Pub Date : 2025-12-01Epub Date: 2025-09-27DOI: 10.1016/j.cjph.2025.09.022
Yueying Jia , Yu Wang , Peng Tan , Chenxiang Liu , Shuai Li , Jie Liu , Nikolay V. Petrov , Li Li , Hao Tian
We presented a broadband one-dimensional terahertz Airy beam generator with binary-phase elements by exploiting the transparent patterned-electrodes to electrically control nematic liquid crystal. The Airy beam generator can perform switching between Airy and Gaussian beams in a wide range from 2.3 to 2.8 THz by external voltage control. Typical diffraction-free, self-accelerating and self-healing characteristics were experimentally confirmed with the electrically switchable Airy beams at 2.54 THz. The scheme of liquid-crystal-based terahertz Airy beam generator has the advantages of broadband switchable operation, low cost and easy fabrication, with potential application in multi-dimensional simultaneous measurements by inter-switching between Airy and Gaussian beams.
{"title":"Terahertz Airy beam generator with electrically-controlled liquid crystal","authors":"Yueying Jia , Yu Wang , Peng Tan , Chenxiang Liu , Shuai Li , Jie Liu , Nikolay V. Petrov , Li Li , Hao Tian","doi":"10.1016/j.cjph.2025.09.022","DOIUrl":"10.1016/j.cjph.2025.09.022","url":null,"abstract":"<div><div>We presented a broadband one-dimensional terahertz Airy beam generator with binary-phase elements by exploiting the transparent patterned-electrodes to electrically control nematic liquid crystal. The Airy beam generator can perform switching between Airy and Gaussian beams in a wide range from 2.3 to 2.8 THz by external voltage control. Typical diffraction-free, self-accelerating and self-healing characteristics were experimentally confirmed with the electrically switchable Airy beams at 2.54 THz. The scheme of liquid-crystal-based terahertz Airy beam generator has the advantages of broadband switchable operation, low cost and easy fabrication, with potential application in multi-dimensional simultaneous measurements by inter-switching between Airy and Gaussian beams.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 360-367"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145325025","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}
Pub Date : 2025-12-01Epub Date: 2025-08-11DOI: 10.1016/j.cjph.2025.08.002
Dan-Yu Yang
Energy distribution of the degenerate solitons is more concentrated, they are more resistant to external disturbances (such as the noise and dispersion). This paper investigates the degenerate soliton solutions for coupled generalized nonlinear Schrödinger equations with the four-wave mixing effect in a birefringent fiber. Since the interactions of degenerate solitons in this equations are not studied, this paper investigate the properties and inelastic interactions of degenerate solitons. We construct the two-, three- and four-degenerate soliton solutions with one and two spectral parameters. According to the asymptotic analysis method, we find that the amplitudes of the interacting solitons retain unchanged upon the interactions, thus the elastic interactions between two degenerate solitons are depicted. Relative distance between two asymptotic solitons exhibits logarithmic growth with , where represents the retarded time. Soliton separation acceleration decays exponentially with relative distance, eventually tends to zero. Phase shifts vary slowly with . Elastic and inelastic interactions of three and four degenerate solitons with multiple iterations of one and two spectral parameters are presented. Different from the previous literary works, this paper solves the degenerate soliton solutions of this equations using the multiple spectral parameters and obtains some inelastic interactions. Elastic interactions may provide a technical foundation for the high fidelity information transmission. Inelastic interactions may have wide applications in the energy conversion and signal processing. This paper may be helpful for understanding the soliton propagation characteristics in the nonlinear media.
