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Journal of Materials Science & Technology 2022年第5期100卷 246-253页

作者： J.F.Zhao h.p.wang B.Wei School of physical Science and Technology Northwestern Polytechnical UniversityXi’an 710072China

A new intermetallic compound of thermodynamically stable Nb_(2)Ni phase is discovered within Nb-Ni binary system,refreshing the current situation that there are only three stable intermediate phases of Nb_(7)Ni_(6),NbNi_(3) and NbNi_(8).The new stable phase is generated from the peritectoid transition:(Nb)+Nb_(7)Ni_(6)→Nb_(2)Ni,and the transformation temperature is 1533 K.This refreshes the current equilibrium Nb-Ni binary phase diagram.It is confirmed by transmission electron microscopy and the annealing experiments,which is determined to be the FCC structure(pearson:cF96,space grope:Fd-3m O2,a=11.888A).Furthermore,the equilibrium properties of Nb_(2)Ni phase are produced by density functional theory,including the formation energy,cohesive energy,bulk modulus and lattice constant.

关键词： Intermetallic compound peritectoid transition Transmission electron microscopy Density functional theory Nb alloy

primary dendrite growth kinetics and rapid solidification mechanism of highly undercooled Ti-Al alloys

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Journal of Materials Science & Technology 2020年第5期40卷 47-53页

作者： Z.C.Luo h.p.wang Department of Applied physics Northwestern Polytechnical UniversityXi’an 710072China

The rapid solidification processes of undercooled Ti-(47,50,54)at.%Al alloys were investigated by electromagnetic levitation(EML)method combined with a high-speed photoelectric detector.The maximum undercoolings of the three liquid alloys were 376 K,352 K and 316 K,respectively.Recalescence processes corresponding to the primary dendrite growth and subsequent phase transition were recorded at various undercoolings.The primary dendrite growth velocity V meets a double exponential relationship with the undercooling T.Besides,a novel formula with physical meaning is proposed to explain that the more ordered liquid metal atoms accelerate the primary dendrite growth.Three recalescences are found at all undercoolings for Ti-47 at.%Al alloy and at high undercoolings for Ti-50 at.%Al alloy.The microstructures of solidified Ti-47 at.%Al alloys successively appear as coarse lamellar dendrites and finally evolve to refined parallel lamellar dendrites with the increasing undercooling.When T rises,the microstructures of solidified Ti-50 at.%Al alloys appear from coarse primary dendrites and interdendritic dendrites to refined lamellar dendrites.In the process from low undercooling to high undercooling,the primary phase of undercooled Ti-54 at.%Al alloys changes from r-Ti(r)to r-TiAl(r)and the microstructures of solidified alloys evolve from spherical primary dendrites and matrix phases to cellular dendrite phases.Meanwhile,for the Ti-(47,50)at.%Al,the transformation temperature of metastable intermediateγphase decreases with the increase of undercooling.Moreover,the microhardness of the three solidified alloys reaches the maximum when the undercoolings are 185 K,270 K and 316 K,respectively.

关键词： Electromagnetic levitation Rapid solidification Dendrite growth Microstructure Microhardness

Rapid Growth of TiNi intermetallic compound within undercooled Ti_(50)Ni_(50)alloy under electrostatic levitation condition

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Journal of Materials Science & Technology 2021年第18期77卷 82-89页

作者： p.F.Zou C.h.Zheng L.hu h.p.wang School of physical Science and Technology Northwestern Polytechnical University.Xi'an710072China

The undercooling dependence of the solidification mechanism was systematically explored by the electrostatic levitation(ESL)facility.During the experiments,the maximum undercooling reached up to 406 K(0.26 T_L)and the growth velocity of the primary TiNi phase was in-situ determined at various undercoolings.At the initial increase of alloy undercooling,the value of growth velocity sluggishly rose followed by a power function.In this case,the primary TiNi phase preferentially developed as the equiaxed dendrite,then the remnant liquid participated as Ti_(2)Ni andα-Ti phases on the grain boundary.Once the undercooling exceeded the critical value of 350 K,the growth velocity of the primary phase displayed a sharply increase tendency.Meanwhile,the TEM results demonstrated that the precipitation of the intermetallic Ti_(2)Ni compound was gradually restrained during the rapid solidification and the R-phase existing in the TiNi matrix at large undercooling implied that the martensitic transformation was incomplete.

关键词： Undercooling Ti-Ni alloy Solidification Growth kinetics

The Coarse l^(p)-Novikov Conjecture and Banach Spaces with property(h)

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Chinese Annals of Mathematics,Series B 2024年第2期45卷 193-220页

作者： huan wang Qin wang Research Center for Operator Algebras School of Mathematical SciencesEast China Normal UniversityShanghai 200241China Key Laboratory of MEA Ministry of Educationand Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241China

In this paper,for 1<p<∞,the authors show that the coarse l^(p)-Novikov conjecture holds for metric spaces with bounded geometry which are coarsely embeddable into a Banach space with Kasparov-Yu’s property(h).

