Prediction of impedance responses of protonic ceramic cells using artificial neural network tuned with the distribution of relaxation times

A deep-learning-based framework is proposed to predict the impedance response and underlying electrochemical behavior of the reversible protonic ceramic cell(PCC) across a wide variety of different operating conditions.Electrochemical impedance spectra(EIS) of PCCs were first acquired under a variety of opera ting conditions to provide a dataset containing 36 sets of EIS spectra for the model.An artificial neural network(ANN) was then trained to model the relationship between the cell operating condition and EIS response.Finally,ANN model-predicted EIS spectra were analyzed by the distribution of relaxation times(DRT) and compared to DRT spectra obtained from the experimental EIS data,enabling an assessment of the accumulative errors from the predicted EIS data vs the predicted DRT.We show that in certain cases,although the R^(2)of the predicted EIS curve may be> 0.98,the R^(2)of the predicted DRT may be as low as~0.3.This can lead to an inaccurate ANN prediction of the underlying time-resolved electrochemical response,although the apparent accuracy as evaluated from the EIS prediction may seem acceptable.After adjustment of the parameters of the ANN framework,the average R^(2)of the DRTs derived from the predicted EIS can be improved to 0.9667.Thus,we demonstrate that a properly tuned ANN model can be used as an effective tool to predict not only the EIS,but also the DRT of complex electrochemical systems.

Effect of relaxation time on the squeezed correlations of bosons for evolving sources in relativistic heavy-ion collisions

The squeezed back-to-back correlation(SBBC)of a boson-antiboson pair is sensitive to the time distribution of the particle-emitting source,and the SBBC function for an evolving source is expected to be affected by the relaxation time of the system.In this study,we investigated the effect of relaxation time on the SBBC function.We propose a method for calculating the SBBC function with relaxation-time approximation for evolving sources.SBBC functions of D^(0)D^(-0)in relativistic heavy-ion collisions were investigated using a hydrodynamic model.We found that the relaxation time reduces the amplitudes of the SBBC functions.This becomes apparent for long relaxation times and large initial relative deviations of the chaotic and squeezed amplitudes from their equilibrium values in the temporal steps.

The Influence of Organo-Clay Ratio in the HIPS-OMMT Nanocomposites Analyzed by Proton Spin-Lattice and Spin-Spin Relaxation Times

Spin-lattice and spin-spin relaxation times are one of the most attractive tools in the solid-state nuclear magnetic resonance spectroscopy to evaluate the level of clay dispersion in the nanocomposite matrices. The efficiency of the relaxation processes can be used to evaluate the nanoparticles intermolecular interactions and, consequently, the dispersion of them in the polymer matrix, the molecular dynamic of the hybrid compounds, as well as the molecular domains formation in an organic material. The determination of relaxation parameters was carried out to evaluate the organoclay exfoliation and intercalation process in the polymeric matrix, in addition to their dispersion and distribution in the matrix. The proton NMR relaxation data showed that the polymeric nanomaterials investigated presented good intermolecular interaction that promoted good nanoparticles dispersion and distribution in the hybrid materials. The proportion of 2% clay promoted a greater heterogeneity in the matrix compared to other ratios;1% clay influenced only to the higher molecular rigidity phase;and 3% clay had a decrease in heterogeneity compared to 2% though still influenced the matrix as a whole. These results prove the efficiency of NMR technique in the evaluation of nanofillers interaction with polymer matrices, as well as their dispersion and distribution.

Solid State NMR Study of Polystyrene Nanolatex Particles(I) ^(13)C Spin-Lattice Relaxation Time

C spin-lattice relaxtion times for polystyrene nanolatex particles have been investigated. It was found that the dramatic increase at 80℃ annealing temperature is well below the Tg temperature of bulk polystyrene, the increase of relaxation time of aromatic carbons is larger than that of for aliphatic carbons at transition annealing temperature.

Measuring Transverse Relaxation Time of Xenon Atoms Based on Single Beam of Laser in Nuclear Magnetic Resonance Gyroscope

Nuclear magnetic resonance gyroscope (NMRG) has the characteristics of high precision and miniaturization, and is one of the main applications of quantum technology in the field of navigation. The transverse relaxation time (T_(2)) of the xenon nuclear spin in the atomic cell of the NMRG directly affects the angular random walk of the gyro. Accurate and rapid measurement of T_(2) is conducive to further improvement of gyroscope. At present, for the measurement of T_(2), the schemes of two orthogonal lasers for pumping and detecting are usually used. By applying two fast-switching orthogonal static magnetic fields and a single beam of circularly polarized laser with corresponding wavelength to pump the atomic cell, the xenon nuclear macroscopic magnetic moment Larmor precession is generated. The cesium atoms parametric magnetometer in cell is formed to detect the free induction decay signal generated by nuclear spin precession of xenon atoms. The measurement of T_(2) by a single laser simplifies the measurement equipment compared with traditional method with two lasers. The experimental results show that the T_(2) of xenon atoms is more than 10 s, and the effects of temperature are studied, which lay the foundation for the subsequent improvement of gyro performance.

