物理最新文献

{"title":"A novel multi-cavity hyperchaotic map based on the Lissajous curve","authors":"Zeping Zhang,&nbsp;Kehui Sun,&nbsp;Huihai Wang","doi":"10.1140/epjp/s13360-025-06682-6","DOIUrl":"10.1140/epjp/s13360-025-06682-6","url":null,"abstract":"<div><p>Based on the Lissajous curve, this paper designs a new chaotic map. The dynamical analysis shows that the proposed map has large Lyapunov exponents and high permutation entropy complexity. To further enhance the performance of the proposed chaotic map, a multi-cavity hyperchaotic map is constructed by combining with a shift symmetry transformation. The multi-cavity hyperchaotic map has a more complex topological structure and reduces the periodic windows. These hyperchaotic maps are implemented on the digital signal processor platform for practical applications.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814419","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":"The efficient cathode modification enabled by a thermally evaporable p-type layer for organic solar cells","authors":"Wei Zong,&nbsp;Zichen Liu,&nbsp;Dashan Qin","doi":"10.1007/s00339-025-08810-6","DOIUrl":"10.1007/s00339-025-08810-6","url":null,"abstract":"<div><p>The <i>n</i>-type materials have been generally adopted to modify the active layer/cathode interfaces in organic solar cells (OSCs). Here, a thermally evaporated <i>p</i>-type material, <i>N</i>,<i>N</i>ʹ-Bis(naphthalen-1-yl)-<i>N</i>,<i>N</i>ʹ-bis(phenyl)benzidine (NPB), has been demonstrated to enable the efficient cathode modification in the conventional OSCs. Although the lowest unoccupied molecular orbital level of NPB does not match that of acceptor and Fermi level of cathode, the diffusing cathode atoms react with NPB to generate the gap states which realize effective electron extraction and transport. The efficiency of the OSC with 7.5 nm NPB achieves 13.37%, bigger than the one (10.64%) without cathode-modifying layer However, it is smaller than those with 10 nm PDINN (15.51%) and BCP (14.81%), due to the photoinduced hole transfer from acceptor to NPB and the limited diffusion of NPB molecules into active layer. The current research provides a novel insight into the development of cathode-modifying layers towards low-cost and high-stability OSCs.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into neutron stars from gravitational redshifts and universal relations","authors":"Sagnik Chatterjee,&nbsp;Kamal Krishna Nath","doi":"10.1140/epjc/s10052-025-14611-1","DOIUrl":"10.1140/epjc/s10052-025-14611-1","url":null,"abstract":"<div><p>The universal relations in neutron stars form an essential entity to understand their properties. The moment of inertia, dimensionless tidal deformability, mass quadrupole moment, and oscillation modes are some of the properties that have been studied previously in the context of universal relations. All of these quantities are measurable; thus, analyzing them is of utmost importance. In this article we provide new universal relations in the context of a neutron star’s gravitational redshift. Using the redshift measurements of RBS 1223, RX J0720.4-3125, and RX J1856.5-3754, we provide theoretical estimates of moment of inertia, dimensionless tidal deformability, mass quadrupole moment, the mass of the star times the ratio of angular frequency over the spin angular moment, and the average of the speed of sound squared. In the case of the redshift measurement of RX J0720.4-3125, we found that the theoretical estimate using universal relations aligns closely with the Bayesian estimate. Our findings indicate that such theoretical predictions are highly reliable for observations with low uncertainty and can be used as an alternative for statistical analysis. Additionally, we report a violation of the universality of the dimensionless tidal deformability and average of the speed of sound squared with respect to the gravitational redshift. Our calculations further indicate that, under current astrophysical constraints, the maximum gravitational redshift attainable by neutron stars does not exceed 0.763.