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Reactive destabilization and bidirectional catalyzation for reversible hydrogen storage of LiBH_(4) by novel waxberry-like nano-additive assembled from ultrafine Fe_(3)O_(4) particles

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Journal of materials Science & Technology 2024年第6期173卷 63-71页

作者： S.Wang m.H.wu y.y.Zhu Z.L.Li y.X.yang y.Z.Li H.F.Liu m.X.Gao Department of material Science Shenzhen MSU-BIT UniversityShenzhen 518172China State Key Laboratory of Silicon and Advanced Semiconductor materials&School of materials Science and Engineering Zhejiang UniversityHangzhou 310027China Institute of Resources Utilization and Rare Earth Development State Key Laboratory of Rare Metals Separation and Comprehensive UtilizationGuangdong Provincial Key Laboratory of Rare Earth Development and ApplicationGuangdong Academy of SciencesGuangzhou 510650China Institute of Science and Technology for New Energy Xi’an Technological UniversityXi’an 710021China National Supercomputing Center in Shenzhen Shenzhen 518055China

LiBH_(4) containing 18.5 wt.%H_(2) is an attractive high-capacity hydrogen storage material,however,it suffers from high operation temperature and poor ***,a novel and low-cost bifunctional additive,waxberry-like Fe_(3)O_(4) secondary nanospheres assembled from ultrafine primary Fe_(3)O_(4) nanoparticles,is synthesized,which exhibits significant destabilization and bidirectional catalyzation towards(de)hydrogenation of LiBH_(4).With an optimized addition of 30 wt.% waxberry-like Fe_(3)O_(4),the system initiated dehydrogenation below 100℃ and released a total of 8.1 wt.%H_(2) to 400℃.After 10 cycles,a capacity retention of 70% was achieved,greatly superior to previously reported oxides-modified *** destabilizing and catalyzing mechanisms of waxberry-like Fe_(3)O_(4) on LiBH_(4) were systematically analyzed by phase and microstructural evolutions during dehydrogenation and hydrogenation cycling as well as density functional theory(DFT)*** present work provides new insights in developing advanced nano-additives with unique structural and multifunctional designs towards LiBH4 hydrogen storage.

关键词： LiBH_(4) Hydrogen storage Waxberry-like Fe_(3)O_(4) Destabilization Catalysis

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New interpretation of specific sign of Reynolds stress in the boundary layer on a flat plate

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Theoretical & Applied mechanics Letters 2018年第6期8卷 372-377,I0003页

作者： L.m.Lin y.X.wu Key Laboratory for mechanics in Fluid Solid Coupling Systems Institute of Mechanics Chinese Academy of Sciences School of Engineering Sciences University of Chinese Academy of Sciences

The specific sign of Reynolds stress in the boundary layer on a flat plate at zero incidence is newly interpreted in present paper based on the theory of vortex-induced vortex. It avoids some problems appeared in a traditional explanation, on the basis of relationship between mean and fluctuating flows due to the transport of momentum. Through the analysis of local flow field in the immediate neighborhood of wall, the characteristics of Reynolds stress are identified through introducing turbulence-induced small-scale streamwise eddies above the flat plate. The positive Reynolds stress is theoretically verified. And such new interpretation illustrates that the generation of Reynolds stress, as well as fluctuating velocity, is intrinsically independent of the mean flow. But its specific sign would be determined by the mean flow due to the inertial forces. Other features,such as the intensity relationship among three components of fluctuating velocity, are also presented.

关键词： Reynolds shear stress Sign Boundary layer Flatplate Turbulence

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2D free-standing ultra-large ferromagnetic nanosheets via a topotactic transformation strategy

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Science China Chemistry 2025年

作者： Haofeng Sun minghao Wang Wenjie Li yang Liu Xinyu Sun Wenjie Wang yuqiao Guo yi Xie Changzheng wu Key Laboratory of Precision and Intelligent Chemistry University of Science&Technology of China National Synchrotron Radiation Laboratory University of Science and Technology of China

Considerable progress has been made in synthesizing two-dimensional （2D） materials by exfoliating layered ***,for tremendous non-layered inorganic materials,especially magnet solids,usually with closely packed bulk phases by strong chemical bonds,it is challenging to obtain their high-quality 2D ***,we highlighted a new structure of free-standing ferromagnetic nanosheets featuring （111） *** magnet,Fe3O4,its inversed spinel crystalline has limited abilities to exfoliate into 2D forms and rarely exists as free-standing nanosheets owing to aggregation induced by magnetic *** realized a breakthrough in achieving free-standing ferromagnetic nanosheets with dramatically surpassing size limitations via topotactic conversion from layered *** Fe3O4nanosheets exhibited a maximum width of 60μm while only～4 nm thick,prominently exposing （111） facets.2D Fe3O4behaved anisotropic magnetism,which displayed a 4.6 emu g-1moment（H=500 Oe） in the （111） plane but 2.1 emu g-1out of the （111） plane,indicating a （111） in-plane easy *** anticipated our topotactic conversion strategy would inspire the creation of 2D non-layered materials and enrich the 2D materials family.

