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Plastic deformation of a Zr-based bulk metallic glass fabricated by selective laser melting

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Journal of Materials Science & Technology 2021年第1期60卷 139-146页

作者： l.Deng K.Kosiba r.limbach l.Wondraczek u.Kühn S.Pauly IFW Dresden Institute for Complex MaterialsHelmholtzstraße 20D-01069DresdenGermany Otto Schott Institute of Materials research University of JenaFraunhoferstraße 6D-07743JenaGermany university of Applied Sciences Aschaffenburg Würzburger Straße 45D-63743AschaffenburgGermany

Fully amorphous Zr_(52.5)Cu_(17.9)Ni_(14.6)Al_(10)Ti_(5) bulk metallic glass(BMg) samples with a relative density exceeding 98% were fabricated via selective laser melting(SlM).High fracture stresses of around1700 MPa and a reproducible plastic strain of about 0.5% were obtained for cylindrical SlM *** analysis of the observed serrations during compressive loading implies that the shear-band dynamics in the additively manufactured samples distinctly differ from those of the as-cast *** phenomenon appears to originate from the presence of uniformly dispersed spherical pores as well as from the more pronounced heterogeneity of the glass itself as revealed by instrumented *** these heterogeneities,the shear bands are straight and form in the plane of maximum shear *** manufacturing,hence,might not only allow for producing large BMg samples with complex geometries but also for manipulating their deformation behaviour through tailoring porosity and structural heterogeneity.

关键词： Powder bed fusion Selective laser melting Bulk metallic glass Serrated flow Heterogeneity

Anti-amyloid antibodies in Alzheimer’s disease: what did clinical trials teach us?

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Neural regeneration research 2025年第4期20卷 1092-1093页

作者： Danko Jeremic lydia Jiménez-Díaz Juan D.Navarro-lópez NeuroPhysiology&Behavior lab University of Castilla-La ManchaBiomedical Research Center(CRIB)School of Medicine of Ciudad RealCiudad RealSpain

Although many causes of Alzheimer’s disease(AD)may exist,both the original amyloid cascade and tau hypotheses posit that abnormal misfolding and accumulation of amyloid-β(Aβ)and tau protein is the central event causing the ***,that conclusion could be only partly true,and there is conflicting evidence about the role of both proteins in AD,being able to precede and influence one *** researchers argue that these proteins are mere executors rather than primary causes of ***,there have been continuing refinements of both hypotheses,with alternative explanations proposed.Aβand tau proteins may be independently involved in specific neurotoxic pathways;yet there may be other crucial processes going on in early ***,accumulating evidence suggests that Aβand tau act synergistically,rather than additively in disease onset(Jeremic et al.,2021,2023a).

关键词： amyloid Alzheimer additive

uniform and l-convergence of logarithmic Means of Walsh-Fourier Series

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Acta Mathematica Sinica,English Series 2006年第2期22卷 497-506页

作者： g.gáT u.gOgINAVA Institute of Mathematics and Computer Science College of Nyiregyhaza Department of Mechanics and Mathematics Tbilisi State University

The （NSrlund） logarithmic means of the Fourier series of the integrable function f is：1/lnn-1∑k=1Sk（f）/n-k, where ln：=n-1∑k=11/k.In this paper we discuss some convergence and divergence properties of this logarithmic means of the Walsh-Fourier series of functions in the uniform, and in the l^1 lebesgue norm. Among others, as an application of our divergence results we give a negative answer to a question of Móricz concerning the convergence of logarithmic means in norm.

关键词： Walsh system Norlund logarithmic means Convergence divergence properties

Semi-solid rheocasting of grain refined aluminum alloy 7075

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中国有色金属学会会刊：英文版 2010年第S3期20卷 832-836页

作者： u.A.CurlE g.gOVENDEr Materials Science and Manufacturing Council for Sci entific and Industrial Research(South Africa)

Near-net shape rheocasting with the Council for Scientific and Industrial research rheo casting system(CSIr-rCS) and a high pressure die casting machine was successfully performed on Al-5Ti-1B grain refined aluminum alloy *** refinement levels used were 0.03% Ti,0.13% Ti and 0.29% Ti(mass fraction).Tensile tests reveal that the ultimate tensile strengths,at all levels of grain refinement,are at least 97% of the specified *** at fracture increases with the increase of level of grain refinement although a maximum elongation is only 76% of the required minimum elongation in the case of 0.29% *** melting,during solution treatment,of the low melting point multinary eutectic causes porosity in the material and accounts for poor elongation results.0.03% Ti has a coarse eutectic structure forming larger pores while 0.29% Ti has a fine structure forming fine pores in the multinary *** 0.2% offset yield strengths of all the grain refinement levels are at least equal to or above the specified minimum and a decrease is observed with the increase of grain refinement *** is a clear reduction in grain size from 0.03% Ti to 0.29% Ti in the as-cast *** underlying grain structure develops in the T6 condition material which has an inverse size to the as-cast structure;coarse grained as-cast material results in fine grained T6 condition material after solution heat *** decrease in the offset yield strength as grain refinement increases correlates very strongly with the T6 grain sizes according to a Hall-Petch type relationship.

