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Progress in Natural Science:Materials International 2022年第1期32卷 79-86页

作者： CH.Suresh Vidyasagar d.b.karunakar department of Architecture and Planning Indian Institute of Technology Roorkee Mechanical and Industrial Engineering department Indian Institute of Technology Roorkee

This study reports the influence of sintering mechanism and reinforcement materials on the formation of ultra-fine and nanograins in Al-Tib-Y nanohybrid composites. The mechanical properties of the composites and their corresponding micro and nanostructures are correlated. The experimental and characterization results revealed that despite the addition of Tib, the hard and brittle AlTi phase formation in the composites was suppressed and hence, their ductility was retained. It was found that yttrium content of 0.3 wt% was the optimum amount which created advantageous spark plasma sintering conditions, and the addition of 0.3 wt% promoted the formation of bi-modal size grains（ultra-fine and nano） along with micro grains, Ω and other nano precipitates, resulting in a significant enhancement in the composite properties. The formation of ultra-fine and nanograins may be attributed to the combined effect of melting and rapid solidification at necking zones due to Joule’s heating and thermomechanical fatigue. Among all the sintered composites, the highest hardness（137 HV）, ultimate tensile strength（UTS）(496 MPa), yield strength（YS）(438 MPa) with 15.7% elongation were obtained in the sintered sample reinforced with 1.0 wt% Tiband 0.3 wt% yttrium.

关键词： Hybrid composites Ultra-fine grains Nano grains Spark plasma sintering Nano precipitates Microstructure

放电等离子烧结和冷轧AA2024-Y复合材料的力学性能和显微组织

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Transactions of Nonferrous Metals Society of China 2020年第6期30卷 1439-1451页

作者： CH.S.VIdYASAGAR d.b.karunakar Metallurgical and Materials Engineering department Indian Institute of TechnologyRoorkee-247667India Mechanical and Industrial Engineering department Indian Institute of TechnologyRoorkee-247667India

研究放电等离子烧结AA2024-Y复合材料低温轧制后的显微组织与力学性能的关系。添加钇有促进晶粒细化和析出的作用,可以提高复合材料的力学性能;但随着钇含量的增加,力学性能有明显的先增加后减小的趋势。当钇含量为0.3%(质量分数)时,复... 详细信息

研究放电等离子烧结AA2024-Y复合材料低温轧制后的显微组织与力学性能的关系。添加钇有促进晶粒细化和析出的作用,可以提高复合材料的力学性能;但随着钇含量的增加,力学性能有明显的先增加后减小的趋势。当钇含量为0.3%(质量分数)时,复合材料的力学性能最佳。为了进一步提高复合材料的抗拉强度,在标准低温条件下对复合材料进行多道次低温轧制,总压下量为25%。对低温轧制后复合材料的力学性能及相应的显微组织进行研究。扫描电镜和透射电镜显微组织表明,样品具有双尺寸晶粒,即在实际晶粒内部形成纳米级的亚晶粒。低温轧制后,由于晶粒尺寸的减小和位错密度的增加,复合材料的拉伸性能明显提升;添加0.3%钇的复合材料具有最优的力学性能,其硬度、屈服强度和极限抗拉强度分别为HV 153、539 MPa和572MPa,延展性适中。

关键词：二次加工低温轧制纳米晶钇添加双尺寸晶粒放电等离子烧结

添加钇和时效对多级搅拌铸造AA2024力学性能的影响（英文）

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Transactions of Nonferrous Metals Society of China 2020年第2期30卷 288-302页

作者： CH.S.VIdYASAGAR d.b.karunakar Metallurgical and Materials Engineering department Indian Institute of Technology Roorkee-247667India Mechanical and Industrial Engineering department Indian Institute of Technology Roorkee-247667India

研究钇和人工时效对AA2024的影响。样品在190℃人工时效1~10 h,时效时间间隔为1 h。采用扫描电子显微镜和X射线衍射对样品进行表征,利用维氏硬度试验机和万能试验机对样品进行硬度和拉伸强度等力学性能测试。显微组织显示,添加钇能够细... 详细信息

研究钇和人工时效对AA2024的影响。样品在190℃人工时效1~10 h,时效时间间隔为1 h。采用扫描电子显微镜和X射线衍射对样品进行表征,利用维氏硬度试验机和万能试验机对样品进行硬度和拉伸强度等力学性能测试。显微组织显示,添加钇能够细化α(Al)基体,并形成汉字形状的Al-Cu-Y金属间化合物强化相。与母材相比,添加钇的试样具有更好的力学性能。添加0.3%钇(质量分数)的样品表现出最高的力学性能,其硬度为66HV、极限抗拉强度(UTS)为223 MPa、屈服强度(YS)为180 MPa、伸长率为20.9%。人工时效样品表明,在190℃时效5 h内,所有样品均出现峰值硬化,且均有Al2Cu析出。随着时效的延长,汉字形状的金属间化合物逐渐演变为纤维状。AA2024中钇的最佳添加量为0.3%(质量分数)。

