The European Physical Journal Plus最新文献

{"title":"Designed amine-graphene/silver nanohybrid for high-performance thermally conductive nanofluids","authors":"Ali Pourabbasi,&nbsp;Mohammad Behbahani,&nbsp;Aminreza Noghrehabadi,&nbsp;Rashid Pourrajab","doi":"10.1140/epjp/s13360-026-07709-2","DOIUrl":"10.1140/epjp/s13360-026-07709-2","url":null,"abstract":"<div><p>The practical application of nanofluids in thermal management systems is often hindered by challenges related to colloidal instability and aggregation. This study addresses this critical issue through the rational design and synthesis of a novel amine-functionalized graphene/silver nanohybrid, engineered specifically to achieve exceptional dispersion stability and thermal performance in aqueous media. The amine functionality serves a dual purpose: it acts as an anchor for the in-situ synthesis of silver nanoparticles, preventing their agglomeration, and enhances the electrostatic repulsion between nanosheets in the colloidal system, as confirmed by zeta potential measurements. We systematically investigated the interplay of key factors—temperature, nanohybrid concentration, and ultrasonication duration—on the thermal conductivity enhancement using a Box-Behnken statistical design. The optimized nanofluid, prepared under conditions of 41.9 °C, 550.8 ppm concentration, and 9.7 min of ultrasonication, achieved a remarkable thermal conductivity enhancement of 40.3% relative to the base fluid. Furthermore, a highly accurate empirical model was developed to predict the thermal behavior, with analysis of variance (ANOVA) validating the model's significance. The findings underscore that the superior thermal performance is intrinsically linked to the synergistic effects of the hybrid nanostructure and the robust colloidal stability imparted by the surface functionalization. This work provides a fundamental insight into the design of stable, high-performance nanofluids by tailoring interfacial chemistry, offering a significant advancement for colloidal science and heat transfer applications.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"A symmetry-based study of nonlocal structures in the modified Benjamin–Bona–Mahony equation","authors":"Mustafa Bazghandi","doi":"10.1140/epjp/s13360-026-07737-y","DOIUrl":"10.1140/epjp/s13360-026-07737-y","url":null,"abstract":"<div><p>The nonlocal symmetry structure of the modified Benjamin–Bona–Mahony (mBBM) equation is analysed through conservation-law (CL) coverings and symmetry-induced inverse potential systems (IPSs) in the sense of Bluman and Yang. The local conservation laws of the equation are classified, showing that the associated CL covering generates no essentially new symmetry reductions beyond the local Lie framework. Inverse potential systems corresponding to the fundamental spatial and temporal translation symmetries are then constructed via non-invertible symmetry-induced mappings. These IPSs are not reducible to any CL covering. This non-reducibility is caused by the mixed dispersive term <span>(u_{xxt})</span>, which obstructs the existence of a divergence representation compatible with conservation laws. As a consequence, the resulting nonlocal symmetries are genuinely distinct from conservation-law-induced potential symmetries. The IPS-induced symmetries give rise to intrinsically nonlocal reductions of the mBBM equation, yielding exact invariant solutions that cannot be obtained by classical Lie or CL-based methods.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Thermophysical aspects of photovoltaic module I–V characteristics under combined environmental and fault conditions","authors":"Nazgul K. Tanasheva,&nbsp;Dmitriy A. Afanasyev,&nbsp;Gulden A. Ranova,&nbsp;Ainura N. Dyusembaeva,&nbsp;Eduard V. Sheinmaier,&nbsp;Temirbek A. Rakhimgaliyev,&nbsp;Asem R. Bakhtybekova","doi":"10.1140/epjp/s13360-026-07706-5","DOIUrl":"10.1140/epjp/s13360-026-07706-5","url":null,"abstract":"<div><p>This study develops a thermophysically informed diagnostic framework for the KZ PV 230 M60 photovoltaic module to distinguish genuine electrical faults from temperature-induced shifts of the current–voltage (I–V) curve. A single-diode equivalent-circuit model was calibrated from manufacturer data using a Lambert W-based parameter extraction method, yielding <i>R</i>_s = 6.3 mΩ, <i>R</i>_sh = 1.2214 Ω, <i>I</i>_pv = 8.3425 A, <i>I</i>₀ = 9.84 × 10⁻11 A, and ideality factor <i>n</i> = 0.9484. The analysis covered five representative fault classes: partial shading, local short circuit, open-circuit fault, aging, and potential-induced degradation (PID). A one cell short circuit produced ΔVoc =  − 0.6 V, equivalent to an approximately + 5 °C temperature increase for this module, whereas faults involving five or more shorted cells yielded ΔVoc &gt; 3.0 V, exceeding the thermally explainable range. Under 25% partial shading, Pmax decreased by approximately 50% and the I–V curve developed a bypass-diode-induced step; distributed aging modeled as an increase in Rs from 6.3 to 10.3 mΩ reduced the fill factor from 0.728 to 0.689 (− 5.4%) and Pmax by 7.4%. The influence of additional, secondary thermal effects on the current–voltage characteristics of solar panels under partial shading conditions has been investigated. The secondary thermal effects considered were the local cooling of shaded solar cells and the heating of bypass diodes. Experimental validation against measured I–V curves under unshaded and partially shaded conditions and additional temperature-dependent validation cases at 20–26 °C gave <i>R</i>² = 0.96–0.996, RMSE = 0.06–0.09 A, NRMSE = 1.92–4.87%, and MAPE = 1.75–6.74%. A two-stage diagnostic protocol based on continuous maximum power-point monitoring and triggered full I–V acquisition was implemented on a low-cost Arduino-based platform. The proposed framework provides physically interpretable diagnostics for decentralized PV monitoring.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Conditions for positivity of energy in superrenormalizable polynomial gravity","authors":"Públio Rwany B. R. do Vale","doi":"10.1140/epjp/s13360-026-07643-3","DOIUrl":"10.1140/epjp/s13360-026-07643-3","url":null,"abstract":"<div><p>At the quantum level, the polynomial models of gravity with six and eight derivatives are superrenormalizable, but suffer from higher derivative ghost and/or tachyonic ghost states. On the other hand, these models may have advantages in the control of negative effects of ghosts, compared to the more common fourth-derivative theory. We explore the positiveness of energy of the individual plane wave solutions in the general models with six and eight derivatives. Different from the fourth-order gravity, the part of the energy which may be seen as the leading one in the UV, is positively defined in the tensor sector. We extend this investigation to the scalar sectors of the free theory.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-07643-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"The impact of Allee effect and poaching in eco-epidemic model with gestation delay for predator","authors":"Richa Rajawat,&nbsp;Joydip Dhar,&nbsp;Jyoti Gupta,&nbsp;Poonam Sinha","doi":"10.1140/epjp/s13360-026-07704-7","DOIUrl":"10.1140/epjp/s13360-026-07704-7","url":null,"abstract":"<div><p>This study examines the dynamics of an eco-epidemic model incorporating the Allee effect in prey populations, a Holling type II functional response for predation and gestation delay in predator. Additionally, it considers the impact of poaching on predators. We first show that the model solutions are positive and bounded. We also evaluate the basic reproduction number, which reveals that predation and infection dynamics influence the population’s ability to control or sustain the disease. Further, we investigate all possible system equilibria and examine their local stability for the system without delay and the delayed system. The numerical simulation allows qualitative analysis to depict this work. The results show that the system is stable for significant values of Allee and poaching parameters. We focus on the dynamic migration of predators with oscillatory migration and poaching. Our findings provide valuable insights into the anthropogenic and eco-epidemiological factors influencing the system’s behavior.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Leveraging SDE-PINNs with sinusoidal activations to address both forward and inverse problems of the coupled Ablowitz–Ladik equations","authors":"Jian-Chen Zhou,&nbsp;Xiao-Yong Wen,&nbsp;Pei-Kun Yang","doi":"10.1140/epjp/s13360-026-07688-4","DOIUrl":"10.1140/epjp/s13360-026-07688-4","url":null,"abstract":"<div><p>This study proposes symmetric difference data enhancement physics-informed neural networks (SDE-PINNs), a novel deep learning framework for solving both forward and inverse problems of first- and second-order discrete rogue wave (RW) solutions in the coupled Ablowitz–Ladik (AL) equations. By incorporating sinusoidal activation functions, the model significantly enhances complex waveform characterization. Key findings demonstrate: (1) high-fidelity forward modeling with relative errors down to <span>(mathcal {O}(10^{-4}))</span> for first-order RW and <span>(mathcal {O}(10^{-3}))</span> for second-order RW; (2) according to the results of the Wilcoxon signed-rank test <span>((p&lt;0.001))</span>, the