{"title":"Degenerate soliton solutions and their dynamics in a coupled generalized nonlinear Schrödinger equations with the four-wave mixing effect","authors":"Dan-Yu Yang","doi":"10.1016/j.cjph.2025.08.002","DOIUrl":"10.1016/j.cjph.2025.08.002","url":null,"abstract":"<div><div>Energy distribution of the degenerate solitons is more concentrated, they are more resistant to external disturbances (such as the noise and dispersion). This paper investigates the degenerate soliton solutions for coupled generalized nonlinear Schrödinger equations with the four-wave mixing effect in a birefringent fiber. Since the interactions of degenerate solitons in this equations are not studied, this paper investigate the properties and inelastic interactions of degenerate solitons. We construct the two-, three- and four-degenerate soliton solutions with one and two spectral parameters. According to the asymptotic analysis method, we find that the amplitudes of the interacting solitons retain unchanged upon the interactions, thus the elastic interactions between two degenerate solitons are depicted. Relative distance between two asymptotic solitons exhibits logarithmic growth with <span><math><mrow><mo>|</mo><mi>t</mi><mo>|</mo></mrow></math></span>, where <span><math><mi>t</mi></math></span> represents the retarded time. Soliton separation acceleration decays exponentially with relative distance, eventually tends to zero. Phase shifts vary slowly with <span><math><mi>t</mi></math></span>. Elastic and inelastic interactions of three and four degenerate solitons with multiple iterations of one and two spectral parameters are presented. Different from the previous literary works, this paper solves the degenerate soliton solutions of this equations using the multiple spectral parameters and obtains some inelastic interactions. Elastic interactions may provide a technical foundation for the high fidelity information transmission. Inelastic interactions may have wide applications in the energy conversion and signal processing. This paper may be helpful for understanding the soliton propagation characteristics in the nonlinear media.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 1204-1215"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733158","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}
Pub Date : 2025-12-01Epub Date: 2025-08-29DOI: 10.1016/j.cjph.2025.08.037
Jiawei Cui , Yinchang Zhao , Jun Ni , Zhenhong Dai
The thermoelectric properties of Zintl compounds KAs ( = Sn, Ge) were systematically investigated using first-principles calculations in combination with density functional theory (DFT), self-consistent phonon (SCP) theory, and the Boltzmann transport equation (BTE). Both three-phonon and four-phonon scattering processes were explicitly considered. The results reveal that the lattice thermal conductivity () remains significantly below 1 W/mK at high temperatures, which is mainly attributed to strong quartic anharmonicity induced by weak bonding between K atoms and their neighboring atoms, together with enhanced Umklapp scattering, effectively suppressing phonon transport. For electronic transport, multiple carrier scattering mechanisms were incorporated to provide a reasonable estimation of the carrier relaxation time. Furthermore, spin-orbit coupling (SOC)-induced Rashba splitting leads to a remarkable reconstruction of the electronic band structure, exerting a pronounced influence on the thermoelectric performance. The significant asymmetry in the band-edge curvature between the conduction and valence bands results in an imbalance of electron and hole contributions, giving rise to an unusual negative Seebeck coefficient under -type doping conditions, thereby challenging the conventional bipolar transport theory. Overall, the maximum thermoelectric figure of merit () along the axis reaches 2.88 for KSnAs and 2.78 for KGeAs at 800 K, demonstrating excellent thermoelectric performance and broad application potential.