Combined immersed boundary method and multiple-relaxation-time lattice Boltzmann flux solver for numerical simulations of incompressible flows

A method combining the immersed boundary technique and a multirelaxation-time(MRT) lattice Boltzmann flux solver(LBFS) is presented for numerical simulation of incompressible flows over circular and elliptic cylinders and NACA 0012 Airfoil. The method uses a simple Cartesian mesh to simulate flows past immersed complicated bodies. With the Chapman-Enskog expansion analysis, a transform is performed between the Navier-Stokes and lattice Boltzmann equations(LBEs). The LBFS is used to discretize the macroscopic differential equations with a finite volume method and evaluate the interface fluxes through local reconstruction of the lattice Boltzmann solution.The immersed boundary technique is used to correct the intermediate velocity around the solid boundary to satisfy the no-slip boundary condition. Agreement of simulation results with the data found in the literature shows reliability of the proposed method in simulating laminar flows on a Cartesian mesh.

Multiple Relaxation Time Lattice Boltzmann Simulation of 2D Natural Convection in a Square Cavity at High Rayleigh Numbers

Natural convection in a square cavity at high Rayleigh numbers is simulated by multiple relaxation time(MRT)lattice Boltzmann method(LBM)with a separate distribution function to solve the temperature.The Rayleigh numbers examined here range from Ra=103 to Ra=10^(8).For Rayleigh numbers below 10^(8),the flow remains stationary and transition occurs beyond Ra=2×10^(8).Unsteady results at higher Rayleigh numbers(Ra=10^(9) and Ra=10^(10))are also investigated.To the best of our knowledge,this is the first accurate study which involves the high Rayleigh numbers Ra=10^(9),10^(10).

Talk about Several Time Periodic Pulse Electroosmotic Flow of Maxwell Fluid in a Circular Microchannel

Using the method of Laplace transform, analytical expressions are derived for the time periodic pulse electroosmotic flow (EOF) velocity of the triangle and sawtooth of Maxwell fluid in circular microchannel. The solution involves analytically solving the linearized Poisson-Boltzmann (P-B) equation, together with the Cauchy momentum equation and the general Maxwell constitutive equation. By numerical computations of inverse Laplace transform, the effects of electrokinetic width K, relaxation time and pulse width a on the above several pulse EOF velocities are investigated. In addition, we focused on the comparison and analysis of the formulas and graphs between the triangle and sawtooth pulse EOF with the rectangle pulse EOF. The study found that there are obvious differences in formulas and graphs between triangle and sawtooth pulse EOF with rectangle pulse EOF, and the difference mainly depends on the different definitions of the three kinds of time periodic pulse waves. Finally, we also studied the stability of the above three kinds of pulse EOF and the influence of relaxation time on pulse EOF velocity under different pulse widths is discussed. We find that the rectangle pulse EOF is more stable than the triangle and sawtooth pulse EOF. For any pulse, as the pulse width a increases, the influence of the relaxation time on the pulse EOF velocity will be weakened.

Role of Peripheral Regulatory T Lymphocytes in Patients with Thyroid Associated Ophthalmopathy During Systemic Glucocorticoid Treatment:A Prospective Observational Study

Objective Thyroid-associated ophthalmopathy(TAO)is an autoimmune disorder involving the orbital tissue.This study aimed to understand the role of regulatory T cells(Tregs)in TAO during 12-week systemic glucocorticoid(GC)treatment.Methods Thirty-two moderate-severe TAO patients with a clinical activity score(CAS)≥3/7 or with prolonged T2 relaxation time(T2RT)on at least one side of extraocular muscle(EOM)were enrolled.The percentage of the peripheral CD4+CD25(high)CD127(−/low)Tregs was analyzed using flow cytometry before and after the GC treatment.The activity and severity of TAO,T2RT,and the clinical outcomes after the GC treatment were assessed.Their correlation with the peripheral Tregs was investigated.Results There was no significant association between the baseline Treg fraction and the activity and severity of TAO or the treatment response.A significant reduction of Tregs was observed after the GC therapy merely in patients without any clinical improvement.Conclusion Treg reduction after systemic GC therapy is indicative of a poor therapeutic response.Accordingly,dynamic alterations of Tregs could help to evaluate the effectiveness of the GC treatment.