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 8","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14611-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810891","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":"Understanding the electronic phase separation in La0.6A0.4MnO3 (A = Ca and Sr) thin films at low temperature and high magnetic fields","authors":"Aradhana Kumari,&nbsp;Asokan Kandasami,&nbsp;Vijay Raj Singh","doi":"10.1007/s00339-025-08848-6","DOIUrl":"10.1007/s00339-025-08848-6","url":null,"abstract":"<div><p>Chemical doping, external pressure, and oxygen stoichiometry are known to modulate the interplay between charge, spin, orbital, and lattice degrees of freedom in manganites, thereby altering both their electronic and crystallographic structures. In this study, we investigate the magnetotransport and magnetic properties of La₀.₆Ca₀.₄MnO₃ (LCMO) and La₀.₆Sr₀.₄MnO₃ (LSMO) thin films fabricated via RF magnetron sputtering onto single-crystal substrates. The films, each with a nominal thickness of ~ 7 nm, were deposited on (001) Nb-doped SrTiO₃ (designated LCMO-S and LSMO-S), while LSMO was also grown on (110) NdGaO₃ substrates (LSMO-N) to introduce distinct epitaxial strain conditions. Atomic force microscopy revealed atomically smooth surfaces with step-terrace morphologies, and X-ray diffraction confirmed high-quality epitaxial growth without secondary phases. Current–voltage (I–V) measurements exhibited strong correlations between curve linearity and the metal–insulator transition (MIT), consistent with nanoscale phase separation comprising coexisting metallic and insulating regions. This intrinsic inhomogeneity is a characteristic signature of mixed-valence manganites and persists under a range of thermal and magnetic field conditions. Magnetization data acquired via SQUID magnetometry, fitted with the Langevin function, indicate the onset of a ferromagnetic state at 220 K under an external magnetic field of 2 T. Notably, in this temperature regime, the I–V response approaches linearity, suggesting the emergence of a high-temperature ferromagnetic insulating phase. These findings underscore the persistence of electronic phase separation even at low temperatures and in strong magnetic fields. The study highlights the critical role of strain, dimensionality, and substrate orientation in governing the magnetoelectronic landscape of manganite thin films. The observed properties render these systems promising for advanced applications in magnetoresistive sensors, thermoelectric modules, multifunctional oxide electronics, and magnetocaloric technologies.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, magnetic, electrical, dielectric, and energy density properties of Sr2+ and Co2+ co-substituted LaFeO3 perovskites for dielectric ceramic capacitor applications","authors":"M. A. Gabal,&nbsp;D. S. Alosaimi,&nbsp;Y. M. Al Angari,&nbsp;A. Awad,&nbsp;A. A. Al-Juaid,&nbsp;Saleh A. Alghamdi,&nbsp;Abdu Saeed","doi":"10.1007/s00339-025-08816-0","DOIUrl":"10.1007/s00339-025-08816-0","url":null,"abstract":"<div><p>Herein, we report the development of Sr²⁺ and Co²⁺ co-substituted LaFeO₃ perovskite nanoparticles prepared using a sucrose-assisted sol-gel auto-combustion route for advanced dielectric ceramic capacitor applications. Incorporating Sr²⁺ and Co²⁺ ions into La_{1− <i>x</i>}Sr_<i>x</i>Fe_1−<i>y</i>Co_<i>y</i>O₃ (<i>x</i> = <i>y</i> = 0.0, 0.1, 0.2, 0.3, and 0.5) enhanced their structural, electrical, and dielectric properties. XRD and FTIR analyses confirmed lattice distortion, mixed valence states, and bond strengthening, contributing to improved charge carrier mobility and polarization mechanisms. TEM showed quasi-spherical nanoparticles (~ 15 nm), while magnetic measurements indicated weak ferromagnetic ordering attributed to double exchange interactions (Fe²⁺–O–Fe³⁺). Dielectric studies demonstrated a significant enhancement in the dielectric constant (ε′) and a reduction in dielectric loss (tanδ) for co-substituted samples. The La_{1− <i>x</i>}Sr_<i>x</i>Fe_1−<i>y</i>Co_<i>y</i>O₃ (x = y = 0.2) sample exhibited the most optimized performance, showing high capacitance stability over a wide frequency range (1 kHz to 2 MHz) and a superior energy storage density of ~ 650 J/m³ at 600 K. Additionally, the energy storage efficiency reached ~ 90% at higher frequencies, further reinforcing its suitability for capacitor applications. These findings confirm that Sr²⁺ and Co²⁺ co-substituted LaFeO₃ perovskites, particularly the <i>x</i> = <i>y</i> = 0.2 composition, are promising candidates for dielectric ceramic capacitors in electronics at high-temperature energy storage applications.