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Unmixing detrital zircon U-Pb ages reveals tectonic and climatic depositional influences on the Carboniferous Ansilta Formation,Calingasta-Uspallata Basin,Western Argentina

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Geoscience Frontiers 2024年第4期15卷 61-77页

作者： j.R.Malone j.E.Malone j.l.Isbell D.h.Malone j.P.Craddock K.n.Pauls Department of Geological Sciences Jackson School of GeosciencesUniversity of Texas at AustinAustinTX 78712USA Iowa Geological Survey University of IowaIowa CityIA 52240USA Department of Geosciences University of Wisconsin-MilwaukeeMilwaukeeWI 53211USA Department of Geography Geology and the EnvironmentIllinois State UniversityNormalIL 61790-4400USA

The late Paleozoic Ice Age(lPIA)was a principal control of sedimentation across Gondwana from the late Devonian through early *** assess the hypothesis that glacial to interglacial transitions in western Argentina were the primary control influencing sediment routing patterns among the various Carboniferous-Permian basins in western *** Carboniferous Ansilta Formation consists of glaciomarine,nearshore,and fluvial systems deposited during the lPIA along the eastern margin of the Calingasta-Uspallata Basin in *** lower,glacially influenced succession of the Ansilta Formation records at least five glacial advances;the upper succession of consists of progradational shallow marine,deltaic,and fluvial *** combine 1225 new U-Pb zircon ages from six samples of the Carboniferous Ansilta Formation in the Calingasta-Uspallata Basin with 5864 U-Pb ages from 147 pub-lished samples in the detrital Pymix forward mixture model to characterize provenance *** the glacially influenced lower Ansilta Formation,sediment was derived locally from the Protoprecordillera,which was a prominent highland with alpine glaciers flowing west and east into the Calingasta-Uspallata and Paganzo basins,***,there was little or no connection between these two basins during Serpukhovian-Bashkirian *** fluvial/deltaic upper Ansilta had distal sediment sources in the Sierras ***,our results support the collapse of the Protoprecordillera topographic barrier,enabling drainage patterns connecting the Paganzo and Calingasta-Uspallata basins by late Pennsylvanian-early Permian time.

关键词： late Paleozoic Ice Age Argentina Calingasta-Uspallata Basin Ansilta Formation Detrital zircon provenance

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Optical spectroscopy study of charge density wave order in Sr3Rh4Sn13 and(Sr0.5Ca0.5)3Rh4Sn13

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Science China(Physics,Mechanics & Astronomy) 2017年第4期60卷 51-56页

作者： W.j.Ban h.E Wang C.W.Tseng C.n.Kuo C.S.lue n.l.Wang Institute of Physics Chinese Academy of SciencesBeijing 100190China Department of Physics Cheng Kung UniversityTainan 70101China International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13. Formation of CDW energy gap was clearly observed for both single-crystal samples when they undergo the phase transitions. The existence of residual Drude components in σ1（ω） below Tcow indicates that the Fermi surface is only partially gapped in the CDW state. The obtained value of 2A/kBTcow is roughly 13 for both Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13 compounds, which is considerably larger than the mean-field value based on the weak-coupling BCS theory. The measurements provide optical evidence for the strong coupling characteristics of the CDW phase transition.

关键词： charge density wave optical spectroscopy intermetallic compounds

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Deep convolutional Ritz method: parametric PDE surrogates without labeled data

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Applied Mathematics and Mechanics(English Edition) 2023年第7期44卷 1151-1174页

作者： j.n.FUhG A.KARMARKAR T.KADEEThUM h.YOOn n.BOUKlAS Sibley School of Mechanical and Aerospace Engineering Cornell UniversityNew York 14853U.S.A Geomechanics Department Sandia National LaboratoriesAlbuquerque 87123U.S.A.

