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laser-modified luminescence for optical data storage

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Chinese Physics B 2022年第11期31卷 89-99页

作者： Xin Wei Weiwei Zhao Ting Zheng Junpeng lü Xueyong Yuan Zhenhua Ni School of Physics and Key laboratory of MEMS of the Ministry of Education Southeast UniversityNanjing 211189China

The yearly growing quantities of dataflow create a desired requirement for advanced data storage *** materials,which possess adjustable parameters such as intensity,emission center,lifetime,polarization,etc.,can be used to enable multi-dimensional optical data storage(ODS)with higher capacity,longer lifetime and lower energy *** storage based on luminescent materials can be easily manipulated by lasers,and has been considered as a feasible option to break through the limits of ODS *** progresses in laser-modified luminescence based ODS have been made during the past *** this review,we recapitulated recent advancements in laser-modified luminescence based ODS,focusing on the defect-related regulation,nucleation,dissociation,photoreduction,ablation,*** conclude by discussing the current challenges in laser-modified luminescence based ODS and proposing the perspectives for future development.

关键词： laser luminescence data storage

Numerical Modeling and Analysis of Grooved Surface Applied to Film Cooling

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Journal of Bionic Engineering 2011年第4期8卷 464-473页

作者： l. Guo Z. C. liu Y. Y. Yan Z. W. Han Faculty of Engineering University of Nottingham Nottingham NG7 2RD UK Department of Internal Combustion Engine Jilin University Changchun 130022 P. R. China Key laboratory of Bionic Engineering （Ministry of Education China） Jilin University Changchun 130022 P. R. China

In order to improve the efficiency of film cooling, numerical investigation was carried out to study the effects of different film-cooled plates on surface heat transfer. Both grooved and non-grooved surfaces were concerned. The modeling was per- formed using Fluent software with the adoption of Shear-Stress Transport （SST） k-ωmodel as the turbulence closure. The coolant was supplied by a single film cooling hole with an inclination angle of 30°. The Mach numbers for the coolant flow and the mainstream flow were fixed at 0 and 0.6, respectively. At three blowing ratios of 0.5, 1.0 and 1.5, the aerodynamic behaviour of the mixing process as well as the heat transfer performance of the film cooling were presented. The numerical results were validated using experimental data extracted from a benchmark test. Good agreements between numerical results and the ex- perimental data were observed. For the film cooling efficiency, it shows that both local and laterally averaged cooling effectiveness can be improved by the non-smooth surface at different blowing ratios. Using the grooved surface, the turbulence intensity upon the plate can be reduced notably, and the mixing between the two flows is weakened due to the reduced turbu lence level. The results indicate that the cooling effectiveness of film cooling can be enhanced by applying the grooved surface.

关键词： film cooling non-smooth surface cooling effectiveness grooved structure blowing ratio

Nickel ferrite spinel as catalyst precursor in the dry reforming of methane:Synthesis,characterization and catalytic properties

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Journal of Natural Gas Chemistry 2012年第5期21卷 595-604页

作者： Rafik Benrabaa Hamza Boukhlouf Axel lfberg Annick Rubbens Rose-Nelle Vannier Elisabeth Bordes-Richard Akila Barama laboratoire de Matériaux Catalytiques & Catalyse en Chimie Organique Faculté de ChimieUSTHBBP32 El Alia16111 Bab EzzouarAlgerAlgérie Unité de Catalyse et de Chimie du Solide UMR CNRS 8181Ecole Nationale Supérieure de Chimie de LilleUniversitédes Sciences et Technologies de LilleCité Scientif ique59655 Villeneuve d'AscqFrance

Dry reforming of methane by CO2 using nickel ferrite as precursor of catalysts was *** ferrite crystalline particles were prepared by coprecipitation of nitrates with NaOH or ammonia followed by calcination,or by hydrothermal synthesis without calcination *** textural and structural properties were determined by a number of analysis methods,including X-ray diffraction （XRD）,Raman spectroscopy and X-ray photoelectron spectroscopy （XPS）,among which X-ray diffraction （XRD） was at room and variable *** synthesized oxides showed the presence of micro or nanoparticles of NiFe2O4 inverse spinel,but Fe2O3 （hematite） was also present when ammonia was used for *** reducibility by hydrogen was studied by temperature-programmed reduction （TPR） and in situ XRD,which showed the influence of the preparation *** surface area （BET）,particle size （Rietveld refinement）,as well as surface Ni/Fe atomic ratio （XPS） and the behavior upon reduction varied according to the synthesis *** catalytic reactivity was investigated using isopropanol decomposition to determine the acid/base *** catalytic performance of methane reforming with CO2 was measured with and without the pre-treatment of catalysts under H2 in 650-800 C *** catalytic conversions of methane and CO2 were quite low but they increased when the catalysts were pre-reduced.A significant contribution of reverse water gas shift reaction accounted for the low values of H2 /CO *** coking was observed as shown by the reoxidation step performed after the catalytic *** possible formation of nickel-iron alloy observed during the study of reducibility by hydrogen was invoked to account for the catalytic behavior.

