Vacuum最新文献

{"title":"Surface potential evolution and DC discharge measurement of the microstrip antenna dielectric under electron beam irradiation","authors":"Zhuoxi Lian ,&nbsp;Kaiwen Yao ,&nbsp;Dan Wang ,&nbsp;Keyue Zhang ,&nbsp;Rui Wang ,&nbsp;Yongning He","doi":"10.1016/j.vacuum.2025.114270","DOIUrl":"10.1016/j.vacuum.2025.114270","url":null,"abstract":"<div><div>Surface charging and electrostatic discharge are prone to occur in space environments. Here, to evaluate the effect of surface charging on the dielectric of an electronic device, we take a microstrip antenna as an example to study its charge and discharge characteristics by modulating the surface total electron emission yield (TEEY). Through theoretical calculations, it is revealed that the secondary critical energy, <em>E</em>_P2, significantly influences the surface potential. The surface negative potential may reach very high level when the difference between <em>E</em>_P2 and the incident electron energy is large. To modulate TEEY, MgO and Al₂O₃ films were deposited on the surface of the original antenna. The results show that the <em>E</em>_P2 value increased from 3 keV to 6.6 keV for the antenna coated with MgO, and 5.7 keV for the antenna coated with Al₂O₃. The discharging tests show that after 70 s irradiation with a 30 keV electron beam and 0.3 μA beam current, the antennas coated with MgO and Al₂O₃ films did not exhibit any discharge phenomenon, indicating the discharge threshold was significantly improved. Additionally, the S-parameter tests indicate that the changes in S-parameters are minimal both after coating functional films and before and after irradiation.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114270"},"PeriodicalIF":3.8,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study of self-healing of symmetric single-source magneto-fluid seals with large clearances","authors":"Xiaolong Yang,&nbsp;Yanyan Zhou,&nbsp;Xuankai Dou,&nbsp;Liping Jiang","doi":"10.1016/j.vacuum.2025.114269","DOIUrl":"10.1016/j.vacuum.2025.114269","url":null,"abstract":"<div><div>In order to reduce the leakage of vacuum sealing equipment due to vibration and effectively improve the self-healing (SH) performance of magneto-fluid seals (MFS), a symmetric single-source MFS structure is proposed. Experimental research was done to determine how the structure's SH capabilities were affected by various radial and axial sealing clearances (SC), the number of axial and radial pole teeth (PT), step height, and PT positions. According to findings, symmetric MFS' ability to SH gradually decreases as SC increases. As the symmetric MFS's axial teeth count increases, its SH capabilities progressively get better. When the step height and the number of radial PT were increased, respectively, the SH ability first trended downward before increasing. When the PT are all on the shaft, the MFS's capacity for SH is at its peak.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114269"},"PeriodicalIF":3.8,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical analysis of Solvothermally synthesized MoS2 nanostructures for high performance supercapacitor","authors":"Sunil Kumar ,&nbsp;Mamta Bulla ,&nbsp;Sarita Sindhu ,&nbsp;Raman Devi ,&nbsp;Ajay Kumar Mishra ,&nbsp;Vinay Kumar","doi":"10.1016/j.vacuum.2025.114265","DOIUrl":"10.1016/j.vacuum.2025.114265","url":null,"abstract":"<div><div>This study investigates the influence of different solvents, including ethylene glycol (EG), dimethylformamide (DMF) and water, on the structure and electrochemical properties of MoS₂ synthesized via a single-step pot synthesis technique. These solvents facilitate the formation of MoS₂ nanostructures with diverse dimensions. The synthesized material was analyzed using XRD, FTIR, Raman spectroscopy, FE-SEM and BET analysis. The hierarchical microflower structure of MoS₂, with exfoliated edge-enriched nanosheets, exhibited the highest specific capacitance of 428 F g⁻¹ at 1 mV s⁻¹ and 280 F g⁻¹ at 1 A g⁻¹ when synthesized using water as a solvent, surpassing the results achieved with other solvents. The MoS₂ nanostructure-based symmetric supercapacitor achieved an energy density of 7.5 Wh kg⁻¹, a power density of 1980 W kg⁻¹ and retained ∼95 % capacitance after 1000 cycles at 2 A g⁻¹, highlighting its potential for future applications with exceptional stability and durability.