关键词：钇人工时效力学性能多级搅拌铸造析出显微组织表征

The magnetosheath at high spectral resolution

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Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： K.d.Küntz d.Koutroumpa W.R.dunn A.Foster F.S.Porter d.G.Sibeck b.Walsh The Henry A.Rowland department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NASA Goddard Space Flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOS-OVSQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary Science at UCL/birkbeck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for Space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

Additively manufactured Ti–Ta–Cu alloys for the next-generation load-bearing implants

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International Journal of Extreme Manufacturing 2024年第1期6卷 353-374页

作者： Amit bandyopadhyay Indranath Mitra Sushant Ciliveri Jose d Avila William dernell Stuart b Goodman Susmita bose W.M.Keck biomedical Materials Research Laboratory School of Mechanical and Materials EngineeringWashington State UniversityPullmanWA 99164United States of America Veterinary Clinical Sciences College of Veterinary MedicineWashington State UniversityPullmanWA 99164United States of America department of Orthopedic Surgery Stanford University Medical CenterRedwood CityCA 94063United States of America

bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.

关键词： Ti6Al4V load-bearing implants additive manufacturing 3d printing antibacterial performance

Chemical-assisted MMP reduction on methane-oil systems:Implications for natural gas injection to enhanced oil recovery

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Petroleum 2024年第1期10卷 101-108页

作者： Mohamed Almobarak Matthew b.Myers Colin d.Wood Yongbing Liu Ali Saeedi Quan Xie discipline of Petroleum Engineering WA School of Mines: Minerals Energy and Chemical Engineering Curtin University Commonwealth Scientific and Industrial Research Organization Curtin University Oil and Gas Innovation Centre Management State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation

Miscible natural gas injection is widely considered as a practical and efficient enhanced oil recovery technique. However, the main challenge in this process is the high minimum miscibility pressure（MMP）between natural gas and crude oil, which limits its application and recovery factor, especially in hightemperature reservoirs. Therefore, we present a novel investigation to quantify the effect of chemicalassisted MMP reduction on the oil recovery factor. Firstly, we measured the interfacial tension（IFT） of the methane-oil system in the presence of chemical or CO2to calculate the MMP reduction at a constant temperature（373K） using the vanishing interfacial tension（VIT） method. Afterwards, we performed three coreflooding experiments to quantify the effect of MMP reduction on the oil recovery factor under different injection *** interfacial tension measurements show that adding a small fraction（1.5 wt%） of the tested surfactant（SOLOTERRA ME-6） achieved 9% of MMP reduction, while adding 20 wt% of CO2to the methane yields 13% of MMP reduction. Then, the coreflooding results highlight the significance of achieving miscibility during gas injection, as the ultimate recovery factor increased from 65.5% under immiscible conditions to 77.2% using chemical-assisted methane, and to 79% using gas mixture after achieving near miscible condition. The results demonstrate the promising potential of the MMP reduction to significantly increase the oil recovery factor during gas injection. Furthermore, these results will likely expand the application envelop of the miscible gas injection, in addition to the environmental benefits of utilizing the produced gas by re-injection/recycling instead of flaring which contributes to reducing the greenhouse gas emissions.

关键词： Gas injection Enhanced oil recovery Miscibility Coreflooding

Ion heat transport in electron cyclotron resonance heated L-mode plasma on the T-10 tokamak

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Plasma Science and Technology 2024年第4期26卷 52-60页

作者： V.A.KRUPIN M.R.NURGALIEV A.R.NEMETS I.A.ZEMTSOV S.d.SUNTSOV T.b.MYALTON d.S.SERGEEV N.A.SOLOVEV d.V.SARYCHEV d.V.RYJAKOV S.N.TUGARINOV N.N.NAUMENKO National Research Centre“Kurchatov Institute” Moscow 123182Russia bauman Moscow State Technical University Moscow 105005Russia Institution“Project Center ITER” Moscow 123098Russia JSC“SOLAR” Minsk 220034Belarus

Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECRH power. The EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. The scan over the heating power is presented with on-axis and mixed ECRH regimes. discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. The high ion heat transport regimes are distinguished by three parameters: the ratio Te/Ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. The combination of high Te/Ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak L-mode electron cyclotron resonance heating ion heat transport

Temperature and structure measurements of heavy-ion-heated diamond using in situ X-ray diagnostics

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Matter and Radiation at Extremes 2024年第4期9卷 80-89页