关键词： dry reforming of methane NiFe2O4 spinel hydrothermal synthesis coprecipitation isopropanol decomposition

layered double hydroxide(lDH)-based materials:A mini-review on strategies to improve the performance for photocatalytic water splitting

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Journal of Energy Chemistry 2022年第1期31卷 406-431,I0011页

作者： Hanane Boumeriame Eliana S.Da Silva Alexey S.Cherevan Tarik Chafik Joaquim l.Faria Dominik Eder laboratory of Separation and Reaction Engineering-laboratory of Catalysis and Materials(lSRE-lCM) Faculdade de EngenhariaUniversidade do PortoRua Dr Roberto Frias s/n4200-465 PortoPortugal Institute of Materials Chemistry Technische Universicat Wien(TU Wien)Getreidemarkt 9Vienna 1060Austria laboratory of Chemical Engineering and Valorization of Resources(lGCVR-UAE/l01FST).Faculte des Sciences et Techniques Universite Abdelmalek EssaadiTangierMorocco

The high energy demand we currently face in society and the subsequent large consumption of fossil fuels cause its depletion and increase the pollution *** quest for the production of clean energy from renewable and sustainable sources remains *** conversion of solar energy into hydrogen via the water-splitting process,assisted by pho tores pons ive semiconductor catalysts,is one of the most promising *** progress has been made on water splitting in the past few years and a variety of photocatalysts active not only under ultra-violet(UV) light but especially with the visible part of the electromagnetic spectrum have been *** double hydroxides(lDH)-based materials have emerged as a promising class of nanomaterials for solar energy applications owing to their unique layered structure,compositional flexibility,tunable bandgaps,ease of synthesis and low manufacturing *** review covers the most recent research dedicated to lDH materials for photocatalytic water-splitting applications and encompasses a range of synthetic strategies and post-modifications used to enhance their ***,we provide a thorough discussion of the experimental conditions crucial to obtaining improved photoactivity and highlight the impact of some specific parameters,namely,catalysts loading,cocatalysts,sacrificial agents,and irradiation *** review provides the necessary tools to select the election technique for adequately enhancing the photoactivity of lDH and modified lDH-based materials and concludes with a critical summary that outlines further research directions.

关键词： layered double hydroxides Water splitting Photocatalysis Hydrogen generation Oxygen evolution Nanomaterials

Electron capture in collisions of li3+ ions with ground and excited states of li atoms

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Chinese Physics B 2020年第1期29卷 246-253页

作者： M X Ma B H Kou l liu Y Wu J G Wang Institute of Modern Physics Fudan UniversityShanghai 200433China Key laboratory of Nuclear Physics and Ion-beam ApplicationMOE Fudan UniversityShanghai 200433China Institute of Applied Physics and Computational Mathematics Beijing 100088China Kents Hill School 12 th GradeMaine 04349USA

The electron capture processes in collisions of li3+ion with li(1s22s)and li(1s22p0,1)are investigated by using the two-center atomic orbital close-coupling method in the energy range from 0.1 keV/u to 300 keV/*** interaction of the active electrons with the target ion is represented by a model *** present results for the li3+–li(1s22s)system are compared with the available theoretical data and general agreement is obtained for the high collision *** is also found that the total and partial electron capture cross sections are sensitive to the initial charge cloud alignment in the low energy region.

关键词： two-center atomic orbital closed coupling electron capture cross section

Microstructure Dependent Fatigue Cracking Resistance of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloy

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Journal of Materials Science & Technology 2012年第7期28卷 614-621页

作者： Z.M. Song l.M. lei B. Zhang X. Huang G.R Zhang Shenyang National laboratory for Materials Science Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China AVIC Commercial Aircraft Engine Co. Ltd. Shanghai 200241 China Titanium Alloys laboratory Beijing Institute of Aeronautical Materials Beijing 100095 China Key laboratory for Anisotropy and Texture of Materials of Ministry of Education School of Materials and MetallurgyNortheastern University Shenyang 110819 China

Fatigue cracking behavior from a notch was investigated at room temperature for ***-3.5Mo-1.5Zr- 0.3Si （TClI） alloys with four different microstructures obtained at different cooling rates from the β transus temperature. It was found that the alloy with lamellar structures consisting of α/β lamellae or acicular α＇ martensite laths had a higher fatigue crack initiation threshold from the notch, while the bimodal structure with coarse a grain had a lower fatigue cracking resistance. The alloy with α/β lamellar structure showed a higher fatigue crack growth resistance. The length scales of the microstructures were characterized to correlate with fatigue cracking behavior. Fatigue cracking mechanism related to microstructures was discussed.

