The European Physical Journal Plus最新文献_第2页

Study of magnetic field frequency effect on the atomic and thermal behavior of paraffin/Cu nanostructure in a tube with non-connected rotating ribs 磁场频率对非连接旋转肋管中石蜡/铜纳米结构原子和热行为影响的研究

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-06 DOI: 10.1140/epjp/s13360-025-06266-4

Behrouz Salahshour, Davood Toghraie, Saeed Jafari Mehrabadi, Arash Karimipour, Peyman Yousefi

{"title":"Study of magnetic field frequency effect on the atomic and thermal behavior of paraffin/Cu nanostructure in a tube with non-connected rotating ribs","authors":"Behrouz Salahshour, Davood Toghraie, Saeed Jafari Mehrabadi, Arash Karimipour, Peyman Yousefi","doi":"10.1140/epjp/s13360-025-06266-4","DOIUrl":"10.1140/epjp/s13360-025-06266-4","url":null,"abstract":"<div>This study uses molecular dynamics simulations to examine the effects of different external magnetic field frequencies on the atomic and thermal properties of a paraffin/copper composite in a tube with rotating ribs. A stable starting state was first achieved via a 10-ns equilibration phase, which produced a temperature of 300 K and kinetic and potential energies of 0.026 kcal/mol and 1.424 kcal/mol, respectively. Several important properties of the simulated atomic sample were found to be dramatically changed when the external magnetic field frequency increased from 0.1 to 0.5 fs⁻1. The highest atomic velocity decreased somewhat from 0.00499 to 0.00490 Å/fs, whereas the maximum density increased significantly from 0.0842 to 0.0847 atom/Å3. Furthermore, the highest temperature of the system decreased from 775 to 758 K, suggesting a decrease in thermal energy associated with the higher frequencies. Alongside this shift, the heat flow decreased from 5.68 to 5.60 W/m2, indicating changes in the properties of thermal transport. Additionally, thermal conductivity decreased from 0.79 to 0.71 W/m·K. It seems that the material increased more sensitivity to magnetic fields at higher frequencies since the charging time increased from 6.06 to 6.18 ns. The phase change material’s discharge time increased from 7.11 to 7.15 ns when the external magnetic field frequency increased from 0.1 to 0.2 fs−1. It is interesting to note that a little increase in frequency to 0.3 fs−1 caused the discharge time to decrease to 7.14 ns; nevertheless, when the frequency increased to 0.5 fs−1, the discharge time increased once again and stabilized at 7.15 ns.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143913871","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}

引用次数: 0

Multi-scroll dynamics and coexisting attractors in electromagnetic-induced Hopfield networks 电磁诱导Hopfield网络中的多涡旋动力学和共存吸引子

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-06 DOI: 10.1140/epjp/s13360-025-06310-3

T. M. C. Priyanka, D. Vignesh, A. Gowrisankar, Jun Ma

{"title":"Multi-scroll dynamics and coexisting attractors in electromagnetic-induced Hopfield networks","authors":"T. M. C. Priyanka, D. Vignesh, A. Gowrisankar, Jun Ma","doi":"10.1140/epjp/s13360-025-06310-3","DOIUrl":"10.1140/epjp/s13360-025-06310-3","url":null,"abstract":"<div>Excitatory and inhibitory neuronal activity generates neural oscillations, these oscillations are vital for functioning of brain. Improving knowledge about these neural oscillations helps us better comprehend neurological disorders. This article explores a 4D Hopfield neural network combined with memristive electromagnetic induction and pulse current stimulation, which has practical significance in the emerging field of artificial intelligence. The research analyzes the dynamical behavior of proposed Hopfield network consisting of four neurons by supplying external stimulus to second neuron via memristor and exposing fourth neuron to pulse current. Lyapunov exponents and bifurcation diagrams are studied with the choice of memristive internal parameter as bifurcation parameter. As a result of sensitivity to initial conditions, various biscroll and multilayer attractors are generated illustrating their state transitions with time series plots. In addition, coexisting bifurcation and attractors are presented for different selection of multilevel-logic pulse current and it is observed that the pulse current parameter governs the number of scrolls and structure of attractors. Multilayer attractors corresponding to the external input applied to the memristor elements are displayed to investigate the transition of the system states through time series plots and phase plane portraits. This work, in particular, improves our understanding of brain activity while also providing insights into the neural mechanisms, leading to neurological conditions.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908816","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}

