Chinese Journal of Physics最新文献

{"title":"Lattice boltzmann method for mixed convection with non-uniform and fractal Al2O3/water nanofluid in differently vertical moving lid cavities","authors":"Dwesh K. Singh ,&nbsp;Rajan Kumar ,&nbsp;Vinod Kumar Venkiteswaran","doi":"10.1016/j.cjph.2025.02.023","DOIUrl":"10.1016/j.cjph.2025.02.023","url":null,"abstract":"<div><div>Mesoscale Lattice Boltzmann simulation is used to solve the mixed convection of Al₂O₃/H₂O nanofluid medium in two-sided lid-driven cavities. Flow governing equations like Navier-Stokes and energy equations in the form of particle distribution functions have been solved by the Lattice Boltzmann Method (LBM). The effect of fractal dimension (minimum to maximum diameter) and non-uniform diameter of Al₂O₃ nanoparticles for different concentrations in water inside the cavities has been considered. Based on the vertical walls motion, three different cases of lid-driven problems have been considered. First, only the left wall is moving in the upward direction (Case-I), second, when the vertical walls are moving in the same direction (Case-II), and third, when the vertical walls are moving in the opposite direction (Case-III). Results are depicted in the form of streamline, isotherms, Nusselt number, and vertical velocity variation. A significant decrease in Nusselt number is found for the range of mean nanoparticle diameter from 1 nm to 20 nm. Increasing the fractal dimension of Al₂O₃ increases the heat transfer in all three different cases. Fractal distribution R = 0.001 has the capability of a lower heat transfer rate than at R = 0.007. Quantitatively a maximum of 51 % increment in <span><math><mover><mrow><mi>N</mi><mi>u</mi></mrow><mo>‾</mo></mover></math></span> for Case III is observed in comparison to Case I at Ri = 0.1 for the same parameters. This increment is 46 % for Case II in comparison to Case I, which is observed. Case-III with a higher value of fractal distribution and smaller mean diameter of nanoparticles is suggested for better heat transfer.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1259-1277"},"PeriodicalIF":4.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraints on τ electromagnetic moments via tau pair production at the Muon colliders","authors":"H. Denizli ,&nbsp;A. Senol ,&nbsp;M. Köksal","doi":"10.1016/j.cjph.2025.04.020","DOIUrl":"10.1016/j.cjph.2025.04.020","url":null,"abstract":"<div><div>The anomalous magnetic (<span><math><msub><mrow><mover><mrow><mi>a</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></math></span>) and electric dipole (<span><math><msub><mrow><mover><mrow><mi>d</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></math></span>) moment of tau lepton described in <span><math><mrow><mi>τ</mi><mover><mrow><mi>τ</mi></mrow><mrow><mo>̄</mo></mrow></mover><mi>γ</mi></mrow></math></span> vertices are studied via <span><math><mrow><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>→</mo><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math></span> process at the Muon colliders designed with the proposed center-of-mass-energy/integrated luminosity configurations of 3 TeV/ 1 ab⁻¹ and 10 TeV/ 10 ab⁻¹. We obtained the 95% confidence level limits on the <span><math><msub><mrow><mover><mrow><mi>a</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></math></span> and <span><math><msub><mrow><mover><mrow><mi>d</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></math></span> parameters without and with systematic uncertainty of 10% and compared with the experimental results. The most stringent limits on the anomalous couplings without systematic uncertainty are <span><math><mrow><mo>−</mo><mn>2</mn><mo>.</mo><mn>63</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup><mo>&lt;</mo><msub><mrow><mover><mrow><mi>a</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub><mo>&lt;</mo><mn>2</mn><mo>.</mo><mn>65</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> and <span><math><mrow><mo>∣</mo><msub><mrow><mover><mrow><mi>d</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub><mo>∣</mo><mo>≤</mo><mn>1</mn><mo>.</mo><mn>47</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>18</mn></mrow></msup><mi>e</mi><mi>c</mi><mi>m</mi></mrow></math></span> at <span><math><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>10</mn><mspace></mspace><mi>TeV</mi></mrow></math></span> and <span><math><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>i</mi><mi>n</mi><mi>t</mi></mrow></msub><mo>=</mo></mrow></math></span> 10 ab⁻¹ option of the Muon collider. Our results show that the Muon colliders lead to a remarkable improvement on the current experimental limits of the anomalous magnetic and electric dipole moments of the tau lepton.