The parametric surrogate models for partial differential equations(PDEs)are a necessary component for many applications in computational sciences,and the convolutional neural networks(Cnns)have proven to be an excellent tool to generate these surrogates when parametric fields are *** are commonly trained on labeled data based on one-to-one sets of parameter-input and PDE-output ***,residual-based deep convolutional physics-informed neural network(DCPInn)solvers for parametric PDEs have been proposed to build surrogates without the need for labeled *** allow for the generation of surrogates without an expensive *** this work,we present an alternative formulation termed deep convolutional Ritz method(DCRM)as a parametric PDE *** approach is based on the minimization of energy functionals,which lowers the order of the differential operators compared to residualbased *** on studies involving the Poisson equation with a spatially parameterized source term and boundary conditions,we find that Cnns trained on labeled data outperform DCPInns in convergence speed and generalization *** surrogates generated from the DCRM,however,converge significantly faster than their DCPInn counterparts,and prove to generalize faster and better than the surrogates obtained from both Cnns trained on labeled data and *** hints that the DCRM could make PDE solution surrogates trained without labeled data possibly.

关键词： physics-informed constraint physics-informed neural network(PInn) deep energy network convolutional neural network(Cnn)

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Sol-Gel Synthesized Adsorbents for Metal Separation

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Tsinghua Science and Technology 2006年第2期11卷 233-240页

作者： l. l. Tavlarides j. S. lee K. h. nam n. Agarwal Department of Chemical Engineering and Materials Science Syracuse University Syracuse NY 13244 USA

A series of organo-ceramic adsorbents have been synthesized by a sol-gel processing technique for metal ion extraction. These adsorbents generally have significantly high metal uptake capacities, good physical-chemical stabilities, and well-designed pore geometries compared to other pre-existing metalchelating ceramic-based adsorbents. This work describes the synthesis and evaluation of pyrazole and calix[4]arene crown adsorbents for selective separation of platinum, palladium, and gold and cesium ions, respectively, from solutions. These materials exhibit mesoporous properties with high surface areas and pore volumes. The sol-gel synthesis starting with precursor silanes and titania results in gel particles of desired pore characteristics and high capacity and stability. Characterization studies, such as adsorption isotherms, breakthrough curves for fixed bed operation, and material stability, show promising results for applications to metal sepation.

关键词： metal separation organo-ceramic adsorbent calixarene sol-gel synthesis mesoporous

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Simultaneously Enhanced Mechanical Properties and Damping Capacities of ZK60 Mg Alloys Processed by Multi-Directional Forging

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Acta Metallurgica Sinica(English letters) 2021年第2期34卷 265-277页

作者： l.B.Tong j.h.Chu D.n.Zou Q.Sun S.Kamado h.G.Brokmeier M.Y.Zheng School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055China School of Materials Science and Engineering.harbin Institute of Technology Harbin 150001China College of Materials Science and Engineering.jilin University Changchun 130025China Department of Mechanical Engineering Nagaoka University of TechnologyNagaoka 940-2188Japan Institute of Materials Science and Engineering Clausthal University of TechnologyAgricolastrasse 638678 Clausthal-Zellerfeld.Germany

In this study,the mechanical properties and damping capacities of cast Mg-5.5 Zn-0.6 Zr(weight percent,ZK60)alloys have been simultaneously improved by a facile multi-directional forging(MDF)processing,and the mechanisms of microstructure evolution and texture modification are systematically *** activation of tension twinning occurs during the initial MDF stage,due to the coarse-grained structure of the as-cast *** increasing MDF passes,the continuous dynamic recrystallization(CDRX)results in a fine equiaxed-grain *** typical non-basal texture is formed in the as-MDFed alloy for 6 passes,with the(0001)planes inclined 60°–70°to forged direction and 10°–20°to transverse direction,respectively.A good balance between the strength(~194.9 MPa)and ductility(~24.9%)has been achieved,which can be ascribed to the grain refinement,non-basal texture and fine precipitate *** damping capacity is remarkably improved after MDF processing,because the severe deformation increases the dislocation density,which effectively enlarges the sweep areas of mobile dislocations.

关键词： Mg alloy Multi-directional forging Microstructure Texture evolution Mechanical properties Damping capacity

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Opportunities and challenges of biodegradable Zn-based alloys

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journal of Materials Science & Technology 2020年第11期42卷 136-138页

作者： h.F.li Z.Z.Shi l.n.Wang Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing100083China

Following the footsteps of biodegradable Mg-based and Fe-based alloys,biodegradable Zn-based alloy is a newcomer and rising star in the family of biodegradable metals and *** combined superior mechanical properties,appropriate degradation rates,excellent biocompatibility of biodegradable Zn-based alloys have brought worldwide research interest on the design,development and clinical translation of Zn-based *** present perspective has summarized opportunities and challenges in the development of biodegradable Zn-based alloys.

