Japanese Journal of Applied Physics最新文献

{"title":"Optimized cooling design of solid targets for 2.5 MeV H⁺ accelerator-based neutron sources to enhance fast neutron yield","authors":"Hongfu Liu, Naoto Hagura, Tomohiro Kobayashi","doi":"10.35848/1347-4065/ade484","DOIUrl":"https://doi.org/10.35848/1347-4065/ade484","url":null,"abstract":"Abstract Developing neutron-generating targets will facilitate the widespread use of compact accelerator-driven neutron sources. The RIKEN compact accelerator neutron systems (RANS) was used for neutron imaging research. RANS uses solid Be targets to produce neutrons based on <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant=\"normal\">Be</mml:mi> </mml:mrow> <mml:none/> <mml:none/> <mml:mprescripts/> <mml:none/> <mml:mrow> <mml:mn>9</mml:mn> </mml:mrow> </mml:mmultiscripts> <mml:mspace width=\"1em\"/> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi mathvariant=\"normal\">p</mml:mi> <mml:mo>,</mml:mo> <mml:mi mathvariant=\"normal\"> n</mml:mi> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mspace width=\"1em\"/> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant=\"normal\">B</mml:mi> </mml:mrow> <mml:none/> <mml:none/> <mml:mprescripts/> <mml:none/> <mml:mrow> <mml:mn>9</mml:mn> </mml:mrow> </mml:mmultiscripts> <mml:mspace width=\"1em\"/> </mml:math> nuclear reactions, whereas RANS-II uses solid Li targets to produce neutrons based on <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant=\"normal\">Li</mml:mi> </mml:mrow> <mml:none/> <mml:none/> <mml:mprescripts/> <mml:none/> <mml:mrow> <mml:mn>7</mml:mn> </mml:mrow> </mml:mmultiscripts> <mml:mspace width=\"1em\"/> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi mathvariant=\"normal\">p</mml:mi> <mml:mo>,</mml:mo> <mml:mi mathvariant=\"normal\">n</mml:mi> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mspace width=\"1em\"/> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant=\"normal\">Be</mml:mi> </mml:mrow> <mml:none/> <mml:none/> <mml:mprescripts/> <mml:none/> <mml:mrow> <mml:mn>7</mml:mn> </mml:mrow> </mml:mmultiscripts> <mml:mspace width=\"1em\"/> </mml:math> nuclear reactions. For the existing solid lithium target used in RANS-II, the design of the cooling water structure in the direction of neutron extraction influences the yield of the fast-neutron beam. Based on RANS-II, in this study, a new target cooling structure was designed and fabricated, and its cooling performance was verified through beam irradiation experiments and thermal calculations. The fabricated circulation system was found to increase the fast neutron yield by 40% at the 0 m position.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"64 7","pages":"076001-076001"},"PeriodicalIF":0.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147894911","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":"Experimental investigations of self-propelled water surface mini-robots based on droplets motion on superhydrophilic cone channels","authors":"Zhi Hua Xu, Zenghua Fan, Kun Zhang, Jun Gao, Changyu He","doi":"10.1063/5.0266457","DOIUrl":"https://doi.org/10.1063/5.0266457","url":null,"abstract":"Self-propelled micro-robots with external devices and chemical reactions have broad applications in energy conservation, biomedical engineering, and targeted drug delivery. However, the utilization of the self-propelled micro-robots is challenging due to the expensive external devices, low durability, and toxic substance emission. In the present study, a green self-propelled water surface mini-robot (SWSM) was reported based on droplet-driven. The SWSM with superhydrophilic cone channels and a superhydrophobic surface was fabricated by laser etching and surface modification. The droplet jets were observed after the droplet entered the water from the superhydrophilic cone channels. An experimental platform was established to observe the SWSM motion. The effects of the droplet volume and the cone angle on the SWSM motion were investigated based on the experimental platform. The maximum swimming velocity and the swimming distance of the SWSM were 68 mm/s and 78 mm with the superhydrophilic cone angle of 7° and the droplet volume of 35 μl, respectively. Triangular and circular cargoes were transported successfully by controlling the droplets on the superhydrophilic cone channels. In addition, a centrosymmetric SWSM with two superhydrophilic cone channels was designed to achieve rotational motion. The surface energy of the droplets was converted into the mechanical energy of the SWSM without external power. The reported self-propelled mini-robots provide a solution for rainwater harvesting and energy conservation.