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Communications in Theoretical Physics 2024年第9期76卷 85-96页

作者： Riasat Ali Xia Tiecheng Muhammad Awais Rimsha Babar department of mathematics Shanghai University and Newtouch Center for Mathematics of Shanghai University department of mathematics University of Engineering and Technology department of mathematics GC University Faisalabad Layyah Campus

We investigate the light deflection in the weak field approximation from the accelerating charged AdS black hole. For this purpose, we apply the Gauss–Bonnet theorem to calculate the light deflection in the weak field area and use the Gibbons–Werner approach to analyze the optical geometry of the accelerating charged AdS black hole in the non-magnetic plasma absence/presence of a non-magnetic medium. We also represent the graphical behavior of the light deflection angle w.r.t. the impact parameter. We also compute the light deflection angle using Keeton and Petters approximations under the impact of accelerating charged AdS black hole geometry. Furthermore, by using the ray-tracing approach, we determine the shadow in the nonmagnetic plasma presence and also demonstrate that graphical shadow has an impact on the gauge potential, non-magnetic plasma frequencies and charge.

关键词： accelerating charged AdS black hole deflection angle Gibbons-Werner approach ray-tracing approach shadow

Study of bending angle and shadow in a new Schwarzschild-like black hole affected by plasma and non-plasma mediums

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Chinese Physics C 2024年第5期48卷 309-318页

作者： Riasat Ali Tiecheng Xia Muhammad Awais Rimsha Babar department of mathematics Newtouch Center for Mathematics of Shanghai UniversityShanghai 200444China department of mathematics University of Engineering and Technology Lahore-54890Pakistan department of mathematics GC University Faisalabad Layyah CampusLayyah-31200Pakistan

In this study,we analyze the models of the deflection angle of a new Schwarzschild-like black hole(BH)and employ the optical metric of the *** achieve this,we use the Gaussian curvature of the optical metric and the Gauss-Bonnet theorem,known as the Gibbons-Werner technique,to determine the deflection ***,we examine the deflection angle in the presence of a plasma medium and the effect of the plasma medium on the deflection *** deflection angle of the BH solution in the gauged super-gravity is computed using the Keeton-Petters *** the ray-tracing technique,we investigate the shadow of the corresponding BH and analyze the plots of the deflection angle and shadow to verify the influence of the plasma and algebraic thermodynamic parameters on the deflection angle and shadow.

关键词： new Schwarzschild-like black hole Gibbons-Werner and Keeton-Petters techniques deflection angle ray-tracing approach shadow

Enhanced entropy generation and heat transfer characteristics of magnetic nano-encapsulated phase change materials in latent heat thermal energy storage systems

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Applied mathematics and Mechanics(English Edition) 2024年第6期45卷 1051-1070页

作者： P.S.REDDY P.SREEDEVI department of mathematics Rajeev Gandhi Memorial College of Engineering and TechnologyNandyal 518501India

The objective of the current study is to investigate the importance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temperature contours within a thermal energy storage device filled with magnetic nanoencapsulated phase change materials(NEPCMs).The versatile finite element method(FEM)is implemented to numerically solve the governing *** effects of various parameters,including the viscosity parameter,ranging from 1 to 3,the thermal conductivity parameter,ranging from 1 to 3,the Rayleigh parameter,ranging from 102 to 3×10^(2),the radiation number,ranging from 0.1 to 0.5,the fusion temperature,ranging from 1.0 to 1.2,the volume fraction of NEPCMs,ranging from 2%to 6%,the Stefan number,ranging from 1 to 5,the magnetic number,ranging from 0.1 to 0.5,and the irreversibility parameter,ranging from 0.1 to 0.5,are examined in detail on the temperature contours,isentropic lines,heat capacity ratio,and velocity ***,the heat transfer rates at both the cold and hot walls are analyzed,and the findings are presented *** results indicate that the time taken by the NEPCMs to transition from solid to liquid is prolonged inside the chamber region as the fusion temperatureθf ***,the contours of the heat capacity ratio Cr decrease with the increase in the Stefan number Ste.

关键词： volume fraction of nano-encapsulated phase change material(NEPCM) radiation Stefan number heat capacity ratio entropy generation

Deep bed filtration model for cake filtration and erosion

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Applied mathematics and Mechanics(English Edition) 2024年第2期45卷 355-372页

作者： L.I.KUZMINA Y.V.OSIPOV A.R.PESTEREV department of Applied mathematics HSE UniversityMoscow 101000Russia department of Computer Science and Applied mathematics Moscow State University of Civil EngineeringMoscow 129337Russia

