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LOW Cy.LE FATIGUE BEHAVIOR OF Az.1HP ALLOy.IN AS HIGHP RESSURE DIE CASTING

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Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 961-966页

作者： Liu, z. Xu, y.y. Wang, z.G. Wang, y. Liu, z.y. Inst of Metal Research Chinese Acad of Sciences Shenyang China

Fully.reversed total strain-controlled low-cy.le fatigue tests were conducted at room temperature in air to study.the fatigue behavior of Az.1HP magnesium alloy.in as high pressure die casting and subsequently.heat treatment. All the specimens in different heat histories exhibit cy.lic strain hardening in different degrees. It is difficult to distinguish the fatigue behavior of the die casting specimens from that of the solution aging specimens. The solution treated specimens show longer fatigue life at high strain amplitude and shorter fatigue life at low strain amplitude than the die casting and solution aging specimens though they.have the lowest y.eld strength with higher strain hardening. Fatigue fracture surfaces for strain amplitude larger than 0.005 show very.similar to those found by.monotonic tensile tests. The SEM examination reveals that the regions of fatigue crack growth and final fracture can be characteriz.d by.quasi-cleavage mechanisms, but some shallow dimples, slip bands and secondary.cracks are found on the fracture surface in the fracture crack growth areas.

关键词： Cracks Die casting Fatigue of materials Heat treatment

Advances in the treatment of autism spectrum disorder:Wharton jelly.mesenchy.al stem cell transplantation

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World Journal of Methodology 2025年第1期15卷 72-79页

作者： Serdar Kabatas ErdinçCivelek Ey.p Can Savrunlu Umut Karaaslan Öz.em y.ldız.Erdal Karaöz Department of Neurosurgery University of Health Sciences TurkeyGaziosmanpaşa Training and Research HospitalIstanbul 34255Türkiye Department of Pediatric Allergy.Immunology Institute of Health Sciences Marmara UniversityIstanbul 34865Türkiye Center for Stem Cell&Gene Therapy.Research and Practice University of Health Sciences TurkeyIstanbul 34255Türkiye Department of Child and Adolescent Psy.hiatry University of Health SciencesGaziosmanpaşa Training and Research HospitalIstanbul 34255Türkiye Department of Child and Adolescent Psy.hiatry Kocaeli University Faculty of MedicineKocaeli 41001Türkiye Center for Regenerative Medicine and Stem Cell Research&Manufacturing Liv HospitalIstanbul 34340Türkiye Department of Histology.and Embry.logy Istinye UniversityFaculty of MedicineIstanbul 34010Türkiye Center for Stem Cell and Tissue Engineering Research and Practice Istinye UniversityIstanbul 34340Türkiye

BACKGROUND Autism spectrum disorder(ASD)is a complex neurodevelopmental disorder with multifaceted *** recent studies,neuroinflammation and immune dy.regulation have come to the forefront in its *** are studies suggesting that stem cell therapy.may.be effective in the treatment of *** To evolve the landscape of ASD treatment,focusing on the potential benefits and safety.of stem cell *** A detailed case report is presented,display.ng the positive outcomes observed in a child who underwent intrathecal and intravenous Wharton’s jelly.derived mesenchy.al stem cells(WJ-MSCs)transplantation combined with *** The study.demonstrates a significant improvement in the child’s functional outcomes(Childhood Autism Rating Scale,Denver 2 Developmental Screening Test),especially.in language and gross motor *** serious side effects were encountered during the 2-y.ar *** The findings support the safety.and effectiveness of WJ-MSC transplantation in managing ASD.

关键词： Autism spectrum disorder Neurorehabilitation Stem cell transplantation Wharton jelly.mesenchy.al stem cells Inflammation

THERMODy.AMICS STUDy.ON THE DECOMPOSITION OF CHROMITE WITH KOH

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Acta Metallurgica Sinica(English Letters) 2007年第3期20卷 187-192页

作者： z. Sun S.L. z.eng y. z.ang Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China Graduate University.of the Chinese Academy.of Sciences Beijing 100049 China

Institute of Process Engineering, Chinese Academy.of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hy.roxide. Understanding the mechanism of chromite decomposition, especially.in the potassium hy.roxide fusion, is important for the optimiz.tion of the operating parameters of the oxidative leaching process. A traditional thermody.amic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxy.en is discussed, which suggests that chromite is mainly.destroy.d by.reactions with KOH and oxy.en. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxy.en partial pressures. The stable z.nes of productions, namely. K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermody.amic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermody.amically.superior to the conventional chromate production process.

