Chinese Journal of Physics最新文献

{"title":"Generalized Hawking radiation power corresponding to Sharma–Mittal entropy","authors":"Hasan Dashtianeh,&nbsp;Jafar Sadeghi","doi":"10.1016/j.cjph.2024.12.017","DOIUrl":"10.1016/j.cjph.2024.12.017","url":null,"abstract":"<div><div>The effective radius of the black hole radiation as <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>A</mi></mrow></msub></math></span>, determines the area in space–time around the black hole with radius <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>B</mi><mi>H</mi></mrow></msub></math></span>, which is the source of the black hole’s Hawking radiation. Also here, it should be noted that, the effective radius as a geometric bound of a specific area around the black hole plays an important role in understanding the thermodynamics of the black hole. The general belief based on Hawking’s opinion was that <span><math><mrow><msub><mrow><mi>r</mi></mrow><mrow><mi>A</mi></mrow></msub><mo>∼</mo><msub><mrow><mi>r</mi></mrow><mrow><mi>B</mi><mi>H</mi></mrow></msub></mrow></math></span> but Giddings concluded that <span><math><mrow><msub><mrow><mi>r</mi></mrow><mrow><mi>A</mi></mrow></msub><mo>∼</mo><mn>2</mn><msub><mrow><mi>r</mi></mrow><mrow><mi>B</mi><mi>H</mi></mrow></msub></mrow></math></span>. On the other hand, many researches have shown that the generalized entropies for the describing gravitational phenomena more appropriate than the Boltzmann–Gibbs entropy. Among the generalized entropies, we can mention Tsallis, Renyi and Sharma–Mittal entropies. Generally one can say that the Sharma–Mittal entropy can be converted into Tsallis and Renyi entropies under certain conditions. Therefore, the question that arises here is that, by changing surface entropy of black hole to Sharma–Mittal entropy, how will be compatible the effective radius of the black hole with Hawking’s and Gidding’s point of view ? Or how is changed the effective radius by changing the surface entropy of black hole? Our main motivation for presenting this paper is that we have to give answer the above mentioned question.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 430-436"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168055","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":"Raman spectroscopy of HgPSe3 thin flakes and its application to near UV-to-visible photodetectors","authors":"Yung-Lan Chuang ,&nbsp;Yu-Tsun Yao ,&nbsp;Bo-Cheng Yang ,&nbsp;Chin-Shan Lue ,&nbsp;Chia-Nung Kuo ,&nbsp;Ming-Lun Lee ,&nbsp;Jinn-Kong Sheu","doi":"10.1016/j.cjph.2024.12.016","DOIUrl":"10.1016/j.cjph.2024.12.016","url":null,"abstract":"<div><div>This study investigates the dependence of Raman spectroscopy on the number of layers in HgPSe₃ using excitation lasers at 532 nm and 633 nm. Notably, both bulk HgPSe₃ and mechanically exfoliated thin flakes exhibit two prominent Raman peaks at 147.8 and 213.9 cm⁻¹. This observation suggests that flake thickness has an insignificant influence on the characteristic Raman spectra, indicative of a high degree of structural uniformity within the material. HgPSe₃ thin flakes are used as light-absorbing materials for photodetector (PD) devices. The fabricated PDs demonstrate remarkably low dark currents on the order of femtoamperes. Their spectral response ranges from 400 nm to 630 nm, with a well-defined cutoff around 590 nm, suggesting a bandgap of approximately 2.1 eV for HgPSe₃. Furthermore, the photodetectors achieve a response time of approximately 28 ms at a bias voltage of 5 V and an illumination wavelength of 500 nm. These promising results underscore the potential of HgPSe₃ thin films as active materials in ultraviolet-visible photodetectors.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 409-417"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168066","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":"Exploring heat generation and magnetic effects on unsteady ternary nanofluid flow over a dynamic wedge in porous media","authors":"Yun Ouyang ,&nbsp;Md Faisal Md Basir ,&nbsp;Kohilavani Naganthran ,&nbsp;Ioan Pop","doi":"10.1016/j.cjph.2024.12.026","DOIUrl":"10.1016/j.cjph.2024.12.026","url":null,"abstract":"<div><div>In the die-slit process, unsteady MHD ternary nanofluid flow over a moving wedge helps enhance material quality and production efficiency. This study specifically examines unsteady MHD flow dynamics involving heat generation/absorption, viscous dissipation, and Ohmic heating effects, using a ternary nanofluid composed of <span><math><mrow><msub><mrow><mtext>Al</mtext></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mtext>O</mtext></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>-CuO-Cu/water over a moving wedge. Mathematical modeling and numerical computation analyze how heat generation/absorption impacts flow characteristics. Critical values for single and dual solutions are obtained using BVP4C in MATLAB, with dual solutions for leftward wedge motion and a single solution for rightward motion. Graphical results illustrate the influence of key