Many phenomena in nature and technology are associated with the filtration of suspensions and colloids in porous media. Two main types of particle deposition,namely, cake filtration at the inlet and deep bed filtration throughout the entire porous medium, are studied by different models. A unified approach for the transport and deposition of particles based on the deep bed filtration model is proposed. A variable suspension flow rate, proportional to the number of free pores at the inlet of the porous medium, is considered. To model cake filtration, this flow rate is introduced into the mass balance equation of deep bed filtration. For the cake filtration without deposit erosion,the suspension flow rate decreases to zero, and the suspension does not penetrate deep into the porous medium. In the case of the cake filtration with erosion, the suspension flow rate is nonzero, and the deposit is distributed throughout the entire porous medium. An exact solution is obtained for a constant filtration function. The method of characteristics is used to construct the asymptotics of the concentration front of suspended and retained particles for a filtration function in a general form. Explicit formulae are obtained for a linear filtration function. The properties of these solutions are studied in detail.

关键词： deep bed filtration cake filtration porous medium particle deposition and erosion analytical solution concentration front

Test of the Brans–Dicke theory with GW200105 and GW200115

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Communications in Theoretical Physics 2024年第7期76卷 85-95页

作者： Qin Fei Yingjie Yang department of mathematics and Physics School of Biomedical Engineering Southern Medical University School of mathematics and Physics Hubei Polytechnic University

We study whether it is possible to constrain the Brans–Dicke（BD） theory from the measurement of gravitational waves（GW） released in neutron star-black hole collisions. Considering the scalar field modifications through monopole and dipole radiations, we find additional contributions to the phase evolution in the emitted gravitational waveform. After effectively calculating such effect in the post-Newtonian order, we are in a position to measure the scalar field and give bounds on the BD coupling parameter ωBD. We derive the analytical expression for the phase modification due to the orbital eccentricity of eccentric binaries in both general relativity and BD theory. Employing the Bayesian analysis, we obtain the constraints on ωBDfrom the GW events, GW200105 and GW200115.

关键词： Brans-Dicke theory cosmology gravitational wave

Chemically Radiative MHD Flow of a Micropolar Nanofluid over a Stretching/ Shrinking Sheet with a Heat Source or Sink

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Fluid Dynamics & Materials Processing 2024年第2期20卷 257-274页

作者： Parakapali Roja Shaik Mohammed Ibrahim Thummala Sankar Reddy Giulio Lorenzini department of mathematics Annamacharya Institute of Technology and SciencesKadapa516126India department of engineering mathematics College of EngineeringKoneru Lakshmaiah Education FoundationVaddeswaram522302India department of mathematics Annamacharya Institute of Technology and SciencesKadapa516003India department of engineering and Architecture University of ParmaParma43124Italy

This study examines the behavior of a micropolar nanoﬂuidﬂowing over a sheet in the presence of a transverse magneticﬁeld and thermal *** addition,chemical(ﬁrst-order homogeneous)reactions are taken into account.A similarity transformation is used to reduce the system of governing coupled non-linear partial differ-ential equations(PDEs),which account for the transport of mass,momentum,angular momentum,energy and species,to a set of non-linear ordinary differential equations(ODEs).The Runge-Kutta method along with shoot-ing method is used to solve *** impact of several parameters is *** is shown that the micro-rota-tional velocity of theﬂuid rises with the micropolar ***,the radiation parameter can have a remarkable inﬂuence on theﬂow and temperature proﬁles and on the angular momentum distribution.

关键词： Chemical(ﬁrst order homogeneous)reaction magnetohydrodynamics micropolar nanoﬂuid stretching/shrinking sheet heat source

Quintessence anisotropic stellar models in quadratic and Born-Infeld modified teleparallel Rastall gravity

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Chinese Physics B 2024年第3期33卷 179-189页

作者： Allah Ditta 夏铁成 Irfan Mahmood Asif Mahmood department of mathematics Shanghai University and Newtouch Center for Mathematics of Shanghai UniversityShanghai 200444China Centre for High Energy Physics University of the PunjabLahorePakistan College of engineering Chemical Engineering DepartmentKing Saud University RiyadhSaudi Arabia

This study aims to discuss anisotropic solutions that are spherically symmetric in the quintessence field,which describe compact stellar objects in the modified Rastall teleparallel theory of *** achieve this goal,the Krori and Barua arrangement for spherically symmetric components of the line element is *** explore the field equations by selecting appropriate off-diagonal tetrad ***-Infeld function of torsion f(T)=β√λT+1-1 and power law form h(T)=δTn are *** Born-Infeld gravity was the first modified teleparallel gravity to discuss *** use the linear equation of state pr=ξρto separate the quintessence *** obtaining the field equations,we investigate different physical parameters that demonstrate the stability and physical acceptability of the stellar *** use observational data,such as the mass and radius of the compact star candidates PSRJ 1416-2230,Cen X-3,&4U 1820-30,to ensure the physical plausibility of our findings.