引用次数: 0

A novel time-delayed stochastic epidemic modeling approach incorporating Crowley–Martin incidence and nonlinear holling type II treatment rate 一种考虑Crowley-Martin发病率和非线性II型治疗率的时滞随机流行病建模方法

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-06 DOI: 10.1140/epjp/s13360-025-06300-5

Abdeldjalil Kadri, Ahmed Boudaoui, Seham M. Al-Mekhlafi, Saif Ullah, Mohammed Asiri, Muhammad Bilal Riaz

{"title":"A novel time-delayed stochastic epidemic modeling approach incorporating Crowley–Martin incidence and nonlinear holling type II treatment rate","authors":"Abdeldjalil Kadri, Ahmed Boudaoui, Seham M. Al-Mekhlafi, Saif Ullah, Mohammed Asiri, Muhammad Bilal Riaz","doi":"10.1140/epjp/s13360-025-06300-5","DOIUrl":"10.1140/epjp/s13360-025-06300-5","url":null,"abstract":"<div>Mathematical modeling of infectious disease is essential for understanding the impact of various epidemiological factors and stochastic influences on disease spread. In this study, we investigate a stochastic compartmental epidemic model with time delays, featuring a Crowley–Martin (C-M) incidence rate alongside a holling type II (HT-II) treatment rate. Initially, we demonstrate the existence and uniqueness of a positive global solution to the model. Subsequently, we establish sufficient conditions that lead to the extinction of the disease. A suitability constructed Lyapunov function is used to confirm the presence of a stationary distribution (SD). In epidemiology, the presence of a stationary distribution indicates that the disease will persist over the long term. Additionally, the Fokker–Planck equation is solved to obtain the exact analytical form of the probability density function (PDF) that describes the behavior of the stochastic model near its unique endemic quasi-equilibrium. In statistical analysis, the explicit density function can capture and represent all the dynamical features of an epidemic model. Finally, a comprehensive simulation is provided to support and illustrate our theoretical results, offering practical insights into the model’s behavior. This work contributes to the development of more accurate predictive models that can assist public health policymakers in designing effective disease control strategies and intervention plans to mitigate the spread of infectious diseases.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143913870","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}

引用次数: 0

(fleft( R,phi right) ) cosmology with the parametrization of H(z) parameter (fleft( R,phi right) ) 用H(z)参数化的宇宙学

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-05 DOI: 10.1140/epjp/s13360-025-06299-9

Neeru Goyal, Anil Kumar Yadav, S. H. Shekh, Aditya Sharma Ghrera

{"title":"(fleft( R,phi right) ) cosmology with the parametrization of H(z) parameter","authors":"Neeru Goyal, Anil Kumar Yadav, S. H. Shekh, Aditya Sharma Ghrera","doi":"10.1140/epjp/s13360-025-06299-9","DOIUrl":"10.1140/epjp/s13360-025-06299-9","url":null,"abstract":"<div>Building FRW cosmological models within the context of the (f(R,phi )) theory of gravity is our goal in this effort. We investigate the universe’s accelerating behavior for a specific form of the (f(R,phi )) gravity model by employing a new, straightforward parametrization of the Hubble parameter in the form (H(z)=frac{H_0}{sqrt{2}}left[ 1+(1+z)^{(2(1+alpha )) } right] ^{frac{1}{2}}). Using the (chi ^2)-minimization approach, we impose constraints on the related free parameters that are present in H(z) within the (1sigma ), (2sigma ), and (3sigma ) confidence bounds. It has been observed that the values obtained are all within the range that is indicated by cosmological observations. Through the utilization of the free parameter best-fit values, we have ascertained the current geometrical parameter values and illustrated the Universe’s accelerating behavior. Through the use of physical characteristics such as energy density, pressure, and equation of state parameter, we have talked about the physical behavior of the cosmos in our model. Additionally, we have looked at the kinematic parameters such as the jerk, deceleration, and Hubble parameters of the cosmos in our model. The deceleration parameter q(z) in our model represents the phase transition of the cosmos from deceleration to acceleration. Additionally, the deceleration parameter’s current value is (q_0=-0.361), and the transition redshift value is (z_t=0.62). This kind of situation is closely linked to the conventional (Lambda )CDM model.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904685","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}

引用次数: 0

High dielectric constant in calcium-substituted GdMnO3 for storage device applications 高介电常数钙取代GdMnO3的存储器件应用

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-05 DOI: 10.1140/epjp/s13360-025-06307-y

