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Effect of Ce-base mischmetal addition on the microstructure and mechanical properties of hot-rolled ZK60 alloy

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Journal of Magnesium and Alloys 2021年第3期9卷 995-1006页

作者： E.p.Silva R.H.Buzolin F.Marques F.Soldera U.Alfaro H.C.pinto Institute of Engineering Science and Technology(IECT)Federal University of Vales do Jequitinhonha e Mucuri(UFVJM)JanaúbaMGBrazil São Carlos School of Engineering(EESC) University of São Paulo(USP)Department of Materials EngineeringCEP 13563-120 São Carlos-SPBrazil Christian Doppler Laboratory for Design of high-performance alloys by thermomechanical processing Kopernikusgasse 24/I8010 GrazAustria Technische Universität Graz(TU Graz) Institute of Materials ScienceJoining and FormingKopernikusgasse 24/I8010 GrazAustria Institute of Functional Materials Department of Materials Science and EngineeringSaarland UniversitySaarbrueckenGermany German Aerospace Center(DLR)Institute of Materials Research Linder Höhe51147 CologneGermany

Mg-Zn-Zr(ZK)alloys exhibit notably high mechanical strength amongst all magnesium alloy ***,due to the formation of low melting point Mg_3Zn_7-precipitates,these alloys are susceptible to hot cracking,thus compromising their metallurgical *** addition of rare earths to ZK alloys is an alternative to form higher melting point intermetallic compounds,speed up dynamic recrystallization,refine grain size,enhance corrosion resistance and extend the service temperature due to improved creep *** work deals with the effect of Ce-base mischmetal addition on the hot rolling behaviour of as-cast ZK60 *** microstructure investigation conducted using electron microscopy and X-Ray diffraction shows that precipitation of Mg_(7)Zn_(3) intermetallics occur during hot rolling,whereas no further precipitation is observed for the ZK60-Mm *** fragmentation of the intermetallic compounds occur during hot rolling and finer particles of Mg_(7)Zn_(3) are observed for the ZK60,whereas Mg_(7)Zn_(3) and Mg Zn_(2) Ce intermetallics are formed in the alloy modified with mischmetal addition.A higher fraction of dynamically recrystallized grains is observed for the ZK60-Mm in comparison to the *** recrystallization takes place in ZK60 with the formation of sub-grains near to the intermetallics and the addition of mischmetal promotes the occurrence of discontinuous recrystallization with the nucleation of new grains close to the *** mechanical strength and,in particular,the ductility of the hot-rolled alloys are notably improved when compared to the same alloys in the as-cast *** mechanical strength is,however,higher for the ZK60 *** solid solution strengthening,softer Mg Zn_(2) Ce intermetallics and more extensive recrystallization contribute to reduce the mechanical strength of *** in both alloys are initiated at coarse intermetallics and propagate through intermetallic-rich regions.

关键词： Magnesium alloys Hot rolling Mischmetal Recrystallization Microstructure Mechanical properties

Earth observation and geospatial big data management and engagement of stakeholders in Hungary to support the SDGs

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Big Earth Data 2021年第3期5卷 306-351页

作者： Szabolcs Mihály Gábor Remetey-Fülöpp Dániel Kristóf Anna Czinkóczky Tamás palya Lászlópásztor pál Rudan György Szabó LászlóZentai Hungarian Society of Surveying Mapping and Remote Sensing(MFTTT)BudapestHungary Earth Observation Department Lechner Nonprofit LtdBudapestHungary Department of Laboratory of Spatial Analysis and Environment Hungarian University of Agriculture and Life Sciences(MATE)GödöllőHungary GIS Department Lechner Nonprofit Ltd BudapestHungary Department of Soil Mapping and Environmental Institute for Soil SciencesCentre for Agricultural ResearchBudapestHungary Governmental Agency for IT Development BudapestHungary Faculty of Civil Engineering Department of Photogrammetry and GeoinformaticsBudapest University of Technology and EconomicsBudapestHungary ELTE Eötvös Loránd University Institute of Cartography and GeoinformaticsBudapestHungary

To support the monitoring and reporting processes during imple-mentation of the Sustainable Development Goals,well-developed,commonly recognized Earth observations and geospatial data,methods,innovations,committed professionals,and strong sus-tainability policies are *** article informs the readers on the Earth observation and geoinformation developments and innovations,and on the engagement of profession,academy and governance to support implementation of the Sustainable Development Goals in ***,analyses and critical assessments are given on the elements selected from Hungarian sustainable-oriented Earth observation and geospatial novelties:(a)Working Group for Sustainable Development mission and national sustainabilitypolicy,(b)international partnerships,domestic activities and achievements,(c)status of the professional education,(d)spatial databases and services to support implementation of the sustain-able development,(e)a case study on the internationally recog-nized soil geoinformation system,(f)national Earth Observation Information System and perspectives of its applications for mon-itoring the *** article conclusion strongly advises the Hungarian realization of(a)institutionalization of the Earth observation and geospatial tools and capacity for sustainable development,(b)their use in integration with statistical data,(c)establishment of national spatial information infrastructure and(d)development and spreading of the use of big data.