parameters — involving the moving parameter, wedge parameter, Eckert number, magnetic parameter, heat source/sink parameter, and Darcy number — on flow dynamics and thermal transfer. The main results show that convective thermal transfer rises with larger values of the suction/injection parameter, unsteadiness parameter, Eckert number, and magnetic parameter, while it decreases during the rinsing process for the wedge angle parameter, Darcy number, and heat source/sink parameter. When the moving wedge parameter is −4, the heat transfer of THNF is 0.44% higher than NHF and 1.30% higher than NF. This study proposes a novel formulation for the time-varying permeability of a porous medium influenced by a moving wedge, offering valuable insights to enhance material properties, minimize waste, and improve precision in the extrusion process.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 531-548"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167078","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":"Analytical and numerical study of MHD natural convection in a slender porous cavity due to lateral uniform heat flux: Effect of LTNE state","authors":"Harish Chandra ,&nbsp;Abhishek K. Sharma","doi":"10.1016/j.cjph.2024.11.022","DOIUrl":"10.1016/j.cjph.2024.11.022","url":null,"abstract":"&lt;div&gt;&lt;div&gt;In this work, the study of local thermal non-equilibrium (LTNE) state on magnetohydrodynamic (MHD) natural convection inside a radiative porous enclosure is investigated numerically as well as analytically. The motion of the flow is induced due to constant heat flux on side walls, while horizontal walls are insulated. A Darcy model to describe the two-dimensional flow governing equations has been adopted. These equations are solved numerically by using the Alternate Direction Implicit (ADI) method and analytically by implementing the parallel flow assumption valid for large aspect ratios. Boundary layer analysis is also carried out to describe the boundary layer thickness &lt;span&gt;&lt;math&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;∼&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/math&gt;&lt;/span&gt; as well as the heat transfer rate &lt;span&gt;&lt;math&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;∼&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/math&gt;&lt;/span&gt; of the fluid phase. This study is carried out to get a better perspective of the LTNE state between fluid and solid phases inside the radiative porous medium. The influence of LTNE parameters (&lt;span&gt;&lt;math&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;), aspect ratio (&lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;), Hartmann number (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), and radiation parameter &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; on the flow dynamics and heat transfer mechanism are analyzed. From our numerical investigation, it is found that in the entire study, the flow structure is controlled by unicellular, and the average Nusselt number of the solid phase increases with the value of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. However, on increasing the value of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, the heat transfer rate of the fluid phase depends on the values of LTNE parameters. For increasing the value of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; from 1 to 10, the maximum reduction in the heat transfer rate of the fluid (solid) phase is reported to be up to 178% (7.31%) at 10 times enhancement in the electric field. For small values of &lt;span&gt;&lt;math","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 389-408"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167088","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":"Corrigendum to “Hybrid differential evolutional algorithm for Falkner-Skan flow with rotation” [Chinese Journal of Physics 91 (2024) 977–1003 / 0577-9073/© 2024]","authors":"Javaid Ali ,&nbsp;Muhammad Rafiq ,&nbsp;Nauman Ahmed ,&nbsp;Sultan Alqahtani ,&nbsp;Ilyas Khan ,&nbsp;Abha Singh","doi":"10.1016/j.cjph.2024.10.003","DOIUrl":"10.1016/j.cjph.2024.10.003","url":null,"abstract":"","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Page 649"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167159","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":"Effects of stochastic electromagnetic fluctuation on signal detection of astrocyte-dressed neuron","authors":"Yasemin Erkan","doi":"10.1016/j.cjph.2024.12.001","DOIUrl":"10.1016/j.cjph.2024.12.001","url":null,"abstract":"<div><div>Signal transmission in the nervous system is frequently studied considering its different biological or environmental characteristics. Recent studies have revealed that dynamic neuronal behaviors in the brain are significantly modulated by both astrocytes and magnetic fluctuations. Moreover, the contact of the noisy electromagnetic environment with the biological nerve cells is also inevitable. However, the effects of stochastic electromagnetic