物理最新文献

{"title":"Dose comparison of slowing-down protons and secondary electrons by gold nanoparticle in proton therapy: simulation study","authors":"Farshid Tabbakh","doi":"10.1140/epjp/s13360-025-06197-0","DOIUrl":"10.1140/epjp/s13360-025-06197-0","url":null,"abstract":"<div><p>A large number of researches on using gold nanoparticle in proton therapy have focused only on the effect of the secondary electrons in enhancing the radio-sensitization. Although experimental studies have addressed the significant impact of gold nanoparticles, simulations have shown that the electrons ejected from nanoparticles cause only a small enhancement within nanometer range from the nanoparticle, according to several publications. The disagreement has been explained in the present study by introducing the proton slowing-down mechanism as another contributor in dose enhancement in the presence of gold nanoparticles. The protons traversing the nanoparticles are slowed-down, leading to slight increase in their LET and, consequently, the extra dose induction in medium. This mechanism acts in a longer distance from gold nanoparticle within micrometer range. The contributions of both mechanisms to radio-sensitization enhancement have been compared, and the total elevated dose has been quantified. Additionally, the LET increase with respect to different nanoparticle sizes has been investigated.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 4","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749035","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":"Investigation of the atomic structure and structural transformation in mullite glass under densification","authors":"Dung Tri Pham,&nbsp;Lan Thi Mai,&nbsp;Ha Thi Thanh Nguyen,&nbsp;Hong Van Nguyen","doi":"10.1140/epjb/s10051-025-00903-8","DOIUrl":"10.1140/epjb/s10051-025-00903-8","url":null,"abstract":"<div><p>This work reports the application of Classical Molecular Dynamics simulation to elucidate the atomic structure and process of structural transformation in mullite glass (g-3Al₂O₃·2SiO₂) at 600 K. Under densification, g-3Al₂O₃·2SiO₂ undergoes a structural transformation from a disordered state (low-density phase, with four-coordinated Si and Al at a density of 2.41 g/m³) to a more ordered state (high-density phase, with six-coordinated Si and six- and seven-coordinated Al at a density of 4.06 g/cm³). By structural visualization and analysis of various characteristics, such as the pair correlation functions, coordination number (CN), running CN of Si–O/Al–O, oxygen packing fraction (OPF), and ring statistics, we identified the structural phase transition point at 6 GPa, which corresponds to a mullite glass density of 3.80 g/cm³ and an OPF of 0.5595. The DBSCAN clustering algorithm is applied to identify the polyamorphism and density heterogeneity in g-3Al₂O₃·2SiO₂ under compression.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749194","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":"Transport phenomena and KSS bound in quantum-corrected AdS black holes","authors":"Behnam Pourhassan,&nbsp;İzzet Sakallı","doi":"10.1140/epjc/s10052-025-14103-2","DOIUrl":"10.1140/epjc/s10052-025-14103-2","url":null,"abstract":"<div><p>In this paper, we study quantum effects on transport properties of charged anti-de Sitter (AdS) black holes, focusing on non-perturbative corrections to the shear viscosity-to-entropy ratio. We consider exponential corrections to both the entropy and transport coefficients, examining their impact on the Kovtun–Son–Starinets (KSS) bound. Through detailed analysis, we demonstrate that quantum corrections significantly modify transport phenomena, particularly in the small-horizon-radius regime. We explore three scenarios: unmodified shear viscosity with quantum-corrected entropy, quantum corrections to both quantities, and preservation of the universal ratio. Our results show that electrical conductivity, bulk viscosity, and thermal conductivity receive substantial modifications from quantum effects while maintaining consistency with established transport laws. The analysis reveals that for the positive correction coefficient, the KSS bound can be violated, while for the negative correction coefficient, it remains valid. We demonstrate these effects through numerical analysis and graphical representations, providing insight into quantum transport phenomena in strongly coupled systems.