SDE-PINNs exhibit a statistically significant improvement in accuracy compared to traditional PINNs. Notably, while conventional PINNs perform better with Tanh activations than with sinusoidal functions, the SDE-PINNs demonstrate the opposite effect: Sinusoidal activations markedly enhance accuracy compared to Tanh activations. This synergy between architecture and activation function allows the SDE-PINNs to achieve superior performance in modeling complex second-order waveforms, even reducing errors to <span>(mathcal {O}(10^{-4}))</span> magnitude, significantly outperforming Tanh-activated PINNs; (3) robust parameter inversion with coupling parameter errors <span>(&lt;0.006)</span> and <span>(sigma )</span> errors <span>(&lt;0.010)</span> for first-order RW, while maintaining <span>(sigma )</span> errors <span>(&lt;0.032)</span> for second-order RW under equivalent conditions. The spectral matching property of sinusoidal activations is shown to critically improve high-frequency oscillation modeling. Moreover, we systematically compare fixed and adaptive loss weighting strategies, showing that adaptive weighting further refines SDE-PINNs accuracy while reducing training time by more than half and lowering variance. The analysis also reveals that recovering the nonlinear parameter <span>(sigma )</span> is inherently more challenging due to its coupling with squared field magnitudes, especially in higher-order waves. Future work will focus on extending the framework by incorporating more physical information of integrable systems and exploring hybrid activation strategies to enhance system stability and performance.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Creeping flow of the micropolar fluid past a slip–stick drop in a porous region: magnetic effect","authors":"Sivaprasad Jammula,&nbsp;Phani Kumar Meduri","doi":"10.1140/epjp/s13360-026-07664-y","DOIUrl":"10.1140/epjp/s13360-026-07664-y","url":null,"abstract":"<div><p>A uniform, steady, incompressible, creeping flow of micropolar fluid past a slip–stick liquid drop in a porous medium under the influence of a magnetic field is considered. The front of the drop surface is with slip, whereas the back of the drop is assumed to be no-slip. The stream function formulations are derived utilizing the separable variable method. The drag force and the coefficient of drag are expressed in terms of polar angle. The exceptional case results are matched with those in previous research. It is observed that the drag increases with increasing micropolar coupling parameter and Hartmann number. Graphical analysis showed that the coefficient of drag is higher under no-slip conditions than in slip conditions. Streamlines are analyzed for different Hartmann numbers and micropolar coupling parameters. It is observed that stronger external micropolar coupling enhances interaction with the drop’s exterior by distorting both external and internal streamlines. The rise in internal micropolar coupling mostly reorganizes the internal streamlines, having minimal effect on the external flow.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Experimental and numerical investigation of the effect of forced air-cooling parameters on temperature distribution at lithium-ion battery module","authors":"Seyda Ozbektas,&nbsp;Bilal Sungur,&nbsp;Furkan Mumcu,&nbsp;Alirıza Kaleli","doi":"10.1140/epjp/s13360-026-07715-4","DOIUrl":"10.1140/epjp/s13360-026-07715-4","url":null,"abstract":"<div><p>The air-cooling system is an advantageous cooling method for battery modules due to its low cost, light weight, simple design, and no sealing required. In this study, the thermal performance of an air-cooled lithium-ion battery module was investigated through both numerical and experimental approaches, considering the influence of various design and operating parameters. The experimental investigation was conducted to examine the thermal behavior of an air-cooled lithium-ion battery module under specific operating conditions, providing temperature distribution data to validate the numerical model. Distinguishing itself from previous studies, this research replaces simplified assumptions with a high-accuracy approach by employing the mesh motion technique for dynamic airflow generation and an Equivalent Circuit Model (ECM) validated with experimental HPPC data. After the numerical model was validated against experimental data in terms of battery cell temperature, demonstrating high statistical reliability with an average <i>R</i>² of 0.979, comprehensive numerical analyses were conducted to investigate the effects of six critical design and operating parameters: fan speed, ambient temperature, discharge rate, air