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114265"},"PeriodicalIF":3.8,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-concentration and high-efficiency detection of triethylamine (TEA) based on Sn-doped WO3 gas sensors","authors":"Junsheng Wen ,&nbsp;Boyan Fu ,&nbsp;Leyao Bi ,&nbsp;Jiahui Lin ,&nbsp;Jiaxing Fu ,&nbsp;Wenyue Tian ,&nbsp;Chunjie Wang ,&nbsp;Yue Wang","doi":"10.1016/j.vacuum.2025.114266","DOIUrl":"10.1016/j.vacuum.2025.114266","url":null,"abstract":"<div><div>Recently, the monitoring of TEA has garnered significant attention, particularly concerning food safety, which could potentially lead to health risks. However, current studies on the detection of TEA using tungsten trioxide (WO₃) materials are suboptimal and require the exploration of effective WO₃-based sensitive materials. This work employs a one-step solvothermal method to synthesize Sn-doped WO₃ materials with varying ratios and analyzes their selectivity and sensitivity to gases. The physicochemical properties of materials were characterized using multiple techniques including XRD, SEM, XPS, BET and Raman spectroscopy. The high response to TEA gas is successfully achieved by adjusting the doping amount of Sn⁴⁺ (∼12 wt%). Qualitative analyses indicate that 10 wt% Sn-WO₃ exhibits superior response to TEA in all samples, showcasing a response of 94.5 at 175 °C for 100 ppm TEA, which is 5.7 times higher than that of WO₃. Also, the related mechanisms were studied in detail. The low-intensity ratio of the (002) facet, small particle size, large specific surface area, and high concentration of oxygen vacancy defects resulting from Sn⁴⁺ doping play pivotal roles in enhancing the response to TEA. It is expected that this work will contribute to advancements in WO₃-based materials in the field of gas sensing.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114266"},"PeriodicalIF":3.8,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoscale material design of LiAl and LiZn alloy interlayers by room temperature sputtering deposition technique","authors":"L. Fallarino ,&nbsp;E. Gonzalo ,&nbsp;B. Acebedo ,&nbsp;S. Gadea ,&nbsp;U. Urruela ,&nbsp;N. Ortiz-Vitoriano ,&nbsp;L. Bertoli ,&nbsp;V. Giordani ,&nbsp;J. Rikarte","doi":"10.1016/j.vacuum.2025.114264","DOIUrl":"10.1016/j.vacuum.2025.114264","url":null,"abstract":"<div><div>Lithium metal is one of the most superior negative electrodes in electrochemical energy storage devices. However, lithium dendrite formation and infinite dimensional change are plaguing its applications. To solve these problems, effective and straightforward lithium-surface modification methods are needed. Herein, we propose a nanoscale material design to control and tune the Li surface trough lithium-aluminium (Li_1-<em>x</em>Al<em>_x</em>) and lithium-zinc (Li_1-<em>x</em>Zn<em>_x</em>) alloy layers formation, by means of room temperature sputtering deposition. Upon depositing pure Al or Zn onto self-standing Li foils, we found that the alloy layers are naturally forming, with no need of any post-deposition thermal or electrochemical process. Compared to Li–Li_1-<em>x</em>Al<em>_x</em> and Li–Li_1-<em>x</em>Zn<em>_x</em> produced via conventional chemical immersion methods, the sputtered samples exhibit superior control over alloy thickness, morphology, composition, and purity. We envision a wide application potential, since we succeed in engineering Li-electrode surfaces through a simple and scalable method, which would advance the potential applications of Li-metal-based systems.