fluctuation on signal detection in an astrocyte-dressed neuron have never been studied in detail. In this study, an improved astrocyte-dressed Hodgkin–Huxley neuron model subjected to electromagnetic fluctuation is examined. Sinus-Wiener limited noise is used to model the random structure of the electromagnetic field. Simulation results show that, without considering noisy electromagnetic induction, the optimum value of the electromagnetic feedback gain parameter and the weak signal frequency used optimize the response of the astrocyte-dressed Hodgkin–Huxley neuron to a weak signal. However, when electromagnetic noise is included in the model, it is found that as the electromagnetic noise intensity increases, the signal detection performance of the model decreases significantly compared to the without-noise case. The most interesting result of the study is the demonstration that electromagnetic fluctuations have the power to accelerate slow astrocyte dynamics. When electromagnetic noise is not included in the model, the concentration of <span><math><mrow><mi>C</mi><msup><mrow><mi>a</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></mrow></math></span> in the astrocyte increases with the increasing in electromagnetic feedback gain. By considering noisy electromagnetic model, the concentration of <span><math><mrow><mi>C</mi><msup><mrow><mi>a</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></mrow></math></span> in the astrocyte increases with increasing the electromagnetic noise strength. Moreover, the duration for the <span><math><mrow><mi>C</mi><msup><mrow><mi>a</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></mrow></math></span> concentration to reach the maximum level is significantly shortened. The results of the study show the degree to which the membrane potential of the neuron depends on changes in transmembrane current, astrocyte-induced regulation, and even the effect of electromagnetic induction and noise within the cell.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 34-45"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167160","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":"Magnetohydrodynamics (MHD) flow of ternary nanofluid and heat transfer past a permeable cylinder with velocity slip","authors":"Umi Nadrah Hussein ,&nbsp;Najiyah Safwa Khashi'ie ,&nbsp;Norihan Md Arifin ,&nbsp;Ioan Pop","doi":"10.1016/j.cjph.2024.12.002","DOIUrl":"10.1016/j.cjph.2024.12.002","url":null,"abstract":"<div><div>The increasing demand for energy-efficient and environmentally sustainable solutions has driven the exploration of ternary nanofluids for enhanced heat transfer applications. This numerical study investigates the magnetohydrodynamics (MHD) flow and heat transfer characteristics of a ternary hybrid nanofluid (copper-alumina-titania/water) over a shrinking/stretching cylinder, considering the effects of velocity slip, suction, and curvature parameters. The variable wall temperature is also included in the physical model. The model in PDEs is transformed into a simplified version of differential equations (ODEs) which can be solved using the bvp4c solver. Validation against previously published data confirms the accuracy of the model. Two solutions are possible if the shrinking surface is permeable (with suction effect), while only a unique solution is for the stretching case. Surprisingly, the copper-alumina-titania/water exhibits a lower heat transfer rate but higher skin friction as compared to the copper-alumina/water. Specifically, the heat transfer coefficient decreases by 5-10 % when incorporating the titania nanoparticle, while an increase of 8-12 % for the skin friction coefficient. Additionally, the velocity slip and curvature parameters accelerate the boundary layer separation, whereas increased suction delays this process. These findings provide insights into optimizing thermal management systems using ternary hybrid nanofluids, particularly under MHD effect.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 328-339"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167919","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":"Fluid-structure interaction analysis of blood flow in collapsible channels: Implications for sports performance","authors":"Rongbao Huang ,&nbsp;Bo Zhang ,&nbsp;Xu Han ,&nbsp;Yizhou Xing ,&nbsp;Lei Zhu","doi":"10.1016/j.cjph.2024.12.023","DOIUrl":"10.1016/j.cjph.2024.12.023","url":null,"abstract":"<div><div>The flow of fluid in collapsible channels is a topic of great interest with numerous physiological applications, including blood flow during sports and exercise. This paper presents a fluid-structure interaction (FSI) model for the study of single-phase fluid flow through a microchannel with a two-sided collapsible wall. The model considers the viscoelastic properties of the fluid and incorporates a moving mesh approach to analyze the deformation of the channel walls. Three distinct modes of motion are observed in the elastic walls involving the elastic walls bulge outward, they undergo