{"title":"Microscopic mechanism of low lattice thermal conductivity induced by strong anharmonic vibrations in thermoelectric zintl compounds KXAs (X = Sn, Ge)","authors":"Jiawei Cui , Yinchang Zhao , Jun Ni , Zhenhong Dai","doi":"10.1016/j.cjph.2025.08.037","DOIUrl":"10.1016/j.cjph.2025.08.037","url":null,"abstract":"<div><div>The thermoelectric properties of Zintl compounds K<span><math><mi>X</mi></math></span>As (<span><math><mi>X</mi></math></span> = Sn, Ge) were systematically investigated using first-principles calculations in combination with density functional theory (DFT), self-consistent phonon (SCP) theory, and the Boltzmann transport equation (BTE). Both three-phonon and four-phonon scattering processes were explicitly considered. The results reveal that the lattice thermal conductivity (<span><math><msub><mi>κ</mi><mi>L</mi></msub></math></span>) remains significantly below 1 W/mK at high temperatures, which is mainly attributed to strong quartic anharmonicity induced by weak bonding between K atoms and their neighboring atoms, together with enhanced Umklapp scattering, effectively suppressing phonon transport. For electronic transport, multiple carrier scattering mechanisms were incorporated to provide a reasonable estimation of the carrier relaxation time. Furthermore, spin-orbit coupling (SOC)-induced Rashba splitting leads to a remarkable reconstruction of the electronic band structure, exerting a pronounced influence on the thermoelectric performance. The significant asymmetry in the band-edge curvature between the conduction and valence bands results in an imbalance of electron and hole contributions, giving rise to an unusual negative Seebeck coefficient under <span><math><mi>p</mi></math></span>-type doping conditions, thereby challenging the conventional bipolar transport theory. Overall, the maximum thermoelectric figure of merit (<span><math><mrow><mi>Z</mi><mi>T</mi></mrow></math></span>) along the <span><math><mi>c</mi></math></span> axis reaches 2.88 for KSnAs and 2.78 for KGeAs at 800 K, demonstrating excellent thermoelectric performance and broad application potential.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 175-190"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119482","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}
Pub Date : 2025-12-01Epub Date: 2025-11-02DOI: 10.1016/j.cjph.2025.10.029
Sanatan Das , Poly Karmakar , Biswajit Mandal , Chanchal Mandal , Rabindra Nath Jana
This study investigates the electrothermal hemodynamics of carbon nanotube-blended blood (CNT-blood) flow over an electromagnetic (EM) sensor plate under time-ramping shear stress and thermal flux conditions. Our computational model enables analysis of transient flow patterns and thermal profiles of CNT-blood under applied magnetic and electric fields. The flow regulating equations, considering porous medium resistance and infrared radiation, are solved analytically to examine the flow, and thermal distributions over the EM sensor plate. The results reveal that time-dependent shear stress and thermal flux significantly influence the flow dynamics and thermal response, enhancing the sensitivity of the EM sensor. Electrode/magnet width variation enables precise regulation of blood flow dynamics Infrared radiation intensity serves as the control parameter for blood temperature regulation. The sensor plate temperature is 18-22 % higher under a constant heat flux than a ramped one, due to continuous energy input. CNT-blood also exhibits 12-15 % greater thermal performance than nano-blood, as the hybrid CNTs network enhances phonon transport by reducing interfacial resistance. This research establishes a theoretical foundation for advancing electromagnetic biosensor technology, specifically for the continuous monitoring of hemorheological and thermal irregularities. The model’s inherent flexibility in responding to temporal variations extends its potential applications to dynamic biomedical environments, encompassing next-generation wearable sensors and implantable devices for cardiovascular assessment.
{"title":"Electrothermal flow of CNT-blood on a sensor plate with ramping shear and thermal flux: Electromagnetic biosensor applications","authors":"Sanatan Das , Poly Karmakar , Biswajit Mandal , Chanchal Mandal , Rabindra Nath Jana","doi":"10.1016/j.cjph.2025.10.029","DOIUrl":"10.1016/j.cjph.2025.10.029","url":null,"abstract":"<div><div>This study investigates the electrothermal hemodynamics of carbon nanotube-blended blood (CNT-blood) flow over an electromagnetic (EM) sensor plate under time-ramping shear stress and thermal flux conditions. Our computational model enables analysis of transient flow patterns and thermal profiles of CNT-blood under applied magnetic and electric fields. The flow regulating equations, considering porous medium resistance and infrared radiation, are solved analytically to examine the flow, and thermal distributions over the EM sensor plate. The results reveal that time-dependent shear stress and thermal flux significantly influence