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Characterization for Fusion Candidate Vanadium Alloys

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Plasma Science and Technology 2004年第4期6卷 2395-2399页

作者： T.muroga T.Nagasaka J.m.Chen Z.y.Xu Q.y.Huang y.C.wu NationalInstituteforFusionScience Toki509-5292Japan SouthwesternInstituteofPhysics Chengdu610041China InstituteofPlasmaPhysics ChineseAcademyofSciencesHefei230031China

This paper summarizes recent achievements in the characterization ofcandidate vanadium alloys obtained for fusion in the framework of the Japan-China Core UniversityProgram. National Institute for Fusion Science (NIFS) has a program of fabricating high-purityV-4Cr-4Ti alloys. The resulting products (NIFS-HEAT-1,2), were characterized by various researchgroups in the world including Chinese partners. South Western Institute of Physics (SWIP) fabricateda new V-4Cr-4Ti alloy (SWIP-Heat), and carried out a comparative evaluation of hydrogenembrittlement of NIFS-HEATs and SWIP-Heat. The tensile test of hydrogen-doped alloys showed that theNIFS-HEAT maintained the ductility to relatively high hydrogen levels. The comparison of the datawith those of previous studies suggested that the reduced oxygen level in the NIFS-HEATs should beresponsible for the increased resistance to hydrogen embrittlement. Based on the chemical analysisdata of NIFS-HEATs and SWIP-Heats, neutron-induced activation was analyzed in Institute of PlasmaPhysics (IPP-CAS) as a function of cooling time after the use in the fusion first wall. The resultsshowed that the low level of Co dominates the activity up to 50 years followed by a domination of Nbor Nb and Al in the respective alloys. It was suggested that reduction of Co and Nb, both of whichare thought to have been introduced via cross-contamination into the alloys from the molds usedshould be crucial for reducing further the activation.

关键词： vanadium alloys characterization nuclear fusion

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Synthesis and Characterization of mesoporous Alumina via a Reverse Precipitation method

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Journal of materials Science & Technology 2012年第6期28卷 572-576页

作者： y.S.wu J.ma F.Hu m.C.Li College of materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

mesoporous aluminaΥ-AI203 with high specific surface area and large pore volume is prepared by using a facile reverse precipitation method from sodium aluminate and nitric acid. The effects of terminal pH value, aging time and thermal stability on the characterization of Υ-Al2Oa are studied by means of X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, Brunauer-Emmett-Teller （BET） method and scanning electron microscopy （SEm）. The results show that Υ-A1203 with better properties can be obtained by changing the preparation parameters. High BET surface area of 340 m2/g can be obtained by calcining at 500℃ for 4 h with large pore volume of 0.90 cm3/g and average pore size of 7.6 nm. After calcining at 1000°, the surface area is still 86 m2//g and the pore volume is 0.37 cm31/g.

关键词： mesoporous alumina Reverse precipitation Thermal stability

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Improving corrosive wear resistance of mg-Zn-y-Zr alloys through heat treatment

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Journal of magnesium and Alloys 2023年第6期11卷 1981-1995页

作者： S.D.Wang m.y.wu D.K.Xu En-hou Han Northwestern Polytechnical University Xi’an 710072China Key Laboratory of Nuclear materials and Safety Assessment Chinese Academy of SciencesInstitute of Metal ResearchShenyang 110016China Department of Chemical and materials Engineering University of AlbertaEdmonton T6G 2G6Canada

The wear behavior of an as-received mg-Zn-y-Zr alloy before and after a facile heat treatment was investigated under sliding in air and 0.5 wt.%NaCl *** revealed that the wear resistance of the alloy was remarkably enhanced after the heat treatment,irrespective of testing *** wear mechanism was predominantly abrasive wear accompanied by oxidation under the dry sliding condition,while corrosive wear was dominant under sliding in the NaCl *** superior corrosive wear resistance was attributed to the homogenous distribution of fine I-phase precipitates in the alloy by the heat treatment,leading to a reduction in wear,corrosion as well as wear-corrosion *** wear-accelerated corrosion rate was remarkably alleviated after the heat treatment.

关键词： magnesium alloy Heat treatment Corrosion Wear Tribocorrosion

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Intrinsic relationship of vorticity between modes A and B in the wake of a bluff body

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Theoretical & Applied mechanics Letters 2018年第5期8卷 320-325,362页

作者： L.m.Lin S.y.Shi y.X.wu Key Laboratory for mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of Sciences School of Engineering Sciences University of Chinese Academy of Sciences

The intrinsic physical relationship of vorticity between modes A and B in the three-dimensional wake transition is *** numerical simulations for the flow past a square-section cylinder are carried out at Reynolds numbers of 180 and 250,associated with modes A and B,*** on the analysis of spacial distributions of vorticity in the near wake,characteristics of the vertical vorticity in modes A and B are ***,the relationship of three vorticity components with specific signs is summarized into two sign laws,as intrinsic physical relationships between two instability *** the theory of vortex-induced vortex,such two sign laws confirm that there are two and only two kinds of vortex-shedding patterns in the near wake,just corresponding to modes A and *** brief,along the free stream direction,mode A can be described by the parallel shedding vertical vortices with the same sign,while mode B is described by the parallel shedding streamwise vortices with the same ***,it is found out that the|-type vortex is a basic kind of vortex structure in both modes A and B.