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114264"},"PeriodicalIF":3.8,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular dynamics simulations of the evolution of primary radiation damage in Ti-6Ta alloy for spent nuclear fuel reprocessing","authors":"Huan Li ,&nbsp;Bohai Yang ,&nbsp;Jianping Xu ,&nbsp;Jinping Wu ,&nbsp;Zhenzhi Chen ,&nbsp;Junjie Wang","doi":"10.1016/j.vacuum.2025.114259","DOIUrl":"10.1016/j.vacuum.2025.114259","url":null,"abstract":"<div><div>Ti-6Ta (in wt%) alloy is extensively used in critical components for nuclear spent fuel reprocessing due to its excellent mechanical and resistance to boiling nitric acid corrosion properties. However, the study of defect formation and evolution mechanisms under irradiation conditions is still limited. This study employs molecular dynamics simulations to investigate the evolution of irradiation damage in Ti-6Ta alloy and compares its irradiation resistance mechanisms with those of pure Ti. Isothermal and differential temperature simulations were performed on primary knock-on atom with energies ranging from 1 to 20 keV to understand the irradiation resistance of Ti-6Ta alloy. During the thermal peak stage, Ti-6Ta alloy exhibits a higher number of displaced atoms, but fewer surviving defects after relaxation and recombination. After irradiation stabilization, Ti-6Ta alloy is less likely to form large defect clusters, and Ta atoms tend to appear in these larger clusters. As the temperature increases, tantalum atoms gradually appear in the defect clusters of the low Primary Knock-on Atom (PKA) energy system. Elevated temperatures enhance defect recombination rates and further reduce the migration effects of irradiation-induced defects.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114259"},"PeriodicalIF":3.8,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rarefied gas flows in complex microfluidic 3D-structures fabricated via additive manufacturing","authors":"Franz Schweizer ,&nbsp;Klaus Bade ,&nbsp;Lucien Baldas ,&nbsp;Samuel Bergdolt ,&nbsp;Stéphane Colin ,&nbsp;Celine Deutschbein ,&nbsp;Stefan Hengsbach ,&nbsp;Jan G. Korvink ,&nbsp;Marcos Rojas-Cárdenas ,&nbsp;Jürgen J. Brandner","doi":"10.1016/j.vacuum.2025.114213","DOIUrl":"10.1016/j.vacuum.2025.114213","url":null,"abstract":"<div><div>In this work, two-photon-polymerization (TPP) is introduced as a method for manufacturing three-dimensional devices for rarefied gas flow applications. The novel 3D manufacturing capabilities of TPP are demonstrated by the fabrication of a microfluidic structure that consists of a circular micro-tube with a varying radius (tapered channel). The micro-tube has interesting features, such as a conical structure with one order of magnitude difference between minimum and maximum radii, that is <span><math><mrow><mn>14</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> and <span><math><mrow><mn>215</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, respectively, and a very high aspect ratio, that is defined as the length over the minimum radius, of 72.3. To our knowledge, this is the first time that such a geometrical configuration has been successfully tested for rarefied gas flow applications. It supports the suitability of the presented fabrication method for further 3D new-generation applications in the field. The geometrical characteristics of the device were measured by <span><math><mi>μ</mi></math></span>-tomography and subsequently analyzed allowing the assessment of the geometrical precision of the fabrication method. From a fluid dynamics perspective, the device was tested by imposing pressure-driven gas flows in the converging and diverging directions of the structure for a wide range of rarefaction. The flow parameters linked to the structure, such as mass flow rates and conductances, were obtained experimentally using the constant volume technique. The experimental results were compared to numerical simulations obtained via Computational Fluid Dynamics solving the Navier–Stokes equation in the slip and hydrodynamic flow regimes. The experimental vs. numerical comparison showed good agreement within geometrical uncertainty.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114213"},"PeriodicalIF":3.8,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure evolution and strengthening mechanism of Al2O3/Kovar joints brazed with TiB enhanced Ag-Cu-Ti based composite fillers","authors":"Guo-Fu Ma ,&nbsp;Xiao-Qiang Li ,&nbsp;Qi Jiang ,&nbsp;De-Zhi Zhu ,&nbsp;Chao Yang","doi":"10.1016/j.vacuum.2025.114241","DOIUrl":"10.1016/j.vacuum.2025.114241","url":null,"abstract":"<div><div>This paper achieved reliable joining of Al₂O₃ ceramics and Kovar alloys using Ag-Cu-Ti single filler and Ag-Cu-Ti + B composite filler. The synergistic effect of Ti and B on phase formation and the mechanical properties of the Al₂O₃/Kovar joints was systematically investigated. By optimizing the B content and brazing parameters, the typical interfacial structure of the joints obtained using Ag-Cu-6Ti+0.5B (wt.