作者： J.Lutgert P.Hesselbach M.Schorner V.bagnoud R.belikov P.drechsel b.Heuser O.SHumphries P.Katrik b.Lindqvist C.Qu R.Redmer d.Riley G.Schaumann S.Schumacher A.Tauschwitz d.Varentsov K.Weyrich X.Yu b.Zielbauer Zs.Major P.Neumayer d.Kraus Institut fur Physik Universitat RostockAlbert-Einstein-Str.2318059 RostockGermany GSI Helmholtzzentrum fur Schwerionenforschung Planckstr.164291 DarmstadtGermany Institut für Angewandte Physik Goethe-Universität Frankfurt am MainMax-von-Laue-Str.160438 Frankfurt am MainGermany Institut fur Geowissenschaften Goethe-Universitat Frankfurt am MainAltenhoferallee 160438 Frankfurt am MainGermany Helmholtz-Zentrum dresden-Rossendorf Bautzner Landstr.40001328 DresdenGermany European XFEL GmbH Holzkoppel 422869 SchenefeldGermany Centre for Plasma Physics School of Mathematics and PhysicsQueen’s University BelfastUniversity RoadBelfast BT71NNUnited Kingdom Institut für Kernphysik Technische Universität DarmstadtSchlossgartenstr.964289 DarmstadtGermany State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion PhysicsPeking UniversityBeijing 100871China Helmholtz Institut Jena Frobelstieg 307743 JenaGermany

We present in situ measurements of spectrally resolved X-ray scattering and X-ray diffraction from monocrystalline diamond samples heatedwith an intense pulse of heavy *** this way,we determine the samples’heating dynamics and their microscopic and macroscopic structuralintegrity over a timespan of several *** the ratio of elastic to inelastic scattering with state-of-the-art density functionaltheory molecular dynamics simulations allows the inference of average temperatures around 1300 K,in agreement with predictions fromstopping power *** simultaneous diffraction measurements show no hints of any volumetric graphitization of the material,butdo indicate the onset of fracture in the diamond *** experiments pave the way for future studies at the Facility for Antiproton andIon Research,where a substantially increased intensity of the heavy ion beam will be available.

关键词： heated intense structure

Spatiotemporal dynamics in butterfly hybrid zones

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Insect Science 2024年第2期31卷 328-353页

作者： Ananda R.Pereira Martins Natalie b.Warren W.Owen McMillan Rowan d.H.barrett Redpath Museum McGill University859 Sherbrooke Street WestMontrealQuebecCanada Smithsonian Tropical ResearchInstitute GamboaPanama CityPanama

Evaluating whether hybrid zones are stable or mobile can provide novelinsights for evolution and conservation biology. butterflies exhibit high sensitivity to envi-ronmental changes and represent an important model system for the study of hybrid zoneorigins and maintenance. Here, we review the literature exploring butterfly hybrid zones,with a special focus on their spatiotemporal dynamics and the potential mechanisms thatcould lead to their movement or stability. We then compare different lines of evidenceused to investigate hybrid zone dynamics and discuss the strengths and weaknesses ofeach approach. Our goal with this review is to reveal general conditions associated withthe stability or mobility of butterfly hybrid zones by synthesizing evidence obtained us-ing different types of data sampled across multiple regions and spatial scales. Finally, wediscuss spatiotemporal dynamics in the context of a speciation/divergence continuum, therelevance of hybrid zones for conservation biology, and recommend key topics for futureinvestigation.

关键词： butterflies human impacts hybrid zones movement spatiotemporaldynamics stability

Generalized time-dependent generator coordinate method for induced fission dynamics

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Frontiers of physics 2024年第4期19卷 1-12页

作者： b.Li d.Vretenar T.Nikšić J.Zhao P.W.Zhao J.Meng State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China Physics department Faculty of ScienceUniversity of Zagreb10000 ZagrebCroatia Center for Circuits and Systems Peng Cheng LaboratoryShenzhen 518055China

The generalized time-dependent generator coordinate method(Td-GCM)is extended to include pairing *** correlated GCM nuclear wave function is expressed in terms of time-dependent generator states and weight *** particle–hole channel of the effective interaction is determined by a Hamiltonian derived from an energy density functional,while pairing is treated dynamically in the standard bCS approximation with time-dependent pairing tensor and single-particle occupation *** the inclusion of pairing correlations,various time-dependent phenomena in open-shell nuclei can be described more *** model is applied to the description of saddle-to-scission dynamics of induced *** generalized Td-GCM charge yields and total kinetic energy distribution for the fission of 240Pu,are compared to those obtained using the standard time-dependent density functional theory(Td-dFT)approach,and with available data.

关键词： nuclear density functional theory generator coordinate method fission dynamics