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superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.jeong s.W.Lee W.j.Kim Department of Materials science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy superplasticity severe plastic deformation Grain size Grain growth

Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition

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journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： j.A.Liu s.j.Liu B.Wang W.B.sun X.j.Liu Z.W.Han College of Materials science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of Bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics.j.lin University Weihai 264205PR China

In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and LPsO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 Mj/m^(3)to 10.97 Mj/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

Characterization of bright betatron radiation generated by direct laser acceleration of electrons in plasma of near critical density

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Matter and Radiation at Extremes 2024年第2期9卷 26-35页

作者： j.Cikhardt M.Gyrdymov s.Zähter P.Tavana M.M.Günther N.Bukharskii N.Borisenko j.jacoby X.F.shen A.Pukhov N.E.Andreev O.N.Rosmej Faculty of Electrical Engineering Czech Technical University in Prague16627 Prague 6Czech Republic Goethe University FrankfurtMax-von-Laue-Straße 160438 Frankfurt am MainGermany GsI Helmholtzzentrum für schwerionenforschung GmbH Planckstraße 164291 DarmstadtGermany Focused Energy GmbH Im Tiefen See 4564293 DarmstadtGermany National Research Nuclear University MEPhI Kashirskoe shosse 31115409 MoscowRussian Federation Lebedev Physical Institute RAs Leninskiy Prospekt 53119991 MoscowRussian Federation Heinrich-Heine-University Düsseldorf Universitätsstrasse 1DüsseldorfGermany joint Institute for High Temperatures RASIzhorskaya st.13Bldg.2125412 MoscowRussian Federation Moscow Institute of Physics and Technology Institutskiy Pereulok 9141700 DolgoprudnyRussia

Directed x-rays produced in the interaction of sub-picosecond laser pulses of moderate relativistic intensity with plasma of near-critical density are investigated. synchrotron-like (betatron) radiation occurs in the process of direct laser acceleration (DLA) of electrons in a relativisticlaser channel when the electrons undergo transverse betatron oscillations in self-generated quasi-static electric and magnetic fields. In anexperiment at the PHELIX laser system, high-current directed beams of DLA electrons with a mean energy ten times higher than the ponderomotive potential and maximum energy up to 100 MeV were measured at 10^(19) W/cm^(2)laser intensity. The spectrum of directed x-raysin the range of 5–60 keV was evaluated using two sets of Ross filters placed at 0°and 10°to the laser pulse propagation axis. The differential x-ray absorption method allowed for absolute measurements of the angular-dependent photon fluence. We report 10^(13) photons/sr withenergies >5 keV measured at 0°to the laser axis and a brilliance of 10^(21) photons s^(−1) mm^(−2) mrad−2(0.1%BW)−1. The angular distributionof the emission has an FWHM of 14°–16°. Thanks to the ultra-high photon fluence, point-like radiation source, and ultra-short emissiontime, DLA-based keV backlighters are promising for various applications in high-energy-density research with kilojoule petawatt-class laserfacilities.

关键词： laser acceleration critical

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气凝胶复合材料的制备及保温隔热应用进展

材料导报 2024年第14期38卷 291-304页

作者：穆锐刘元雪欧忠文胡志德姚未来成鑫磊雷屹欣杨秀明中国人民解放军陆军勤务学院重庆401331 高原山地环境下设施破坏机制与防护重庆市重点实验室重庆401331

气凝胶复合材料由于具有密度低、比表面积大、孔隙率高和导热系数低等结构功能特性,成为最主要的新型保温隔热材料之一。本文简述了气凝胶复合材料的发展历程、制备工艺及方法,从气凝胶复合材料的微观形貌结构、热量传递组成、隔热传热... 详细信息

气凝胶复合材料由于具有密度低、比表面积大、孔隙率高和导热系数低等结构功能特性,成为最主要的新型保温隔热材料之一。本文简述了气凝胶复合材料的发展历程、制备工艺及方法,从气凝胶复合材料的微观形貌结构、热量传递组成、隔热传热表征等方面对其保温隔热性能及机理进行分析,重点介绍了近年来气凝胶复合材料的保温隔热性能应用在军事航空航天、建筑节能环保、能源存储转化、极端环境材料、电动汽车电池、冷藏(冻)运输以及供热锅炉管道等诸多领域中取得的新进展。同时,对其在各个领域应用中遇到的问题进行了详细讨论并给出建议。此外,文末对气凝胶复合材料在未来的研发、生产及应用中的研究方向进行了展望。