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1250-1258"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EHD nonlinear instability of a cylindrical interface between two williamson liquids","authors":"Asma Alanazy ,&nbsp;Galal M. Moatimid ,&nbsp;Doaa R. Mostapha","doi":"10.1016/j.cjph.2025.03.051","DOIUrl":"10.1016/j.cjph.2025.03.051","url":null,"abstract":"<div><div>The investigation of electrohydrodynamic (EHD) nonlinear instability at a cylindrical interface concerning two Williamson fluids (W) is distinctive owing to its significance in industrial and biomedical contexts, including inkjet printing, electro-spinning, and enhanced oil recovery, where comprehending the stability of viscoelastic liquid interfaces under electric fields is significant for performance optimization and fluid behavior regulation. The study uses a nonlinear methodology to analyze the stability of a vertical cylindrical interface between two WF through porous media, concentrating on the impact of an axial uniform EF. The nonlinear methodology expresses the essential linear partial differential equations (PDEs) and implements the applicable nonlinear boundary conditions (BCs). This method produces a nonlinear distinguishing PDE. The non-perturbative approach (NPA) is employed to examine nonlinear stability. The main impartial of NPA is to transform a nonlinear ordinary differential equation (ODE) into a linear one. The NPA is differentiated from traditional perturbation techniques by its ability to precisely scrutinize the behavior of extremely nonlinear oscillators. This distinctive methodology is advanced by extending He's frequency formula (HFF) to orchestrate the movement of the interface. The study demonstrates that the structure stabilizes by elevating both the axial wavenumber and axial EF. It is found that the stability mechanism remains unchanged irrespective of whether the coefficients of the distinguishing ODE are real or complex. PolarPlots are generated independently for real and complex cases to grantee the impact of numerous variables and the effectiveness of the stability profile.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1018-1042"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Violation of Svetlichny’s inequality in a system of spins j","authors":"Yang Xiang,&nbsp;Yuan Tao","doi":"10.1016/j.cjph.2025.04.017","DOIUrl":"10.1016/j.cjph.2025.04.017","url":null,"abstract":"<div><div>Quantum multi-particle correlations are one of the most intriguing properties of quantum entanglement, arising from collective entangled states of multiple particles. Svetlichny’s inequality (SI) was the first method proposed to test the existence of such correlations. Previous studies have primarily focused on <span><math><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math></span>-spin particle systems. In this paper, we present a unified scheme that enables the violation of SI in arbitrary non-zero spin particle systems. Specifically, for all fermion systems, our scheme achieves the maximal quantum violation of SI for any number of particles. For boson systems, when the particle spin <span><math><mrow><mi>j</mi><mo>≥</mo><mn>2</mn></mrow></math></span>, our scheme consistently realizes the violation of SI for any number of particles. When the particle spin <span><math><mrow><mi>j</mi><mo>=</mo><mn>1</mn></mrow></math></span>, our scheme can yield SI violation for up to 7 particles. Furthermore, as the particle spin <span><math><mi>j</mi></math></span> approaches infinity, our scheme achieves the maximal quantum violation of SI. To obtain these results, we also prove that the upper bound of Svetlichny’s operator within the framework of local hidden variable theory is <span><math><msqrt><mrow><msup><mrow><mn>2</mn></mrow><mrow><mi>N</mi><mo>+</mo><mn>1</mn></mrow></msup></mrow></msqrt></math></span>. These findings not only enhance our understanding of quantum correlations across various particle systems but also provide valuable insights for the development of quantum communication protocols that utilize entanglement and non-locality in multi-particle configurations.