关键词： Earth observation environment GIS soil sustainable development

FORMULAS OF TENSION OF CONTINUOUS ROLLING pROCESS

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Acta Metallurgica Sinica(English Letters) 2007年第6期20卷 403-416页

作者： J.Z. Zhang X.p. Zhang Central Iron and Steel Research Institute Beijing 100081 China School of Aeronautic Science and Engineering Beijing University of Astronauticsand Astronautics Beijing 100083 China School of Material Science and Engineering Taiyuan University of Science andTechnology Taiyuan 030024 China

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of ＂constant flow＂. Tension is the link of the continuous rolling process. From the condition of clynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.

关键词： tension continuous rolling formula

Effects of a liquid lithium curtain as the first wall in a fusion reactor plasma

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Chinese physics B 2007年第11期16卷 3312-3318页

作者：李承跃邓柏权 J.p.Allain School of physical Electronics University of Electronic Science and Technology of ChinaChengdu610054China Argonne National Laboratory 9700 South Cass AvenueArgonneIL 60439USA Southwestern Institute of physics Chengdu 610041China

This paper explores the effect of a liquid lithium curtain on fusion reactor plasma, such curtain is utilized as the first wall for the engineering outline design of the Fusion Experimental Breeder （FEB-E）. The relationships between the surface temperature of a liquid lithium curtain and the effective plasma charge, fuel dilution and fusion power production have been derived. Results indicate that under normal operation, the evaporation of liquid lithium does not seriously affect the effective plasma charge, but effects on fuel dilution and fusion power are more sensitive. As an example, it has investigated the relationships between the liquid lithium curtain flow velocity and the rise of surface temperature based on operation scenario II of the FEB-E design with reversed shear configuration and high power density. Results show that even if the liquid lithium curtain flow velocity is as low as 0.5 m/s, the effects of evaporation from the liquid lithium curtain on plasma are negligible. In the present design, the sputtering of liquid lithium curtain and the particle removal effects of the divertor are not yet considered in detail. Further studies are in progress, and in this work implication of lithium erosion and divertor physics on fusion reactor operation are discussed.

关键词： liquid lithium curtain first wall fuel dilution effective plasma charge,plasma-wall interaction

Influence of Deposition Conditions on the Crystal Structure of MoS_2 Coating

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Journal of Materials Science & Technology 2006年第3期22卷 324-328页

作者： Jihui WANG Yang XIA E. Wieers L.M.Stals X.Zhang J.p.Celis School of Materials Science and Engineering Tianjin University Tianjin 300072 China Institute-for Materials Research Limburg University Centrum B-3590 Diepenbeek Belgium Department of Metallurgy and Materials Engineering Katholieke Universiteit Leuven B-3001 Leuven Belgium

MoS2 coatings were prepared using an unbalanced bipolar pulsed DC （direct current） magnetron sputtering apparatus under different targets, cathode current densities, power modes and bias voltages. The morphology, structure and growth characteristics of MoS2 coatings were observed and identified respectively by scanning electron microscopy, X-ray diffractometry and mass spectrometry. The results show that MoS2 coatings evolve with the （002） basal plane parallel to the surface by using cold pressed target with lower density, lower cathodic current density, bipolar pulse DC power and minus bias voltage, whereas the coatings deposited under hot pressed target, higher cathodic current density, simple DC power and positive bias voltage have the （002） basal plane perpendicular to the surface. The influence of deposition conditions on the crystal structure of MoS2 coating is implemented by altering its growth rate and the energy of sputtering-deposition particles.