关键词：气凝胶复合材料制备方法基体增强传热表征隔热机理保温隔热

Associations between health-related fitness and patient-reported symptoms in newly diagnosed breast cancer patients

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journal of sport and Health science 2024年第6期13卷 851-862页

作者： Ki-Yong An Fernanda Z.Arthuso Myriam Filion spencer j.Allen stephanie M.Ntoukas Gordon j.Bell jessica McNeil Qinggang Wang Margaret L.McNeely jeff K.Vallance Lin Yang s.Nicole Culos-Reed Leanne Dickau john R.Mackey Christine M.Friedenreich Kerry s.Courneya Faculty of Kinesiology Sportand RecreationCollege of Health SciencesUniversity of AlbertaEdmonton T6G 2H9Canada Department of Kinesiology School of Health and Human SciencesUniversity of North Carolina at GreensboroGreensboroNC 27412USA Department of Cancer Epidemiology and Prevention Research Cancer Care AlbertaAlberta Health ServicesCalgary T2S 3C3Canada Faculty of Rehabilitation Medicine University of AlbertaEdmonton T6G 2H9Canada Faculty of Health Disciplines Athabasca UniversityAthabasca T9S 3A3Canada Department of Oncology Cumming School of MedicineUniversity of CalgaryCalgary T2N 4N1Canada Faculty of Kinesiology University of CalgaryCalgary T2N 1N4Canada Faculty of Medicine and Dentistry University of AlbertaEdmonton T6G 2H9Canada

Background:Newly diagnosed breast cancer patients experience symptoms that may affect their quality of life,treatment outcomes,and *** and managing breast cancer-related symptoms soon after diagnosis is *** purpose of this study was to investigate the associations between health-related fitness(HRF)and patient-reported symptoms in newly diagnosed breast cancer ***:This study utilized baseline data from the Alberta Moving Beyond Breast Cancer Cohort study that were collected within 90 days of *** measures included peak cardiopulmonary fitness(peak volume of oxygen consumption(VO_(2peak))),maximal muscular strength and endurance,flexibility,and body *** measures included depression,sleep quality,and *** multivariable logistic regression was performed for ***:Of 1458 participants,51.5%reported poor sleep quality,26.5%reported significant fatigue,and 10.4%reported moderate *** multivariable-adjusted models,lower relative VO_(2peak)was independently associated with a greater likelihood of all symptom measures,including moderate depression(psleep quality(p=0.009),significant fatigue(p=0.008),any symptom(psymptoms(pstrated threshold associations with all symptom measures such that all 3 lower quartiles exhibited similar elevated risk compared to the highest *** strength of the threshold associations varied by the symptom measure with odds ratios ranging from-1.5 for poor sleep quality to-3.0 for moderate depression and multiple ***,lower relative upper body muscular endurance was also independently associated with fatigue in a dose-response manner(p=0.001),and higher body weight was independently associated with poor sleep quality in an inverted U pattern(p=0.021).Conclusion:Relative VO_(2peak)appears to be a critical HRF component associated with multiple patient-reported symptoms in newly diag

关键词： Breast cancer Fatigue Depression sleep quality Cardiorespiratory fitness

文献快报(5):社交媒体使用消极体验而非使用时长增加青少年自杀意念

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中国学校卫生 2024年第5期45卷 614-614页

作者： HAMILTON j LDALACK M BOYD s I 李琪(编译) Department of Psychology Rutgers University Piscataway NJ USA. Department of Psychology George Washington University Washington DC USA. Department of Psychiatry University of Pittsburgh Pittsburgh PA USA.

社交媒体使用与青少年自杀风险的关联受到广泛关注。匹兹堡大学David教授领衔的团队在美国各地招募了60名青少年进行了为期8周的监测,通过每日3次生态瞬时评估询问青少年社交媒体使用相关的消极体验(如感到焦虑)、积极体验(如受到鼓励)... 详细信息

社交媒体使用与青少年自杀风险的关联受到广泛关注。匹兹堡大学David教授领衔的团队在美国各地招募了60名青少年进行了为期8周的监测,通过每日3次生态瞬时评估询问青少年社交媒体使用相关的消极体验(如感到焦虑)、积极体验(如受到鼓励)及自杀意念,首次通过密集监测设计探讨青少年社交媒体体验与自杀意念间的关联,结果显示,频繁经历消极的社交媒体体验的青少年更可能报告自杀意念,而积极的社交媒体体验与自杀意念报告率降低有关。此外,未发现社交媒体的使用时间(视屏时间)与自杀意念间的显著关联。研究提示社交媒体经历可能是青少年自杀可修饰的风险因素,未来的研究应将增强青少年社交媒体的积极体验感作为改善青少年心理健康和预防自杀的目标,而不仅仅是限制视屏时间。