关键词： anisotropic spheres quintessence field modified Rastall teleparallel gravity equation of state(EoS) f(T)gravity

Cauchy matrix approach to three non-isospectral nonlinear Schrödinger equations

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Communications in Theoretical Physics 2024年第5期76卷 1-15页

作者： Alemu Yilma Tefera Shangshuai Li Da-jun Zhang department of mathematics Shanghai UniversityShanghai 200444China Newtouch Center for mathematics of Shanghai University Shanghai 200444China department of Applied mathematics Faculty of Science and EngineeringWaseda UniversityTokyo 169-8555Japan

This paper aims to develop a direct approach,namely,the Cauchy matrix approach,to non-isospectral integrable *** the Cauchy matrix approach,the Sylvester equation plays a central role,which defines a dressed Cauchy matrix to provideτfunctions for the investigated *** this paper,using the Cauchy matrix approach,we derive three non-isospectral nonlinear Schrödinger equations and their explicit *** equations are generically related to the time-dependent spectral parameter in the Zakharov–Shabat–Ablowitz–Kaup–Newell–Segur spectral *** solutions are obtained from the solutions of unreduced non-isospectral nonlinear Schrödinger equations through complex *** solutions are analyzed and illustrated to show the non-isospectral effects in dynamics of solitons.

关键词： Cauchy matrix approach Sylvester equation nonlinear Schrödinger equation non-isospectral integrable system explicit solution

Discrete Boltzmann model with split collision for nonequilibrium reactive flows

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Communications in Theoretical Physics 2024年第8期76卷 166-188页

作者： Chuandong Lin Kai H Luo Huilin Lai Sino-French Institute of Nuclear engineering and Technology Sun Yat-sen University Key Laboratory for Thermal Science and Power engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University department of Mechanical engineering National University of Singapore department of Mechanical engineering University College London School of mathematics and Statistics Key Laboratory of Analytical Mathematics and Applications (Ministry of Education) Fujian Key Laboratory of Analytical Mathematics and Applications (FJKLAMA) Center for Applied Mathematics of Fujian Province (FJNU) Fujian Normal University

A multi-relaxation-time discrete Boltzmann model(DBM) with split collision is proposed for both subsonic and supersonic compressible reacting flows, where chemical reactions take place among various components. The physical model is based on a unified set of discrete Boltzmann equations that describes the evolution of each chemical species with adjustable acceleration, specific heat ratio, and Prandtl number. On the right-hand side of discrete Boltzmann equations, the collision,force, and reaction terms denote the change rates of distribution functions due to self-and crosscollisions, external forces, and chemical reactions, respectively. The source terms can be calculated in three ways, among which the matrix inversion method possesses the highest physical accuracy and computational efficiency. Through Chapman–Enskog analysis, it is proved that the DBM is consistent with the reactive Navier–Stokes equations, Fick's law and the Stefan–Maxwell diffusion equation in the hydrodynamic limit. Compared with the one-step-relaxation model, the split collision model offers a detailed and precise description of hydrodynamic, thermodynamic, and chemical nonequilibrium effects. Finally, the model is validated by six benchmarks, including multicomponent diffusion, mixture in the force field, Kelvin–Helmholtz instability, flame at constant pressure, opposing chemical reaction, and steady detonation.

关键词： detonation discrete Boltzmann method nonequilibrium effect reactive flow

Categorizing methods for integrating machine learning with executable specifications

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Science China(Information Sciences) 2024年第1期67卷 5-19页

作者： David HAREL Raz YERUSHALMI Assaf MARRON Achiya ELYASAF department of Computer Science and Applied mathematics Weizmann Institute of Science department of Software and Information Systems engineering Ben-Gurion University of the Negev

Deep learning(DL),which includes deep reinforcement learning(DRL),holds great promise for carrying out real-world tasks that human minds seem to cope with quite *** promise is already delivering extremely impressive results in a variety of ***,while DL-enabled systems achieve excellent performance,they are far from *** has been demonstrated,in several domains,that DL systems can err when they encounter cases they had not hitherto ***,the opacity of the produced agents makes it difficult to explain their behavior and ensure that they adhere to various requirements posed by human *** the other end of the software development spectrum of methods,behavioral programming(BP) facilitates orderly system development using self-standing executable modules aligned with how humans intuitively describe desired system *** this paper,we elaborate on different approaches for combining DRL with BP and,more generally,machine learning(ML) with executable specifications(ES).We begin by defining a framework for studying the various approaches,which can also be used to study new emerging approaches not covered *** then briefly review state-of-the-art approaches to integrating ML with ES,continue with a focus on DRL,and then present the merits of integrating ML with *** conclude with guidelines on how this categorization can be used in decision making in system development,and outline future research challenges.

关键词： machine learning artificial intelligence grey box learning domain knowledge rules behavioral programming deep reinforcement learning survey