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147901705","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":"Experiments and numerical modeling of the visco-hyperelastic behaviors of polyelectrolyte elastomers","authors":"Mohammad Reza Adibeig, Canhui Yang","doi":"10.1063/5.0267552","DOIUrl":"https://doi.org/10.1063/5.0267552","url":null,"abstract":"Solvent-free polyelectrolyte elastomers, which are resistant to leakage, hold significant promise for large-scale engineering applications of stretchable ionotronic devices. However, the viscoelastic nature of ionized polymer networks introduces complexities in mechanical performance, highlighting the need for a deeper understanding of their visco-hyperelastic properties. In this study, a poly[1-[2-acryloyloxyethyl]-3-butylimidazolium bis(trifluoromethane) sulfonimide-co-methyl acrylate] elastomer is synthesized as the model material, with controlled covalent crosslinker densities and tailored ionic-to-neutral segment ratios to systematically modify its molecular structures. Through experimental mechanical characterizations—including tensile, hysteresis, and relaxation tests—the effects of network structure and strain rates on the material's responses are investigated. The results reveal a significant rate dependence and the Mullins effect. To model these behaviors, the Yeoh hyperelastic model, incorporating the Mullins effect, is employed to describe the nonlinear elastic response, while a nonlinear power law model is introduced to capture the time-dependent viscoelastic deformation. The proposed modeling framework demonstrates excellent agreements with the experimental data, effectively capturing the complex mechanical behaviors in various tests. This study provides valuable insights into the visco-hyperelastic behaviors of polyelectrolyte elastomers by mapping microscopic molecular structures to macroscopic mechanical performance.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147331077","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":"Can magnetic fields necessarily regulate electrocatalysis in catalysts with bulk ferromagnetism/ferrimagnetism?","authors":"Yuhu Huang, Fei Zheng, Han‐Shu Xu","doi":"10.1063/5.0264799","DOIUrl":"https://doi.org/10.1063/5.0264799","url":null,"abstract":"The magnetic field represents a potent tool for modulating electrocatalytic performance, with diverse forms of physical mechanisms governing this regulation. Currently, catalysts capable of effectively enabling field regulation of oxygen evolution reaction typically exhibit bulk ferromagnetism or ferrimagnetism at room temperature. However, it is essential to note that electrocatalytic reactions are fundamentally surface chemical reaction phenomena, and discrepancies between bulk and surface magnetism may impede the achievement of magnetic field-regulated electrocatalysis, a facet seldom explored in prior research on field regulation. Importantly, our results confirm that magnetic fields do not achieve a regulatory effect in bulk ferrimagnetic Fe3O4 and CoFe2O4 catalysts at room temperature, thereby enhancing insight into the understanding of reaction mechanisms of filed-regulated electrocatalysis.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147910075","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":"Low-dimensional quantum antiferromagnetism in frustrated potassium 3<i>d</i> transition metal (II) phosphates: Insights from experimental and first-principles investigations","authors":"Xingliang Xu, Yun Wang, Liang Xu, Yuke Li, Xing’ao Li","doi":"10.1063/5.0262043","DOIUrl":"https://doi.org/10.1063/5.0262043","url":null,"abstract":"Anhydrous phosphate compounds based on 3d transition metal ions can exhibit rich physical behaviors in fundamental condensed matter physics. Herein, we report the structures and low-dimensional quantum magnetism in potassium-based phosphates, KMPO4 (M = Cu, Co), by cooperation of experimental investigations and first-principles density functional theory (DFT) calculations. Magnetic susceptibility measurement performed on KCuPO4 reveals the presence of strong quasi-one-dimensional antiferromagnetic (AFM) behavior with S=12 Cu2+ Heisenberg spin chains. The analysis of heat capacity data verifies the distinct AFM order occurs at TN = 14.1 K obtained