检索结果-南通市图书馆

Influence of curing conditions on the shrinkage behavior of three-dimensional printed concrete formwork

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第8期18卷 1225-1236页

作者： m.BEKAERT K.van TITTELBOOm g.de SCHUTTER magnel-Vandepitte Laboratory for structural Engineering and Building materials Department of Structural Engineering and Building MaterialsFaculty of Engineering and ArchitectureGhent UniversityGhent 60 B-9052Belgium

The use of three-dimensional(3d)printed concrete as formwork is becoming more widely applied within the ***,the technology is still not optimized and there are many reports of preliminary cracking during the curing of cast *** is believed to result from differential shrinkage between the printed and cast *** cracks(in the printed concrete or at the interface between the infill and printed concrete)form a preferential path for aggressive substances and can reduce the durability of the combined concrete *** ensure the desired service life of the structure,it is important that the differential shrinkage between cast and printed concrete is *** study investigated the effect of curing conditions on the differential shrinkage behavior of 3d and cast *** influence of prewetting of the dry-cured 3d printed formwork was also *** the experimental program,a vibrated and self-compacting concrete were used as cast *** 3d printed formwork was produced and combined with cast concrete to simulate a concrete *** formwork was cured for 1,7,or 28 d exposed to the air(relative humidity:60%or 95%)or submerged in *** length change of the combined elements was observed over 56 d after concrete casting and throughout the thickness of the *** show that increasing the curing period in dry conditions of the printed concrete leads to an expansion of the formwork on the first day after *** expansion leads to a non-uniform strain evolution throughout the curing period of the combined *** concrete formwork stored in wet conditions does not expand after the casting process but tends to show a decreasing linear deformation within the whole elements.

关键词： 3d concrete printing formwork shrinkage curing

The magnetosheath at high spectral resolution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Tensile deformation of fine-grained mg at 4K,78K and 298K

在线全文

学校读者我要写书评

暂无评论

Journal of magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： m.Walag A.Kula P.Noga T.Tokarski g.Cios m.Niewczas AgH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AgH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland materials Science and Engineering McMaster UniversityHamiltonCanada

The impact of grain size, ranging from 0.9 μm to 9 μm, on the mechanical properties of commercially pure mg is investigated at temperatures of 4K, 78K, and 298K. The mechanisms governing plastic flow are influenced by both grain size and temperature. At 4K and 78K, dominant deformation modes in mg involve dislocation glide and extension twinning, regardless of grain size. The interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime, leading to premature failure. The yield stress follows the Hall-Petch relationship σy~ k/√d, with the slope k increasing with decreasing temperature. At 298K, in addition to dislocation glide and twinning, grain boundary sliding(gBS) becomes significant in samples with grain sizes below 3 μm, considerably enhancing the material's deformability. gBS activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries, facilitating their absorption during sliding and rotation. Analysis of σ Θ relationship suggests that the basal slip is the dominant dislocation mode in mg at 298K. decreasing grain size suppresses dislocation activity and twinning and increases gBS, resulting in lower Θ and σ Θ values. Suppressing conventional deformation modes coupled with enhanced.gBS yields stress softening, breaking down the Hall-Petch relationship in mg below 3 μm grain size, leading to an inverse Hall-Petch behaviour. The work reports new data on the strength, ductility, work hardening and fracture behaviour, and their variations with mg grain size across different temperature regimes.

关键词： Polycrystalline mg mechanical properties deformation mechanisms Work-hardening Texture evolution Cryogenic temperatures Hall-Petch relationship

Assessing the biennial conference on science and technology (BICOST IX) 2023 technical output on renewable energy, energy storage, and.green hydrogen in line with UN Sdg commitments

在线全文

学校读者我要写书评

暂无评论

CLEAN ENERgY 2024年第2期8卷 85-88页

作者： Silva, S. K. B. d. Piyumali, K. g. d. Perera, Rasitha Thilini Suranjana Kaluarachchi, K. d. K. g. munagamage, Thilini Ahammed, R. m. R. Piyankarage, C. S. P. Shahmy, Seyed Karunaratne, Veranja Natl Sci & Technol Commiss Sri Lanka Colombo Sri Lanka Sri Lanka Technol Campus Padukka 10500 Sri Lanka Univ Peradeniya Peradeniya Sri Lanka