In this paper,for 1phe authors show that the coarse l^(p)-Novikov conjecture holds for metric spaces with bounded geometry which are coarsely embeddable into a Banach space with Kasparov-Yu’s property(h).

关键词： The coarse l^(p)-Novikov conjecture Banach spaces with property(h) Coarse geometry K-Theory

Effect of rare earth on primary carbides in h13 die steel and their addition method:a review

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Journal of Iron and Steel Research(International) 2024年第3期31卷 531-551页

作者： Jing-feng wang Lin-zhu wang Chao-yi Chen Xiang wang Fei Zhao School of Materials and Metallurgy Guizhou UniversityGuiyang 550025GuizhouChina Zhengzhou Railway Vocational and Technical College Zhengzhou 450000HenanChina Guizhou provincial University Key Laboratory of high performance Battery Materials Guizhou UniversityGuiyang 550025GuizhouChina Shougang Guiyang Special Steel Co. Guiyang 550005GuizhouChina

Larger-sized primary carbides lead to stress concentration during the application of h13 hot-work die steel,resulting in microcracks and fatigue failure.Rare earth was usually added to modify the carbides and inclusions.The existing literature is reviewed on the effect of rare earth on primary carbides in h13 steel.A comprehensive review on the effect of rare earth on the characteristics of primary carbides,i.e.,number,size,morphology,and thermal stability in h13 steel,was done.The precipitation mechanism and nucleation of primary carbides with rare earth were summarized.The position and form of rare earth in steel and their effects on alloying elements segregation were reviewed.The addition techniques of rare earth in h13 steel were compared,and the prospects for other uncommon rare earth and emerging technology were present.Based on the current references,it can be known that adding rare earth facilitated refined and dispersed primary carbides.The size of primary carbides would be reduced,and their morphology would be improved because the rare earth inclusions formed in h13 steel can act as nucleation cores forγ-Fe orδ-Fe,refining the dendritic structure.Besides,the number of primary carbides at grain boundaries would be significantly reduced.however,rare earth had little impact on thermal stability.The nucleation of primary carbides tended to be inhibited due to the modification of inclusions by rare earth which were likely to be nucleation cores for primary carbides.Rare earth had been reported to affect the mechanism and process of primary carbide precipitation.Additionally,the addition of rare earth can inhibit the segregation of alloying elements and carbon diffusion by calculation.Thus,laboratory experiments and theoretical calcu-lations need to be conducted to study the states and evolution of rare earth steels.

关键词： Rare earth h13 die steel primary carbide Nucleation Dendritic structure

Connections Between Induction Generator Effect and Open-loop Modal proximity to Cause Sub-synchronous Oscillations in Series-compensated power System

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CSEE Journal of power and Energy Systems 2024年第3期10卷 963-973页

作者： Wenjuan Du Yang wang h.F.wang Tao Zhao Tim Littler College of Electrical Engineering Sichuan UniversityChengduChina School of Electrical Engineering the Queen’s University of BelfastBelfastUK IEEE

The induction generator effect(IGE)and the openloop modal proximity(OLMp)are two different reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCpS)may occur.The IGE attributes the growing SSOs to negative resistance,while the OLMp explains the SSO mechanism from the standpoint of modal conditions.In this paper,we investigate the connections between the IGE and the OLMp through equivalent RLC circuit and open-loop modal analysis.Our investigation is conducted for two types of seriescompensated power systems where either a synchronous generator or a DFIG is connected at the sending end.The investigation reveals the conditions,in which the IGE and the OLMp may jointly cause the growing SSOs,i.e.,both the IGE and the OLMp can explain why the growing SSOs occur.Furthermore,the investigation indicates that the IGE and the OLMp may be totally irrelevant and lead to growing SSOs separately.This implies that it is possible that in a SCpS,the growing SSOs are only due to the IGE,and the OLMp is non-existent,and vice versa.hence,when the growing SSOs occurs in a SCpS,examination based on both the IGE and the OLMp should be carefully conducted in order to find if the oscillatory instability is due to the IGE,or the OLMp,or both of them.

关键词： Induction generator effect open-loop modal proximity series compensation sub-synchronous oscillations

Experimental and numerical study regarding h-steel all-bolted connection steel frame with composite wall boards

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 427-443页

作者： Fan Min Guo hongchao Li Shen wang Zhenshan wang huaqiang School of Civil Engineering and Architecture Xi’an University of TechnologyXi’an 710048China State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an 710048China

h-steel all-bolted connection steel frame structures with heat preservation and decoration composite wall boards were investigated and the seismic performances of three scaled specimens were studied.The failure modes,hysteresis curves,bearing capacity,ductility,energy dissipation capacity,stiffness degradation and strain distribution were discussed.The calculation method of structural theoretical internal force was presented.The results showed that the overall structural seismic performance was better,and the structural ductility met the demands of elastic-plastic inter-story drift angle for seismic design.The h-steel weak-axis connection structure obtained better energy dissipation capacity,and its bearing capacity and stiffness were slightly different from the strong-axis connection.The heat preservation and decoration performance of composite wallboard and the all-bolted connection of the steel frame realized prefabrication during the whole construction period.The plastic hinge of the steel beam can be moved outwards because of the L-angles,which effectively avoids stress concentration in joint areas and expands the plastic hinge range.The errors between the theoretical structural capacity calculated by the plastic analysis method and the test results were within 2.44%.In addition,structural failure mechanisms and bearing capacities were verified by the finite element(FE)analysis,and the effects of the main parameters on the structures were investigated.The FE verification results were the same as in the test.The research results provide theoretical support and technical guidance for the application of thermal insulation and decorative composite wall panels in h-shaped steel all-bolted steel frames.

