物理最新文献

{"title":"Acoustically-inspired force-driven separation of hydrogen from methane through nanoporous graphene membranes: a molecular dynamics study","authors":"Zabiholah Zabihi Lahrami","doi":"10.1007/s00339-025-08824-0","DOIUrl":"10.1007/s00339-025-08824-0","url":null,"abstract":"<div><p>This study explores the selective separation of hydrogen (H₂) from methane (CH₄) using graphene-based nanoporous membranes, focusing on the effects of pore size, pore density, and externally applied forces. Nanopores of varying sizes were engineered by selectively removing 6 to 16 carbon atoms from a pristine graphene sheet. Classical molecular dynamics (MD) simulations were conducted at 300 K, where equimolar mixtures of H₂ and CH₄ were subjected to constant external forces ranging from 0 to 0.01 eV/Å, applied perpendicular to the membrane. Although the applied force is temporally constant, it serves as a phenomenological approximation of net momentum transfer that may result from high-frequency acoustic excitation in experimental or industrial environments. The results demonstrate that hydrogen permeation increases significantly with force magnitude, while methane transport remains strongly restricted by pore size. Notably, nanopores formed by removing 8 or 9 carbon atoms exhibited the highest selectivity, effectively permitting hydrogen passage while excluding methane. Furthermore, increasing the pore density reduced the hydrogen saturation time, highlighting the role of pore architecture in enhancing separation efficiency. These findings offer insight into the design of acoustically-assisted, graphene-based membranes for efficient H₂/CH₄ separation.</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":"144810796","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":"Effect of Nd2O3 substitution on properties and photoluminescence performance of magnesium borotellurite glass system","authors":"Mohammad Ayman Abuallan,&nbsp;Mohd Hafiz Mohd Zaid,&nbsp;Khamirul Amin Matori,&nbsp;Yazid Yaakob,&nbsp;Zhi Wei Loh","doi":"10.1140/epjp/s13360-025-06667-5","DOIUrl":"10.1140/epjp/s13360-025-06667-5","url":null,"abstract":"<div><p>This research examined the structural and optical characteristics of neodymium-doped magnesium borotellurite glasses with the composition of (60−<i>x</i>)TeO₂–30B₂O₃–10MgO–<i>x</i>(Nd₂O₃), with <i>x</i> = 0, 1, 2, 3, and 4 mol%. Glass samples were prepared using the melting and quenching method. The density of the samples rose from 3.97 g/cm³ to 4.10 g/cm³ with Nd₂O₃ concentration. The molar volume, on the other hand, illustrated an opposing trend, and it decreased from 30.42 cm³/mol to 29.50 cm³/mol and then increased to 31.13 cm³/mol. XRD analysis showed evidence of the amorphous structure of glasses, and the Urbach energy peaked at MBTNd-2, whereas the optical band gap reached its lowest value at MBTNd-1 (direct: 3.291 eV; indirect: 2.356 eV), then increased to higher Nd concentrations. Photoluminescence analysis revealed prominent emission peaks at 444, 488, 545, and 614 nm under 400 nm excitation, with MBTNd-4 exhibiting the strongest intensity. Chromaticity analysis showed all doped samples fall within the blue region, indicating suitability for photonic applications. These findings demonstrate that Nd₂O₃ effectively enhances the optical performance of magnesium borotellurite glasses, making them viable for optoelectronic devices.</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":"144810790","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 influence of gravitational wave on tripartite quantum mutual information harvesting","authors":"Si-Yu Liu,&nbsp;Xiao-Li Huang,&nbsp;Shu-Min Wu","doi":"10.1140/epjc/s10052-025-14566-3","DOIUrl":"10.1140/epjc/s10052-025-14566-3","url":null,"abstract":"<div><p>We examine quantum mutual information (QMI) extraction through local interactions of three Unruh–DeWitt detectors with the vacuum massless scalar field, comparing scenarios with and without gravitational wave perturbations in Minkowski spacetime. Our analysis reveals that gravitational waves can either enhance or diminish tripartite QMI compared to the flat spacetime case, demonstrating their dual capacity to amplify or suppress tripartite QMI harvesting. A significant resonance phenomenon emerges when detector energy gaps match the gravitational wave frequency. Furthermore, when harvesting a certain amount of tripartite QMI, gravitational wave modifies the spatial parameters for effective tripartite QMI harvesting: the achievable separation range undergoes extension or contraction depending on three critical parameters-detector energy gap, gravitational wave frequency, and the duration of the gravitational wave interaction.