The development, production and utilization of renewable energy, energy storage and.green hydrogen and the associated technologies in Sri Lanka have great potential to contribute to the United Nations' Sustainable development goals (Sdgs). The island aims to achieve 70% electricity generation from renewable energy sources by 2030 (within the target of 40% utilization of renewable energy sources for the entire energy generation of the country by 2030). The power sector has to invest US$11 billion from 2023 to 2030 to contribute to reaching this target. This commentary aims to provide a critical perspective on the recommendations of the report from the National Science and Technology Commission's 9th biennial conference in 2023 on science and technology, the sub-thematic technical report on clean energy, energy storage and.green hydrogen in line with the Sdgs in the Sri Lankan context. The technical report provides insightful recommendations for Sri Lanka's energy sector under three main sections: renewable energy, energy storage and.green hydrogen. Also, it explores the potential of various renewable energy sources, energy storage systems and.green hydrogen as sustainable solutions to address the country's energy challenges while emphasizing the spillover effects of them, which could contribute to the enterprise's job creation and uplift the economy. This commentary provides a critical perspective on clean energy, energy storage and.green hydrogen in line with the United Nations Sdgs in the Sri Lankan context based on a recent report from the National Science and Technology Commission of Sri Lanka. graphical Abstract

关键词： renewable energy energy storage green hydrogen sustainable development goals Sri Lanka social economic environmental sustainable affordable

Plasma electrolytic formation and characterization of mnWO_(4)/WO_(3) film heterostructures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ChemPhysMater

ChemPhysmater 2024年第3期3卷 293-302页

作者： m.S.Vasilyeva I.V.Lukiyanchuk Yu.B.Budnikova V.g.Kuryavyi d.H.Shlyk g.A.Zverev department of Chemistry and materials of Institute of High Technology and Advanced materials Far Eastern Federal UniversityFEFU CampusVladivostok 690922Russia Institute of Chemistry Far Eastern BranchRussian Academy of SciencesVladivostok 690022Russia

mnWO_(4)/WO_(3) p-n heterojunction films were fabricated using a one-step method consisting of the plasma electrolytic oxidation(PEO)of titanium in homogeneous electrolytes containing paratungstate ions and stable watersoluble EdTA-chelated *** influences of the formation current density and W:mn molar ratio of the electrolyte,which was varied from 1:2 to 2:1,on the composition,morphology,and optical and photocatalytic properties of the resulting coatings were studied.X-ray diffraction analysis,scanning electron microscopy,energy dispersive X-ray analysis,Raman spectroscopy,and ultraviolet diffuse reflectance spectroscopy were used to characterize the formed *** of the W:mn ratio of the electrolyte,the coatings contained crystalline t-WO_(3) and m-mnWO_(4).depending on the formation conditions,the optical band.gap energies of the composites varied from 2.63 to 3.01 *** largest absorption red shift and lowest band.gap energy were observed in the film composite formed in an electrolyte with W:mn=2:1,at a current density of 0.2 A cm^(−2).Composites obtained in electrolytes with W:mn ratios of 2:1 and 1:1 exhibited photocatalytic activity in the d.gradation of rhodamine C and methyl orange dyes in the presence of 10 mmol L^(–1) H2O_(2) under ultraviolet and visible light *** role of hydrogen peroxide in this dye d.gradation on PEO-coated composites under light irradiation is discussed.

关键词： Plasma electrolytic oxidation manganese tungstate Tungsten oxide Titanium Optical properties p-n heterojunction

Atomistic Investigation of Shock-Induced Amorphization within micro-shear Bands in Hexagonal Close-Packed Titanium

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta metallurgica Sinica(English Letters) 2024年第9期37卷 1590-1600页

作者： Z.C.meng K.g.Wang T.Ali d.Li C.g.Bai d.S.Xu S.J.Li A.H.Feng g.J.Cao J.H.Yao Q.B.Fan H.Wang R.Yang Institute of metal Research Chinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Interdisciplinary Centre for Additive manufacturing(ICAm) School of Materials and ChemistryUniversity of Shanghai for Science and TechnologyShanghai 200093China School of materials Science and Engineering Tongji UniversityShanghai 201804China Key Laboratory for Light-Weight materials Nanjing Tech UniversityNanjing 210009China National Key Laboratory of Science and Technology on materials Under Shock and Impact School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401135China

The mechanical response of a single crystal titanium sample against(0001)α surface impact was investigated using molecular dynamics ***,non-uniform plastic deformation was observed in the *** high strain rates,amorphization occurred near the edge of the contact region where severe shear strain induced a large number of stacking faults(SFs)and *** contrast,the central part of the contact region underwent less deformation with significantly fewer ***,instead of amorphization by consuming SFs and dislocations,there was a gradual increase in the density of dislocations and SFs during the process of *** local amorphous regions eventually grew into shear bands.

