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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

Energy flux and waveform of gravitational wave generated by coalescing slow-spinning binary system in effective one-body theory

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Science China(Physics,Mechanics & Astronomy) 2024年第9期Mechanics & Astronomy) .卷 77-87页

作者： Weike Deng Sheng Long Jiliang Jing Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Educationand Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal University Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou University

We extend our research on the energy flux and waveform characteristics of gravitational waves generated by merging nonspinning binary black holes through self-consistent effective one-body theory to include binary systems with slowly spinning black ***, we decompose the equation for the null tetrad component of the gravitationally perturbed Weyl tensor ψ4Binto radial and angular parts, leveraging the second-order approximation of the rotation parameter a. Subsequently, we derive an analytical solution for the radial equation and observe that our results are contingent upon the parameters a2, a3, and a, which represent the second-and third-order correction parameters, respectively. Ultimately, we calculate the energy flux, the radiation-reaction force and the waveform for the “plus” and “cross” modes of the gravitational waves generated by merging slowly spinning binary black holes.

关键词： post-Minkowskian approximation effective-one-body theory gravitational waveform template

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Energy flux and waveforms by coalescing spinless binary system in effective one-body theory

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 58-68页

作者： Sheng Long Weike Deng Jiliang Jing Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We present a study on the energy radiation rate and waveforms of the gravitational wave generated by coalescing spinless binary systems up to the third post-Minkowskian approximation in the effective one-body *** derive an analytical expansion of the null tetrad components of the gravitational perturbed Weyl tensorΨ4in the effective spacetime,we utilize the method proposed by Sasaki et *** this investigation,we discover more general integral formulas that provide a theoretical framework for computing the results in any ***,we successfully compute the energy radiation rate and waveforms of the gravitational wave,which include the results of the Schwarzschild case and the correction terms resulting from the dimensionless parameters a2and a3in the effective metric.

关键词： post-Minkowskian approximation effective one-body theory gravitational waveform template

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Kerr black hole shadows cast by extraordinary light rays with Weyl corrections

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 18-26页

作者： Songbai Chen Jiliang Jing Department of Physics Institute of Interdisciplinary StudiesKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We investigate the equation of motion for photons with Weyl corrections in a Kerr black hole spacetime in a small coupling *** results show that Weyl corrections yield phenomena of *** light rays propagating in the spacetime are separated into the ordinary rays and the extraordinary rays,and the propagation of the latter depends on the *** probe the effects of Weyl corrections on the Kerr black hole shadows casted by the extraordinary rays and find that such corrections result in a weak stretching or squeezing in the vertical direction for the black hole ***,we also study the change of the length of the Near-Horizon Extremal Kerr line(NHEK line)with Weyl *** features could help us to understand the electrodynamics with Weyl corrections from black hole shadows.

关键词： correction light stretching

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Merger estimates for a disformal Kerr black hole in quadratic degenerate higher-order scalar-tensor theories

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Chinese Physics C 2024年第5期48卷 284-292页

作者：蒋洪鑫杜欣怡潘启沅陈松柏荆继良 Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education Synergetic Innovation Center for Quantum Effects and Applicationsand Department of PhysicsHunan Normal UniversityChangsha 410081China Institute of Interdisciplinary Studies Hunan Normal UniversityChangsha 410081China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We investigate the main features of a disformal Kerr black hole merger in quadratic degenerate higher-order scalar-tensor *** the ringdown stage of the black hole merger,for the prograde orbit,the real part of the quasinormal modes decreases with an increase in the disformal parameter,and the imaginary part also decreases,except in the Kerr case for a large spin ***,for the retrograde orbit,the real part increases with an increase in the disformal parameter,and the imaginary part always decreases with *** the approximate final spin,regardless of an equal spin,unequal spin,or generic spin configuration merger,the final black hole spin always increases with an increase in the disformal *** results show that the disformal parameter in the disformal Kerr solution and the MOG parameter in the Kerr-MOG case have obviously different effects on the black hole merger,which suggests the differences between these two spacetime structures.

关键词： black hole merger quasinormal modes final black hole spin disformal Kerr black hole quadratic degenerate higher-order scalar-tensor(DHOST)theory

Improved catalytic performance of CO_(2) electrochemical reduction reaction towards ethanol on chlorine-modified Cu-based electrocatalyst

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Nano Research 2024年第5期17卷 3761-3768页

作者： Yifan Liu Hehua Tang Yitian Zhou Bo-Lin Lin School of physical Science and Technology ShanghaiTech UniversityShanghai 201210China

Effective electrochemical conversion of CO_(2) to value-added liquid multi-carbon products driven by renewable energy is a promising approach to alleviate excessive CO_(2) emission and achieve large-scale renewable energy ***,the selectivity and catalytic activity towards liquid multi-carbon products of CO_(2) electroreduction reaction are still unsatisfactory due to the sluggish C-C coupling process and the formation of complex oxygen-containing ***,designing and fabricating highly effective electrocatalysts is crucial for practical applications in this ***,we developed Cl-modified Cu catalyst(Cu-Cl)for efficient electrochemical reduction of CO_(2) to *** optimal Faradaic efficiency and partial current density of ethanol on the Cu-Cl sample reached 26.2%and 343.2 mA·cm^(-2) at-0.74 V(*** hydrogen electrode(RHE)),which were 1.66 and 1.76 times higher than those of the catalyst without Cl decoration,outperforming those in most previously reported *** functional theory(DFT)calculations revealed that the Cl-modified Cu surface suppressed the parasitic hydrogen evolution reaction(HER)and reduced the energy barrier for the C-C coupling process,making the formation of key intermediates favorable for ethanol ***,the decoration of Cl on the Cu surface facilitated ethanol formation.

