Physics Open最新文献

{"title":"Bridgman growth and luminescence properties of Na-doped Li2MoO4 crystals","authors":"Aoqi Xu,&nbsp;Liang Chen,&nbsp;Wei Xiong,&nbsp;Yao Zhou,&nbsp;Hui Yuan","doi":"10.1016/j.physo.2026.100412","DOIUrl":"10.1016/j.physo.2026.100412","url":null,"abstract":"<div><div>Na-doped Li₂MoO₄ crystals were grown by the Bridgman method with Na₂Mo₂O₇, Na₂CO₃, and Na₂MoO₄ as dopants. X-ray diffraction and Raman spectroscopy confirmed that Na₂Mo₂O₇ doping preserves the host structure of Li₂MoO₄, while modifying the MoO₄²⁻ group vibrational modes and crystal field environment through the introduction of Mo₂O₇²⁻ units. Fluorescence studies revealed small luminescence enhancements (1.3 and 1.6 times to pure Li₂MoO₄ respectively) for samples doped with 1 mol% Na₂CO₃ and 0.8 mol% Na₂MoO₄. In contrast, Na₂Mo₂O₇ doping yields a 9 times increase in luminescence intensity at room temperature, with an optimal concentration of 0.8 mol%. This substantial enhancement is attributed to the dominant role of Mo₂O₇²⁻ groups, rather than Na ⁺ ions. The Na₂Mo₂O₇-doped crystals display temperature-dependent luminescence behavior similar to pure Li₂MoO₄, with emission intensity increasing markedly as temperature decreases.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"27 ","pages":"Article 100412"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design optimization of a C/X-band metasurface–DGS microstrip antenna using machine learning","authors":"Md. Bipul Islam,&nbsp;A.N.M. Shihab Uddin,&nbsp;Samiul Bashir,&nbsp;Pronab Kumar Paul,&nbsp;Md. Firoz Ahmed,&nbsp;M. Hasnat Kabir","doi":"10.1016/j.physo.2026.100419","DOIUrl":"10.1016/j.physo.2026.100419","url":null,"abstract":"<div><div>Microstrip patch antennas (MPAs) typically suffer from limited bandwidth and low gain in C- and X-band applications. This study presents a machine learning (ML)-assisted antenna design that integrates an elliptical metasurface with a defected ground structure (DGS) to enhance performance. The antenna is implemented on a low-loss F4B substrate (εᵣ = 2.65, tan δ = 0.0015, thickness = 1.6 mm) and excited using a 50 Ω coaxial probe feed. A data-driven optimization framework is developed using two supervised regression models: an artificial neural network (ANN) and a random forest (RF) regressor. These models are trained on 100 full-wave electromagnetic simulations (CST Microwave Studio) to predict return loss (S₁₁), impedance bandwidth, voltage standing wave ratio (VSWR), gain, and directivity. Both models achieve a coefficient of determination (R²) greater than 0.97 and a mean absolute error below 1.5%, demonstrating high predictive accuracy. The integration of ML with electromagnetic design is a key strength of this work. The ML-optimized antenna exhibits simulated performance of −53 dB return loss, 47.6% impedance bandwidth (5.68–9.24 GHz), VSWR of 1.00, peak gain of 4.91 dBi, and radiation efficiency of 98.8%. Compared with similar metasurface-based MPAs, this represents a bandwidth improvement of 17–40%. The ML-assisted approach reduces optimization time by approximately 88% relative to conventional parametric sweeps. All results are simulation-based; experimental validation has not yet been performed. The proposed design is suitable for broadband applications including 5G communication, satellite links, and radar systems. Future work will focus on experimental validation, multilayer gain enhancement, and extension to millimeter-wave frequencies.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"27 ","pages":"Article 100419"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147849679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal and flow characteristics of ternary hybrid nanofluids in a rotating magnetohydrodynamic channel","authors":"I.O. Okunade,&nbsp;O.A. Ajala,&nbsp;A.O. Akindele,&nbsp;A.D. Ohaegbue,&nbsp;M.O. Afolabi","doi":"10.1016/j.physo.2026.100416","DOIUrl":"10.1016/j.physo.2026.100416","url":null,"abstract":"<div><div>This paper investigates the flow and heat transfer of ethylene glycol-based nanofluids, dual hybrid nanofluids, and ternary hybrid nanofluids in a rotating channel under the influence of a magnetic field. The nanofluids are composed of nanoparticles of alumina, iron oxide, and zirconium oxide. The study incorporates the effects of rotation, suction or injection, heat generation, and thermal radiation. The governing highly nonlinear partial differential equations are transformed into ordinary differential equations using similarity variables and solved numerically with the Chebyshev Collocation Method in MATHEMATICA 11.3. Results show that suction increases temperature and velocity, whereas magnetic effects reduce velocities while enhancing temperature distribution. The ternary hybrid nanofluid demonstrates superior thermal performance compared to the dual hybrid nanofluid and the single-component nanofluid, highlighting its potential for efficient thermal management in rotating magneto-hydrodynamic systems.