Vacuum最新文献

{"title":"WITHDRAWN: The Correlation between 25-Hydroxyvitamin D Levels and Testosterone Levels in Type 2 Diabetic Male Patients","authors":"Mohamed M Aboelnaga, Nahed Abdullah","doi":"10.2174/1871530322666220524104929","DOIUrl":"10.2174/1871530322666220524104929","url":null,"abstract":"<p><p>Since the authors are not responding to the editor’s requests to fulfill the editorial requirement, therefore, the article has been withdrawn.</p><p><p>Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused.</p><p><p>The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php.</p><p><p>It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.</p>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"19 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77859805","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":"Development of a high-intensity compact D-D neutron generator based on RF ion sources","authors":"Zhenqing Zhu ,&nbsp;Yuzhong Qian ,&nbsp;Mengmeng Li ,&nbsp;Xin Tao ,&nbsp;Bing Hong ,&nbsp;Jichao Wang ,&nbsp;Jiasheng Chen ,&nbsp;Wei Xu ,&nbsp;Xiancai Meng ,&nbsp;Lizhen Liang ,&nbsp;Chundong Hu","doi":"10.1016/j.vacuum.2024.113909","DOIUrl":"10.1016/j.vacuum.2024.113909","url":null,"abstract":"<div><div>The present paper presents a compact D-D neutron generator designed for imaging applications, capable of producing a neutron yield exceeding 10⁹n/s. Here, a RF ion source ignited by an external antenna is envisaged, and the discharge chamber's design involves a double-layer glass cylinder for active cooling of the discharge chamber. At the same time, by improving the chamber's size and strategically positioning the magnetic field outside -multi-cusp and top magnetic field, the efficiency of the ion source is enhanced, including increased the extract beam current and extended ion source life, thus fostering increased neutron production and prolonged service duration. The experimental results show that under the condition of RF power 400 W and high voltage negative 95 kV, the beam current is extracted by 9.5 mA, and the stable operation of 24 h is realized, which the neutron yield reaches 1.1 × 10⁹ n/s with effective operation time surpassing 95 %.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113909"},"PeriodicalIF":3.8,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759437","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":"Compositional design of slag for homogenized rare earth treatment by slag-steel interaction under vacuum","authors":"Yu Liu ,&nbsp;Liqin Zhu ,&nbsp;Pengzhao Zhang ,&nbsp;Ke Hu ,&nbsp;Guangqiang Li ,&nbsp;Xijie Wang","doi":"10.1016/j.vacuum.2024.113905","DOIUrl":"10.1016/j.vacuum.2024.113905","url":null,"abstract":"<div><div>Reduction of La₂O₃ in molten slag by the C in liquid steel during slag-steel interaction under vacuum is expected to achieve homogenized La treatment for steel. To develop the appropriate slag for La treatment, the liquidus temperature, viscosity and fluoride vaporization of 50 wt%CaF₂-30 wt%CaO-(20-<em>x</em>)wt%Al₂O₃-<em>x</em>wt%La₂O₃ slag were studied, as well as the La distribution between the La₂O₃ containing slag and GCr15 steel under vacuum. The results show that the liquidus temperature of slag firstly decreases with the increase of La₂O₃ content from 0 to 5 wt%, and then increases as the La₂O₃ content continuously increases. The LaAlO₃ phase starts to precipitates in slag when La₂O₃ content of slag exceeds 10 wt%, which accounts for the increases on liquidus temperature. Thus, the La₂O₃ content in slag should not exceed 15 wt%. La₂O₃ can play the depolymerization role on slag melts, which contributes to the decrease in slag viscosity. Furthermore, the increase of La₂O₃ content in slag decreases vapor pressure of CaF₂ and AlF₃, and fluoride vaporization is inhibited. Rare earth treatment with considerable La content through slag-steel interaction that dissolved C in liquid GCr15 steel reacts with La₂O₃ in molten slag is realized under vacuum. The La content in GGr15 equilibrated with slag bearing 15 wt% La₂O₃ under 0.5–1 kPa is 0.0135 wt%.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113905"},"PeriodicalIF":3.8,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759436","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":"Degradation effects of the rafts and dislocation network on creep property of single crystal superalloy at medium temperature","authors":"Yuan Cheng ,&nbsp;Fugen Xu ,&nbsp;Xinbao Zhao ,&nbsp;Quanzhao Yue ,&nbsp;Bin Yu ,&nbsp;Wanshun Xia ,&nbsp;Yuefeng Gu ,&nbsp;Ze Zhang","doi":"10.1016/j.vacuum.2024.113904","DOIUrl":"10.1016/j.vacuum.2024.113904","url":null,"abstract":"<div><div>Generally, raft structure and interfacial dislocation networks enhance the creep resistance at elevated temperatures above 1000 °C and low stresses in Ni-based single crystal superalloys. However, the formation of raft structure and dislocation networks by raising the Mo content increased the creep rate at 900 °C and 392 MPa, accelerating the final failure. The formation of rafts was closely related to the creep rate acceleration, promoting dislocations piling up at the γ′/γ interface and the shearing events in the γ′ phase. Moreover, the dislocation networks formed at 900 °C and 392 MPa did not differentiate significantly with different Mo content, which could not enhance the creep resistance as expected. This work revealed the microstructural evolution at medium temperature and provided a new perspective for understanding the creep mechanisms and alloy design.