\u0000\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/s10052-025-14566-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810892","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":"AdS(_{3}) spacetime wormhole fluctuations and their impact on false vacuum decay","authors":"Hong Wang,&nbsp;Jin Wang","doi":"10.1140/epjc/s10052-025-14587-y","DOIUrl":"10.1140/epjc/s10052-025-14587-y","url":null,"abstract":"<div><p>In this work, we studied the boundary wormhole fluctuations of AdS<span>(_{3})</span> spacetime and their impact on false vacuum decay. The model consists of three dimensional general relativity coupled to a real scalar field with self-interaction potential. Our analysis focuses on handlebody spacetimes, which correspond to boundary wormhole fluctuations. These fluctuations result in variations in the spacetime genus. Using the dilute wormhole gas approximation, we computed the boundary wormhole creation rate in the semiclassical region. Our results indicate that boundary wormholes are more likely to be created in spacetimes with larger absolute values of the cosmological constant. Furthermore, we find that smaller wormholes are more easily created compared to larger ones. Additionally, we investigated the impact of boundary wormhole fluctuations on false vacuum decay. The vacuum decay rate increases when the effects of wormhole fluctuations are considered. We show that all results remain qualitatively unchanged when certain parameter values are varied.\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/s10052-025-14587-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814316","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":"Constructing theoretical spectra for some Ar ions from Ar X to Ar XIII","authors":"Safeia Hamasha","doi":"10.1140/epjd/s10053-025-01044-4","DOIUrl":"10.1140/epjd/s10053-025-01044-4","url":null,"abstract":"<div><p>This study presents detailed analysis of theoretical atomic spectra of various argon (Ar) ions, specifically F-like, O-, N-, and C-like Ar ions, calculated using a method implemented in the flexible atomic code, which combines the relativistic configuration interaction method with many-body perturbation theory (FAC-MBPT). Radiative transition rates and oscillator strengths were calculated in terms of length and velocity forms which highlights the accuracy of the calculated data. A collisional-radiative model was developed to calculate theoretical spectra for optically allowed transitions of the four Ar ions. The spectral features and spectral ranges were analyzed and identified. A comparison with available data shows good agreement with the findings. The resulting spectra and the calculated data provide valuable insights for Ar plasma diagnostics and contribute to the understanding of complex astrophysical spectra.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><img></picture></div></div></figure></div></div>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Optimizing metachronal paddling with reinforcement learning at low Reynolds number.","authors":"Alana A Bailey, Robert D Guy","doi":"10.1140/epje/s10189-025-00511-5","DOIUrl":"10.1140/epje/s10189-025-00511-5","url":null,"abstract":"<p><p>Metachronal paddling is a swimming strategy in which an organism oscillates sets of adjacent limbs with a constant phase lag, propagating a metachronal wave through its limbs and propelling it forward. This limb coordination strategy is utilized by swimmers across a wide range of Reynolds numbers, which suggests that this metachronal rhythm was selected for its optimality of swimming performance. In this study, we apply reinforcement learning to a swimmer at zero Reynolds number and investigate whether the learning algorithm selects this metachronal rhythm, or if other coordination patterns emerge. We design the swimmer agent with an elongated body and pairs of straight, inflexible paddles placed along the body for various fixed paddle spacings. Based on paddle spacing, the swimmer agent learns qualitatively different coordination patterns. At tight spacings, a back-to-front metachronal wave-like stroke emerges which resembles the commonly observed biological rhythm, but at wide spacings, different limb coordinations are selected. Across all resulting strokes, the fastest stroke is dependent on the number of paddles; however, the most efficient stroke is a back-to-front wave-like stroke regardless of the number of paddles.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 8-9","pages":"48"},"PeriodicalIF":2.2,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12334496/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144797916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Green-mediated synthesis of bixbyite α-Mn2O3 nanoparticles via Moringa oleifera: impact of calcination on properties and visible-light photocatalytic degradation of Eosin yellow and eriochrome black T dyes","authors":"V. Archana,&nbsp;M. John Abel,&nbsp;S. Kalainathan,&nbsp;N. Senthilkumar","doi":"10.1007/s00339-025-08790-7","DOIUrl":"10.1007/s00339-025-08790-7","url":null,"abstract":"<div>\u0000 \u0000 <p>The leaf extraction of <i>Moringa oleifera</i> was used to synthesize α-Mn₂O₃ nanomaterials. The synthesized manganese oxide nanostructures were subjected to various annealing temperatures (500 °C, 600 °C, and 700 °C). Powder X-ray diffraction (PXRD) was employed to verify the phase purity and crystallinity characteristics. The PXRD analysis revealed the pristine phase of a cubic bixbyite structure. Diffuse reflectance spectroscopy (DRS) showed that the optical band gap of α-Mn₂O₃ NPs were 1.91 eV, 1.75 eV, and 1.65 eV, respectively for 500 °C, 600 °C, and 700 °C. Photoluminescence spectroscopy showed multicolour emissions in the UV and visible regions because of Mn₂O₃ defect centers. Fourier Transformed Infrared Spectroscopy (FTIR) was used to identify the functional groups that are liable for the nanoparticle formation. The SEM and TEM analyses