a mode-2 deformation characterized by two half-wavelengths along the elastic walls, and the walls indent inward towards the channel. Furthermore, the study shows that as the Weissenberg number increased, there is an associated increase in pressure on the central part of the plate, particularly the major portion. This increase in pressure leads to a decrease in the deflection of the plate. Additionally, the results reveals that the thickness of the plate influences the wall deformations. Thicker plates exhibites minimal deformation compared to thinner plates, which display more pronounced deformations. Moreover, an increase in plate thickness results in a gradual upward (downward) movement of the lowest point of the upper wall (the highest point of the down wall), eventually shifting towards the midpoint of the elastic walls.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 601-610"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167973","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":"Electronic structure regulation of AlN/SiC nanoribbons through edge passivation with different atoms and doping with various transition metal atoms","authors":"Maoye Yin ,&nbsp;Xiangyang Tan ,&nbsp;Keyuan Wang ,&nbsp;Hengshuai Li ,&nbsp;Dong Fan ,&nbsp;Zhihao Wang ,&nbsp;Haiquan Hu ,&nbsp;Zhaogang Nie ,&nbsp;Feng Guo ,&nbsp;Zhenbao Feng ,&nbsp;Jun Li ,&nbsp;Dong Zhang ,&nbsp;Minghui Zhu ,&nbsp;Fei Wang","doi":"10.1016/j.cjph.2024.11.007","DOIUrl":"10.1016/j.cjph.2024.11.007","url":null,"abstract":"<div><div>In this paper, based on first principles, density functional theory is used to investigate the doping of transition metal atoms (Mn, Fe, Co, Ni) in AlN/SiC nanoribbons with edge passivation by different atoms (Cl, F, H, O) to induce magnetism and modulate properties. The research results show that the new structures proposed in this study with doping of transition metal atoms induce magnetism and a transition of properties. First, calculations determined the ferromagnetic coupling state to be the most stable state of the initial magnetic structure. Then, band structures, the density of states, and charge densities were analyzed to investigate the transition of properties. The AlN/SiC nanoribbons with Ni doping in Cl, F, and H atom edge-passivated structures all transitioned to half-metallic properties. Half-metal properties appeared in the AlN/SiC nanoribbons with Fe and Co doping in O atom edge-passivated structures, enabling the generation of 100 % spin-polarised current at the Fermi level. In addition, other structures exhibited properties of narrow bandgap semiconductors and metals. Furthermore, we used molecular dynamics simulations to verify the stability of the structures, demonstrating that the structures proposed in this study can stably exist. This provides more ideas and potential applications for the development of spintronics devices.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 202-220"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167975","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":"Dynamic interplay of anisotropy and matter–geometry coupling in stellar structures: A comprehensive study on the stability of pulsars 4U 1820-30 and LMC X-4","authors":"Tayyab Naseer ,&nbsp;M. Sharif ,&nbsp;Fatima Chand ,&nbsp;Assmaa Abd-Elmonem ,&nbsp;Nagat A.A. Suoliman","doi":"10.1016/j.cjph.2024.11.032","DOIUrl":"10.1016/j.cjph.2024.11.032","url":null,"abstract":"<div><div>This study investigates the behavior of dense celestial objects within the context of <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>,</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span> theory. We develop modified Einstein field equations that account for the anisotropic configured static interior spacetime. By applying two specific constraints associated with the radial metric function and anisotropic pressure, we find a couple of solutions to these highly non-linear gravitational equations. For both models, we encounter differential equations whose integration yield constants which are determined through matching conditions. Additionally, the requirement of vanishing radial pressure at the hypersurface also plays an important role in this context. Furthermore, we graphically evaluate certain conditions whose fulfillment ensures the model’s feasibility under different parametric values. For this, we take into account the observational data of two compact stars 4U 1820-30 and LMC X-4. We conclude both our models to be well-aligned with the required viability and stability criteria. We must highlight here that our study advances the understanding of how <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>,</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span> gravity affects the internal structure of compact stars, providing valuable insights for future explorations.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"93 ","pages":"Pages 75-93"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168052","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}