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"27 ","pages":"Article 100416"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive performance comparison and applicability analysis of bidirectional flow passage pump device based on hub ratio under multi-operating conditions","authors":"Yi Yang ,&nbsp;Zhaohui Shen ,&nbsp;Wei Shi ,&nbsp;Xuejiao Huang ,&nbsp;Xianglin Xia ,&nbsp;Lijian Shi ,&nbsp;Wenyu Xia ,&nbsp;Muzi Xue","doi":"10.1016/j.physo.2026.100399","DOIUrl":"10.1016/j.physo.2026.100399","url":null,"abstract":"<div><div>To investigate the applicability of modified pump unit designs in actual pumping station projects, this study employs a combined approach of numerical simulation and model testing. It compares the hydraulic performance of pump units with different hub ratios, analyzes the patterns of internal flow losses under various configurations, and proposes operational conditions for different hub ratios in practical pumping station engineering. Research indicates that the hub ratio significantly influences the pump unit's high-efficiency range, hydraulic loss distribution in the discharge flow path, and cavitation performance. At a hub ratio λ = 0.4, the pump unit exhibits the widest high-efficiency range, shifted toward higher flow rates by approximately 20% <em>Q</em>_<em>d</em>. Pump units with smaller hub ratios demonstrate higher hydraulic efficiency under low-head, high-flow conditions. At a hub ratio λ = 0.467, the pump unit's high-efficiency zone shrinks and shifts toward lower flow rates by approximately 15% <em>Q</em>_<em>d</em>, while cavitation performance improves under high-head, low-flow conditions. Hydraulic losses in the pump assembly primarily occur in the discharge flow passage and guide vane assembly. Under design conditions, hydraulic losses in the discharge flow passage account for approximately 73.43% of total hydraulic losses, while those in the guide vane assembly constitute about 22.01%. Entropy production analysis based on the turbulent dissipation theory shows that the larger the hub ratio, the smaller the high entropy production regions at the outlet guide cone and the diffuser, thereby reducing the hydraulic loss in the outlet passage. Therefore, the selection of the hub ratio must be comprehensively determined based on the actual operating conditions of the pump station (head and flow requirements). The findings of this study provide a theoretical basis for the optimized design of bidirectional flow passage pump units.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"27 ","pages":"Article 100399"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational study of gamma ray attenuation parameters of polymers using Phy-X/PSD and WinXcom Programs","authors":"Eman Mosa Rashed ,&nbsp;Ali Abid Abojassim ,&nbsp;Ali Saeed Jassim","doi":"10.1016/j.physo.2026.100415","DOIUrl":"10.1016/j.physo.2026.100415","url":null,"abstract":"<div><div>This work sheds light on the attenuation of gamma rays by various polymer types, which identifies their potential suitability for further investigation as radiation-shielding materials. Gamma-ray attenuation behavior of a broad range of polymers such as (dimethyl sulfoxide, polyethyleneimine, high-density polyethylene, and polymethyl pentane) were investigated using the Phy-X/PSD code and the well-established XCOM program across several gamma-ray sources and an extended energy range (0.01 - 3 MeV). Among the polymers analyzed, for gamma-ray-in the purpose of gamma-ray shielding, the most suitable polymer used for gamma-ray shielding was found to be dimethyl sulfoxide compared to others. This method showed better performance with its high mass attenuation coefficient and effective atomic number. In addition, the results indicate that the half-value layers, tenth-value layers, and the mean free path are less in depth for dimethyl sulfoxide; this signifies its superior shielding ability and its potential use in radioprotective purposes. Additionally, this work underscores the relationship between polymer composition and photon-matter interactions and the need to utilize appropriate materials in accordance with relevant gamma-energy ranges during radiation protection-related applications.