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14103-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749097","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":"Bound states of a fermion-dyon system","authors":"A. Yu. Loginov","doi":"10.1140/epjc/s10052-025-14073-5","DOIUrl":"10.1140/epjc/s10052-025-14073-5","url":null,"abstract":"<div><p>The bound states of fermions in the external field of an Abelian dyon are studied here both analytically and numerically. Their existence is due to the dyon’s electric charge resulting from a polarization of the fermionic vacuum. The configuration of the dyon’s field is not invariant under <i>P</i> or <i>CP</i> transformations. The dependence of the energy levels of the fermion-dyon system on a parameter of <i>CP</i> violation is investigated. The absence of <i>P</i> invariance results in nonzero electric dipole moments of the bound fermionic states. These depend nontrivially on the parameter of <i>CP</i> violation. The bound fermionic states also possess nonzero magnetic dipole moments. Unlike the electric dipole moments, the magnetic dipole moments are practically independent of the parameter of <i>CP</i> violation. In addition, the magnitudes of the electric dipole moments significantly exceed those of the magnetic dipole moments.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14073-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749098","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":"Study on laser processing characteristics of single-crystal diamond with different pulse widths","authors":"Jiancai Zhang,&nbsp;Jiadong Lan,&nbsp;Jiabin Lu,&nbsp;Ziyuan Luo,&nbsp;Qiusheng Yan,&nbsp;Shaolin Xu","doi":"10.1007/s00339-025-08461-7","DOIUrl":"10.1007/s00339-025-08461-7","url":null,"abstract":"<div><p>Due to challenges and low efficiency in processing single-crystal diamonds, its large-scale application has been limited. However, laser processing emerges as an effective method for diamond machining, where the laser pulse width plays a crucial role in determining processing efficiency and quality. In this study, we utilized lasers with different pulse widths ranging from 300 fs to 3 ps, to perform microgrooving on the surface of a single-crystal diamond. Our research focused on evaluating various aspects, including the ablation threshold, material removal rate (MRR), microgroove dimensions, surface morphology, bottom region roughness, and material removal mechanisms of single-crystal diamonds under different laser pulse widths. The primary objective was to investigate the processing characteristics and the corresponding variations of single-crystal diamonds under these different laser pulse width conditions. The results of our study reveal that ultra-short pulse lasers with varying pulse widths significantly influence the ablation threshold, MRR, microgroove dimensions, surface morphology, and roughness of diamonds through their peak power. Remarkably, reducing the laser pulse width from 3 ps to 300 fs resulted in an impressive 75% decrease in the diamond ablation threshold. Additionally, the microgroove dimensions and <i>MRR</i> demonstrated gradual increments. Particularly, during the high average power stage, the influence of pulse width on groove depth and <i>MRR</i> became more pronounced due to incubation effects and plasma shielding. Another notable finding was the evolution of the surface morphology of diamond microgrooves, transitioning from periodic ripple structures to the appearance of damage, cracks, and even microgroove fragmentation. Moreover, the roughness (Rz) of the microgroove bottom region increased from 40 to 264 nm. While the effect of laser pulse width on the material removal mechanism of diamond was relatively weak, it was observed to induce less subsurface damage (sp³ + sp²). Additionally, in our experimental conditions, we detected the involvement of oxygen in the laser processing of diamonds. However, the main material removal mechanisms were identified to be evaporation or sublimation.