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Study of Thermodynamic Properties of Nonstoichiometric Phase with Compound Energy Model

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Journal of Materials Science & Technology 2002年第5期18卷 422-426页

作者： ShuigenHUANG LinLI O.V.D.Biest J.Vleugels PeilingWANG Sch. of Mat. Sci. and Eng. Shanghai Univ. Shanghai 200072 China Dept. MTM Katholieke Univ. Leuven B-3001 Heverlee Belgium Shanghai Inst. of Ceramics Chinese Acad. of Sci. Shanghai 200050 China

Using compound energy model (CEM), the thermodynamic properties of and were evaluated. The evaluation was based on the optimization of ZrIO2-CeO2 and ZrO2-CeO1.5 systems, as well as the miscibility gap in CeO1.5-CeO2 system. Except the cubic fluorite structure phase assessed with compound energy model, all the other solution phases were assessed with subsitutional solution model. The model parameters were evaluated through fitting the selected experimental data by means of thermodynamic optimization. A set of parameters with thermodynamics self-consistency was obtained and satisfactorily described the complex relation between y in and the partial pressure of oxygen at different temperatures, also the interdependence among miscellaneous factors such as temperature, oxygen partial pressure, the reduction amount of CeO2 as well as the nonstoichiometry in cubic phase - The calculated results seem to be reasonable when put into the explanation of pressureless sintering of Ce02-stabilized ZrO2 powder compacts at a controlled oxygen partial pressure.

关键词： Zirconia Ceria Nonstoichiometry Thermodynamic

Unidirectional expansion of lattice parameters in GaN induced by ion implantation

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Chinese Physics B 2011年第5期20卷 319-322页

作者：法涛李琳姚淑德吴名枋周生强 State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking University

This paper reports that the 150-keV Mn ions are implanted into CaN thin film grown on A1203 by metalorganic chemical vapour deposition. The X-ray diffraction reciprocal spacing mapping is applied to study the lattice parameter variation upon implantation and post-annealing. After implantation, a significant expansion is observed in the perpendicular direction. The lattice strain in perpendicular direction strongly depends on ion fluence and implantation geometry and can be partially relaxed by post-annealing. While in the parallel direction, the lattice parameter approximately keeps the same as the unimplanted GaN, which is independent of ion fluence, implantation geometry and post-annealing temperature.

关键词： GaN ion implantation unidirectional strain X-ray reciprocal space mapping

Influence of Phase Constitution on Mechanical Performance of 12Ce-3Y-ZrO_2/2.5 wt pct Al_(2)O_(3) Composites

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Journal of Materials Science & Technology 2004年第3期20卷 284-286页

作者： ShuigenHUANG LinLI J.Vleugels O.V.D.Biest SchoolofMaterialsScienceandEngineering.ShanghaiUniversity Shanghai200072China DepartmentofMTM KatholiekeUniversiteitLeuvenB-3001HeverleeBelgium

The phase constitution of a composite consisting of 12 at. pct CeO_2-3 at. pct Y_2O_3-ZrO_2/2.5 wt pct Al_2O_3 (3Y12Ce2.5Al)was determined by thermodynamic calculation. It is a combination of 36.9 at. pct cubic phase and 63.1 at. pct tetragonalphase at 1450℃. Green compacts were fabricated by cold isostatic pressing with powder synthesized by coating technique,and pressureless sintered at 1450℃. The fracture toughness and Vickers hardness, evaluated by the micro-indentation method,are 2.02 MPa·m^(1/2) and 11.395 GPa, respectively. The addition of 3 at. pct Y_2O_3 to 12 at. pct CeO_2-ZrO_2 ceramic leads todrastically decrease in toughness compared to composites without yttria stabilizer. No monoclinic phase is detected on thesudece of all the ground samples. The high content of cubic phase and lack of phase transformation can be attributed to thelow toughness based on the thermodynamic prediction.