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"27 ","pages":"Article 100415"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis of slip-induced MHD radiative nanofluid flow near a rear stagnation point over a stretching sheet using Corcione's correlation","authors":"Khadija Rafique ,&nbsp;Zafar Mahmood ,&nbsp;Ioan-Lucian Popa ,&nbsp;Erkin Kholiyarov ,&nbsp;Iskandar Allazov ,&nbsp;Abhinav Kumar","doi":"10.1016/j.physo.2026.100413","DOIUrl":"10.1016/j.physo.2026.100413","url":null,"abstract":"<div><div>The study conducts a numerical investigation of unsteady magnetohydrodynamic rear stagnation-point flow and heat transfer in an <span><math><mrow><mi>A</mi><msub><mi>l</mi><mn>2</mn></msub><msub><mi>O</mi><mn>3</mn></msub><mo>–</mo><msub><mi>H</mi><mn>2</mn></msub><mi>O</mi></mrow></math></span> nanofluid. The investigation seeks to determine the impact of nanoparticle properties and surface transport conditions on flow behaviour and thermal performance. The mathematical model integrates mass suction, thermal radiation, Navier slip, and temperature jump effects, with the effective viscosity and thermal conductivity of the nanofluid assessed by Corcione's correlation. The governing partial differential equations are simplified into a system of ordinary differential equations using the appropriate similarity transformations. Then, the MATLAB bvp4c solver is used to obtain the numerical solution. The findings demonstrate that a reduced nanoparticle diameter (dp = 28 nm) and an increased nanoparticle volume percentage augment both the skin-friction coefficient and the heat-transfer rate. Increasing suction from <span><math><mrow><mi>S</mi><mo>=</mo><mn>0.5</mn></mrow></math></span> to <span><math><mrow><mn>2.0</mn></mrow></math></span> makes heat transmission 67% better, while increasing the magnetic parameter from <span><math><mrow><mi>M</mi><mo>=</mo><mn>0.5</mn></mrow></math></span> to <span><math><mrow><mn>1.5</mn></mrow></math></span> makes wall shear stress 74.5% lower. Greater surface unsteadiness and bigger temperature-jump effects reduce heat transport, whereas thermal radiation increases the fluid temperature. These findings help improve rear stagnation-point flow nanofluid-based thermal systems for cooling, thermal management, and energy applications.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"27 ","pages":"Article 100413"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Mass-Energy-Information Equivalence: A bottom-up identification of the particle spectrum via FCC lattice error correction","authors":"Raghu Kulkarni","doi":"10.1016/j.physo.2026.100414","DOIUrl":"10.1016/j.physo.2026.100414","url":null,"abstract":"<div><div>Does information possess physical mass? Modelling the physical vacuum as a substrate-free quantum error-correcting code suggests that an elementary particle’s mass is simply its fault-tolerant verification cost. We test this Mass-Energy-Information (M/E/I) equivalence on the Face-Centred Cubic (FCC) lattice, tracking defects within a <span><math><mrow><mo>[</mo><mspace></mspace><mrow><mo>[</mo><mn>192</mn><mo>,</mo><mn>130</mn><mo>,</mo><mn>3</mn><mo>]</mo></mrow><mspace></mspace><mo>]</mo></mrow></math></span> CSS code. Through a bottom-up classification of all possible defect geometries, we filter 25 candidate states through four strict thermodynamic and topological axioms — Minimum Topological Dimension, Sector Completeness, Boundary Closure, and Kinematic Shedding — each derived from established QEC theory or lattice gauge theory. Exactly 5 physically stable states survive this sieve. Their verification costs — 1, 207, 273, 1836, and 1839 — match the empirical mass ratios of the electron, muon, pion, proton, and neutron to within 0.12%. The rejected configurations violate specific physical constraints and match no known particles. No parameters are fitted. This offers highly constrained macroscopic evidence that inertial rest mass is the thermodynamic shadow of quantum error correction overhead.