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1096-1104"},"PeriodicalIF":4.6,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase transition of a colloidal suspension in the vicinity of a fluctuating membrane using the lattice gas model","authors":"Hamid Kaidi","doi":"10.1016/j.cjph.2025.04.007","DOIUrl":"10.1016/j.cjph.2025.04.007","url":null,"abstract":"<div><div>This investigation aims to study the phase transition of colloidal particles near a fluctuating membrane using the lattice gas model. The first step is to derive a new Ising-like Hamiltonian. We addressed this problem in the continuous limit by applying the Hubbard–Stratonovich transformation. The values predicted by the mean-field approximation, or its generalization namely, the Landau approximation are <span><math><mrow><msup><mrow><mi>α</mi></mrow><mrow><mo>′</mo><mo>+</mo></mrow></msup><mo>=</mo><msup><mrow><mi>α</mi></mrow><mrow><mo>′</mo><mo>−</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow></math></span>, <span><math><mrow><msup><mrow><mi>β</mi></mrow><mrow><msup><mrow></mrow><mrow><mo>′</mo></mrow></msup></mrow></msup><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>γ</mi></mrow><mrow><mo>+</mo></mrow></msub><mo>=</mo><msub><mrow><mi>γ</mi></mrow><mrow><mo>−</mo></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span>, <span><math><mrow><mi>δ</mi><mo>=</mo><mn>3</mn></mrow></math></span>, <span><math><mrow><mi>η</mi><mo>=</mo><mn>0</mn></mrow></math></span> and <span><math><mrow><mi>ν</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math></span>. We have also established scaling relations between these critical exponents. The gas-on-network model was employed to demonstrate the <em>hysteresis</em> phenomenon, providing a quantitative description at the microscopic scale of the phase transition in the colloidal suspension, from the ordered phase to the disordered phase. In comparison with recent studies, the lattice gas model remains a valuable tool and promising for describing the organization of colloidal particles near a soft interface.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1314-1327"},"PeriodicalIF":4.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observational constraints on a modified-gravity model with an exponential function of the curvature using the expansion history, the RSD, and the Pantheon+SH0ES data","authors":"Mario A. Acero,&nbsp;A. Oliveros","doi":"10.1016/j.cjph.2025.04.014","DOIUrl":"10.1016/j.cjph.2025.04.014","url":null,"abstract":"<div><div>Considering a well-motivated <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> modified-gravity model, in which an exponential function of the curvature is included, in this paper we implement a statistical data analysis to set constraints on the parameters of the model, taking into account an analytic approximate solution for the expansion rate, <span><math><mrow><mi>H</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span>. Using a Monte Carlo Markov Chain-based analysis of the expansion rate evolution, the standardized SN distance modulus and the redshift space distortion observational data, we find that the preferred value for the perturbative parameter, <span><math><mi>b</mi></math></span>, quantifying the deviation of the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> model from <span><math><mi>Λ</mi></math></span>CDM, lies in a region that excludes <span><math><mrow><mi>b</mi><mo>=</mo><mn>0</mn></mrow></math></span> at <span><math><mrow><mo>≳</mo><mn>3</mn><mo>.</mo><mn>5</mn><mi>σ</mi></mrow></math></span> C.L., and that the predicted current value of the Hubble parameter, <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, locates in between the two observational results currently under scrutiny from Planck and SH0ES collaborations. Under the implemented approximate solution, and with the constraints obtained for the parameters, the proposed <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> model successfully reproduces the observational data and the predicted evolution of interesting cosmological parameters resemble the results of <span><math><mi>Λ</mi></math></span>CDM, as expected, while an oscillatory behavior of the dark energy equation of state is observed, pointing to deviation from the concordance cosmological model. The results presented here reinforce the conclusion that the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> modified-gravity model represents a viable alternative to describe the evolution of the Universe, avoiding the challenges faced by <span><math><mi>Λ</mi></math></span>CDM.