Chinese Journal of Physics最新文献

{"title":"Low-temperature magnetic refrigeration in Gd20Tb20Er20Al20M20 (M = Fe, Co) high-entropy metallic glasses","authors":"Huaijin Ma ,&nbsp;Lei Gao ,&nbsp;Xiang Jin ,&nbsp;Jing Zhao ,&nbsp;Jianjun Zhao ,&nbsp;Jiaohong Huang","doi":"10.1016/j.cjph.2024.09.021","DOIUrl":"10.1016/j.cjph.2024.09.021","url":null,"abstract":"<div><div>This paper focuses on the magnetocaloric effect (MCE) of Gd₂₀Tb₂₀Er₂₀Al₂₀M₂₀ (M = Fe, Co) high-entropy metallic glasses (HE-MGs). XRD and TEM results indicate that both HE-MGs are amorphous. Magnetic studies show that both HE-MGs display spin-glass behavior, undergo a second-order phase transition from ferromagnetic to paramagnetic, and exhibit soft magnetic properties at the Curie temperature (<em>T</em>_C). Notable large and broad table-like magnetic entropy change characteristics of Gd₂₀Tb₂₀Er₂₀Al₂₀Fe₂₀ (Gd₂₀Tb₂₀Er₂₀Al₂₀Co₂₀) appear near a <em>T</em>_C of 92 (51) K. Hence, under 7 T magnetic field, |-∆<em>S</em>_M^max|, ∆ <em>T</em>_FWHM, and <em>RCP</em> are 7.83 (10.10) J·kg^-1·K^-1, 120.07 (71.88) K, and 1008.26 (805.70) J·kg^-1, respectively. Furthermore, the modulation of the magnetic and magnetocaloric properties of the samples after substitution of Fe for Co was revealed by the intricate 3d-3d and 3d-4f exchange interactions within the system. The magnetic phase transition critical behaviors in both HE-MGs were analyzed using the scaling law to clarify the deviation of amorphous materials from the mean-field theory. Thus, this study not only highlights the potential of this material for low-temperature magnetic refrigeration applications, but also expands our understanding of its physical properties.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 353-365"},"PeriodicalIF":4.6,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417819","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":"Nonlinear Jeans instability analysis of gravitating astrofluids in Eddington-inspired Born-Infeld gravity framework","authors":"Mritunjoy Das,&nbsp;Pralay Kumar Karmakar","doi":"10.1016/j.cjph.2024.09.018","DOIUrl":"10.1016/j.cjph.2024.09.018","url":null,"abstract":"<div><div>The nonlinear Jeans instability dynamics in viscoelastic astrofluids within the Eddington-inspired Born-Infeld (EiBI) gravitational framework excitable in star-forming interstellar cloud fluids is semi-analytically investigated. Application of multiple scaling techniques here results in a unique form of the Korteweg-de Vries (KdV) equation moderated with a peculiar set of distinctive fluid polyparametric coefficients. A numerical illustrative platform portrays the excitation of diversified compressive solitary-chain wave patterns. The evolutionary existence of such structural patterns is further confirmed geometrically with the help of illustrative phase-plane analyses. The various parametric stabilizers and destabilizers, alongside accelerating and decelerating factors on the clouds, are illustratively analysed. It is seen that the composite cloud stability is significantly influenced by the strength polarity of the gravitational EiBI-parameter <span><math><mrow><mo>(</mo><mi>χ</mi><mo>)</mo></mrow></math></span>. The dependency of the obtained solitary wave patterns on the EiBI-polarity is further confirmed in a numerical simulation platform illustratively. Our analysis also highlights that the influence of material density on the system stability is dependent on the EiBI-polarity. The nonlinear spatiotemporal evolution of the instability reveals a unique type of soliton fission phenomenon, indicative of inherently produced additional disturbances within the astrofluid. Our obtained results could be widely helpful in application to the EiBI-centric diverse astrocosmic phenomena, such as bounded structure formation and evolution in diverse complex astroenvirons.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 675-687"},"PeriodicalIF":4.6,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417818","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":"Robot-assisted pedestrian evacuation in fire scenarios based on deep reinforcement learning","authors":"Chuan-Yao Li ,&nbsp;Fan Zhang ,&nbsp;Liang Chen","doi":"10.1016/j.cjph.2024.09.008","DOIUrl":"10.1016/j.cjph.2024.09.008","url":null,"abstract":"<div><div>Indoor fires pose a significant challenge to the safe evacuation of pedestrians. In response to fire hazards, pedestrians instinctively seek alternative evacuation routes to avoid the hazard zone. However, the specific location and intensity of the fire hazard zone can influence pedestrians' decisions, leading to varying congestion levels in different areas. To address this challenge and enhance overall evacuation efficiency, this paper introduces an improved social force model to depict