关键词： Ti alloy Fatigue crack initiation Crack propagation Microstructure

Wear protection assessment of ultralow viscosity lubricants in high-power-density engines:A novel wear prediction algorithm

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Friction 2024年第8期12卷 1785-1800页

作者： Javier BlANCO-RODRÍGUEZ Jacobo PORTEIRO JoséA.lÓPEZ-CAMPOS MartíCORTADA-GARCÍA Silvia FERNÁNDEZ-CASTEJÓN CINTECX Universidade de VigoLagoas-Marcosende s/nVigo 36310Spain Repsol SA MadridSpain

Durability and reliability have been studied for decades through intensive trial-error ***,there are numerous fields of application where the costs associated with this approach are not *** lubricated machines with severe dynamic loads,such as high-power-density engines,simulation tools offer clear advantages over intensive *** and multiple scenarios can be cost-effectively simulated to assess different lubricants and engine *** work presented here details the study of wear based on a validated elastohydrodynamic(EHD)simulation model of the connecting rod journal *** model accounts for elastic deformation through a connecting rod finite element model(FEM).In addition,multiple lubricant rheological and tribological dependences,determined by specific experimental tests,are applied in the model through their interaction with the simulation ***,a novel wear algorithm is proposed to predict wear depth over time evolution along a proposed wear cycle based on the typical working ranges of high-performance engines.A final assessment is presented to compare 4 different ultralow-viscosity lubricants in their protective performance under severe *** results show the evolution of the wear load and wear depth over the wear *** evaluation is key to describing a lubricant selection procedure for high-power-density engines.

关键词： wear modelling finite element modelling mixed lubrication elastohydrodynamic(EHD) internal combustion engines bearings

PRISMS-Fatigue computational framework for fatigue analysis in polycrystalline metals and alloys

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npj Computational Materials 2021年第1期7卷 349-360页

作者： Mohammadreza Yaghoobi Krzysztof S.Stopka Aaditya lakshmanan Veera Sundararaghavan John E.Allison David l.McDowell Materials Science and Engineering University of MichiganAnn ArborMIUSA Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGAUSA Aerospace Engineering University of MichiganAnn ArborMIUSA School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGAUSA

The PRISMS-Fatigue open-source framework for simulation-based analysis of microstructural influences on fatigue resistance for polycrystalline metals and alloys is presented *** framework uses the crystal plasticity finite element method as its microstructure analysis tool and provides a highly efficient,scalable,flexible,and easy-to-use ICME community *** PRISMS-Fatigue framework is linked to different open-source software to instantiate microstructures,compute the material response,and assess fatigue indicator *** performance of PRISMS-Fatigue is benchmarked against a similar framework implemented using *** indicate that the multilevel parallelism scheme of PRISMS-Fatigue is more efficient and scalable than ABAQUS for large-scale fatigue *** performance and flexibility of this framework is demonstrated with various examples that assess the driving force for fatigue crack formation of microstructures with different crystallographic textures,grain morphologies,and grain numbers,and under different multiaxial strain states,strain magnitudes,and boundary conditions.

关键词： fatigue alloys grain

Atomic-scale roles of Zn element in age-hardened AlMgSiZn alloys

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Journal of Materials Science & Technology 2021年第11期70卷 105-112页

作者： N.N.Jiao Y.X.lai S.l.Chen P.Gao J.H.Chen Center for High-Resolution Electron Microscopy College of Materials Science&EngineeringHunan UniversityChangsha410082China Electron Microscopy laboratory and International Center for Quantum Materials School of PhysicsPeking UniversityBeijing100871China

Adding alloying elements to improve the performances or the manufacturing processes of Al-Mg-Si alloys has long been a serious issue in developing advanced automotive aluminum *** Zn element,among those promising ones,has demonstrated positive alloying effects on Al-Mg-Si ***,the atomic-scale roles of Zn in an age-hardened Al-Mg-Si-Zn alloy have not been adequately *** atomic-resolution electron microscopy,here we report the precise locations of Zn elements in all hardening precipitates involved and their alloying mechanism at the atomic scale when alloying the *** results show that Zn atoms enter all the major hardening phases to occupy specific featured atomic sites of the original elements,*** Si1 and Mg2 sites in theβ’-2 phase,and modify their crystal structures,interfacial structures and morphologies in characteristic *** is revealed that for theβ’-phase,Zn atoms occupy unique atomic sites,whereas for other phases,they demonstrate similar behaviors as other additive alloying elements such as Ag and Cu do.

关键词： Al-Mg-Si alloy Zn addition Precipitate Electron microscopy