关键词： Thermodynamics Mechanical properties ZrO_2-CeO_2-Y_2O_3

Minimal Lagrangian submanifolds of the complex hyperquadric

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Science china Mathematics 2020年第8期63卷 1441-1462页

作者： Haizhong Li Hui Ma Joeri Van der Veken Luc Vrancken Xianfeng Wang Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China Department of Mathematics KU LeuvenLeuven 3001Belgium Institut des Sciences et Techniques de Valenciennes Universite Polytechnique Hauts-de-FranceCampus du Mont HouyValenciennes 59313France School of Mathematical Sciences and LPMC Nankai UniversityTianjin 300071China Mathematical Sciences Institute Australian National UniversityCanberraACT 2601Australia

We introduce a structural approach to study Lagrangian submanifolds of the complex hyperquadric in arbitrary dimension by using its family of non-integrable almost product *** particular,we define local angle functions encoding the geometry of the Lagrangian submanifold at *** prove that these functions are constant in the special case that the Lagrangian immersion is the Gauss map of an isoparametric hypersurface of a sphere and give the relation with the constant principal curvatures of the *** also use our techniques to classify all minimal Lagrangian submanifolds of the complex hyperquadric which have constant sectional curvatures and all minimal Lagrangian submanifolds for which all local angle functions,respectively all but one,coincide.

关键词： minimal Lagrangian submanifolds the complex hyperquadric constant sectional curvature Gauss map isoparametric hypersurface

Cenozoic low temperature cooling history of the eastern Lhasa terrane:Implications for high-relief topography of external drainage area in the southern Tibetan Plateau

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Geoscience Frontiers 2023年第5期14卷 126-140页

作者： Wenbo Su Zhiyuan He Linglin Zhong Stijn Glorie Kanghui Zhong Johan De Grave Laboratory for Mineralogy and Petrology Department of GeologyGhent UniversityKrijgslaan 281 S89000 GhentBelgium College of Earth Sciences Chengdu University of TechnologyChengdu 610059China Department of Earth Sciences School of Physical SciencesThe University of AdelaideSA-5005Australia

The Tibetan Plateau geographically contains internal and external drainage areas based on the distributions of river flows and *** internal and external drainage areas display similar highelevations,while their topographic reliefs are not comparable;the former shows a large low-relief surface,whereas the latter is characterized by relatively high *** eastern Lhasa terrane is a key tectonic component of the Tibetan *** is characterized by high topography and relief,but the thermal history of its basement remains relatively poorly *** this study we report new apatite fission track data from the eastern part of the central Lhasa terrane to constrain the thermo-tectonic evolution of the external drainage area in the southern Tibetan ***-one new AFT ages and associated thermal history models reveal that the basement underlying the external drainage area in southern Tibet experienced three main phases of rapid cooling in the *** Paleocene-early Eocene(-60–48 Ma)cooling was likely induced by crustal shortening and associated rock exhumation,due to accelerated northward subduction of the NeoTethys oceanic lithosphere.A subsequent cooling pulse lasted from the late Eocene to early Oligocene(-40–28 Ma),possibly due to the thickening and consequential erosion of the Lhasa lithosphere resulted from the continuous northward indentation of the India plate into *** most recent rapid cooling event occurred in the middle Miocene-early Pliocene(-16–4 Ma),likely induced by accelerated incision of the Lhasa River and local thrust *** AFT ages and published low-temperature thermochronological data reveal that the external drainage area experienced younger cooling events compared with the internal drainage area,and that the associated differentiated topographic evolution initiated at ca.30 *** contributing factors for the formation of the high-relief topography mainly contain active surface uplift,fault activity,

关键词： Cenozoic Apatite fission track thermochronology Exhumation Lhasa terrane External drainage area Tibetan Plateau

Study of Thermodynamic Properties of Nonstoichiometric Phase 1-zCezO2-x> with Compound Energy Model 附视频

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Journal of Materials Science & Technology 2002年第5期 422-426页

作者： ShuigenHUANG ,LinLI ,O.V.D.Biest ,J.Vleugels ,PeilingWANG

Using compound energy model (CEM), the thermodynamic properties ofandwere evaluated. The evaluation was based on the optimization of ZrO2-CeO2 and ZrO2-CeO1.5 systems, as well as the miscibility gap in CeO1.5-CeO2 system. Except the cubic fluorite structure phase assessed with compound energy model, all the other solution phases were assessed with subsitutional solution model. The model parameters were evaluated through fitting the selected experimental data by means of thermodynamic optimization. A set of parameters with thermodynamics self-consistency was obtained and satisfactorily described the complex relation between y inand the partial pressure of oxygen at different temperatures, also the interdependence among miscellaneous factors such as temperature, oxygen partial pressure, the reduction amount of CeO2 as well as the nonstoichiometry in cubic phase. The calculated results seem to be reasonable when put into the explanation of pressureless sint

关键词： Zirconia Ceria Nonstoichiometry Thermodynamic