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 4","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740847","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":"Studies on morphology, conduction mechanism and dielectric properties of Li2ZrO3 prepared using solid-state reaction","authors":"Imen Ibrahmi,&nbsp;Samia Aydi,&nbsp;Sondes Hajlaoui,&nbsp;Raja Naouari,&nbsp;Iskandar Chaabane,&nbsp;Abderrazek Oueslati","doi":"10.1007/s00339-025-08455-5","DOIUrl":"10.1007/s00339-025-08455-5","url":null,"abstract":"<div><p>The ceramic materials have recently found a vast variety of applications due to their outstanding structurale and photoluminisenece characteristics. However, despite the promising properties of these materials, there remains a need to explore novel performance for practical applications. For this reason, we focus is on addressing this scientific challenge by synthesizing and characterizing the Li₂ZrO₃. In the present work Li₂ZrO₃ is prepared via solid state process. X-ray diffraction reveals that the compound has a well-defined crystalline structure in the monoclinic phase having a C2/c space group. Scanning electronic microscope indicated a compact microstructure and well grown grains separated by grain boundaries. Furthermore, we also use the complex impedance spectroscopy method to report the electrical and dielectric characteristics of Li₂ZrO₃ in the 100–10⁶ Hz frequency range. Over a temperature range of 353–573 K, the conductivity measurements of the produced ceramic are examined. In addition, the Nyquist plots revealed contributions from both the grains and the grain boundaries suggesting that the material demonstrates a relaxation behaviour characteristic of the non Debye type and provide reasons supporting the semi conducting nature of this sample. In addition, dielectric analysis demonstrated significant frequency-dependent behavior, characterized by various polarization effects and relaxation phenomena. Jonscher’s power law is used to analyze alternating current and conductivity, and it is found that the fluctuation of the exponent “s” adequately describes the conduction mechanism and agrees with CBH models. The findings demonstrate that LZO holds significant potential for various technological applications, including energy storage, micoelectronic devices, highlighting the potential they hold as multifunctional materials.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 4","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740846","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":"Buried interface engineering with amphoteric ion for inverted perovskite solar cells","authors":"Liquan Zhang,&nbsp;Zhuo Chen,&nbsp;Jiayu Han,&nbsp;Tingfeng Wang,&nbsp;Chongyang Xu,&nbsp;Sheng Wu,&nbsp;Zhihai Liu","doi":"10.1007/s00339-025-08372-7","DOIUrl":"10.1007/s00339-025-08372-7","url":null,"abstract":"<div><p>The efficiency of perovskite solar cells (PSCs) primarily depends on the quality of the perovskite films. The buried interface, located at the bottom surface of the perovskite layer, significantly influences the performance of perovskite photovoltaics. This study utilizes cetyltrimethylammonium bromide (CTAB), an amphoteric organic salt, on the surface of poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) to modify the bottom interface between the perovskite film and the hole transport layer. The ammonium group and bromine ion in CTAB can passivate vacancy defects at the PEDOT: PSS/perovskite interface, while the long carbon chain enhances the humidity stability of PEDOT: PSS. The application of CTAB significantly improved the photoelectric performance of PSCs, increasing the power conversion efficiency (PCE) from 15.16 to 17.30%, with excellent reproducibility. The unencapsulated device retained over 60% of its initial PCE after 400 h. As an emerging technology, modifying the buried interface of the perovskite film presents new strategies for achieving high-performance and long-lasting PSCs.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 4","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740868","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 the Breit interaction on spin polarization of Auger electrons following electron-impact excitation of Be-like ions","authors":"Y. Li,&nbsp;Z. Q. Tian,&nbsp;J. Q. Wang,&nbsp;C. Z. Dong,&nbsp;S. Fritzsche,&nbsp;Z. W. Wu","doi":"10.1140/epjd/s10053-025-00980-5","DOIUrl":"10.1140/epjd/s10053-025-00980-5","url":null,"abstract":"<p>Spin polarization of Auger electrons emitted from nonradiative Auger decay <span>(1s2s^{2}2p_{1/2},J!=!1 !rightarrow ! 1s^{2}2s,J_{f}!