigate the way to suppress the soliton self frequency shift and timing jitter in the picosecond and femtosecond soliton communication system using a combined control method of time domain and frequency domain. By the use of the variational approach, the evolution of the chirping Gaussian quasi-soliton pulse is analyzed in the presence of the effects including third order dispersion, intrapulse Raman scattering (IRS), and self steepening. Considering the soliton evolution properties and the mechanism of the timing jitter under the higher-order effects, the combined control method is adopted to eliminate the influence from Raman scattering and self-steepening. The soliton central frequency is stabilized and the timing jitter is suppressed effectively. A 160 Gb/s long-haul soliton transmission system is designed and its performance is numerically simulated. The simulation results are in good agreement with our theoretical analysis.

High compression of similariton pulses under the influence of higher-order effects

We present numerical and analytical results that confirm that similariton pulses can be compressed by 2 orders of magnitude in a dispersion-decreasing Raman-pumped fiber amplifier yielding pulses as short as 120 fs. Physical conditions have been derived, subject to which, higher-order nonlinearities and dispersion terms do not affect the shape and slope of the linear chirped sech pulse, although they shift the similariton amplitude in time and downshift it in mean frequency. The developed analytical theory is in good agreement with numerical simulations. This predicted similariton regime with an optimized fiber amplifier and input pulse may, find important applications in optical pulse compression.

The influence of higher order effects on the vortex instability of thermal boundary layer flow in a wedge-shaped domain

We reconsider the onset of streamwise vortices in the thermal boundary layer flow induced by an inclined upward-facing heated semi-infinite surface placed within a Newtonian fluid. Particular emphasis is laid upon how the induced flow in the isothermal region outside the boundary layer affects the boundary layer itself at higher order, and how this, in turn, affects the stability criterion for the onset of vortices. We find that the stability criterion for thermal boundary layers in air is less susceptible to changes in external geometry than for boundary layers in water. In general, we conclude that the variation of the stability criterion with wedge angle (between the heated and the outer boundary surface) is too great for the theory to predict reliably where disturbances first begin to grow.

The influence of higher order effects on the linear wave instability of vertical free convective boundary layer flow

We examine the stability of free convective boundary layer flow over a vertical heated flat plate with respect to two-dimensional wave disturbances. In particular we determine the effect of the overall external geometry on the stability criterion. The fluid domain is taken to be bounded by two semi-infinite flat plates forming a wedge of angle α. The vertical plate is held at a uniform hot temperature while the other is either insulated or is held at the ambient temperature of the fluid. The basic flow used in the analysis is a two-term boundary-layer approximation using the method of matched asymptotic expansions. A modified version of the Keller-box method is used to solve the linearised wave-disturbance equations numerically. The neutral curves have been delineated for different values of wedge angle, α, where the working fluids are water and air. We find that the critical distance from the leading edge beyond which disturbances grow is strongly dependent on α, and this suggests that the external geometry of the fluid domain exerts a considerable influence on stability criteria.

Femto-Second Transform Limited Pulse Generation with Higher Order Dispersion Effects for Dispersion-Shifted Optical Communication System

The paper deals with the influence of higher-order effects of dispersion on the femto-second transform limited pulse generation by compensating for linear chirp of self-phase modulation spectra in the dispersion-shifted fibers. It has been shown that the minimum propagation length with first-order dispersion term is 23 m, as reported earlier. If the higher-order dispersion effects are taken into consideration, this length is reduced to 11.5 m. With compensation of the first-order dispersion term, this length can be enhanced to 6.8161 × 103 km. This length can further be improved to 6.0343 × 109 km by compensation of first- and second-order dispersion terms together. The minimum pulse width and linewidth product without dispersion, with dispersion including higher-order dispersion effects, and with dispersion compensation, is found to be 0.44, 0.4418, and 0.4411, respectively.

Soliton interaction under the influence of higher-order effects

In this paper, we present exact N-soliton solution by employing simple, straightforward Darboux transformation based on the Lax pair for Hirota equation, a higher-order nonlinear Schrödinger (HNLS) equation. As examples, one- and two-soliton solutions in explicit forms are given and their properties are also analyzed. A bound solution without interaction will be theoretically predicted if one can adjust frequency shift for each soliton appropriately. Further, we obtain the approximate eigenvalues by employing two-soliton solution and discuss analytically the interaction between neighboring solitons under the influence of the higher-order effects. It is shown that the combined effects of the higher-order effects can restrain the interaction between neighboring solitons to some extent. The results are proved by directly solving HNLS equation numerically.

The influence of higher-order effects on the linear instability of thermal boundary layer flow in porous media

We examine the instability of free convective boundary layer flows in porous media. The medium is bounded by two semi-infinite plane surfaces forming a wedge of angle α. One of the surfaces is heated uniformly and the other is either cold or insulated. The basic flow used in the analysis is the most accurate obtainable by means of higher order boundary layer theory. In general, the critical distance from the leading edge beyond which disturbances grow is found to be strongly dependent on the outer flow field. The only exception to this arises when the heated surface is close to the vertical and if the wedge is not too close to either 0° or 360°. The main implication of this paper is that instability occurs too close to the leading edge for the basic flow to be represented adequately either by the leading order boundary layer theory used in previous papers, or by even the most accurate higher order theory obtained using matched asymptotic expansions.

Ultrafast two-photon nonlinearities in CdSe near 1.5 μm studied by interferometric autocorrelation

We have used interferometric autocorrelation measurements to study the femtosecond nonlinear optical properties of bulk CdSe crystals in the wavelength region just above the half gap wavelength of 1.42 /spl mu/m. Between 1.42 and 1.55 /spl mu/m, we measured an ultrafast third-order nonlinearity with nonlinear refractive index n/sub 2/=1.3/spl times/10/sup -13/ cm/sup 2//W/sup -1/. Detailed modeling of the autocorrelations revealed the influence of higher order effects due to free carriers generated by nonlinear absorption. We find that CdSe is an interesting alternative material to AlGaAs for applications in this technologically important wavelength region.

Vortex solitons in self-gravitating plasma

Using a two-fluid description of a large, magnetized, self-gravitating plasma cloud, we derive a fully nonlinear system of equations for electrostatic and gravitational potentials. In the regime when nonlinear effects, arising from the particle drift, are dominating over the gravitational condensation, we obtain a stationary solution in the form of travelling double vortex, with the charge separation being localized to the vortex core, and its immediate surroundings. Density perturbation has a long range spatial extend, in the form of alternating condensations and rarefactions with the typical scale length of the order of Jeans' critical length. Influence of higher order effects, and their role in the gravitational contraction of the vortex, is discussed.

Notizen: Die Anwendung von Parametern der gegenseitigen Wechselwirkung in der 29Si-Resonanz.

Silicon 29-chemical shifts can be described in some cases in terms of pairwise interaction parameters, although the influence of higher order effects is always perceptible. These are especially significant where fluorine or oxygen are the ligands around the silicon. Parameter of pairwise interaction for a number of ligands are given.

Improvements in the transmission of a tandem accelerator

First order calculations are given which were carried out to obtain a good optical matching of a polarized ion source to the 12 MeV H.V.E.C. tandem Van de Graaff of the Utrecht State University. Two alternative injection systems are compared with one another and a relative transmission figure is given. The influence of higher order effects may be diminished by relatively simple means. The ion injection energy may be decreased considerably without significant loss in transmission efficiency if this is required for constructional reasons.