from the -susceptibility, while cobalt phosphate KCoPO4 shows no magnetic ordering down to T = 1.9 K. Furthermore, the fairly small ratio of J*/|J| ≈ 3.85 × 10−2, where J/kB (=−141.86 K) is the nearest-neighbor spin-exchange coupling parameter estimated from susceptibility data and J*/kB (≈5.46 K) is the interchain coupling under the mean field approximation, respectively, providing additional evidence that KCuPO4 is almost an ideal one-dimensional AFM compound. Our DFT calculations confirmed that KCuPO4 has a magnetic sublattice in which one-dimensional AFM exchange interactions are weakly coupled ferromagnetic chains. In addition, significant magnetic frustrations are verified in both KCuPO4 and KCoPO4, implying the possibility of a quantum magnetic phase in this phosphate family.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332323","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":"Dielectric and energy-storage properties of NaNbO₃–NdFeO₃ ceramics","authors":"Han Zheng, Dongxu Pan, Ling Zhang, Zhengfa Li, Jinping Li, Zhirong Guo","doi":"10.35848/1347-4065/add06c","DOIUrl":"https://doi.org/10.35848/1347-4065/add06c","url":null,"abstract":"Abstract The design of high-performance dielectrics is critical for next-generation capacitors and electronic devices. Herein, (1- x )NaNbO 3 - x NdFeO 3 bulk ceramics were synthesized to investigate the effects of Nd 3+ /Fe 3+ substitution on their dielectric and energy-storage properties. It is revealed that the narrow single polarization–electric field (P–E) loop evolved from double loops to enhance energy-storage performances with increasing x . The maximal recoverable energy-storage density of 1.673 J cm −3 and the efficiency of 76.7% were obtained at x = 0.06 and 0.08, respectively. Moreover, a negative relative permittivity in specific frequency ranges was the answer for the oscillation of domain walls. These results not only suggest that the substitution of Nd 3+ /Fe 3+ optimizes the energy-storage properties of NaNbO 3 -based ceramics, but also provides a feasible strategy for functional design in electromagnetic metamaterials.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"64 5","pages":"051002-051002"},"PeriodicalIF":0.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147918472","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":"A new mechanism for laser absorption in high-reflectivity metal powder beds modified with ceramic particles","authors":"Yang Liu, Zhaoyang Hu, Lu Wang, Zirong Zhai, Wentao Yan, Zan Li","doi":"10.1063/5.0252992","DOIUrl":"https://doi.org/10.1063/5.0252992","url":null,"abstract":"The high reflectivity of certain metal powders within the infrared laser range hinders the processability and quality of additively manufactured metals via laser powder bed fusion (L-PBF). Here, we report a new mechanism responsible for the unusually high laser absorptivity (exceeding 70%) of high-reflectivity metals such as copper and aluminum modified with micron-sized ceramic particles. It was previously thought that the increment in the absorptivity of a composite powder is ascribed to the enhanced laser multiple reflections in the powder bed, thereby enhancing the interactions between laser beams and powder particles. However, we found that the exceptionally high laser absorptivity is attributed to the synergistic effect between metal and ceramic powders, as evidenced by combining experiments with laser ray-tracing simulations. Most laser beams reflected by the metal powders are eventually absorbed by the ceramic particles, which increases the overall laser absorptivity in a nonlinear manner. In situ monitoring of thermal energy density was conducted to identify this laser absorption mechanism during sample printing. The results from x-ray computed tomography microscopy show a significant improvement in the sample quality of L-PBF high-reflectively metallic materials. Our work provides a potential way to optimize microstructures in L-PBF high-reflectivity metallic materials.