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absorption and scattering of massless scalar waves by black holes in quasi-topological gravity","authors":"Sihao Fan,&nbsp;Chen Wu,&nbsp;Wenjun Guo","doi":"10.1140/epjc/s10052-025-14610-2","DOIUrl":"10.1140/epjc/s10052-025-14610-2","url":null,"abstract":"<div><p>We consider massless scalar field perturbations of regular black holes in quasi-topological gravity. After reviewing various regular black hole solutions, we compute the total absorption cross-section and the partial absorption cross-section for different choices of the parameters using the partial wave method. The results show that the larger the parameter <span>(alpha )</span>, introduced in the context of quasi-topological gravity, the smaller the total absorption cross-section. In addition, we find that the influence of the space-time dimension <i>D</i> on the absorption and scattering of massless scalar waves in this set of regular black holes differs from earlier computations.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 8","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14610-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814276","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":"Uniform design for the multi-layer space radiation shielding optimization","authors":"Shukai Guan,&nbsp;Guicui Fu,&nbsp;Bo Wan,&nbsp;Yang Yang","doi":"10.1140/epjp/s13360-025-06700-7","DOIUrl":"10.1140/epjp/s13360-025-06700-7","url":null,"abstract":"<div><p>This paper proposes a multi-objective optimization strategy for space radiation shielding using a uniform design approach integrated with Monte Carlo simulations. The study investigates the performance of fifteen hydrogen-rich and high-Z materials arranged in multi-layer configurations under three radiation environments: Galactic Cosmic Rays, Solar Proton Events, and the Van Allen belts. Key control parameters include areal density, layer number, material sequence, and type. A stepwise quadratic regression model was developed to correlate these variables with dose equivalent. Simulation results from MCNP6 and FLUKA validate the shielding effectiveness of the proposed designs. Design 6, featuring a layered structure of aluminum, Kevlar, epoxy, LiH, PBO, and BN, achieves a dose reduction from 322.2 to 101.9 mSv/year. This approach not only enables lightweight and adaptable shielding solutions for deep-space missions but also supports the development of integrated sensing systems. By mitigating radiation-induced drift, noise, and damage in sensitive sensor payloads, the proposed shielding framework lays the groundwork for radiation-hardened sensor modules suitable for planetary exploration, diagnostics, and orbital monitoring applications.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814540","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":"Radiological risk and elemental analysis of slimming seeds from Baghdad markets, Iraq","authors":"Itab F. Hussein,&nbsp;Rana O. Abdaljalil,&nbsp;Firas K. Nsaif,&nbsp;Howaida Mansour,&nbsp;Ahmed F. Mkhaiber","doi":"10.1140/epjp/s13360-025-06627-z","DOIUrl":"10.1140/epjp/s13360-025-06627-z","url":null,"abstract":"<div><p>This study explores the radiological risks and elemental composition of slimming seeds sold in Baghdad markets, Iraq. Utilizing X-ray fluorescence (XRF) spectroscopy and gamma spectrometry, the concentrations of heavy metals (Cr, Cu, Zn, Mn, Fe, Ag, Sn, and Ni) and naturally occurring radionuclides including U-238, Th-232, and K-40 were detected. Health risk assessments revealed that chromium concentrations in some samples of S1 (see Table 1 for the meaning of the seed symbols S1–S9) exceed the safety threshold of Cr (7.64 mg/kg), thus becoming a potential carcinogenic risk. The highest iron concentrations were measured (in mg/kg) as 198 for S6 and 199 for S8 seeds contaminants. Radiological indices, such as the outdoor absorbed dose rate D_out (38.69 nGy/h), outdoor annual effective dose (47.44 μSv/y), and excess lifetime cancer risk (ELCR_in of 1254.8 Bq/kg for indoor exposure), highlighted significant risks in specific seeds especially sample (S9). These findings emphasize the necessity for rigorous regulatory measures and consistent monitoring to mitigate health hazards associated with herbal products. This research provides crucial insights into contamination risks, underscoring the importance of ensuring public health and environmental sustainability.