the flow dynamics and thermal response, enhancing the sensitivity of the EM sensor. Electrode/magnet width variation enables precise regulation of blood flow dynamics Infrared radiation intensity serves as the control parameter for blood temperature regulation. The sensor plate temperature is 18-22 % higher under a constant heat flux than a ramped one, due to continuous energy input. CNT-blood also exhibits 12-15 % greater thermal performance than nano-blood, as the hybrid CNTs network enhances phonon transport by reducing interfacial resistance. This research establishes a theoretical foundation for advancing electromagnetic biosensor technology, specifically for the continuous monitoring of hemorheological and thermal irregularities. The model’s inherent flexibility in responding to temporal variations extends its potential applications to dynamic biomedical environments, encompassing next-generation wearable sensors and implantable devices for cardiovascular assessment.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 1084-1102"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614684","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}
Pub Date : 2025-12-01Epub Date: 2025-11-08DOI: 10.1016/j.cjph.2025.11.005
Mohammed Sobhy
New solitary, periodic, super-periodic, and kink (antikink) wave solutions for functionally graded (FG) microtubes reinforced with graphene origami (GOr) and conveying an incompressible fluid under thermal loading are obtained for the first time. Analytical and numerical investigations of nonlinear wave dynamics in the present model are presented. The model incorporates fluid-structure interaction, thermal gradients, and size-dependent material behavior within the framework of Euler-Bernoulli beam theory. The governing nonlinear motion equation is derived from Hamilton’s principle and solved using bifurcation theory to obtain various axial wave solutions. In this theory, the equilibrium points are determined and the phase portraits are plotted to specify the possible physical motion. The fourth-order Runge-Kutta method is employed to calculate the dynamic deflection response. The results reveal that increasing the GOr content, flow velocity, or length scale parameter stiffens the structure and reduces wave amplitudes, while thermal effects and shear layer stiffness enhance deformation. The impact of different GOr distributions through the microtube wall is also examined. This work provides insights into the tunable dynamic behavior of advanced nanocomposite microtubes under multiphysical environments.
{"title":"Solitary, periodic, and kink waves in some fluid-conveying graphene origami-reinforced microtubes exposed to a thermal load","authors":"Mohammed Sobhy","doi":"10.1016/j.cjph.2025.11.005","DOIUrl":"10.1016/j.cjph.2025.11.005","url":null,"abstract":"<div><div>New solitary, periodic, super-periodic, and kink (antikink) wave solutions for functionally graded (FG) microtubes reinforced with graphene origami (GOr) and conveying an incompressible fluid under thermal loading are obtained for the first time. Analytical and numerical investigations of nonlinear wave dynamics in the present model are presented. The model incorporates fluid-structure interaction, thermal gradients, and size-dependent material behavior within the framework of Euler-Bernoulli beam theory. The governing nonlinear motion equation is derived from Hamilton’s principle and solved using bifurcation theory to obtain various axial wave solutions. In this theory, the equilibrium points are determined and the phase portraits are plotted to specify the possible physical motion. The fourth-order Runge-Kutta method is employed to calculate the dynamic deflection response. The results reveal that increasing the GOr content, flow velocity, or length scale parameter stiffens the structure and reduces wave amplitudes, while thermal effects and shear layer stiffness enhance deformation. The impact of different GOr distributions through the microtube wall is also examined. This work provides insights into the tunable dynamic behavior of advanced nanocomposite microtubes under multiphysical environments.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 989-1012"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575900","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}
Pub Date : 2025-12-01Epub Date: 2025-08-29DOI: 10.1016/j.cjph.2025.08.034
Zhi-Long Wan , Hong-Chun Yuan , Xiao-Lei Yin , Chang-Ying Wang , Yi-Xing Wang
Building on our recently completed work [Chinese J. Phys. 94 (2025) 215], we extend the analysis to a general quadratic state and focus on its analytical evolution in a thermal environment, where it retains the same form as the input state throughout. We also investigate the mean photon number, photon counting distribution, and Wigner distribution function in the thermal environment. In addition, using the differential representation of the von Neumann entropy, we analytically and numerically study the entropy evolution of the quadratic state for thermal noise.