关键词： CO_(2)electrochemical reduction halogen chlorine Cu-based catalysts ethanol multi-carbon products

Robust autofocusing propagation in turbulence

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Chinese Physics B 2024年第6期33卷 370-375页

作者：刘娜娜谭柳陈凯健洪佩龙莫小明邹炳锁任煜轩梁毅 Guangxi Key Laboratory for Relativistic Astrophysics Center on Nanoenergy ResearchSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China School of mathematics and Physics Anqing Normal UniversityAnqing 246133China Institute for Translational Brain Research MOE Frontiers Center for Brain ScienceFudan UniversityShanghai 200032China

Turbulence in complex environments such as the atmosphere and biological media has always been a great challenge to the application of beam propagation in optical communication, optical trapping and manipulation. To overcome this challenge, this study comprehensively investigates the robust propagation of traditional Gaussian and autofocusing beams in turbulent environments. In order to select stable beams that exhibit high intensity and high field gradient at the focal position in complex environments, Kolmogorov turbulence theory is used to simulate the propagation of beams in atmospheric turbulence based on the multi-phase screen method. We systematically analyze the intensity fluctuations, the variation of the coherence factor and the change in the scintillation index with propagation distance. The analysis reveals that the intensity fluctuations of autofocusing beams are significantly smaller than those of Gaussian beams, and the coherence of autofocusing beams is better than that of Gaussian beams under turbulence. Moreover, autofocusing beams exhibit less oscillation than Gaussian beams, indicating that autofocusing beams propagate in complex environments with less distortion and intensity fluctuation. Overall, this work clearly demonstrates that autofocusing beams exhibit higher stability in propagation compared with Gaussian beams, showing great promise for applications such as optical trapping and manipulation in complex environments.

关键词： propagation beams autofocusing turbulence

Cooperative activation of sodium channels for downgrading the energy efficiency in neuronal information processing

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Chinese Physics B 2024年第5期33卷 758-763页

作者：严浩然颜家琦俞连春邵玉峰 School of physical Science and Technology Lanzhou Center for Theoretical PhysicsLanzhou UniversityLanzhou 730000China Key Laboratory of Theoretical Physics of Gansu Province and Key Laboratory of Quantum Theory and Applications of MoELanzhou UniversityLanzhou 730000China Department of Neuroscience AnatomyHistologyand EmbryologyKey Laboratory of Preclinical Study for New Drugs of Gansu ProvinceSchool of Basic Medical SciencesLanzhou UniversityLanzhou 730000China

The Hodgkin–Huxley model assumes independent ion channel activation,although mutual interactions are common in biological *** raises the problem why neurons would favor independent over cooperative channel *** this study,we evaluate how cooperative activation of sodium channels affects the neuron’s information processing and energy *** of the stochastic Hodgkin–Huxley model with cooperative activation of sodium channels show that,while cooperative activation enhances neuronal information processing capacity,it greatly increases the neuron’s energy *** a result,cooperative activation of sodium channel degrades the energy efficiency for neuronal information *** discovery improves our understanding of the design principles for neural systems,and may provide insights into future designs of the neuromorphic computing devices as well as systematic understanding of pathological mechanisms for neural diseases.

关键词： energy efficiency ion channel noise action potential generation neuronal dynamics

Self-powered stimuli responsive material for dual stimulation of heat and guest molecules

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Chinese Chemical Letters 2024年第2期35卷 590-593页

作者： Jintao Men Ke Xu Taiting Sha Lei He Yan Xu Jie Mu Tijian Yin Qiong Ye Jiangsu Key Laboratory for Science and applications of Molecular Ferroelectrics and School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China

Stimuli-responsive smart materials exhibit reverse chemical/physical changes in response to external stimuli and research on stimuli-responsive smart materials with self-powered properties is still uncultivated ***,we report perovskite crystalline self-powered multiple stimuli-responsive materials triggered by chemical and thermal stimuli.[HMEP]PbI_(3)·(H_(2)O)(1;HMEP is a hydroxytris(1-methylethyl)phosphorus cation)crystallizes in a chiral space group P 21 at 293 K and has the piezoelectric reaction(d_(33)=10 pC/N and output voltage=1 V)of self-powered modes,this value is larger than the value of 3 pC/N for the classical piezoelectric material *** materials can generate energy due to mechanical deformation,and using thermal heating to lose water,[HMEP]PbI_(3)(2)can be obtained.2 crystallizes in the non-centrosymmetric space group,undergoes two reversible phase transitions at 243/255 K and 315/348 K,and shows second harmonic generation ***,2 can return to the hydrated form 1 after absorbing *** work will lay the foundation for self-powered stimuli-responsive compounds and contribute to the construction of novel organic-inorganic hybrid materials with second harmonic generation switching.

关键词： Self-powered Dual stimulation reactive Phase transition SHG switch Organic-inorganic hybrid perovskite