\u0000</p><div><figure><figcaption><b>Table 1 Details of collected samples</b></figcaption><div><span>Full size table</span><svg><use></use></svg></div></figure></div></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-025-06627-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810789","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":"Thermodynamic geometry of two coupled spins via various Ising Hamiltonians","authors":"Nayyere Einali Saghavaz,&nbsp;Hosein Mohammadzadeh,&nbsp;Zahra Ebadi,&nbsp;Morteza Nattagh Najafi","doi":"10.1140/epjp/s13360-025-06695-1","DOIUrl":"10.1140/epjp/s13360-025-06695-1","url":null,"abstract":"<div><p>We investigate the thermodynamic geometry of systems composed of two coupled spins governed by different Ising Hamiltonians. We construct the thermodynamic parameters space and evaluate the related metric elements. Moreover, we analyze how these geometric structures change with variations in system parameters, such as coupling constants and external magnetic fields. We show that different models exhibit distinct features in thermodynamic parameters space based on the sign of thermodynamic curvature. These insights refine our understanding of the macroscopic thermodynamic behavior emerging from microscopic spin interactions.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810791","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":"Antibacterial coating based on lanthanum-doped nanobioactive glass/chitosan composite of metal implant for orthopedic applications","authors":"Ahlam M. Ibrahim,&nbsp;Areg E. Omar,&nbsp;Hanaa Y. Ahmed,&nbsp;Mohammad M. Farag,&nbsp;Zainab M. Al‑Rashidy,&nbsp;Zainab M. Al Rashidy","doi":"10.1007/s00339-025-08823-1","DOIUrl":"10.1007/s00339-025-08823-1","url":null,"abstract":"<div><p>Although bio-metallic alloys are commonly used as prostheses due to their unique mechanical properties and durability, they are often bioinert and lack antibacterial properties. Coating of metallic implants by composite materials provides mechanical strength, bioactivity and enhances antibacterial properties. In this study, chitosan and chitosan/La-doped nanobioactive glass (LBG) composite were synthesized for coating of 316 L stainless steel using the electrophoretic deposition technique. Thermal, structural and compositional properties of the synthesized glass were studied. Also, microstructure, adhesion strength, wetting, and in-vitro bioactivity of the deposited coatings were evaluated. Moreover, cytotoxicity of the coatings was investigated against normal skin cells. Hemolytic activity of coating was also measured to investigate coating biocompatibility with the hematic system. Furthermore, the deposited coatings were functionalized with antibacterial drug (gentamicin), where drug’s release profile and its kinetic were studied. The antibacterial activity of the functionalized coatings were determined as well. The obtained results showed that the deposited coatings presented good adhesion strengths (1.67 MPa and 0.80 MPa for chitosan and composite coating). The wettability of both coatings enhanced, contact angles are 33°, and 56° for Chit@SS, and LBG/Chit@SS, respectively, compared to SS, 77°. According to the obtained hemolysis values of coatings (less than 10%), they were considered biocompatible materials. As well as, the coatings formed apatite-like crystals on its surface after immersion in SBF, also they didn’t show a cytotoxic effect for normal skin cells. Gentamicin drug was released in a sustained manner by Fickian diffusion mechanism. Also, drug/coating containing LBG showed a higher antibacterial effect than that of chitosan coating. These findings indicated that the prepared composite coating of Lanthanum-doped bioactive glass incorporated with chitosan can be used to avoid bacterial infection and enhance bone healing in orthopedic and dental applications.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00339-025-08823-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}