关键词： Shock compression Amorphization Shear band Titanium molecular dynamics

malargüe Site Remediation: A Successful Solution for Uranium mill Tailings

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

原子能科学技术 2024年

作者： BARARI E díAZ J g gIOmIA KEmPF R A National Atomic Energy Commission Av.Del Libertador 8250 Ciudad Autónoma de Buenos AiresC1429BNP Argentina

Comisión Nacional de Energía Atómica(CNEA) has the responsibility for restoring uranium mining facilities once the operations have finished. CNEA, within its Environmental Program and in compliance with its legal responsibilities, decides to implement a restoration project for all sites related to the mining and processing of uranium ores. The malargüe Site is located within the Province of mendoza in the city of malargüe. It is the first site to successfully complete its remediation. The activities consist of relocation of tailings to an engineering repository. The tailings management(encapsulation) and rehabilitation of the area was finished in June 2017. The remediation alternative for the ore tailings was selected after conducting comparative studies and submitted the project to the society for consideration. The objective of the encapsulation of the mineral tails is to isolate them from the environment, also proceeding with the decontamination and rehabilitation of the area(landscaping,post-closure monitoring and 20 years monitoring period). Encapsulation consisted of the construction of a containment cell for the mine tailings, to isolate them and prevent pollutants from entering the environment through the transfer routes. To clean the impacted areas, the soil was removed, it was incorporated into the encapsulation, and the filling was carried out with natural soils from the *** prevents radon transfer to the environment, as 222Ra is an alpha emitter with a half-life of four days, which produces its own radioactive progeny. Radon progeny are solids, and when a 222Ra nucleus emits an alpha particle into the air, the resulting 218Po nucleus, momentarily electrically charged, adheres to any dust particle. Remediation prevents the discharge into the air containing radon and also containing dust particles charged with intensely radioactive radon progeny. The tasks mentioned make it possible to decrease radon emanation, reduce radiological risks to the

关键词：

ground-based and additional science support for SmILE

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 275-298页

作者： J.A.Carter m.dunlop C.Forsyth K.Oksavik E.donovon A.Kavanagh S.E.milan T.Sergienko R.C.Fear d.g.Sibeck m.Connors T.Yeoman X.Tan m.g.g.T.Taylor K.mcWilliams J.gjerloev R.Barnes d.d.Billet g.Chisham A.dimmock m.P.Freeman d.-S.Han m.d.Hartinger S.-Y.W.Hsieh Z.-J.Hu m.K.James L.Juusola K.Kauristie E.A.Kronberg m.Lester J.manuel J.matzka I.mcCrea Y.miyoshi J.Rae L.Ren F.Sigernes E.Spanswick K.Sterne A.Steuwer T.Sun m.-T.Walach B.Walsh C.Wang J.Weygand J.Wild J.Yan J.Zhang Q.-H.Zhang Planetary Sciences group School of Physics and AstronomyUniversity of LeicesterUniversity RoadLeicesterLE17RHUK Rutherford Appleton Laboratory Space Science Technology Facilities CouncilOxfordshireUK School of Space and Environment Beihang UniversityBeijing 100191China Key Laboratory of Space Environment monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100017China department of Space and Climate Physics UCLMullard Space Science LaboratoryHolmbury St.MaryDorkingSurreyRH56NTUK Birkeland Centre for Space Science Department of Physics and Technology.University of BergenBergenNorway department of Physics and Astronomy University of Calgary2500 University DriveCalgaryAlbertaCanada T2N 1N4 British Antarctic Survey CambridgeUK Swedish Institute of Space Physics KirunaSweden West Highfield Campus University of SouthamptonUniversity RoadSO171BJUK goddard Space Flight Center NASAGreenbeltMarylandUSA Athabasca University AthabascaCanada ESTEC European Space AgencyNetherlands University of Saskatchewan SaskatoonCanada The Johns Hopkins University Applied Physics Laboratory LaurelMarylandUSA Swedish Institude of Space Physics UppsalaSE 75121Sweden Tongji University Shanghai 200092China Center for Space Plasma Physics Space Science Institute4765 Walnut Street Suite BBoulderColorado80301USA Polar Research Institute of China Shanghai 200136China Finnish meteorological Institute(FmI) Finland department of Earth and Environmental Sciences(geophysics) Ludwig Maximilian University of Munich(LMU)MunichTheresienstr.41MunichD-80333Germany Canadian Space Agency MontrealCanada gFZ german Research Centre for geosciences PotsdamGermany Nagoya University Institute for Space Earth Environment ResearchCenter for Integrated Data ScienceNagoyaAichiJP 464-8601 Northumbria University Newcastle upon TyneTyne and WearUK NE18ST National Space Science Center Chinese Academy SciencesBeijing 100190China Arctic geophysics University Centre in Svalbard