Supriya Priyadarshinee, Jayashree Pati, Ranjita Mahapatra, Pragyan Mohanty, Jyoshnarani Mohapatra, Dilip Kumar Mishra

{"title":"High dielectric constant in calcium-substituted GdMnO3 for storage device applications","authors":"Supriya Priyadarshinee, Jayashree Pati, Ranjita Mahapatra, Pragyan Mohanty, Jyoshnarani Mohapatra, Dilip Kumar Mishra","doi":"10.1140/epjp/s13360-025-06307-y","DOIUrl":"10.1140/epjp/s13360-025-06307-y","url":null,"abstract":"<div>Gd0.7Ca0.3MnO3 and Gd0.67Ca0.33MnO3 ceramics have been synthesized by solid-state reaction method at 950 °C. Crystalline nature and orthorhombic structure have been confirmed from the XRD analysis. Loosely packed grains of different shapes with small amount of porosity are observed from the SEM analysis. The room temperature dielectric constant of Gd0.7Ca0.3MnO3 and Gd0.67Ca0.33MnO3 samples are found to be 4775 and 318 with a dielectric loss factor of 1.48 and 2.40, respectively, at 1 kHz frequency. The observed room temperature dielectric constant value of Gd0.7Ca0.3MnO3 is quite higher as compared to the dielectric constant values of substituted GdMnO3 reported in the previous literatures. The observation of these dielectric values at room temperature with low dielectric loss factor makes both the materials suitable for applications in memory storage devices. Non-Debye type of relaxation mechanism has been confirmed from the impedance and modulus analysis. The optical energy band gap of Gd0.7Ca0.3MnO3 and Gd0.67Ca0.33MnO3 is found to be 3.1 eV and 2.89 eV, respectively.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908746","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}

引用次数: 0

An analogue of the Pöschl–Teller anharmonic oscillator on an N-dimensional sphere n维球面上Pöschl-Teller非谐振子的模拟

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-05 DOI: 10.1140/epjp/s13360-025-06252-w

Radosław Szmytkowski

{"title":"An analogue of the Pöschl–Teller anharmonic oscillator on an N-dimensional sphere","authors":"Radosław Szmytkowski","doi":"10.1140/epjp/s13360-025-06252-w","DOIUrl":"10.1140/epjp/s13360-025-06252-w","url":null,"abstract":"<div>A Schrödinger particle on an N-dimensional ((Ngeqslant 2)) hypersphere of radius R is considered. The particle is subjected to the action of a force characterized by the potential (V(theta )=2momega _{1}^{2}R^{2}tan ^{2}(theta /2) +2momega _{2}^{2}R^{2}cot ^{2}(theta /2)), where (0leqslant theta leqslant pi) is the hyperlatitude angular coordinate. In the general case when (omega _{1}ne omega _{2}), this is a model of a hyperspherical analogue of the Pöschl–Teller anharmonic oscillator. Energy eigenvalues and normalized eigenfunctions for this system are found in closed analytical forms. For (N=2), our results reproduce those obtained by Kazaryan et al. (Physica E 52:122, 2013). For (Ngeqslant 2) arbitrary and for (omega _{2}=0), the results of Mardoyan and Petrosyan (J. Contemp. Phys. 48:70, 2013) for their model of an isotropic hyperspherical harmonic oscillator are recovered. The Euclidean limit for the anharmonic oscillator in question is also discussed.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-025-06252-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908747","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}

引用次数: 0

Soliton excitation in a weak relativistic quantum plasma 弱相对论量子等离子体中的孤子激发

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-05 DOI: 10.1140/epjp/s13360-025-06098-2

L. Rajaei, S. Miraboutalebi

{"title":"Soliton excitation in a weak relativistic quantum plasma","authors":"L. Rajaei, S. Miraboutalebi","doi":"10.1140/epjp/s13360-025-06098-2","DOIUrl":"10.1140/epjp/s13360-025-06098-2","url":null,"abstract":"<div>In a weakly relativistic plasma, the influence of quantum mechanics becomes evident through a finite Fermi temperature despite moderately high particle velocities, indicating a degenerate electron gas with significant quantum pressure. The plasma’s inherent nonlinearity allows for forming and propagating solitons, which are self-localized wave packets. The quantum considerations modify solitons’ dispersion and stability compared to a purely classical plasma. However, the ideal picture is often challenged by various interactions that can be incorporated into such a plasma. The effects of exchange, viscosity, and collision, as some inevitable interactions, are studied here to provide a more realistic picture of the soliton excitations in the plasma. The model’s analytical solutions are obtained through the Tanh approach in a perturbation manner. This approach is adopted considering the theory’s nonlinearity and is different from the conventional perturbation methods of linearization. The results show that viscosity and collision or dissipation are correlated and interdependent, so the viscosity coupling constant is four times the dissipation coupling constant. Also, the viscosity and dissipation have diminished effects and reduce the amplitude of the vector potential, while the exchange considerations have intensifying consequences.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904684","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}