Time to Relax星座

白羊座(3月21日-4月20日本月白羊心情不错,偶尔有些小波动也能很快调整过来。生活中若遇到小挫折,只要善用优势,破除猜忌,就能安然渡过。解压方法:通过相机镜头看生活,你将得到对生活与众不同的感受。

Maximizing Terahertz Energy Absorption with MXene Absorber

Achieving high absorption in broad terahertz bands has long been challenging for terahertz electromagnetic wave absorbers.Recently in Nature Photonics,Xiao et al.reported the high absorption approaching the theoretical upper limit across the whole terahertz band of MXene-based terahertz absorbers and,on this basis,constructed an applicable,updated alternating current impedance matching model.

Multi-scale Incremental Analysis Update Scheme and Its Application to Typhoon Mangkhut(2018)Prediction

In the traditional incremental analysis update(IAU)process,all analysis increments are treated as constant forcing in a model’s prognostic equations over a certain time window.This approach effectively reduces high-frequency oscillations introduced by data assimilation.However,as different scales of increments have unique evolutionary speeds and life histories in a numerical model,the traditional IAU scheme cannot fully meet the requirements of short-term forecasting for the damping of high-frequency noise and may even cause systematic drifts.Therefore,a multi-scale IAU scheme is proposed in this paper.Analysis increments were divided into different scale parts using a spatial filtering technique.For each scale increment,the optimal relaxation time in the IAU scheme was determined by the skill of the forecasting results.Finally,different scales of analysis increments were added to the model integration during their optimal relaxation time.The multi-scale IAU scheme can effectively reduce the noise and further improve the balance between large-scale and small-scale increments in the model initialization stage.To evaluate its performance,several numerical experiments were conducted to simulate the path and intensity of Typhoon Mangkhut(2018)and showed that:(1)the multi-scale IAU scheme had an obvious effect on noise control at the initial stage of data assimilation;(2)the optimal relaxation time for large-scale and small-scale increments was estimated as 6 h and 3 h,respectively;(3)the forecast performance of the multi-scale IAU scheme in the prediction of Typhoon Mangkhut(2018)was better than that of the traditional IAU scheme.The results demonstrate the superiority of the multi-scale IAU scheme.

A non-quasi-static model for nanowire gate-all-around tunneling field-effect transistors

Nanowires with gate-all-around(GAA) structures are widely considered as the most promising candidate for 3-nm technology with the best ability of suppressing the short channel effects,and tunneling field effect transistors(TFETs)based on GAA structures also present improved performance.In this paper,a non-quasi-static(NQS) device model is developed for nanowire GAA TFETs.The model can predict the transient current and capacitance varying with operation frequency,which is beyond the ability of the quasi-static(QS) model published before.Excellent agreements between the model results and numerical simulations are obtained.Moreover,the NQS model is derived from the published QS model including the current-voltage(I-V) and capacitance-voltage(C-V) characteristics.Therefore,the NQS model is compatible with the QS model for giving comprehensive understanding of GAA TFETs and would be helpful for further study of TFET circuits based on nanowire GAA structure.

Entropic Multi-Relaxation-Time Lattice Boltzmann Model for Large Density Ratio Two-Phase Flows

We propose a multiple relaxation time entropic realization of a recent twophase flow lattice Boltzmann model[S.A.Hosseini,B.Dorschner,and I.V.Karlin,Journal of Fluid Mechanics 953(2022)].While the original model with a single relaxation time allows us to reach large density ratios,it is limited in terms of stability with respect to non-dimensional viscosity and velocity.Herewe showthat the entropic multiple relaxation time model extends the stability limits of the model significantly,which allows us to reach larger Reynolds numbers for a given grid resolution.The thermodynamic properties of the solver,using the Peng-Robinson equation of state,are studied first using simple configurations.Co-existence densities and temperature scaling of both the interface thickness and the surface tension are shown to agree well with theory.The model is then used to simulate the impact of a drop onto a thin liquid film with density and viscosity ratios matching those of water and air both in two and three dimensions.The results are in very good agreement with theoretically predicted scaling laws and experimental data.

Analysis of thermal responses in a two-dimensional porous medium caused by pulse heat flux

In this article, the generalized model for thermoelastic waves with two relaxation times is utilized to compute the increment of temperature, the displacement components, the stress components, and the changes in the volume fraction field in a two-dimensional porous medium. By using the Fourier-Laplace transform and the eigenvalue method, the considered variables are obtained analytically. The derived approach is estimated with numerical outcomes which are applied to the porous media with a geometrical simplification. The numerical results for the considered variables are performed and presented graphically. Finally, the outcomes are represented graphically to display the difference among the classical dynamical(CD) coupled, the Lord-Shulman(LS), and the Green-Lindsay(GL) models.