关键词： composite wall boards all-bolted steel frame h-steel low-cyclic loading failure modes

DLX3(Q178R)mutation delays osteogenic differentiation via h19/miR-29c-3p/KDM5B axis in TDO-ipSCs-derived MSCs

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Genes & Diseases 2024年第4期11卷 49-52页

作者： Liying Dong Na Zhao Dongmei wang Meng wang Yixin Zhang Liangjie Sun Chong Ding Yixiang wang Zeyun Ma Central Laboratory Peking University School and Hospital of StomatologyBeijing 100081China Department of Oral and Maxillofacial Surgery Peking University School and Hospital of StomatologyBeijing 100081China National Engineering Laboratory for Digital and Material Technology of Stomatology Peking University School and Hospital of StomatologyBeijing 100081China Beijing Key Laboratory of Digital Stomatology Peking University School and Hospital of StomatologyBeijing 100081China The Second Clinical Division Peking University School and Hospital of StomatologyBeijing 100081China Department of VIp Service Peking University School and Hospital of StomatologyBeijing 100081China Department of Restorative Dentistry and Biomaterials Sciences Harvard School of Dental MedicineBostonMA 02115USA Department of prosthodontics Fudan UniversityShanghai 200001China Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases Shanghai Stomatological HospitalFudan UniversityShanghai 200001China

Tricho-dento-osseous(TDO)syndrome is a rare autosomal dominant disease resulting from distal-less homeobox 3(DLX3)mutation.1,2 Accumulative bone density in alveolar bone is a clinically favorable phenotype for TDO patients.however,the limited number of bone marrow mesenchymal stem cells(BMSCs)in TDO patients restricts their application.

关键词： patients clinically alveolar

Insight into the adsorption behavior and mechanism of trace impurities from h_(2)O_(2)solution on functionalized zirconia by tuning the structure of amino groups

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 83-94页

作者： Yu Meng Yitong wang Guozhu Li Guozhu Liu Li wang Key Laboratory for Green Chemical Technology of Ministry Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

primary,secondary and tertiary amino-functionalized zirconia(ZrO_(2)-Nh_(2),ZrO_(2)-Nh and ZrO_(2)-N)was synthesized by the postgrafting method for the adsorption removal of typical metallic ions,phosphate and total oxidizable carbon from a real h_(2)O_(2)solution.ZrO_(2)-Nh_(2),ZrO_(2)-Nh and ZrO_(2)-N exhibited similar pore sizes and sequentially increased zeta potentials.The adsorption results of single and binary simulated solutions showed that the removal efficiency increased in the order of Fe^(3+)>Al^(3+)>Ca^(2+)>Na^(+).There is competitive adsorption between metallic ions,and Fe^(3+)has an advantage over the other metals,with a removal efficiency of 90.7%.The coexisting phosphate could promote the adsorption of metallic ions,while total oxidizable carbon had no effect on adsorption.The adsorption results of the real h_(2)O_(2)solution showed that ZrO_(2)-Nh_(2)exhibited the best adsorption affinity for metallic ions,as did phosphate and total oxidizable carbon,with a total adsorption capacity of 120.9 mg·g_(-1).Density functional theory calculations revealed that the adsorption process of metallic ions involves electron transfer from N atoms to metals and the formation of N-metal bonds.

关键词： adsorption metallic ion phosphate total oxidizable carbon zirconia h_(2)O_(2)

Density determination and simulation of Inconel 718 alloy at normal and metastable liquid states

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Journal of Materials Science & Technology 2018年第3期34卷 436-439页

作者： h.p.wang C.h.Zheng p.F.Zou S.J.Yang L.hu B.Wei Department of Applied physics Northwestern Polytechnical University

The density of liquid Incone1718 alloy was experimentally measured by electrostatic levitation technique, where the maximum undercooling of 100 K was realized for the commercial sample. The measured density of liquid lnconel 718 alloy is 7.39 g cm^-3 at the liquidus temperature of 1663 K which was confirmed by DSC experiment, with the linear temperature coefficient of -6.89 × 10^-4 gcm^-3 K^-1. Correspondingly, four ternary Ni-Cr-Fe compositions were designed to simulate the density of liquid lnconel 718 alloy with 16000 atoms, from which the liquid structure is revealed by pair distribution function, The predicted result shows a remarkable enhancement with the decrease of temperature at the first neighbor distance.

关键词： Undercooling Density Liquid metal and alloy Levitation