=!1/2)</span> following inner-shell electron-impact excitation from the ground state of highly charged Be-like ions is studied by using the density-matrix theory and the relativistic distorted-wave theory. The question is raised: How does the Breit interaction affect spin polarization of the emitted Auger electrons? Generally, both alignment and intrinsic anisotropy parameters determine the anisotropy of the emitted electrons in this excitation–autoionization process. Here, we calculate and analyze intrinsic spin-polarization parameter for Be-like <span>(hbox {Mg}^{8+})</span>, <span>(hbox {Fe}^{22+})</span>, <span>(hbox {Mo}^{38+})</span>, <span>(hbox {Nd}^{56+})</span>, <span>(hbox {Au}^{75+})</span>, and <span>(hbox {U}^{88+})</span> ions to obtain spin polarization of the Auger electrons. It is found that the Breit interaction hardly contributes to the spin polarization for low-<i>Z</i> Be-like ions such as <span>(hbox {Mg}^{8+})</span>, even at high impact electron energies, whereas for medium- and high-<i>Z</i> ions the situation becomes fairly different. To be specific, the spin polarization becomes nearly zero and almost independent of the emission angle of the Auger electrons owing to the Breit interaction, which becomes more and more prominent with increasing nuclear charge. Moreover, the Breit interaction even changes the direction of the spin polarization vector for high-<i>Z</i> ions especially at low impact energies, for example, for <span>(hbox {U}^{88+})</span> ions at impact energies below the threefold excitation threshold.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749145","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":"Scalar dark matter production through the bubble expansion mechanism: the role of the Lorentz factor and non-renormalizable interactions","authors":"Jose A. R. Cembranos,&nbsp;Jesús Luque,&nbsp;Javier Rubio","doi":"10.1140/epjc/s10052-025-14064-6","DOIUrl":"10.1140/epjc/s10052-025-14064-6","url":null,"abstract":"<div><p>We consider a <i>Bubble Expansion</i> mechanism for the production of scalar dark matter during a first-order phase transition in the very early Universe. Seeking for a dark matter energy density in agreement with observations, we study different renormalizable and non-renormalizable interactions between the dark matter species and the field undergoing the transition, considering all possible regimes for the Lorentz boost factor associated with the motion of the bubble wall. By employing a combination of analytical and numerical techniques, we demonstrate that sufficient dark matter production is achievable even in the previously unexplored low-velocity bubble expansion regime, enlarging the parameter space and possibilities of the scenario. Notably, for the non-renormalizable interactions it is found that the produced dark matter abundances exhibit a similar qualitative behavior to the renormalizable case, even for low Lorentz boost factors. Furthermore, for a transition around the electroweak scale, the associated gravitational wave spectrum is within the reach of future detectors. \u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14064-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749099","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":"The enhancement of the optical, magnetic, and ferroelectric properties of BaTiO3-δ by doping with SrFeO3-δ","authors":"E. K. Abdel-Khalek,&nbsp;A. Abd El-Naser,&nbsp;E. Nabhan,&nbsp;M. S. Gaafar,&nbsp;N. S. Abd El-Aal","doi":"10.1007/s00339-025-08398-x","DOIUrl":"10.1007/s00339-025-08398-x","url":null,"abstract":"<div><p>In the present work, (1-x) BaTiO_3-δ − xSrFeO_3-δ (where x = 0 and 0.05) perovskite samples were prepared. The structure of these samples was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), high-resolution TEM (HR-TEM), EDS elemental mapping, X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC). The optical properties of BaTiO_3-δ were enhanced with introducing SrFeO_3-δ (x = 0.05) by the reduction of the direct and indirect band gap energies. The magnetic measurements of these samples confirmed the ferromagnetic ordering and it was enhanced with introducing SrFeO_3-δ (x = 0.05). The dielectric constant (ε_r) of BaTiO_3-δ enhanced with introducing SrFeO_3-δ (x = 0.05). The polarization-electric field (P-E) hysteresis loops and the bipolar strain-electric field (S-E) loops measurements showed that these samples have ferroelectric and piezoelectric nature, respectively. The sample at x = 0.05 showed good ability to generate ultrasonic waves with nominal frequency of proximately 5 MHz.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 4","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00339-025-08398-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749033","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}