关键词：社交媒体匹兹堡大学自杀意念青少年自杀积极体验青少年心理健康监测设计消极体验

single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： samuel s.Hardisty Xiaoqian Lin Anthony R.j.Kucernak David Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOR).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(sWCNTs)via a redox *** via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the *** electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the *** single-atom samples showed higher HOR activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating *** selective activity toward HOR arose as the main fingerprint of the catalyst confinement in the sWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

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Piezo2电压阻滞调节机械痛敏感性

中国疼痛医学杂志 2024年第10期30卷 735-736页

作者：张宇欣(译) 王子龙(校) 南方科技大学医学院

PIEZO2是由背根神经节(dorsal root ganglion,DRG)中大多数感觉神经元表达的一种三聚体机械门控离子通道。在遗传学层面上,机械敏感的PIEZO2通道是小鼠和人类产生正常触觉所必需的。PIEZO2通道受膜电压调节,只有在去极化的膜电压下,所... 详细信息

PIEZO2是由背根神经节(dorsal root ganglion,DRG)中大多数感觉神经元表达的一种三聚体机械门控离子通道。在遗传学层面上,机械敏感的PIEZO2通道是小鼠和人类产生正常触觉所必需的。PIEZO2通道受膜电压调节,只有在去极化的膜电压下,所有通道才能被机械力打开;而在正常负的静息膜电位下,大多数PIEZO2通道受到电压的阻滞。然而,PIEZO2通道这种不寻常的生物物理特性的生理功能尚不清楚。该研究通过基因敲入构建Piezo2基因特定突变的小鼠模型,揭示体内改变PIEZO2电压敏感性所产生的生理影响。本文作者检测了从DRG分离的感觉神经元中的内源性机械敏感电流,使用电生理技术表征了机械感受器和伤害感受器的功能,并且对小鼠进行行为和形态学评估。研究结果发现,PIEZO2通道中进化保守的精氨酸(R2756)位点的突变减轻了电压阻滞,降低了通道激活的机械阈值。R2756位点突变导致伤害感受器的机械敏感电流显著增强,而其他机械感受器仅受轻微影响。行为学上,Piezo2点突变敲入小鼠展现出对伤害性机械刺激的超敏反应。该研究指出在人类慢性疼痛综合征中出现的伤害感受器的持续激活和敏化可能与PIEZO2离子通道电压阻滞的减轻有关。

关键词：机械感受器感觉神经元静息膜电位机械刺激超敏反应电生理技术伤害性去极化

自主机器人使能技术在制造业中的应用（英文）

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Transactions of Nanjing University of Aeronautics and Astronautics 2024年第4期 403-431页

作者： ERD?s Gábor ABAI Kristóf BEREGI Richárd CsEMPEsZ jános CsERTEG Tamás GODó Gábor HAjós Mátyás HáY Borbála HORVáTH Dániel HORVáTH Gergely jUNIKI ádám KEMéNY Zsolt KOVáCs András NACsA jános PANITI Imre PEDONE Gianfranco TAKáCs Emma TIPARY Bence ZAHORáN László VáNCZA józsef 匈牙利研究网络计算机科学与控制研究所布达佩斯经济与技术大学制造科学与技术系 EPIC非盈利创新实验室厄特沃什·罗兰大学

自主制造系统的研究既受益于信息物理融合系统这一新技术的推动，也响应工业实际需求的号召。目前，先进的传感器技术、数字孪生、人工智能和新型通信技术可以支持半结构化工业环境中的自主操作，可实现对生产过程的实时监控、情况识别... 详细信息

自主制造系统的研究既受益于信息物理融合系统这一新技术的推动，也响应工业实际需求的号召。目前，先进的传感器技术、数字孪生、人工智能和新型通信技术可以支持半结构化工业环境中的自主操作，可实现对生产过程的实时监控、情况识别和预测、自动和自适应（重新）规划、团队合作，以及通过学习提高性能。本文总结了实现自主工业机器人技术的主要需求，提出了实现此类系统的通用工作流程，并介绍了HUN-REN sZTAKI最近在装配、焊接、打磨、拾取和放置以及机械加工等多个应用领域的广泛实践。这些解决方案的共同点是以通用的数字孪生概念为核心。最后，本文提出实现工业自主机器人解决方案的一般建议，并讨论了未来要研究的一些开放性问题。

关键词：工业机器人自动化数字孪生使能技术