outlet and fan positions, and inter-cell spacing. The battery cells’ temperature inside the module decreased as the fan speed increased up to 4000 rpm, but no significant change in temperature was observed after this speed value. As the ambient temperature increased, cell temperatures and module voltage increased, and the maximum temperature difference between cells decreased. It was revealed that the cooling capacity of the system was insufficient for the 7C discharge rate. As the distance between cells increased, cell temperatures decreased, and a more homogeneous temperature distribution occurred. Lower cell temperatures and homogeneous temperature distributions occurred in the front-dual-side and top-dual-side fan positions, where three-dimensional air flow was provided with multiple fan placements. Among all configurations, when <i>T</i>ₘₐₓ and Δ<i>T</i>ₘₐₓ are evaluated together, the best thermal performance was achieved in the top-outlet configuration, with values of 36.75 °C and 6.78 °C, respectively. These findings provide significant contributions to the design optimization of air-cooled lithium-ion battery systems.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-07715-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"A neural circuit without consuming Joule heat, and synchronization coupled by a memristor","authors":"Qi Cao,&nbsp;Binchi Wang,&nbsp;Chunni Wang","doi":"10.1140/epjp/s13360-026-07682-w","DOIUrl":"10.1140/epjp/s13360-026-07682-w","url":null,"abstract":"<div><p>Resistive elements dissipate electrical energy as Joule heat, whereas capacitors and inductors store electric and magnetic field energy and thus enable reversible energy exchange that can sustain oscillations when explicit dissipation is removed in an electric circuit composed of capacitor, inductor, and even memristor. Motivated by energy-efficient neuromorphic design without using resistor, we investigate a memristive neural circuit in which a magnetic-flux-controlled memristor provides nonlinear, history-dependent feedback to the devices including capacitor and inductors. The circuit is formulated in both current-driving and voltage-driving forms, and a Hamilton energy function is constructed to quantify the activity level and the energy partition between capacitive and inductive channels. Simulations show that driving frequency and memristive feedback switch the circuit between stable periodic firing and chaotic oscillations. Mode transitions are accompanied by systematic shifts in the energy level and by a clear redistribution of energy sharing between the capacitive and inductive storage channels. When additive noise is included, firing regularity varies nonmonotonically, revealing a noise-assisted window consistent with coherence resonance. We further illustrate an energy adaptation law that steers the system toward a steady operating regime, and show that memristive coupling between two neurons promotes energy balance and phase synchronization, with noise potentially assisting synchronization when coupling is weak.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Memory effects and non-local time evolution in driven two-level systems","authors":"Alexander Lopez,&nbsp;Sébastien Fumeron,&nbsp;Malte Henkel,&nbsp;Trifce Sandev,&nbsp;Esther D. Gutiérrez","doi":"10.1140/epjp/s13360-026-07629-1","DOIUrl":"10.1140/epjp/s13360-026-07629-1","url":null,"abstract":"<div><p>Fractional quantum dynamics provides a natural framework to describe nonlocal temporal behavior and memory effects in quantum systems. Building on this idea, we develop a fractional Green’s function formulation for the time-dependent Schrödinger equation based on the Caputo fractional derivative, which enables a systematic treatment of fractional-order quantum evolution. When applied to an extended two-level Rabi model, a paradigmatic setting for coherent quantum control, we find that even the static Hamiltonian term leads to non-trivial spin dynamics with damping features directly linked to fractional temporal nonlocality. Upon introduction of a periodic driving field, the fractional regime produces controllable damping and dephasing governed by the order of the fractionality, which could be observed through the Loschmidt echo and autocorrelation function, offering potential routes to probe fractional quantum dynamics experimentally. Our findings open pathways to explore memory-induced dynamical phenomena in other systems effectively described by two-level approximations, such as graphene-like materials and topological SSH chains, where non-integer-order evolution may reveal novel topological or relaxation regimes.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}