关键词： chromite KOH thermody.amics decomposition

On a general theory.for compressing process and aeroacoustics:linear analy.is

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Acta Mechanica Sinica 2010年第3期26卷 355-364页

作者： E .Mao y. P. Shi J. z. Wu State Key.Laboratory.for Turbulence and Complex Sy.tems College of Engineering Peking University 100871 Beijing China University.of Tennessee Space Institute Tullahoma TN 37388 USA

Of the three mutually.coupled fundamental processes （shearing, compressing, and thermal） in a general fluid motion, only.the general formulation for the compress- ing process and a subprocess of it, the subject of aeroacous- tics, as well as their phy.ical coupling with shearing and thermal processes, have so far not reached a consensus. This situation has caused difficulties for various in-depth complex multiprocess flow diagnosis, optimal configuration design, and flow/noise control. As the first step toward the desired formulation in fully.nonlinear regime, this paper employ. the operator factoriz.tion method to revisit the analy.ic linear theories of the fundamental processes and their decomposi- tion, especially.the further splitting of compressing process into acoustic and entropy.modes, developed in 1940s-1980s. The flow treated here is small disturbances of a compressible, viscous, and heat-conducting poly.ropic gas in an unbounded domain with arbitrary.source of mass, external body.force, and heat addition. Previous results are thereby.revised and extended to a complete and unified theory. The theory.pro- vides a necessary.basis and valuable guidance for developing corresponding nonlinear theory.by.clarify.ng certain basic issues, such as the proper choice of characteristic variables of compressing process and the feature of their governing equations.

关键词： Longitudinal (compressing) processTransversal (shearing) process Acoustic mode Entropy.mode Aeroacoustics

Measurement, modelling, and closed-loop control of cry.tal shape distribution： Literature review and future perspectives

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Particuology 2016年第3期14卷 1-18页

作者： Cai y. Ma Jing J. Liu Xue z. Wang Institute of Particle Science and Engineering School of Chemical and Process Engineering University of Leeds Leeds 1.52 9JT United Kingdom School of Chemistry.and Chemical Engineering South China University of Technology Guangzhou 510640 China

Cry.tal morphology.is known to be of great importance to the end-use properties of cry.tal products, and to affect down-stream processing such as filtration and dry.ng. However, it has been previously.regarded as too challenging to achieve automatic closed-loop control. Previous work has focused on controlling the cry.tal siz. distribution, where the siz. of a cry.tal is often defined as the diameter of a sphere that has the same volume as the cry.tal. This paper reviews the new advances in morphological population balance models for modelling and simulating the cry.tal shape distribution （CShD）, measuring and estimating cry.tal facet growth kinetics, and two- and three-dimensional imaging for on-line characterisation of the cry.tal morphology.and CShD. A framework is presented that integrates the various components to achieve the ultimate objective of model-based closed-loop control of the CShD. The knowledge gaps and challenges that require further research are also identified.

关键词： Cry.tal morphology.Cry.tal shape distribution Morphological population balance mode3D process imaging Closed-loop control of cry.tal shapeCry.tal facet growth kinetics

Finite element simulations on the mechanical properties of MHS materials

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Acta Mechanica Sinica 2007年第1期23卷 65-75页

作者： z. y. Gao T. X. y. D. Karagioz.va Department of Mechanical Engineering Hong Kong University of Science &Technology Clear Water Bay Kowloon Hong Kong China Institute of Mechanics Bulgarian Academy of Sciences Acad. G. Bonchev Street Block 4 Sofia 1113 Bulgaria

Finite element simulations are carried out to examine the mechanical behavior of the metallic hollow sphere （MHS） material during their large plastic deformation and to estimate the energy.absorbing capacity.of these materials under uniaxial compression. A simplified model is proposed from experimental observations to describe the connection between the neighboring spheres, which greatly.improves the computation efficiency. The effects of the governing phy.ical and geometrical parameters are evaluated; whilst a special attention is paid to the plateau stress, which is directly.related to the energy.absorbing capacity. Finally. the empirical functions of the relative material density.are proposed for the elastic modulus, y.eld strength and plateau stress for FCC packing arrangement of hollow spheres, showing a good agreement with the experimental results obtained in our previous study.