关键词： Deposition condition Molybdenum disulfide Coating Crystal structure

Estimation of Soil Carbon Input in France: An Inverse Modelling Approach

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pedosphere 2013年第4期23卷 422-436页

作者： J.MEERSMANS M.p.MARTIN E.LACARCE T.G.ORTON S.DE BAETS M.GOURRAT N.p.A.SABY J.WETTERLIND A.BISpO T.A.QUINE D.ARROUAYS French National Institute for Agriculture Research (INRA) Earth and Life Institute (ELI) Universit Catholique de Louvain College of Life and Environmental Sciences (CLES) Department of Geography University of Exeter Agriculture and Forestry Department French Environment and Energy Management Agency (ADEME)

Development of a quantitative understanding of soil organic carbon （SOC） dynamics is vital for management of soil to sequester carbon （C） and maintain fertility, thereby contributing to food security and climate change mitigation. There are well-established process-based models that can be used to simulate SOC stock evolution; however, there are few plant residue C input values and those that exist represent a limited range of environments. This limitation in a fundamental model component （i.e., C input） constrains the reliability of current SOC stock simulations. This study aimed to estimate crop-specific and environment-specific plant-derived soil C input values for agricultural sites in France based on data from 700 sites selected from a recently established French soil monitoring network （the RMQS database）. Measured SOC stock values from this large scale soil database were used to constrain an inverse RothC modelling approach to derive estimated C input values consistent with the stocks. This approach allowed us to estimate significant crop-specific C input values （p 〈 0.05） for 14 out of 17 crop types in the range from 1.84 =h 0.69 t C ha-1 year-1 （silage corn） to 5.15 =k 0.12 t C ha-1 year-1 （grassland/pasture）. Furthermore, the incorporation of climate variables improved the predictions. C input of 4 crop types could be predicted as a function of temperature and 8 as a function of precipitation. This study offered an approach to meet the urgent need for crop-specific and environment-specific C input values in order to improve the reliability of SOC stock prediction.

关键词： climate crop types RothC soil organic carbon yield

A New Buck-Based Configuration AC Chopper Voltage Conditioner

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Journal of Systems Engineering and Electronics 2001年第2期12卷 36-43页

作者： Tang Fuliang, Xiong Youlun & Ma Jianfeng Huazhong University of Science and Technology, Wuhan 430074, p. R. China Huazhong University of Science and Technology Wuhan 430074 P. R. China

This paper presents a new AC chopper voltage conditioner, which can generate high quality sinusoidal waveforms with adjustable amplitudes. The circuit structure, operation principle, and control mode are analyzed in detail, the system essentially consisting of an equal duty cycle modulation AC voltage buck chopper and a voltage polarity change H-bridge, a full-wave rectifier, to perform tightly closed-loop control of the AC chopper voltage condtioner, a digital controller on a new converter model has been developed. The controller has very well dynamic response. To evaluate the new circuit and proposed control scheme, a 5kW conditioner is developed and the experimental results demonstrate that the system has good performances.

关键词： Voltage conditioner Equal duty cycle modulation power supply.

Isometric Immersions into Warped product Spaces

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Acta Mathematica Sinica,English Series 2010年第12期26卷 2269-2282页

作者： Qun CHEN Cai Rong XIANG~1) School of Mathematics and Statistics, Wuhan University, Wuhan 430072, p.R. China School of Mathematics and Statistics Wuhan University Wuhan 430072 China

This paper concerns the submanifold geometry in the ambient space of warped productmanifolds F^n×σ R, this is a large family of manifolds including the usual space forms R^m, S^m and H^m. We give the fundamental theorem for isometric immersions of hypersurfaces into warped product space R^n×σ R, which extends this kind of results from the space forms and several spaces recently considered by Daniel to the cases of infinitely many ambient spaces.

关键词： Isometric immersion hypersurface warped product the fundamental theorem

Stability Investigation of Colloidal Fept Nanoparticle Systems by Spectrophotometer Analysis

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Chinese physics Letters 2009年第2期26卷 248-250页

作者： M. Farahmandjou S. A. Sebt S. S. parhizgar p. Aberomand M. Akhavan physics Research Center Science and Research Branch Islamic Azad University Tehran Iran Magnet Research Laboratories (MRL) Department of Physics Sharif University of Technology Tehran Iran

Fept magnetic nanoparticle systems are an excellent candidate for ultrahigh-density magnetic recording. Monodisperse Fept nanoparticles are synthesized by superhydride reduction of FECl2·4H2O and pt （acac）2 at 263℃ under N2 atmosphere. Transmission electron microscopy （TEM） images show monosize Eept nanoparticles with diameter of 4 nm and a standard deviation of about 10%. The average distance between monodispesre particles is nearly 3 nm, and oleic acid and oleylamine surround the nanoparticles as surfactants. Stability investigation of nanoparticle colloidal solution is done via speetrophotometery analysis. The results for Fept nanoparticles dispersed in hexane indicate that adding surfactants with concentration of 3 × 10^-3 part by volume for centrifugation stage increases the stability of Fept nanoparticles solution with concentration of 16 mg/mL, about 67%.

关键词： field emission molybdenum dioxide enhancement factor