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1105-1120"},"PeriodicalIF":4.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating strange stars in Rastall theory","authors":"Malick Sallah ,&nbsp;M. Sharif","doi":"10.1016/j.cjph.2025.04.013","DOIUrl":"10.1016/j.cjph.2025.04.013","url":null,"abstract":"<div><div>This study explores the structural formation of various spherically symmetric anisotropic stars within the framework of Rastall theory. To achieve this, we derive modified field equations which are then resolved using the Finch–Skea ansatz, which involve unknown parameters <span><math><mrow><mo>(</mo><msub><mrow><mi>A</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>A</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>A</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>)</mo></mrow></math></span>. These parameters are found by using appropriate constraints given by the junction conditions, in addition to observational data from some selected stars. The <span><math><mi>EOS</mi></math></span> given by the <span><math><mi>MIT</mi></math></span> bag model is employed to examine the interior structure and various physical properties of these compact objects. For calculated values of the bag constant <span><math><mi>B</mi></math></span> and two values of the Rastall parameter, <span><math><mrow><mi>ξ</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>3</mn><mo>,</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span>, we investigate the regularity and viability of the state variables. Additionally, we analyze stability of the developed model by employing three distinct criteria. We find that the obtained model is stable and provides an accurate approximation for the mass and radius of strange stars when the Rastall parameter <span><math><mrow><mi>ξ</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>3</mn></mrow></math></span> is considered.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1141-1154"},"PeriodicalIF":4.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of internal heat and gravity modulation on convection of Jeffrey fluid in a porous media: A weakly non-linear analysis","authors":"Suman Shekhar ,&nbsp;Lakshmi Sangeeta Syamala ,&nbsp;Ravi Ragoju","doi":"10.1016/j.cjph.2025.04.011","DOIUrl":"10.1016/j.cjph.2025.04.011","url":null,"abstract":"<div><div>Internal heat, primarily generated by nuclear fusion and radioactive decay, serves as a key energy source for celestial bodies. In porous media, small-scale exothermic reactions can contribute to local heat generation, enabling convective flow under various practical conditions. The Jeffrey fluid model, widely used for biological fluids such as blood, synovial fluid, chyme, gastric fluid, and saliva, is considered in this study. This paper examines the influence of internal heat generation and gravity modulation on the convection of Jeffrey fluids using a weak nonlinear analysis and a power series expansion method. Heat transfer is evaluated through the Nusselt number and the mean Nusselt number (<span><math><mover><mrow><mi>N</mi><mi>u</mi></mrow><mo>¯</mo></mover></math></span>), which is determined as the area under the curve. For an internal Rayleigh number <span><math><mrow><mi>R</mi><msub><mrow><mi>a</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span>, the area under the curve is smaller, whereas for <span><math><mrow><mi>R</mi><msub><mrow><mi>a</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>5</mn></mrow></math></span>, it is larger, indicating enhanced heat transport. Similarly, for the Vadasz number, <span><math><mrow><mi>V</mi><mi>a</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span> results in a smaller area under the mean Nusselt number curve, while <span><math><mrow><mi>V</mi><mi>a</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>5</mn></mrow></math></span> leads to a larger area, suggesting increased heat transport and greater system instability.