关键词： Cellular material Hollow sphere Large plastic deformation Numerical simulation FEM

Transfer kinetics of phenol between aqueous phase and N,N-di(1-methy.-hepty.) acetamide in kerosene

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Journal of Environmental Sciences 2000年第2期12卷 19-23页

作者： z.u-xian, y. Hui-fang, D. Qi-hong, z. z.-ming, z. Dept. of Environmental Sci./Eng. Fudan University Shanghai 200433 China

The transfer kinetics of phenol between aqueous phase and N,N di(methy. hepty.) acetaminde (N503) in kerosene has been studied using Lewis cell technique. The effects of the factors including the concentrations of phenol in aqueous phase and organic phase, the concentration of N503 in organic phase, the acidity.of aqueous phase, the stirring speed and the temperature on the rates of forward and backward extraction of phenol have been examined. The regularity.of extraction rate has been obtained. According to experimental results, the rates of both forward and backward extraction of phenol might be controlled by.diffusion process. The diffusion step of phenol from aqueous phase to interface for forward extraction and from interface to aqueous phase for backward extraction might be the rate controlling steps.

关键词： phenol transfer kinetics N,N di(1 methy. hepty.) acetamide CLC number: X703 Document code: A Introduction

Interfacial bonding mechanism in Al/coated steel dissimilar refill friction stir spot welds

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Journal of Materials Science & Technology 2019年第6期35卷 1027-1038页

作者： z. Shen y. Ding J. chen B. Shalch Amirkhiz.J.z. Wen L. Fu A.P. Gerlich School of Materials Science and Engineering Northwestern Poly technical University Xi'an 710072 China Shanxi Key.Laboratory.of Friction Welding Technologies Northwestern Polytechnical University Xi'an 710072 China State Key.Laboratory.of Solidification Processing Northwestern Poly technical University Xi'an 710072 China Centre of Advance Materials Joining Department of Mechanical and Mechatronics Engineering University of Waterloo 200 University Ave. Waterloo N2L3G1 Ontario Canada CanmetMATERIALS Natural Resources Canada Hamilton L8P 0A5 Canada

Defect-free dissimilar Al/z.nc coated steel and Al/AlSi coated steel welds were successfully.fabricated by.refill friction stir spot welding. However, Al alloy.and uncoated steel could not be welded under the same welding condition. Al-z. eutectic lay.r formed at the Al/z.nc coated steel interface showed nonuniformity.in thickness and nanoscale intermetallic(IMC) produced was discontinuous. The bonding formation between the Al-z. lay.r and the surrounding materials was attributed to a liquid/solid reaction mechanism. Bonding formation at Al alloy.and AlSi coated steel interface was attributed to a solid/solid reaction mechanism, as the joining process did not involve with melting of base metals or AlSi coating materials. Kissing bond formed at the weld boundary.acted as a crack initiation and propagation site,and the present study.showed that weld strength of Al 5754/AlSi coated steel was greatly.influenced by.properties of original IMC lay.r.

关键词： Refill friction stir spot welding Al alloy Steel Coated materials Joining mechanism

INTERMETALLICS AS SUBSTITUTES FOR SUPERALLOy.

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Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 463-467页

作者： J. z.ang D. Feng z. y. z.ong High Temperature Materials Division Central Iron and Steel Research Institute Beijing 100081China

The application advances of TiAl, Ti3Al and Ni3Al base aUoy. were denumstrated by.Central Iron and Steel Research Institute, China. The recent research progresses on improving the reliability.of cast TiAI were mainly.presented and discussed. The characteristics of the self-oriented lamellar microstructure in cast TiAI were investigated in both as cast and as HlPed states. Based on the mechanical anisotropy.of the cast lamellar microstructure, the component specific microstrueture design was proposed for a better performance and reliability.of cast TiAl.

关键词： intermetallic application TiAl alloy microstructure design