revealed that the α-Mn₂O₃ nanoparticles exhibited a spherical morphology with particle sizes ranging approximately from 50 to 100 nm. The characteristic hysteresis graph observed in VSM measurements illustrated the paramagnetic behaviour at room temperature (RT). Impedance analysis, AC conductivity, and frequency-dependent electrical characteristics were investigated. The photocatalytic performance of α-Mn₂O₃ was assessed for the degradation of Eosin Y (EY) and Eriochrome Black-T (EB-T) dyes under visible light irradiation. At a calcination temperature of 600 °C, the degradation efficiencies achieved within 90 min were 98% for Eosin Y (EY) and 88% for Eriochrome Black-T (EB-T) dyes. The photodegradation mechanism of EY and EBT dyes was investigated using radical scavenger agents. Furthermore, the synthesized nanoparticles demonstrated excellent reusability, retaining their photocatalytic activity over five consecutive cycles under the same optimal conditions.</p>\u0000 </div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810807","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":"Linear dielectric spectroscopy of a polymer network stabilizing a ferroelectric liquid crystal.","authors":"Mohammed Hanine, Abdelylah Daoudi, Jamal Hemine","doi":"10.1140/epje/s10189-025-00504-4","DOIUrl":"https://doi.org/10.1140/epje/s10189-025-00504-4","url":null,"abstract":"<p><p>In this study, the linear dielectric characterization of a ferroelectric liquid crystal (FLC) stabilized by an anisotropic polymer network (PSFLC) was investigated. The liquid crystal employed in the PSFLC composites exhibited the chiral smectic C phase (SmC*), with a short helical pitch, a high tilt angle, and a high degree of spontaneous polarization. Dielectric spectroscopy was preceded by polarizing optical microscopy, as well as structural and electro-optical studies on pure FLC and PSFLC composites at different polymer concentrations. These studies enabled the determination of the pitch of the helix, the tilt angle, and the spontaneous polarization as a function of temperature and electric field. In the absence of a DC voltage, the dielectric response indicated the relaxation of the Goldstone mode as well as a reduction in tilt angle, spontaneous polarization and relaxation amplitude as the polymer density increased. By integrating the experimental data with the Landau model, the physical parameters, including the torsional elastic constant and rotational viscosity, were identified for pure FLC and PSFLC films. In addition, the impact of polymer density on these physical parameters was explored.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 8-9","pages":"47"},"PeriodicalIF":2.2,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144793121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Simulated interference colors chart from birefringence measurements in lyotropic calamitic nematic-biaxial nematic-discotic nematic phases.","authors":"D D Lüders, E Akpinar","doi":"10.1140/epje/s10189-025-00510-6","DOIUrl":"https://doi.org/10.1140/epje/s10189-025-00510-6","url":null,"abstract":"<p><p>In this study, Nematic Discotic (N_D)-Nematic Biaxial (N_B)-Nematic Calamitic (N_C) phase sequences are investigated for some surfactant-based lyotropic mixtures. From the microscopic analysis point of view, the nematic phases, especially N_B one, are characterized by a methodology we developed to create a resultant image via composition of many microscopic textures (images). The resultant image permits recognizing the N_B phase bordered by two verticals imaginary lines contrasting two distinct colors. To consolidate our methodology, we simulated the interference colors chart of the samples for the first time via birefringence measurements performed by laser conoscopy technique. The simulated and experimental results are in good accordance.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 8-9","pages":"46"},"PeriodicalIF":2.2,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144787963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Mixed convection in thermo-gravitational column: a continuous species separation.","authors":"Khairi Sioud, Abdelkader Mojtabi, Marie-Catherine Charrier-Mojtabi, Ali Abdennadher, Alain Bergeon","doi":"10.1140/epje/s10189-025-00512-4","DOIUrl":"10.1140/epje/s10189-025-00512-4","url":null,"abstract":"<p><p>So far, species separation has been achieved in closed vertical thermogravitational columns (TGC). To obtain continuous separation, the initially homogeneous binary solution with a positive thermodiffusion coefficient was introduced at a constant volumetric flow rate through one of the two vertical slots of the TGC and retrieved through the opposite slot. This process required the horizontal dimension separating the two slots to be sufficiently large for the mass regime at the exit slot to reach the steady state associated with a vertical stratification of the mass fraction. Analytical resolution and numerical simulations were developed and showed good agreement between theoretical and numerical results.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 8-9","pages":"45"},"PeriodicalIF":2.2,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12325451/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144783181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}