We present a numerical analysis of the impact of the optical amplification by semiconductor optical amplifiers (SOAs) in a Coherent Optical-Orthogonal Frequency Division Multiplexing transmission link at 100 Gb/s. The numerical modeling of SOA is developed to be able to simulate all of nonlinear effects of the SOA, particularly four-wave mixing effect. This model is integrated into a co-simulation platform to perform a simulation at a system level. Error Vector Magnitude (EVM) measurement is given with respect to the number of subcarriers and phase-amplitude coupling. We show also the dependence of the EVM at the signal wavelength by performing our simulations on a wide optical bandwidth, taking into account the main parameters of the SOA—such as the phase-amplitude coupling factor, the saturation power and the noise figure—that influence the non-linear effects.
In this study, we investigate the tunneling conductance at a finite temperature in a normal metal/ferromagnetic superconductor nano-junction where the ferromagnetic superconductor (FS) is in three different cooper pairing states: spin singlet s-wave pairing (SWP), spin triplet opposite spin pairing (OSP), and spin triplet equal spin pairing (ESP) while including Fermiwave mismatch (FWM) and effective mass mismatch (EMM) in two sides of the nano-junction. We find that the conductance shows clearly different behaviors all depending on the symmetries of cooper pairing in a mannerthat the conductance spectra shows a gap-like structure, two interior dipsstructure and zero bias peak for SWP, OSP, and ESP, respectively. Also, theeffective FS gap (δeff) is a linear and decreasing function of exchange field. The slope of (δeff) versus exchange field for OSP is twice the SWP. Thus, we can determine the spin polarization of N/FS nano-junction based on the dependence of (δeff) to exchange field. 相似文献
Discrete-fracture and rock matrix (DFM) modelling necessitates a physically realistic discretisation of the large aspect ratio
fractures and the dissected material domains. Using unstructured spatially adaptively refined finite-element meshes, we find
that the fastest flow often occurs in the smallest elements. Flow velocity and element size vary over many orders of magnitude,
disqualifying global Courant number (CFL)-dependent transport schemes because too many time steps would be necessary to investigate
displacements of interest. Here, we present a higher-order accurate implicit pressure–(semi)-implicit transport scheme for
the advection–diffusion equation that overcomes this CFL limitation for DFM models. Using operator splitting, we solve the
pressure and the transport equations on finite-element, node-centred finite-volume meshes, respectively, using algebraic multigrid
methods. We apply this approach to field data-based DFM models where the fracture flow velocity and mesh refinement is 2–4
orders of magnitude greater than that of the matrix. For a global CFL of ≤10,000, this implies sub-CFL, second-order accurate
behaviour in the matrix, and super-CFL, at least first-order accurate, transports in fast-flowing fractures. Their greater
refinement, however, largely offsets this numerical dispersion, promoting a highly accurate overall solution. Numerical and
fracture-related mechanical dispersions are compared in the realistic DFM models using second-order accurate runs as reference
cases. With a CFL histogram, we establish target error criteria for CFL overstepping. This analysis indicates that for extreme
fracture heterogeneity, only a few transport steps can be sufficient to analyse macro-dispersion. This makes our implicit
method attractive for quick analysis of transport properties on multiple realisations of DFM models. 相似文献
Flow modeling in fractured reservoirs is largely confined to the so-called sugar cube model. Here, however, we consider vertically
fractured reservoirs, i.e., the situation that the reservoir geometry can be approximated by fractures enclosed columns running
from the base rock to the cap rock (aggregated columns). This article deals with the application of the homogenization method
to derive an upscaled equation for fractured reservoirs with aggregated columns. It turns out that vertical flow in the columns
plays an important role, whereas it can be usually disregarded in the sugar cube model. The vertical flow is caused by coupling
of the matrix and fracture pressure along the vertical faces of the columns. We formulate a fully implicit three-dimensional
upscaled numerical model. Furthermore, we develop a computationally efficient numerical approach. As found previously for
the sugar cube model, the Peclet number, i.e., the ratio between the capillary diffusion time in the matrix and the residence
time of the fluids in the fracture, plays an important role. The gravity number plays a secondary role. For low Peclet numbers,