The joint European Space Agency and Chinese Academy of Sciences Solar wind magnetosphere Ionosphere Link Explorer(SmILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere *** these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SmILE ***,we describe current community efforts to prepare for SmILE,and the benefits and context various experiments that have explicitly expressed support for SmILE can offer.A dedicated.group of international scientists representing many different experiment types and.geographical locations,the ground-based and Additional Science Working group,is facilitating these *** include constructing an online SmILE data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft *** anticipate growing interest and community engagement with the SmILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.

关键词： magnetosphere ionosphere magnetosphere-ionosphere coupling ground-based experimentation SmILE conjunctions missions

metrology for sub-Rayleigh-length target positioning in~10^(22)W/cm^(2)laser-plasma experiments

在线全文

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2024年第3期12卷 90-105页

作者： E.A.Vishnyakov A.Sagisaka K.Ogura T.Zh.Esirkepov B.gonzalez-Izquierdo C.d.Armstrong T.A.Pikuz S.A.Pikuz W.Yan T.m.Jeong S.Singh P.Hadjisolomou O.Finke g.m.grittani m.Nevrkla C.m.Lazzarini A.Velyhan T.Hayakawa Y.Fukuda J.K.Koga m.Ishino K.Kondo Y.miyasaka A.Kon m.Nishikino Y.V.Nosach d.Khikhlukha I.P.Tsygvintsev d.Kumar J.Nejdl d.margarone P.V.Sasorov S.Weber m.Kando H.Kiriyama Y.Kato g.Korn K.Kondo S.V.Bulanov T.Kawachi A.S.Pirozhkov ELI Beamlines Facility The Extreme Light Infrastructure ERICDolníBrežanyCzech Republic Kansai Institute for Photon Science(KPSI) QSTKyotoJapan Central Laser Facility Rutherford Appleton LaboratorySTFCHarwell OxfordDidcotUK Institute for Open and Transdisciplinary Research Initiatives Osaka UniversityOsakaJapan HB11 Energy Holdings FreshwaterAustralia Key Laboratory for Laser Plasmas(ministry of Education) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghaiChina Institute of Plasma Physics ASCR PragueCzech Republic FZU-Institute of Physics ASCR PragueCzech Republic Czech Technical University in Prague FNSPEPragueCzech Republic Institute of Laser Engineering Osaka UniversityOsakaJapan Institute of Physics National Academy of Sciences of UkraineKyivUkraine ISTEQ AR YerevanArmenia

Tight focusing with very small f-numbers is necessary to achieve the highest at-focus ***,tight focusing imposes strong demands on precise target positioning in-focus to achieve the highest on-target irradiance We describe several near-infrared,visible,ultraviolet and soft and hard X-ray diagnostics employed in a~10^(22)W/cm^(2)laser±plasma *** used nearly 10 J total energy femtosecond laser pulses focused into an approximately1.3-μm focal spot on 5±20μm thick stainless-steel *** discuss the applicability of these diagnostics to determine the best in-focus target position with approximately 5μm accuracy(i.e.,around half of the short Rayleigh length)and show that several diagnostics(in particular,3ωreflection and on-axis hard X-rays)can ensure this *** demonstrated target positioning within several micrometers from the focus,ensuring over 80%of the ideal peak laser intensity *** approach is relatively fast(it requires 10±20 laser shots)and does not rely on the coincidence of low-power and high-power focal planes.

关键词： laser-plasma interaction precise target positioning spectroscopy ultra-high intensity X-rays