关键词： Biodegradable Zn-based alloys Clinical applications Mechanical properties Degradation behavior Biocompatibility Corrosion fatigue Bio-tribocorrosion

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Greatly enhanced corrosion/wear resistances of epoxy coating for Mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

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journal of Magnesium and Alloys 2024年第1期12卷 332-344页

作者： Z.Y.Xue X.j.li j.h.Chu M.M.li D.n.Zou l.B.Tong School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State Key laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.

关键词： Mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer

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Electromagnetoelastic behaviors of functionally graded piezoelectric solid cylinder and sphere

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Acta Mechanica Sinica 2007年第1期23卷 55-63页

作者： h. l. Dai Y.M. Fu j.h. Yang Department of Engineering Mechanics Hunan University Changsha 410082 China

Analytical studies on electromagnetoelastic behaviors are presented for the functionally graded piezoelectric material （FGPM） solid cylinder and sphere placed in a uniform magnetic field and subjected to the external pressure and electric loading. When the mechanical, electric and magnetic properties of the material obey an identical power law in the radial direction, the exact displacements, stresses, electric potentials and perturbations of magnetic field vector in the FGPM solid cylinder and sphere are obtained by using the infinitesimal theory of electromagnetoelasticity. numerical examples also show the significant influence of material inhomogeneity. It is interesting to note that selecting a specific value of inhomogeneity parameter β can optimize the electromagnetoelastic responses, which will be of particular importance in modern engineering designs.

关键词： Functionally graded piezoelectric material (FGPM) Electromagnetoelastic Solid cylinder Solid sphere Perturbation of magnetic field vector

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EFFECT OF TESTInG EnVIROnMEnT On FRACTURInG BEhAVIOR OF Fe_3Si BASED AllOY

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Acta Metallurgica Sinica(English letters) 2003年第2期16卷 104-109页

作者： j.h.Peng G.l.Chen national Key laboratory for nuclear Fuel&Materials China Nuclear Power InstituteChengdu 610041ChinaState Key Laboratory for Advanced Metal MaterialsUniversity of Science&Technology BeijingBeijing 100083China

The mechanical behavior of Fes Si based alloy with B2 structure was studied by tension and fracture toughness test in various testing media. The fracture strength σb of Fe3Si alloy decreased in the following order: oxygen, air and hydrogen respectively. The fracture toughness in different testing environment showed that KIC in oxygen is 11.5±0.3MPa·m1/2, and is 8.6±0.4MPa·ml/2 in distilled water. The reduction of fracture toughness is contributed to the environmental reaction of Si with water. Addition of Al element in Fe3Si is not beneficial to improve the intrinsic ductility of Fe-14Si-3Al alloy. The scattering phenomenon of fracture strength was found, and explained by fracture mechanics. It was found by means of SEM that the fracture mode changed from transgranular in oxygen to intergranular in hydrogen gas and distilled water.

关键词： Fe3Si intermetallic mechanical behavior environmental em- brittlement

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Ab initio STUDIES On MAGnETISM OF 3d TRAnSITIOn METAl DIMERS

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Acta Metallurgica Sinica(English letters) 2007年第5期20卷 341-346页

作者： j.h. Gu Z.l. Zhu School of Physical Engineering and Material Physics laboratory Zhengzhou University Zhengzhou 450052 China

Ab initio calculations with the self-consistent full-potential linearized augmented-plane-wave method （FlAPW）, under generalized gradient approximation, have been carried out to describe the electronic and magnetic properties of 3d transition metal dimers. It predicted the antiferromagneticity of Cr2 and ferromagneticity of other species. The Mn2 dimer was shown to be ferromagnetic coupling with a local magnetic moment of 5μB. retaining the value of its free atom state. The V2 and ni2 exhibited low spin-polarization with local magnetic moment of only 1μB per atom. On the other hand, Fe2 and Co2 were highly spin-polarized with local magnetic moments of 3 and 2μB.

关键词： magnetism 3d transition metal dimer ab initio calculation

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