在我们最近完成的工作[Chinese J. Phys. 94(2025) 215]的基础上，我们将分析扩展到一般的二次态，并关注其在热环境中的分析演变，在热环境中，它始终保持与输入状态相同的形式。我们还研究了热环境下的平均光子数、光子计数分布和Wigner分布函数。此外，利用冯·诺依曼熵的微分表示，对热噪声二次态的熵演化进行了解析和数值研究。
{"title":"Decoherence dynamics of a general quadratic state in a thermal environment","authors":"Zhi-Long Wan , Hong-Chun Yuan , Xiao-Lei Yin , Chang-Ying Wang , Yi-Xing Wang","doi":"10.1016/j.cjph.2025.08.034","DOIUrl":"10.1016/j.cjph.2025.08.034","url":null,"abstract":"<div><div>Building on our recently completed work [Chinese J. Phys. 94 (2025) 215], we extend the analysis to a general quadratic state and focus on its analytical evolution in a thermal environment, where it retains the same form as the input state throughout. We also investigate the mean photon number, photon counting distribution, and Wigner distribution function in the thermal environment. In addition, using the differential representation of the von Neumann entropy, we analytically and numerically study the entropy evolution of the quadratic state for thermal noise.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 14-23"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047920","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}
Pub Date : 2025-12-01Epub Date: 2025-10-09DOI: 10.1016/j.cjph.2025.10.005
J. Flores-Farías , P. Contreras-Gallardo , F. Brevis , J.W. González , N. Vidal-Silva , R.A. Gallardo
Magnonic crystals, characterized by their periodic magnetic modulation, are promising metamaterials for nanoscale high-frequency signal processing due to their control over spin-wave properties. This work investigates spin-wave dynamics in bilayer bi-component systems with distinct one-dimensional periodicities, focusing on two configurations: one with a noticeable difference in periodicities and another with a slight mismatch. Both configurations are examined under parallel and antiparallel equilibrium magnetization states. In a system with significantly different periodicities, the parallel configuration exhibits multiple flat bands, which are associated with defect-like behavior, similar to that observed in magnonic crystals with structural defects. In contrast, the antiparallel configuration is characterized by the presence of low-frequency flat bands and the emergence of small band gaps. These dispersionless bands are tunable via the external field. For the bilayer with slightly mismatched periodicities, flat modes appear in both parallel and antiparallel magnetic states. These modes are sensitive to local material arrangement, forming a superlattice of direct and indirect interlayer coupling regions where localization occurs. The findings are supported by micromagnetic simulations, which show good agreement between the two methods. This study demonstrates how interlayer periodicity mismatch, spatial configuration, magnetic coupling, and external fields could control the emergence of localized, flat spin-wave modes, offering routes for reconfigurable magnonic device design.
{"title":"Emergence of flat bands and localized spin-wave modes in coupled bilayer magnonic crystals with different periodicities","authors":"J. Flores-Farías , P. Contreras-Gallardo , F. Brevis , J.W. González , N. Vidal-Silva , R.A. Gallardo","doi":"10.1016/j.cjph.2025.10.005","DOIUrl":"10.1016/j.cjph.2025.10.005","url":null,"abstract":"<div><div>Magnonic crystals, characterized by their periodic magnetic modulation, are promising metamaterials for nanoscale high-frequency signal processing due to their control over spin-wave properties. This work investigates spin-wave dynamics in bilayer bi-component systems with distinct one-dimensional periodicities, focusing on two configurations: one with a noticeable difference in periodicities and another with a slight mismatch. Both configurations are examined under parallel and antiparallel equilibrium magnetization states. In a system with significantly different periodicities, the parallel configuration exhibits multiple flat bands, which are associated with defect-like behavior, similar to that observed in magnonic crystals with structural defects. In contrast, the antiparallel configuration is characterized by the presence of low-frequency flat bands and the emergence of small band gaps. These dispersionless bands are tunable via the external field. For the bilayer with slightly mismatched periodicities, flat modes appear in both parallel and antiparallel magnetic states. These modes are sensitive to local material arrangement, forming a superlattice of direct and indirect interlayer coupling regions where localization occurs. The findings are supported by micromagnetic simulations, which show good agreement between the two methods. This study demonstrates how interlayer periodicity mismatch, spatial configuration, magnetic coupling, and external fields could control the emergence of localized, flat spin-wave modes, offering routes for reconfigurable magnonic device design.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 384-398"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358858","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}
Pub Date : 2025-12-01Epub Date: 2025-10-14DOI: 10.1016/j.cjph.2025.10.003
Yue Liu, Jianwei Shen