%) composite filler at 880 °C for 10 min was identified as Al₂O₃/Ti₃Cu₃O/Ag(s,s) + Cu(s,s) + TiCu + TiB/Fe₂Ti + Ni₃Ti/Ag(s,s) + Cu(s,s) + Fe₂Ti/Kovar. The results showed that B addition refines the joint microstructure by forming fine TiB whiskers and partially inhibits the dissolution and diffusion of alloying elements from the Kovar side. The joints brazed with the Ag-Cu-6Ti + 0.5B (wt.%) composite filler at 880 °C/10 min achieved a maximum shear strength of 131 MPa, representing a 37 % increase compared to the joints brazed with the Ag-Cu-6Ti (wt.%) single filler. The enhancement was attributed to the refinement of the joint microstructure and the alleviation of residual stresses. Additionally, the fracture analysis of the joints containing B revealed the dendritic Ag-Cu eutectic structure and extensive presence of the reactive layer Ti₃Cu₃O, offering new insights into the failure mechanism of brazed ceramic/metal joints.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114241"},"PeriodicalIF":3.8,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrathin g-C3N5 nanosheets: A sustainable metal-free photocatalyst for efficient ciprofloxacin degradation","authors":"Thangapandi Chellapandi ,&nbsp;Muthukani Elamathi","doi":"10.1016/j.vacuum.2025.114256","DOIUrl":"10.1016/j.vacuum.2025.114256","url":null,"abstract":"<div><div>Two-dimensional nanomaterials possess unique electrical, mechanical, and catalytic properties, primarily attributed to their high surface-to-volume ratio and exceptional light absorption capabilities. However, developing simple and efficient methods for synthesizing 2D nanosheets remains a significant challenge. This study presents a facile and effective strategy for the synthesis of ultrathin 2D g-C₃N₅ nanosheets through thermal polymerization and ultrasonication-assisted exfoliation technique. The almost total elimination of ciprofloxacin could be accomplished within 1.5 h, with a rate constant of 0.0286 min⁻¹. The synthesized nanosheets were meticulously characterized for their structural and morphological properties through a variety of analytical techniques. TEM confirmed its ultrathin layered structure, while XRD, FT-IR, and XPS provided comprehensive insights into their elemental composition. The improved photocatalytic activity of ultrathin 2D g-C₃N₅ nanosheets is primarily related to the increase in visible light absorption and electron–hole separation, as this was demonstrated by many distinct characterizations.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114256"},"PeriodicalIF":3.8,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of vacuum arc modes in 252 kV single-break vacuum interrupters based on deep learning image recognition","authors":"Siyuan Liu,&nbsp;Xianglai Bo,&nbsp;Jinchao Chen,&nbsp;Zhiyuan Liu,&nbsp;Yingsan Geng","doi":"10.1016/j.vacuum.2025.114258","DOIUrl":"10.1016/j.vacuum.2025.114258","url":null,"abstract":"<div><div>Replacing traditional SF₆ circuit breakers with environmentally friendly 252 kV single-break vacuum circuit breakers effectively reduce SF₆ greenhouse gas emissions in transmission systems. Understanding the evolution of vacuum arc modes under different conditions is crucial for analyzing 252 kV single-break vacuum interruption. This paper built a test platform using a detachable vacuum chamber and a motor-driven operating mechanism to investigate the vacuum arc modes of a 252 kV single-break vacuum interrupter with 2/3-turn coil-type axial magnetic field contacts under varying arc currents. The arc modes were classified, and a deep learning network was developed for arc mode image recognition. The results revealed the evolution characteristics of vacuum arc modes at a hundred-millimeter range contact gap and demonstrated the influence of arc current from 10 kA to 45 kA on the duration of arc modes.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114258"},"PeriodicalIF":3.8,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}