the results are sensitive to gravity, but relatively insensitive to the water injection rate, lateral matrix column size,
and reservoir geometry, i.e., sugar cube versus aggregated column. At a low Peclet number and sufficiently low gravity number,
the effective permeability model gives good results, which agree with the solution of the aggregated column model. However,
ECLIPSE simulations (Barenblatt or Warren and Root (BWR) approach) show deviations at low Peclet numbers, but show good agreement
at intermediate Peclet numbers. At high Peclet numbers, the results are relatively insensitive to gravity, but sensitive to
the other conditions mentioned above. The ECLIPSE simulations and the effective permeability model show large deviations from
the aggregated column model at high Peclet numbers. We conclude that at low Peclet numbers, it is advantageous to increase
the water injection rate to improve the net present value. However, at high Peclet numbers, increasing the flow rate may lead
to uneconomical water cuts. 相似文献
Journal of Solid State Electrochemistry - A graphene aerogel cross-linked by p-phenylenediamine (PPDA) composite with Sm2O3 nanoparticles (AP.Sm) was synthesized as a novel nanocomposite via a... 相似文献
This review investigates the synthesis and electrochemical performance of the electrode of the electrochemical energy storage (EES) devices obtained from peels and scraps of the citrus fruits. The EES devices include batteries, supercapacitors, and hybrid systems that have considerable value and various applications. The electrode is considered as the most important part of all EES devices. Tremendous efforts have been done to enhance the electrochemical energy storage electrode (EESE). The citrus fruits abundance leads to a decrease in their price and makes possible to use them as ingredients to fabricate EESE. Also, the electrochemical analyses determined that citrus fruits have considerable potential to use as the EESE. Using citrus fruits peels and scraps as biomass substances to prepare EESE leads to the electrodes which have low cost, environmentally friendly and appropriate electrochemical applications. 相似文献
Simultaneous drug release and monitoring using a single polymeric platform represents a significant advance in the utilization of biomaterials for therapeutic use. Tracking drug release by real‐time electrochemical detection using the same platform is a simple way to guide the dosage of the drug, improve the desired therapeutic effect, and reduce the adverse side effects. The platform developed in this work takes advantage of the flexibility and loading capacity of hydrogels, the mechanical strength of microfibers, and the capacity of conducting polymers to detect the redox properties of drugs. The engineered platform is prepared by assembling two spin‐coated layers of poly‐γ‐glutamic acid hydrogel, loaded with poly(3,4‐ethylenedioxythiophene) (PEDOT) microparticles, and separated by a electrospun layer of poly‐ε‐caprolactone microfibers. Loaded PEDOT microparticles are used as reaction nuclei for the polymerization of poly(hydroxymethyl‐3,4‐ethylenedioxythiophene) (PHMeDOT), that semi‐interpenetrate the whole three layered system while forming a dense network of electrical conduction paths. After demonstrating its properties, the platform is loaded with levofloxacin and its release monitored externally by UV–vis spectroscopy and in situ by using the PHMeDOT network. In situ real‐time electrochemical monitoring of the drug release from the engineered platform holds great promise for the development of multi‐functional devices for advanced biomedical applications. 相似文献
Journal of the Iranian Chemical Society - Increasing the interest in the silicon-based devices resulted in developing new methods and techniques to achieve advanced and more reliable designs and... 相似文献
The intermolecular potential energy surface of complex pairing argon with cyanogen molecule (NCCN) was calculated using the coupled cluster with single and double and perturbative triple excitations (CCSD(T)) with aug-cc-pvdz basis set extended with a set of mid-bond (3s3p2d1f1g) functions. The interaction energies were calculated by the supermolecular approach with the full counterpoise correction for the basis set superposition error. The calculated potential energies were fitted to an analytical expression. The calculated Ar–NCCN potential energy surface shows a global minimum at 3.35 Å, the distance between argon and centre of mass of cyanogen, for the T-shaped geometry and two local minimum at distance of 5.54 Å for the linear geometry on one side of cyanogen. Finally, the interaction second virial coefficients were calculated using the fitted potential energy surface and were compared with those obtained by the parameters of the Beattie–Bridgeman equation of states of pure argon and cyanogens fluids, approximately. 相似文献