Understanding and controlling the spatial-temporal spread of infectious diseases are vital challenges, especially in light of increased population mobility and complex human interactions. Traditional epidemic models often neglect the heterogeneous, multiplexed, and time-delay nature of real-world transmission. This work proposes a comprehensive epidemic model on multiplex networks, explicitly incorporating both incubation and infectious period delays. Using local stability and bifurcation theory, we derive precise mathematical criteria for Turing instability and periodic oscillations in these systems, revealing that the self-recovery rate induces subcritical bifurcations, while time delays can trigger supercritical bifurcations and persistent oscillations. Our analysis demonstrates that multiplex network topology and delays jointly regulate the emergence of spatiotemporal patterns—specifically, clustered outbreaks and wave-like, periodic fluctuations. As network connectivity or delays increase, both spatial aggregation and the amplitude of epidemic cycles intensify. Numerical simulations reflect these findings and are quantitatively validated using real COVID-19 data from Brazil, South Africa, and 35 countries in the Americas, confirming our theoretical predictions. These insights advance the mechanistic understanding of epidemic pattern formation and highlight the importance of considering network structure and time delays in early warning and targeted intervention strategies.
{"title":"Multiplex epidemiological networks with delays: mechanisms of Turing instability and spatiotemporal oscillation","authors":"Yue Liu, Jianwei Shen","doi":"10.1016/j.cjph.2025.10.003","DOIUrl":"10.1016/j.cjph.2025.10.003","url":null,"abstract":"<div><div>Understanding and controlling the spatial-temporal spread of infectious diseases are vital challenges, especially in light of increased population mobility and complex human interactions. Traditional epidemic models often neglect the heterogeneous, multiplexed, and time-delay nature of real-world transmission. This work proposes a comprehensive epidemic model on multiplex networks, explicitly incorporating both incubation and infectious period delays. Using local stability and bifurcation theory, we derive precise mathematical criteria for Turing instability and periodic oscillations in these systems, revealing that the self-recovery rate induces subcritical bifurcations, while time delays can trigger supercritical bifurcations and persistent oscillations. Our analysis demonstrates that multiplex network topology and delays jointly regulate the emergence of spatiotemporal patterns—specifically, clustered outbreaks and wave-like, periodic fluctuations. As network connectivity or delays increase, both spatial aggregation and the amplitude of epidemic cycles intensify. Numerical simulations reflect these findings and are quantitatively validated using real COVID-19 data from Brazil, South Africa, and 35 countries in the Americas, confirming our theoretical predictions. These insights advance the mechanistic understanding of epidemic pattern formation and highlight the importance of considering network structure and time delays in early warning and targeted intervention strategies.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 493-514"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358864","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}
Pub Date : 2025-12-01Epub Date: 2025-11-17DOI: 10.1016/j.cjph.2025.11.011
Aruna A , Swarup Barik , Srinivas Jangili
This study utilizes the multiscale homogenization technique to analyze the two-dimensional concentration distribution of a solute in a rotating electro-osmotic flow through parallel plates. A solute injection is used to evaluate mass transport characteristics by deriving the dispersion coefficient, mean and two-dimensional concentration profiles for both primary and secondary flows. Previous studies have investigated solute dispersion in electro-osmotic flow using multi-scale homogenization. However, the influence of rotation remains largely unexplored, despite its significance in many Lab-on-Chip devices. The combined effect of rotation together with the applied electric field can lead to enhanced transport characteristics. The influence of the electro-osmotic parameter (K) and rotational frequency (ω) on the solute transport along both flows is studied. Results show that in the primary flow, the solute concentration exhibits fluctuations for varying K and ω values. For small K, velocity is confined near the boundaries, while rotation enhances transport and flattens concentration distributions. In secondary flow, the mean concentration decreases with increasing K and varies non-monotonically with ω, exerting a stronger influence than K in secondary flows. Importantly, the two-dimensional concentration distribution remains symmetrical and uniform across the channel cross-section along the primary and secondary flows over time (τ). Over time, the bimodal distribution of concentration variation transitions to an unimodal one across the cross-section in both flows. This study contributes to a better understanding of detecting the disease in blood, separation of chemicals, DNA molecules and plasma, which can be seen in a lab-on-a-chip devices.