Dielectric Spectroscopy Study on Vesicles of CTAB/SDBS System

Amphiphilic molecules can form into different structures, such as micelle, microemulsion, vesicle, liposome, liquid crystals, and so on by self-associating. The Dielectric Spectroscopy (DS) method has been applied to the systems of micelle and microemulsion successfully. For the first time the author put the method to the system of vesicle of CTAB/SDBS. The experiments show clear dielectric relaxation and the results were discussed primarily.

Crossover of large to small radius polaron in ionic crystals

The crossover of large to small radius polaron is studied in terms of the inverse-relaxation time and temperature.It is found that the small radius polaron exists at higher temperature than the large radius polaron.A formula which relates the inverse-relaxation time to the ratio of arbitrary temperature and Debye temperature of the crystal is derived.The polaron crossover temperatures in NaCl and KBr are found from plotted graphs.The straight line emerging at the Debye temperature T_d of a graph reflects the increase of the inverse relaxation time for increasing temperature up to the collapse of the small radius polaron.The relationship between the small and large radius polarons is found and known ratios of the effective and the bare masses of the electrons for the two substances are used to validate our results.The small radius polaron's mass is later compared with the mass obtained from the hopping formula and is found to be approximately equal.Finally,we point out that the crossover temperature is material-specific since it depends on the Debye and the effective dielectric function.

Instability of single-walled carbon nanotubes conveying Jeffrey fluid

We report instability of the single-walled carbon nanotubes(SWCNT) filled with non-Newtonian Jeffrey fluid.Our objective is to get the influences of relaxation time and retardation time of the Jeffrey fluid on the vibration frequency and the decaying rate of the amplitude of carbon nanotubes.An elastic Euler-Bernoulli beam model is used to describe vibrations and structural instability of the carbon nanotubes.A new vibration equation of an SWCNT conveying Jeffrey fluid is first derived by employing Euler-Bernoulli beam equation and Cauchy momentum equation taking constitutive relation of Jeffrey fluid into account.The complex vibrating frequencies of the SWCNT are computed by solving a cubic eigenvalue problem based upon differential quadrature method(DQM).It is interesting to find from computational results that retardation time has significant influences on the vibration frequency and the decaying rate of the amplitude.Especially,the vibration frequency decreases and critical velocity increases with the retardation time.That is to say,longer retardation time makes the SWCNT more stable.

Enhancing cathode performance for CO2 electrolysis with Ce0.9M0.1O2-δ（M=Fe, Co, Ni） catalysts in solid oxide electrolysis cell

Electrochemical conversion with solid oxide electrolysis cells is a promising technology for CO2 utilization and simultaneously store renewable energy.In this work,Ce0.9M0.1O2-δ(CeM,M=Fe,Co,Ni)catalysts are infiltrated into La0.6Sr0.4Cr0.5Fe0.5O3-δ-Gd0.2Ce0.8O2-δ(LSCr Fe-GDC)cathode to enhance the electrochemical performance for CO2 electrolysis.CeCo-LSCrFe-GDC cell obtains the best performance with a current density of 0.652 A cm^-2,followed by CeFe-LSCrFe-GDC and CeNi-LSCrFe-GDC cells with the value of 0.603 and 0.535 A cm^-2,respectively,about 2.44,2.26 and 2.01 times higher than that of the LSCrFe-GDC cell at1.5 V and 800℃.Electrochemical impedance spectra combined with distributions of relaxed times analysis shows that both CO2 adsorption process and the dissociation of CO2 at triple phase boundaries are accelerated by Ce M catalysts,while the latter is the key rate-determining step.

Magneto-Thermoelasticity with Thermal Shock Considering Two Temperatures and LS Model

The present investigation is intended to demonstrate the magnetic field,relaxation time,hydrostatic initial stress,and two temperature on the thermal shock problem.The governing equations are formulated in the context of Lord-Shulman theory with the presence of bodily force,two temperatures,thermal shock,and hydrostatic initial stress.We obtained the exact solution using the normal mode technique with appropriate boundary conditions.The field quantities are calculated analytically and displayed graphically under thermal shock problem with effect of external parameters respect to space coordinates.The results obtained are agreeing with the previous results obtained by others when the new parameters vanish.The results indicate that the effect of magnetic field and initial stress on the conductor temperature,thermodynamic temperature,displacement and stress are quite pronounced.In order to illustrate and verify the analytical development,the numerical results of temperature,displacement and stress are carried out and computer simulated results are presented graphically.This study helpful in the development of piezoelectric devices.