pedestrian movement in fire scenarios and proposes a methodology that leverages dynamic robot for pedestrian evacuation, employing Deep Reinforcement Learning (DRL) and Human-Robot Interaction (HRI). The results show that in the no-robot scenario, pedestrians will detour according to the varying locations of fire hazard zones and emergency levels, resulting in congestion at different positions. In the static robot scenario, robots placed in different locations exhibit varied effects on evacuation depending on the fire hazard zones' locations and intensities. In the DRL-control robot scenario, the robot controlled by DRL and HRL can always navigate to the appropriate position to promote evacuation, regardless of the fire's location and emergency levels or the robot's initial placement. Furthermore, our findings reveal that strategically positioned robots can enhance evacuation efficiency by alleviating crowding and increasing the distance between pedestrians and fire hazard zones in most cases, thereby improving pedestrian safety. This study offers practical guidance for managing pedestrian evacuation during fire incidents and establishes a theoretical foundation for refining evacuation strategies and safety measures at fire scenes.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 494-531"},"PeriodicalIF":4.6,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417959","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":"Co-loading of herbal based curcumin and mitoxantrone anticancer drug on PEG and chitosan polymers for targeted cancer therapy: Computational molecular study","authors":"Yan Wang ,&nbsp;Yudi Zhang ,&nbsp;Jinghong Shi,&nbsp;Hui Zhou","doi":"10.1016/j.cjph.2024.09.010","DOIUrl":"10.1016/j.cjph.2024.09.010","url":null,"abstract":"<div><div>In the current study, molecular dynamics (MD) computations were implemented to investigate and evaluate the loading of two drugs, namely mitoxantrone (MTX) and curcumin (CUR) onto polymeric carriers. The carrier considered in this study included polyethylene glycol (PEG) and Chitosan (CHI) as biological macromolecules. Lennard-Jones (LJ) and electrostatic potentials were computed to estimate the molecular interactions between polymer chains and drug molecules for the purpose of drug delivery design. To determine the adsorption site of drug molecules on polymer chains, the radial distribution function (RDF) was computed and analyzed. There was a strong LJ interaction between MTX and CUR and the PEG chains. Furthermore, CHI chains possess strong electrostatic interactions because they contain charged groups. 10C and 10P have been indicated as suitable carriers for MTX. Since 3PC and 5PC contain PEG and CHI, they are appropriate for loading both mitoxantrone and CUR drug molecules. Additionally, 5PC has stronger binding energy than 3PC for MTX and CUR. These results can be used for the design of polymer-based drug carriers.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 298-310"},"PeriodicalIF":4.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358114","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 the dynamics of the heavy magnetized dusty plasma in laboratory experiments and solar wind interaction with lunar terminator: Theoretical predictions into the role of polarization force","authors":"M.S. Afify ,&nbsp;A.M. Abdelghany","doi":"10.1016/j.cjph.2024.09.012","DOIUrl":"10.1016/j.cjph.2024.09.012","url":null,"abstract":"<div><div>This study is motivated by the lack of research that connects the dynamics of space dusty plasma (DP) with the existing experimental findings and the role of the magnetic field in the case of massive DP. For that purpose, we presented a theoretical interpretation of the dynamics of strongly (experimental) and weakly (space) magnetized DP, including the influence of the polarization force (PF). We used the multifluid model to describe the dynamics of dust particles while the hot plasma of electrons and ions is described by the Boltzmann distribution. We derived the dispersion relation to investigate the behavior of the compressive dust-acoustic waves (DAWs). To get a full picture of the mechanism of dust particles, we used the reductive perturbation technique to obtain the periodic solution for the Zakharov–Kuznetsov equation (ZK), which is coincidental with the observed wave profiles. In the case of the experimental application, we observed that the non-propagating instability starts at a small value of the polarization parameter (<span><math><mi>R</mi></math></span>), which is 0.02. Therefore, for values of <span><math><mi>R</mi></math></span> less than 0.02, the linear analysis revealed that increasing the value of the polarization parameter is not significant in distinguishing the growth rates. Moreover, we noted that both <span><math><mi>R</mi></math></span> and the applied magnetic field enhance the strength of the wave electric field. Interestingly, calculating the value of the electric field required to levitate the dust particles that are subject to a high magnetic field agrees with our theoretical findings. The current model has also been applied to DP observed in the lunar terminator. Our results reveal no role for the PF in the lunar terminator. The analysis conducted using the New Hampshire Dispersion Relation Solver (NHDS) confirms the dominance of electrostatic modes in response to the solar wind interaction with the lunar terminator. Moreover, at certain values of plasma parameters such as the temperature of solar wind electrons and ions and the density of dust particles and solar wind electrons, there is a cutoff in the fluid dispersion curve corresponding to certain values of the normalized wavenumber. Such electrostatic profiles could contribute to the observed glow in the horizontal direction of the lunar terminator.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 321-332"},"PeriodicalIF":4.6,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational investigations of nanofluid blood flow in stenosed artery with effects of inflammation and viscous dissipation via finite element method","authors":"Muhammad Salim Khan ,&nbsp;Shafee Ahmd ,&nbsp;Zahir Shah ,&nbsp;Mansoor H. Alshehri ,&nbsp;Elisabeta Antonescu","doi":"10.1016/j.cjph.2024.09.013","DOIUrl":"10.1016/j.cjph.2024.09.013","url":null,"abstract":"<div><div>In this study, we investigate the problem of blood flow through an artery with stenosis, focusing on the effects of inflammation. The flow profile is assumed to be parabolic, and both inflamed and non-inflamed states of stenosis are considered. The governing dimensionless equations are solved using the finite element method. Flow structures and temperature distributions are illustrated using streamlines and isothermal lines. The local Nusselt number is analyzed to understand its significance. The primary objective of this research is to analyze the behavior of nanofluid in blood flow and the associated heat transfer characteristics within an artery, both in the presence and absence of inflamed stenosis. This analysis will take into account the effects of inflammation and viscous dissipation. The finding reveals that the highest temperature gradient is obtained at the stenosis peak. The Re affects the velocity field and increases the kinetic energy. Results show that flow symmetry breaks when stenosis positions are changed. It is found that the Nusselt number is the increasing function of nanoparticle concentration, stenosis peak, viscous dissipation, and Reynolds number.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 453-469"},"PeriodicalIF":4.6,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417847","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":"Effect of laser chirping on third harmonic generation in anharmonic clusters with ripple on cluster density","authors":"Shivani Vij ,&nbsp;Arvinder Singh","doi":"10.1016/j.cjph.2024.09.005","DOIUrl":"10.1016/j.cjph.2024.09.005","url":null,"abstract":"<div><p>A proposed model delves into the resonant enhancement of third harmonic generation (THG) by a short-pulse laser inside nanoclustered plasma under the influence of density ripple. An intense chirped laser pulse incident on a clustered plasma of argon gas displaces the electrons of the medium and produces a restoring force. This force is considered to vary nonlinearly with electron displacement, leading to the anharmonic response of the electron clouds of the cluster. The nonlinear current at the third harmonic frequency arises from the perturbation of the electron density of the cluster by the ponderomotive force exerted on them by the incident laser pulse. Applying ripple in cluster density and electron density of surrounding plasma enables the phase-matching criteria for THG to be satisfied, which leads to enhanced harmonic output. An anharmonic structure of clusters exhibits strong optical nonlinearities, resulting in the plasmon resonance broadening and producing harmonics with greater efficiency. Numerical analysis shows that the chirp parameter of the laser pulse and ripple on cluster density enhance system nonlinearity causing the generation of a third harmonic of enhanced amplitude. The study explores how different factors such as laser intensity, cluster size, ripple parameter, chirp parameter, and electron excursion influence the efficiency of THG.