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147907381","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":"A testable weighting factor for accurate analysis of the organic electrochemical transistors' transient response behavior","authors":"Xiaorong Niu, Zhaoqun Wang, Miaoru Wang, Jiafeng Yao, Xiaojie Chai, Jianlong Ji, Shengbo Sang","doi":"10.1063/5.0241714","DOIUrl":"https://doi.org/10.1063/5.0241714","url":null,"abstract":"Organic electrochemical transistors (OECTs) have shown significant potential in applications ranging from bio-sensing to neuromorphic devices and cell impedance monitors. Transient response plays a pivotal role in varied applications. However, it is still challenging to accurately analyze the complex equilibrium process of transient response. The factor of f is a constant of proportionality about the amplitude ratio of the source current to the gate current. It plays an important role in the analysis of the transient response. Herein, we establish a test method for measuring the source and gate current. Our model fits almost perfectly with the drain current following a gate voltage step when the f is directly obtained from the source current amplitudes divided by gate current amplitudes at the current high-frequency spectra of an OECT. We further deduced empirical expressions for f as a function of the voltage settings, the channel's geometric parameters, and the concentration of the solution. This work is significant for understanding the potential mechanisms of OECT's transient response behavior.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/5.0241714/20442357/115501_1_5.0241714.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147891525","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":"Cryogenic magnetocaloric effect of rare-earth halide perovskites CsEuCl3 and CsEuBr3","authors":"Bingjie Wang, Fengxia Hu, Jing Wang, Jirong Sun, T. S. Zhao, Bao-gen Shen","doi":"10.1063/5.0235949","DOIUrl":"https://doi.org/10.1063/5.0235949","url":null,"abstract":"Adiabatic demagnetization refrigeration (ADR) offers a compelling alternative to traditional ultra-low temperature technologies by eliminating the reliance on scarce 3He and gravitational constraints. The key of ADR development is to find magnetic refrigerants with exceptional magnetocaloric properties. In this study, polycrystalline CsEuCl3 and CsEuBr3 halide perovskites were synthesized by a simple solid-phase reaction method. CsEuCl3 crystallizes in a tetragonal structure, while CsEuBr3 forms an orthorhombic structure, both exhibiting distorted perovskite structures. CsEuCl3 undergoes an antiferromagnetic ordering at TN ∼ 1.1 K, whereas CsEuBr3 shows no magnetic ordering above 0.4 K. Curie–Weiss fitting analysis reveals antiferromagnetic interactions in both compounds, with CsEuBr3 displaying stronger antiferromagnetic coupling. The maximum magnetic entropy change (−ΔSM) values under magnetic field changes of 0–2 T and 0–5 T are 22.4 and 38.6 J kg−1 K−1 at 1.4 K for CsEuCl3, and 15.7 and 26.4 J kg−1 K−1 at 0.4 K for CsEuBr3, respectively. These findings underscore the potential of CsEuCl3 and CsEuBr3 as promising candidates for cryogenic magnetic refrigeration applications.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/5.0235949/20435512/103902_1_5.0235949.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147900962","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":"Estimating transparency and penetration depth enhancement induced by clearing tissue using optical coherence tomography","authors":"Zilai Wang, Wenhui Fang, Xin Wang, Zhiwei Men","doi":"10.1063/5.0245613","DOIUrl":"https://doi.org/10.1063/5.0245613","url":null,"abstract":"Optical Coherence Tomography (OCT) technology offers numerous advantages, including non-contact imaging, rapid imaging capabilities, and high resolution. Although the enhancement of optical transparency through ultrasound is limited, the application of alcohol-based optical clearing agents (OCAs) combined with CaCO3 microspheres significantly improves the optical imaging of skin tissue. Using OCT, it has been demonstrated that the imaging depth of optically cleared skin tissue increases by approximately 14% due to the inclusion of CaCO3 microspheres. Molecular simulations reveal the hydrogen bonding interactions between collagen receptors, which are linked to the strong scattering characteristics of skin tissue, and four commonly used alcohol-based OCA small-molecule ligands. These simulation results correlate with the variations in imaging depth observed in experiments with different OCAs, thereby establishing the relevance and differences among various OCAs in enhancing the optical imaging effectiveness of biological tissues.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/5.0245613/20416675/084901_1_5.0245613.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147911356","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}