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113904"},"PeriodicalIF":3.8,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757581","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 study on the edge effect of single crystal Ni with two indenters nanoindentation","authors":"Ruihan Li ,&nbsp;Ziteng Li ,&nbsp;Shuhao Kang ,&nbsp;Chao Long ,&nbsp;Huan Liu ,&nbsp;Pengyue Zhao ,&nbsp;Duo Li","doi":"10.1016/j.vacuum.2024.113900","DOIUrl":"10.1016/j.vacuum.2024.113900","url":null,"abstract":"<div><div>The edge effect and the formation and evolution of dislocations in nanoindentation were studied using molecular dynamics methods. A series of molecular dynamics models of two indenter nanoindentation was constructed, and diamond indenters were used for indentation simulation. This paper analyzes the effects of two indenters distance and indentation depth on the edge side extrusion, surface collapse, indentation force, internal defects, and stress of single crystal Ni workpieces. The results show that the number of particles extruded from the side does not increase linearly with the indentation distance increasing, the magnitude of indentation force changes with the increase of indentation depth and is influenced by the distance between the indenters, and the internal defects of single crystal nickel workpieces change with the change of indentation distance and increase with the increase of indentation depth. This work has a positive impact on understanding the nanoindentation processing of single crystal Ni and can help to understand the mechanism of internal dislocation formation in workpieces under multiple indenters indentation.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113900"},"PeriodicalIF":3.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759357","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":"Editorial Board and Vacuum units","authors":"","doi":"10.1016/S0042-207X(24)00916-3","DOIUrl":"10.1016/S0042-207X(24)00916-3","url":null,"abstract":"","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113870"},"PeriodicalIF":3.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746449","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":"Synthesis and irradiation behavior of (Gd0.2Sm0.2Dy0.2Er0.2Yb0.2)2Ti2O7 high-entropy pyrochlore waste forms consolidated by spark plasma sintering","authors":"Xiaoyu Ji ,&nbsp;Penghui Lei ,&nbsp;Jiahao Chen ,&nbsp;Jie Qiu ,&nbsp;Qing Peng ,&nbsp;Di Yun","doi":"10.1016/j.vacuum.2024.113893","DOIUrl":"10.1016/j.vacuum.2024.113893","url":null,"abstract":"<div><div>The development of spent fuel reprocessing, which generates large amounts of high-level waste, necessitates effective management of waste containing radioactive elements. Pyrochlore (A₂B₂O₇) is considered one of the most promising immobilized matrixes for high-level waste due to its excellent physicochemical stability and irradiation resistance. A novel kind of high-entropy pyrochlore ceramic (Gd_0.2Sm_0.2Dy_0.2Er_0.2Yb_0.2)₂Ti₂O₇, as an improved waste form matrix, was successfully synthesized using spark plasma sintering in this work. The mechanical properties, physical density, and microstructure of the densified pellets have been investigated in relation to different sintering temperatures (ranging from 1000 °C to 1400 °C). A single-component pyrochlore phase high-entropy ceramic was densified at 1300 °C, achieving a maximum hardness of 12.68 GPa and a density of 97.64 %. The irradiation tolerance of high-entropy pyrochlore was assessed by ion irradiation of 400 keV He⁺ with 10 × 10¹⁷ ions/cm² at room temperature (RT). Ion irradiation can induce the transformation of the pyrochlore superlattice of (Gd_0.2Sm_0.2Dy_0.2Er_0.2Yb_0.2)₂Ti₂O₇ into a fluorite sublattice. Compared to Gd₂Ti₂O₇, (Gd_0.2Sm_0.2Dy_0.2Er_0.2Yb_0.2)₂Ti₂O₇ exhibits significantly reduced irradiation damage with suppressed generation and coalescence of helium bubbles due to chemical disorder and lattice distortion. High-entropy pyrochlore (Gd_0.2Sm_0.2Dy_0.2Er_0.2Yb_0.2)₂Ti₂O₇ exhibits superior mechanical properties and irradiation resistance, suggesting its application as a promising immobilization matrix for nuclear waste.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113893"},"PeriodicalIF":3.