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 211-222"},"PeriodicalIF":4.6,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241962","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":"Frequency chimera state induced by time delays in FitzHugh-Nagumo neural networks","authors":"ShouFang Huang,&nbsp;ChengYu Yu,&nbsp;ZhengGang Cai,&nbsp;JiQian Zhang,&nbsp;MaoSheng Wang,&nbsp;Fei Xu","doi":"10.1016/j.cjph.2024.09.009","DOIUrl":"10.1016/j.cjph.2024.09.009","url":null,"abstract":"<div><p>The delay of information transmission is an inherent factor of the nervous systems, which has great influences on their collective dynamic behaviors. In this paper, we constructed a ring neural network using FitzHugh-Nagumo (FHN) neuron model as the network node and memristive synapses as the connection mode. Our primary focus was on investigating the effects of time delay and coupling strength on the firing frequency of neurons. Simulation results revealed that the frequency chimera state could be induced in the neural network with appropriate time delay, which is a new type of chimera state characterized by firing frequency rather than traditional membrane potential. By adjusting the time delay properly, the neural network can also display multi-cluster frequency chimera states that coexisted with various incoherent regions and coherent regions. Meanwhile, we exhibit that initial value and coupling strength could have great influences on the effects of time delay on inducing frequency chimera state of the nervous systems.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 115-123"},"PeriodicalIF":4.6,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241516","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":"Fractional relaxation model with general memory effects and stability analysis","authors":"Feng-Xia Zheng ,&nbsp;Chuan-Yun Gu","doi":"10.1016/j.cjph.2024.09.006","DOIUrl":"10.1016/j.cjph.2024.09.006","url":null,"abstract":"<div><p>Voigt and Maxwell models are popularly used to model viscoelastic materials’ property. They are often presented in form of fractional relaxation equations. In order to describe rich viscoelasticity, a general Caputo derivative is introduced in fractional modeling. Then this work studies attractivity and asymptotic stability of the Caputo fractional relaxation equation with general memory effects. Firstly, the considered problem is transformed into an integral equation. A mapping and an attractive set are constructed. Furthermore, the existence of fixed points on the attractive set are investigated by using fixed point theorems. Finally, the effectiveness and convenience of the stability theory are verified through two numerical examples.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 1-8"},"PeriodicalIF":4.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168505","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":"Generalization and analytic exploration of soliton solutions for nonlinear evolution equations via a novel symbolic approach in fluids and nonlinear sciences","authors":"Brij Mohan ,&nbsp;Sachin Kumar","doi":"10.1016/j.cjph.2024.09.004","DOIUrl":"10.1016/j.cjph.2024.09.004","url":null,"abstract":"<div><p>In this work, we analyze the new generalized soliton solutions for the nonlinear partial differential equations with a novel symbolic bilinear technique. The proposed approach constructs the soliton solutions depending on the arbitrary parameters, which generalizes the soliton solutions with these additional parameters. Examining phase shifts and their dependence on the parameters influences how solitons collide, merge, or pass through each other, which is essential for the nonlinear analysis of solitons. Using the proposed technique, we examine the well-known (1＋1)-dimensional Korteweg–de Vries (KdV) and (2＋1)-dimensional Kadomtsev–Petviashvili (KP) equations with a comparative analysis of soliton solutions in the Hirota technique. We construct the generalized solitons solutions for both examined equations up to the third order, providing a better understanding of formed solitons with arbitrary parameter choices. The Cole-Hopf transformations are used to construct the bilinear form in the auxiliary function using Hirota’s <span><math><mi>D</mi></math></span>-operators for both investigated KdV and KP equations It discusses the phase shift depending on parameters and compares it to the phase shift in Hirota’s soliton solutions. We utilize <em>Mathematica</em>, a computer algebra system, to obtain the generalized solitons and analyze the dynamic behavior of the obtained solutions by finding the values for the parameters and the relationships among them. Solitons are localized waves that appear in different fields of nonlinear sciences, such as oceanography, plasmas, fluid mechanics, water engineering, optical fibers, and other sciences.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 10-21"},"PeriodicalIF":4.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168504","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}