{"title":"Multi-scale analysis of solute dispersion in a rotating electro-osmotic flow between two plates","authors":"Aruna A , Swarup Barik , Srinivas Jangili","doi":"10.1016/j.cjph.2025.11.011","DOIUrl":"10.1016/j.cjph.2025.11.011","url":null,"abstract":"<div><div>This study utilizes the multiscale homogenization technique to analyze the two-dimensional concentration distribution of a solute in a rotating electro-osmotic flow through parallel plates. A solute injection is used to evaluate mass transport characteristics by deriving the dispersion coefficient, mean and two-dimensional concentration profiles for both primary and secondary flows. Previous studies have investigated solute dispersion in electro-osmotic flow using multi-scale homogenization. However, the influence of rotation remains largely unexplored, despite its significance in many Lab-on-Chip devices. The combined effect of rotation together with the applied electric field can lead to enhanced transport characteristics. The influence of the electro-osmotic parameter (<em>K</em>) and rotational frequency (<em>ω</em>) on the solute transport along both flows is studied. Results show that in the primary flow, the solute concentration exhibits fluctuations for varying <em>K</em> and <em>ω</em> values. For small <em>K</em>, velocity is confined near the boundaries, while rotation enhances transport and flattens concentration distributions. In secondary flow, the mean concentration decreases with increasing <em>K</em> and varies non-monotonically with <em>ω</em>, exerting a stronger influence than <em>K</em> in secondary flows. Importantly, the two-dimensional concentration distribution remains symmetrical and uniform across the channel cross-section along the primary and secondary flows over time (<em>τ</em>). Over time, the bimodal distribution of concentration variation transitions to an unimodal one across the cross-section in both flows. This study contributes to a better understanding of detecting the disease in blood, separation of chemicals, DNA molecules and plasma, which can be seen in a lab-on-a-chip devices.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 1165-1192"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614681","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}
Pub Date : 2025-12-01Epub Date: 2025-09-24DOI: 10.1016/j.cjph.2025.09.019
Zhefeng Wang , Kai Chen , Youmin Xu , Wuyan Zhao , Lingbao Kong , Songyou Wang , Wan-Sheng Su
Comprehensive first-principles calculations were performed to investigate how Ag and Cu alloying modulates the structural, energetic, and electronic properties of two-dimensional Au monolayers, resulting in the formation of AuAg and AuCu alloys. Both alloyed systems are thermodynamically stable and adopt an isosceles triangular lattice structure. The bond lengths in the alloyed monolayers generally fall between those of their elemental counterparts, with AuCu exhibiting notably shorter Au–Cu bonds, reflecting stronger atomic interactions.
Importantly, the binding energy of the AuCu monolayer is more negative than that of both pure Au and pure Cu monolayers, indicating enhanced stability due to cooperative bonding effects and orbital hybridization. Ab initio molecular dynamics (AIMD) simulations confirm thermal stability up to ∼1000 K, beyond which structural degradation occurs. Phonon dispersion calculations reveal no imaginary frequencies, supporting the dynamic stability of both alloyed systems.
Electronic band structure and density of states (DOS) analyses confirm their metallic character, with stronger hybridization observed in AuCu due to its reduced bond length and compact structure. Mechanical property evaluations—including elastic constants, Young’s modulus, and Poisson’s ratio—demonstrate that alloying leads to a reduction in stiffness and an increase in anisotropy. These findings highlight the tunability of 2D noble metal monolayers via alloying, offering promising avenues for future applications in flexible electronics, catalysis, and nanoscale devices.
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