关键词： CSIr-rCS 7075 Al-5Ti-1B high pressure die casting F condition T6 condition incipient melting

Scalable Ir‑Doped NiFe_(2)O_(4)/TiO_(2)Heterojunction Anode for Decentralized Saline Wastewater Treatment and H_(2)Production

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Nano-Micro letters 2025年第3期17卷 1-18页

作者： Sukhwa Hong Jiseon Kim Jaebeom Park Sunmi Im Michael r.Hoffmann Kangwoo Cho Division of Environmental Science and Engineering Pohang University of Science and Technology(POSTECH)Pohang 790−784Korea linde laboratory California Institute of TechnologyPasadenaCA 91125USA Institute for Convergence research and Education in Advanced Technology(I‑CrEATE) Yonsei University International CampusIncheon 21983Republic of Korea

Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2)production can reduce the carbon footprint associated with transportation of water,waste,and energy *** study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2)overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment *** dilute(0.1 M)NaCl solutions,the NFI/TiO_(2)marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).robust operation in near-neutral pH was *** including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic *** electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive *** scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.

关键词： Wastewater electrolysis cell Ir-doped NiFe_(2)O_(4) reactive chlorine species Decentralized H_(2)production On-site wastewater treatment

Wear of semi-solid rheocast SiC_p/Al metal matrix composites

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中国有色金属学会会刊：英文版 2010年第S3期20卷 852-856页

作者： u.A.CurlE l.IVANCHEV Materials Science and Manufacturing Council for Scientific and Industrial Research(South Africa)

rheocasting of plates in Al alloy 359 reinforced with SiC at 11%,27% and 50%(volume fractions) exhibits the capability of the council for scientific and industrial research-rheocasting system(CSIr-rCS) in rheo-processing and high pressure die casting of SiC metal matrix *** metal matrix consisting of nearly spherical proeutectic α(Al) globules was *** of fibrous eutectic silicon took place upon heat treatment of the as-cast metal matrix composites(MMCs).Hardness increases as the volume fractions of SiC *** rates of the MMCs in the F and T6 heat treatment conditions were assessed with a metallographic preparation *** is found that the 11% SiC MMC wear rate is higher on SiC abrasives compared with the 50% SiC MMC wear rate due to wear of the aluminum *** trend is reversed on diamond abrasives due to pull-out of the irregular shaped composite *** 50% SiC MMC suffers from composite particle fracture porosity after high pressure die casting(HPDC).

关键词： CSIr-rCS HPDC SiC F condition T6 condition wear rate hardness porosity

On the detection of closed orbits in time-dependent systems by using double-pulse lasers

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Communications in Theoretical Physics 2020年第9期72卷 111-117页

作者： S u Khan M l Du Institute of Theoretical Physics Chinese Academy of Sciences.Beijing 100190China university of Chinese Academy of Sciences Beijing100049China

In the photodetachment of atoms or negative ions by a double-pulse laser, the first pulse of the double-pulse laser generates waves and the delayed second pulse may detect them. The phenomenon of the excitation and detection of waves by a double-pulse laser can be used to identify the closed orbits in the system. We demonstrate this phenomenon with a negative hydrogen ion(H^-) by analyzing the total population excited by a double-pulse laser in a timedependent field for different physical parameters. By analyzing the total excited population using a double-pulse laser, we can uncover all the closed orbits existing in the system. We demonstrate that this can be realized by scanning the first pulse position and the time delay between the two pulses.

关键词： double-pulse laser detection of closed orbits photodetachment spectra time-dependent systems

Effect of densification distribution on the Young's modulus of porous coatings after nano-indentation

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Acta Metallurgica Sinica(English letters) 2012年第5期25卷 383-390页

作者： Xiaojuan l u Ping XIAO Haiyan lI School of Environment Science and Engineering North China Electric Power University Yonghua North Street Baoding 071000 China School of Materials The University of Manchester Manchester M1 7HS UK School of Mechanical Aerospace and Civil Engineering The University of Manchester P.O. Box 88Sackville Street Manchester M60 1QD UK

Nano-indentation of a porous ceramic coating leads to crushing and densification of the coating under the indenter. In this work, finite element simulations of indentation on the porous coating have been carried out to study the effect of the size and dis- tribution of densification on Youngts modulus measured by nano-indentation. Two totally different distribution patterns have been simulated in this work. In the case of gradient densification, the Youngts modulus increased by 8.6% when the densifi- cation has occurred in the maximum influenced area. While the Young^s modulus increased by 2% with a uniformed densification. Examinations of the cross-section of the coatings have suggested that the densification after the indentation is close to the second model. The measured Young＇s modulus could have differed by 2%. The effect of densification on the Young＇s modulus measured by using nano-indentation is strongly dependent on the densification patterns of the porous coating.

关键词： Film Mechanical property Finite element simulation Porosity Electron Microscopy

Demonstration of Far-Infrared gaAs/AlgaAs Quantum Well Photodetectors for Broadband Wavelength Detection

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Chinese Physics letters 2000年第12期17卷 921-923页

作者： SHEN Wen-Zhong Perera A.g.u Department of Applied Physics Shanghai Jiao Tong UniversityShanghai 200030 National laboratory for Infrared Physics Shanghai Institute of Technical PhysicsShanghai 200083 Department of Physics and Astronomy Georgia State UniversityAtlantaGA 30303USA

We discuss the realization of broadband wavelength detection by demonstrating the longest cutoff wavelength(λc=28.6μm)far-infrared gaAs/AIgaAs quantum well infrared photodetectors(QWIPs).The responsivity is comparable to that of mid-infrared gaAs/AIgaAs and IngaAs/gaAs QWIPs,with a responsivity of 0.265 A/W and detectivity of 3.4x109 ***1/2/W at the peak wavelength of 26.9μm at *** on the temperature-dependent dark current and response results,it is expected that similar performance can be obtained at least up to 20 *** ways to expand the wavelength coverage are also addressed.

关键词： gaAs/AlgaAs Infrared Quantum