引用次数: 0

Derivation, nonlocal symmetry analysis, and exact solutions of modified Broer-Kaup equations 修正Broer-Kaup方程的推导、非局部对称分析及精确解

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-05 DOI: 10.1140/epjp/s13360-025-06302-3

Jinzhou Liu, Zhaowen Yan

引用次数: 0

Self-controlled channeling of relativistic electron flux and associated nuclear processes induced by a powerful polarized laser pulse acting on a crystal 由作用于晶体上的强偏振激光脉冲诱导的相对论性电子通量的自我控制通道和相关的核过程

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-04 DOI: 10.1140/epjp/s13360-025-06304-1

Vladimir Vysotskii, Mykhaylo Vysotskyy

{"title":"Self-controlled channeling of relativistic electron flux and associated nuclear processes induced by a powerful polarized laser pulse acting on a crystal","authors":"Vladimir Vysotskii, Mykhaylo Vysotskyy","doi":"10.1140/epjp/s13360-025-06304-1","DOIUrl":"10.1140/epjp/s13360-025-06304-1","url":null,"abstract":"<div>The formation, motion characteristics and potential applications of a superdense flux of fast electrons generated in a crystal under the direct action of a polarized, powerful laser pulse applied to the crystal surface are investigated. It is demonstrated that under specific orientations of the laser pulse, multiple planar channeling of these electrons occurs in opposite transverse directions. The energy of these electrons reaches relativistic values. For the first time, the significant decelerating effect of the alternating magnetic field generated by the modulated electron beam—formed and controlled by the intense laser—on the acceleration process has been taken into account. A method for completely suppressing this braking effect is proposed. The possible results of interactions of periodically directed channeling electrons with the nuclei and atoms of a \"frozen\" crystal lattice are listed and considered, including such well known phenomena as nuclear excitation, the creation of population inversions in the internal X-ray states of atoms, the inverse beta decay of nuclei inside the crystal, as well as potential modeling of the formation of neutron stars during gravitational collapse.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902814","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}

引用次数: 0

DFT study of (6,0) boron nitride nanotube as a drug delivery system for 5-fluorouracil and hydroxyurea （6,0）氮化硼纳米管作为5-氟尿嘧啶和羟基脲给药系统的DFT研究

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2025-05-04 DOI: 10.1140/epjp/s13360-025-06296-y

Ali Bizaval, Zahra Karami Horastani, S. Javad Hashemifar

{"title":"DFT study of (6,0) boron nitride nanotube as a drug delivery system for 5-fluorouracil and hydroxyurea","authors":"Ali Bizaval, Zahra Karami Horastani, S. Javad Hashemifar","doi":"10.1140/epjp/s13360-025-06296-y","DOIUrl":"10.1140/epjp/s13360-025-06296-y","url":null,"abstract":"<div>This study explores the potential of (6,0) boron nitride nanotube (BNNT60) as an efficient nanocarrier for the anticancer drugs 5-FU (Fluorouracil) and HU (Hydroxyurea) using dispersion-corrected density functional theory (DFT) via the Quantum-ESPRESSO package. The adsorption process is exothermic, with adsorption energies of −0.93 eV (5-FU) and −0.35 eV (HU), ensuring stable drug attachment while preserving molecular integrity. A comprehensive electronic structure analysis demonstrates that drug adsorption significantly modulates the Fermi level and work function of BNNT60, highlighting its potential as a dual-function platform for drug delivery and molecular sensing. Furthermore, the drug release mechanism is investigated under acidic conditions (H⁺ presence), mimicking the tumor microenvironment. The observed increase in equilibrium adsorption distances from 3.2 to 8.3 Å (5-FU) and from 3.4 to 8.7 Å (HU) confirms that BNNT60 can effectively trigger controlled drug release in response to pH variations. These findings underscore the unique potential of BNNT60 as a smart nanocarrier for targeted anticancer therapy, offering a novel approach for pH-sensitive drug delivery.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902813","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}

引用次数: 0