关键词： mode A mode B Wake Bluff body Sign law

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Evaluation of Layered Inorganic Nano-powder modified Bitumen

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武汉理工大学学报 2010年第17期32卷 51-54页

作者： HAN J wu S P CHEN m y yU m Key Laboratory of Silicate materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Thermal oxidative and aging as an inevitable process in the practical application of road asphalt has great effect on the properties of asphalt. In this paper,the influences of short-term thermal oxidative ageing and ultraviolet radiation(UV) aging on the dynamic viscosity,penetration,softening point and rheological properties of two kinds of layered inorganic nano-powder including organo-modified montmorillonite (OmmT) and nanometer brucite (mg(OH)2) modified asphalts were studied respectively. The rheological properties of these binders have been determined using a dynamic shear rheometer (DSR) through temperatures sweep *** rheological and physical analysis showed the two major influences of ageing on the properties for two kinds of layered inorganic nano-powder modified bitumens. On one hand,ageing decreased the viscous behaviors of modified binders,on the other hand,ageing improved the elastic behaviors of modified binders. The performances of binders after aging depended on the combined effect between the modifier and the bitumen. Both the two modifiers resisted the aging of bitumens and the effect of OmmT was better.

关键词： ageing evaluation layered inorganic nano-powder modified bitumen

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Processing, microstructure and mechanical Properties of Ti6Al4V Particles-Reinforced mg matrix Composites

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Acta metallurgica Sinica(English Letters) 2016年第10期29卷 940-950页

作者： X.m.Wang X.J.Wang X.S.Hu K.wu m.y.Zheng School of materials Science and Engineering Harbin Institute of Technology

Novel Ti6Al4V particles-reinforced AZ91 mg matrix composites were successfully fabricated by stir casting method. The stirring time in semisolid condition directly affected the particle distribution and the quality of the ingots. Furthermore, the optimal speed of the heating and the liquid stirring could overcome particle settlement caused by the density difference between the matrix and the particles. Ti6Al4V particles distributed uniformly in the composites with different particle contents. The average grain size decreased with the increase in the particle contents. The Ti6A14V particles bonded pretty well with the alloy matrix. In addition, there were some interfacial reactions in the composites. There were rod-like A13Ti phases at the interface. The precipitates extended from the particle surface to the matrix, and they might improve the interfacial bonding strength. The ultimate tensile strength, yield strength and elastic modulus were enhanced as the particle contents increased, and the elongation was much better than that of the same matrix material reinforced with SiC particles. Thus, the novel composites exhibit better comprehensive mechanical properties.

关键词： magnesium matrix composites Ti6Al4V particles Stir casting microstructure mechanicalproperties

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Deliberate design of mOF-based pre-catalyst rationalizing the structural reconstruction toward efficient oxygen evolution reaction

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Science China Chemistry 2025年

作者： yunhui Chen meng Tian Zhongqi Zhang Guangzhao Wang yan Guo Jing wu Dawei Qi Zhenhua yan Xiangyu Liu Xi Liu State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering College of Chemistry and Chemical EngineeringNingxia University Key Laboratory of Extraordinary Bond Engineering and Advanced materials Technology of Chongqing School of Electronic Information Engineering Yangtze Normal University Frontiers Science Center for New Organic matter Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) State Key Laboratory of Advanced Chemical Power Sources College of Chemistry Nankai University School of Chemistry and Chemical Engineering In-situ Center for Physical Sciences Frontiers Science Center for Transformative Molecules Shanghai Jiao Tong University

metal-organic frameworks （mOFs）,that have emerged as promising electrocatalysts in oxygen evolution reaction （OER）,usually undergo structural reconstruction to form metal hydroxides as active ***,it remains a great challenge to design and synthesize ideal mOF-based pre-catalysts for properly cognizing and utilizing the reconstruction process toward efficient OER ***,the well-defined mOF-808 is post-modified by 2-hydroxyphosphonoacetic acid （HPAA） to form a micro-adsorber that enables to capture of metal ions ***3+and Ni2+ions are synergistically anchored into the microadsorber,developing a Fe/Ni-containing pre-catalyst that can be dynamically electrooxidized to be an active and stable dual-site electrocatalyst denoted by R-mOF-HPAA@FeNi with abundant metal *** a result,R-mOF-HPAA@FeNi exhibits an excellent OER performance with a low overpotential of 272 mV and Tafel slope of 35.9 m V dec-1,as well as long-term stability over 300 h at 10 m A *** and theoretical calculations suggest the resulting catalyst mainly follows a lattice oxygen mechanism （LOm） of dual-metal-site mechanism （DmSm）.Owing to the chelating role of HPAA,the post-synthesized mOF-HPAA behaves as a trap to uniformly and firmly adhere Fe3+and Ni2+ions,leading to a functionalized mOF-based pre-catalyst which can be structurally evolved into atomic level-distributed OER electrocatalysts.

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