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748317","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":"Forming characteristic analysis in twin tungsten electrode – Wire electrode indirect arc based additive manufacturing","authors":"Yanli Zhu ,&nbsp;Sheng Gao ,&nbsp;Shibao Yu ,&nbsp;Dianguo Ma","doi":"10.1016/j.vacuum.2024.113902","DOIUrl":"10.1016/j.vacuum.2024.113902","url":null,"abstract":"<div><div>In this study, the forming characteristics of twin tungsten electrode – wire electrode indirect arc (TTWIA) based additive manufacturing were preliminarily investigated. Arc shape, droplet transfer behavior, molten pool temperature field, and molten pool flow state were obtained respectively. Results showed that the increase of arc current enhanced the coupling degree of TTWIA arc, and promoted the detachment of the droplet from the wire, which contributed to streaming spray transfer of the droplet. Besides, the temperature and fluidity of the molten pool both increased with the increase of the arc current due to the increasing temperature of the arc, enthalpy carried by the droplets, and driving forces acting on the molten pool. Moreover, the driving forces acting on the liquid metal in the deposited layer achieved equilibrium and a stable molten pool was acquired only when the arc current was selected appropriately, which resulted in a well forming quality of the deposited part with a lower surface roughness and a higher material utilization rate.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113902"},"PeriodicalIF":3.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757584","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":"Exploring the edge effect of single crystal silicon in nanoindentation with two indenters: A molecular dynamics investigation","authors":"Rongqi Shen ,&nbsp;Duo Li ,&nbsp;Yuhai Li","doi":"10.1016/j.vacuum.2024.113891","DOIUrl":"10.1016/j.vacuum.2024.113891","url":null,"abstract":"<div><div>Silicon is an important semiconductor material, and its mechanical properties at the workpiece edges are crucial for its applications at the nanoscale. This article uses a molecular dynamics model with two indenters to study the effect of indenter distance on the edge effect of single-crystal silicon. The simulation results show that as the distance between the two indenters gradually increases from 5 Å, the surface edge of the single crystal silicon workpiece collapses, the side accumulates, and the internal phase transition region and stress region gradually change from a whole to two separate entities. The average value of force <em>Fx</em> first decreases and then increases with the increasing indenter distance. This study elucidates the influence of the distance between the dual indenters on the edge effect of single-crystal silicon nanoindentation, enriching our understanding of the edge effects that occur in the single-crystal Si application process.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113891"},"PeriodicalIF":3.8,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748323","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":"Photocurrent and electrical properties of SiGe nanocrystals grown on insulator via solid-state dewetting of Ge/SOI for Photodetection and solar cells applications","authors":"A.K. Aladim ,&nbsp;Mansour Aouassa ,&nbsp;S. Amdouni ,&nbsp;Mohammed Bouabdellaoui ,&nbsp;Walter B. Pessoa ,&nbsp;Mohammed Ibrahim ,&nbsp;K.M.A. Saron ,&nbsp;Isabelle Berbezier","doi":"10.1016/j.vacuum.2024.113892","DOIUrl":"10.1016/j.vacuum.2024.113892","url":null,"abstract":"<div><div>In this study, we present the photocurrent and electrical characterization of silicon-germanium nanocrystals (SiGe NCs) on an insulator (SiO₂). The SiGe NCs were grown through a hybrid process combining solid-phase dewetting of an ultra-thin silicon-on-insulator (UT-SOI) film with the epitaxial deposition of a thin germanium layer using ultra-high vacuum molecular beam epitaxy (UHV-MBE). These SiGe NCs were successfully integrated into the insulator layer of a metal-insulator-semiconductor (MIS) structure for optoelectronic applications. The enhanced MIS structure, featuring integrated SiGe NCs, exhibited notable transport and optoelectric properties as determined by current-voltage and impedance spectroscopy. The results indicated that the MIS structure functions as a Schottky diode, demonstrating a high rectification ratio (RR) of approximately 1000 and a Schottky barrier height (ϕ_B) of 0.73 eV. Additionally, this structure displayed a broad spectral response in the visible range, with a significant photovoltaic effect. The equivalent circuit of the MIS structure was also derived for an AC signal using impedance spectroscopy. These findings offer a promising scalable method for the monolithic integration and efficient growth of SiGe nanocrystals, paving the way for advancements in self-powered photodetectors and ultrathin solar cells.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113892"},"PeriodicalIF":3.8,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748325","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}