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"27 ","pages":"Article 100414"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Different phase matching schemes of terahertz wave generation using periodic poled lithium niobate for real-world applications","authors":"Ugrasen Singh ,&nbsp;Abhinav Kumar ,&nbsp;Prashant Povel Dwivedi ,&nbsp;Ajay Mishra ,&nbsp;Nimish Dixit","doi":"10.1016/j.physo.2025.100357","DOIUrl":"10.1016/j.physo.2025.100357","url":null,"abstract":"<div><div>Terahertz (THz) wave generation through periodic poled lithium niobate (PPLN) has gained significant attention due to its potential applications in spectroscopy, imaging, communication, and security screening. Among various nonlinear optical materials, lithium niobate (LiNbO₃) has emerged as a promising medium for efficient THz generation due to strong nonlinear optical properties and wide transparency range. However, achieving efficient energy conversion requires effective phase matching to overcome phase velocity mismatch between the pump and the generated THz waves. Several phase-matching schemes have been explored to optimize THz generation. This review comprehensively discusses these schemes, analyzing their theoretical principles, experimental implementations, and practical applications. A comparative analyze is also provided to highlight the advantages and limitations of each approach. The presented literature aims to guide researchers in selecting appropriate phase-matching configurations for THz generation.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"26 ","pages":"Article 100357"},"PeriodicalIF":1.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal speed in rain: A numerical model of a dynamically deforming human body","authors":"Cristian Angelo Crespi,&nbsp;Nicola Manini","doi":"10.1016/j.physo.2026.100381","DOIUrl":"10.1016/j.physo.2026.100381","url":null,"abstract":"<div><div>The optimal speed for a person running in the rain trying to get soaked as little as possible has long been discussed in the physics and mathematics community. In practice, so far, the human body has mostly been represented as a simple geometric shape such as a parallelepiped or a cylinder. Here we introduce a far more refined model for the complex and dynamically deforming shape of a walking/running person. We introduce a numerical technique akin to ray tracing to evaluate the total amount of intercepted rain with an accuracy never reached in this field before. The main result is that under most wind conditions, running is preferable to walking, with a notable exception occurring when the following conditions a both met: (i) the advancing speed is close to the tailwind and (ii) the crosswind component is negligible.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"26 ","pages":"Article 100381"},"PeriodicalIF":1.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147395019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, morphological, thermodynamic, and magnetic properties of Sm2Ni2O5: influence of co-precipitation vs sol-gel synthesis","authors":"Khethiwe Cele ,&nbsp;Sibusiso Nqayi ,&nbsp;Reddy Leelakrishna ,&nbsp;Buyisiwe Sondezi","doi":"10.1016/j.physo.2025.100358","DOIUrl":"10.1016/j.physo.2025.100358","url":null,"abstract":"<div><div>Crystalline Sm₂Ni₂O₅ nanoparticles (SNONPs) were synthesized via Co-precipitation and Sol-gel methods to examine how synthesis influences structural, morphological, thermodynamic, and magnetic properties. XRD confirmed both samples crystallized into an orthorhombic <em>Ima</em>2 structure after annealing at 800 °C for 6 h. SEM showed compact, smooth particles for Co-precipitated samples and brittle, fragmented ones for Sol-gel samples. EDS verified all expected elements with slight oxygen variation. Specific heat (0–300 K, 0.5 T) revealed distinct phase transitions: a 6 K anomaly indicating spin freezing in the Sm³⁺–O–Sm³⁺ framework; antiferromagnetic (AFM) ordering at T_N = 9 K from Ni²⁺–O–Ni²⁺ interactions; and a ferromagnetic (FM) transition at T_C = 43.6 K associated with Ni²⁺–O–Ni³⁺ sublattices. Above T_C, a paramagnetic (PM) phase emerged. The synthesis methods significantly affect crystallinity, governing magnetic and thermodynamic activities emphasizing SNONPs promise for spintronic and low-temperature magnetic applications.</div></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"26 ","pages":"Article 100358"},"PeriodicalIF":1.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}