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1167-1177"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Marangoni instability of a Maxwell’s viscoelastic liquid with Cattaneo–Christov heat flux in the absence of gravity","authors":"J. Antonio Ruiz-Díaz,&nbsp;Luis A. Dávalos-Orozco","doi":"10.1016/j.cjph.2025.04.008","DOIUrl":"10.1016/j.cjph.2025.04.008","url":null,"abstract":"<div><div>The Marangoni instability of a viscoelastic liquid film coating a thick wall with finite thermal conductivity is analyzed under the assumption that the liquid heat flux follows the Cattaneo–Christov constitutive equation. This analysis is conducted in the absence of gravity, as buoyancy forces can be neglected for thin liquid films. This study investigates the influence of the Prandtl number (<span><math><mrow><mi>P</mi><mi>r</mi></mrow></math></span>), the viscoelastic relaxation time (<span><math><mi>F</mi></math></span>), the thermal relaxation time (<span><math><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span>), and the wall’s thermal and geometric properties on the onset of thermocapillary convection. The effect of <span><math><mrow><mi>P</mi><mi>r</mi></mrow></math></span> is examined within the range of 5 to 100, which is characteristic of polymeric suspensions. The wall’s thermal conductivity is quantified using the fluid-to-wall conductivity ratio, varying from 10⁻⁷ to 10<span><math><msup><mrow></mrow><mrow><mn>7</mn></mrow></msup></math></span>, thus encompassing the limiting cases of an ideal heat conductor and an adiabatic wall, along with intermediate scenarios. The effect of wall thickness is analyzed by setting the ratio of wall thickness to fluid depth to 0.1 for a thin wall and 100 for a thick wall.</div></div><div><h3>Methodology:</h3><div>A linear stability analysis is performed by perturbing and linearizing the governing equations of motion and energy. A normal mode expansion is applied to velocity and temperature perturbations, leading to an eigenvalue problem that is analytically solvable for the stability parameter, the Marangoni number. This number is then computed numerically to determine the marginal and critical states under varying parameter sets.</div></div><div><h3>Key findings:</h3><div>For large values of <span><math><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> or <span><math><mi>F</mi></math></span>, oscillatory convection dominates over stationary modes. Increasing <span><math><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> enhances instability, while the effect of <span><math><mrow><mi>P</mi><mi>r</mi></mrow></math></span> varies, either stabilizing or destabilizing the system depending on <span><math><mi>F</mi></math></span>. Competing oscillatory modes, characterized by distinct wavenumbers and frequencies, arise within specific parameter regimes. Additionally, wall properties — such as thermal conductivity, specific heat, and thickness — significantly influence the onset conditions for both monotonic and oscillatory instabilities.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"95 ","pages":"Pages 1121-1140"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of continuous graphene with periodic ferroelectric domains for adaptive terahertz photodetector","authors":"Lin Lin ,&nbsp;Junxiong Guo ,&nbsp;Shangdong Li ,&nbsp;Tianxun Gong ,&nbsp;Juan Xia ,&nbsp;Yang Zhang ,&nbsp;Wenjing Jie ,&nbsp;Wen Huang ,&nbsp;Xiaosheng Zhang","doi":"10.1016/j.cjph.2025.04.025","DOIUrl":"10.1016/j.cjph.2025.04.025","url":null,"abstract":"<div><div>Graphene plasmons exhibit significant potential for applications in terahertz (THz) detectors due to their fascinating interactions between electromagnetic radiation and matter. However, the excitation and manipulation of graphene plasmons in continuous graphene that is free of patterned technique remain considerable challenges. Here, we present an adaptive wavelength-sensitive terahertz detector, which comprises continuous graphene integrated onto a ferroelectric thin film featuring periodic polarization domains. This designed device demonstrates the capability to absorb THz waves without the need for an external bias voltage, attributed to the high confinement of surface plasmons at the graphene-ferroelectric interface. By reconfiguring an interweaving squared ferroelectric domain array with alternating upward and downward polarizations, our devices theoretically achieve an ultrahigh responsivity of 17.56 A W^-1 and a specific detectivity of 1.11 × 10¹¹ Jones at room temperature. Furthermore, we demonstrate the feasibility of utilizing these photodetectors for spectrum reconstruction applications in portable spectrometers across a broad frequency range of 4.97 to 7.85 THz and achieving a spectral resolution of up to 0.02 THz when integrated with mathematical algorithms.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"96 ","pages":"Pages 1-8"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}