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Spark Plasma Sintering of Mg-based Alloys:Microstructure,Mechanical Properties,Corrosion behavior,and Tribological Performance

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Journal of Magnesium and Alloys 2024年第2期12卷 405-442页

作者： Alessandro M.Ralls Mohammadreza Daroonparvar Pradeep l.Menezes Department of Mechanical Engineering University of Nevada RenoRenoNV89557United States

Within the past ten years,spark plasma sintering(SPS)has become an increasingly popular process for Mg *** the SPS process,interparticle diffusion of compressed particles is rapidly achieved due to the concept of Joule *** to traditional and additive manufacturing(AM)techniques,SPS gives unique control of the structural and microstructural features of Mg *** doing so,their mechanical,tribological,and corrosion properties can be *** great advancements in this field have been made,these pieces of knowledge are scattered and have not been contextualized into a single *** motivation of this work is to address this scientific gap and to provide a groundwork for understanding the basics of SPS manufacturing for *** do so,the existing body of SPS Mg literature was first surveyed,with a focus on their structural formation and degradation *** was found that successful Mg SPS fabrication highly depended on the processing temperature,particle size,and particle *** addition of metal and ceramic composites also affected their microstructural features due to the Zener pinning *** degradative environments,their performance depends on their structural features and whether they have secondary phased *** industrial applications,SPS'd Mg was found to have great potential in biomedical,hydrogen storage,battery,automotive,and recycling *** prospects to advance the field include using Mg as a doping agent for crystallite size refinement and using bulk metallic Mg-based glass powders for amorphous SPS *** these findings,the interactions of multi-composites on the processing-structure-property relationships of SPS Mg is not well *** total,this work will provide a useful direction in the SPS field and serve as a milestone for future Mg-based SPS manufacturing.

关键词： Spark plasma sintering Magnesium alloys Nanocrystalline Tribology Mechanical properties Corrosion

Highly Defective Dark TiO_(2) Modified with Pt: Effects of Precursor Nature and Preparation Method on Photocatalytic Properties

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Transactions of Tianjin University 2024年第2期30卷 198-209页

作者： E.D.Fakhrutdinova O.A.Reutova T.A.bugrova I.Yu.Ovsyuk l.S.Kibis O.A.Stonkus D.b.Vasilchenko O.V.Vodyankina V.A.Svetlychnyi National Research Tomsk State University TomskRussia 634050 Novosibirsk State University NovosibirskRussia 630090 boreskov Institute of Catalysis NovosibirskRussia 630090 Nikolaev Institute of Inorganic Chemistry NovosibirskRussia 630090

The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.

关键词： Dark(black)TiO_(2) Pulsed laser ablation Platinum reduction method Precursor type Photocatalysis Hydrogen evolution reaction

biomaterials and emerging technologies for tissue engineering and in vitro models

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bio-Design and Manufacturing 2024年第3期7卷 237-239页

作者： J.Miguel Oliveira Rui l.Reis 3b’s Research Group I3Bs-Research Institute on BiomaterialsBiodegradables and BiomimeticsHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3b’s-PT Government Associate laboratory 4806-909 Braga/GuimarãesPortugal

The latest advances in the field of biomaterials have opened new avenues for scientific breakthroughs in tissue engineer-ing which greatly contributed for the successful translation of tissue engineering products into the market/***-materials are easily processed to become similar to natural extracellular matrix,making them ideal temporary supports for mimicking the three-dimensional(3D)microenvironment required for maintaining the adequate cell/tissue functions both in vitro and in vivo^([1]).

关键词： breakthrough biomaterials engineer

A seed and soil model of loneliness in Alzheimer's disease

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Neural Regeneration Research 2024年第12期19卷 2575-2576页

作者： Hannah l.Apostolou Ian M.McDonough Department of Psychology The University of AlabamaTuscaloosaALUSA Department of Psychology Binghamton UniversityBinghamtonNYUSA

loneliness is classically defined as a result of perceiving a discrepancy between the desired quantity and quality of one's social life and actual social relationships(Perlman and Peplau,1984).lifespan research has indicated older adults are among the highest risk for experiencing loneliness because their social network size decreases more frequently than that of younger adults.

关键词： Alzheimer younger soil

Error-based adaptive optimal tracking control of nonlinear discrete-time systems

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Science China(Information Sciences) 2024年第1期67卷 154-167页

作者： Chun lI Jinliang DING Frank l.lEWIS Tianyou CHAI State Key laboratory of Synthetical Automation for Process Industries Northeastern University UTA Research Institute The University of Texas at Arlington

In this paper,for the output tracking problem of nonlinear discrete-time systems,a performance index is newly defined using the adaptive dynamic programming(ADP) technique to completely eliminate tracking errors in *** contrast to traditional definitions of performance indices in other ADP-based methods,the proposed performance index is not only designed from the perspective of output tracking errors but also introduced errors of system states and control inputs at adjacent stages,which is suitable for practical situations in many industrial applications,such as the alumina production,the flotation process,and the mineral grinding *** proved that the obtained controller can make the system output fully track the given reference trajectory by applying the iterative criteria of the ADP *** addition,the proposed algorithm was implemented using a data-driven technique and neural networks to avoid analyzing and deducing the complicated dynamics of actual industrial ***,using historical data for a forced-circulation evaporation system in the alumina production process,the effect of the proposed approach was verified through a numerical simulation and compared with that of the proportional-integral controller.

关键词： adaptive dynamic programming iterative criteria performance index tracking errors tracking problem

Enhancing force sensing in a squeezed optomechanical system with quantum nondemolition measurement

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Communications in Theoretical Physics 2024年第1期76卷 49-60页

作者： Shi-lei Chao Zi-Hao li Xin-You lü School of Physics Huazhong University of Science and Technology430074 WuhanChina

A theoretical scheme is proposed to enhance the sensitivity of force sensors with quantum nondemolition measurement(QND)in an optomechanical setup assisted by four-tone optical driving and an optical parametric amplifier(OPA).With the help of special drive,the system can be simplified as the typical type of QND for force sensing,so that the backaction noise can be evaded to surpass the standard quantum ***,the added noise can be suppressed owing to the modified optical susceptibility resulting from the *** introducing two oscillators coupling with two charged bodies respectively,the signal can be enhanced with the nonlinearity caused by Coulomb interaction,while the noise presents an exponential ***,considering the homodyne detection effect,the range of system parameters and frequency bands will be *** present investigation may provide a route toward simultaneously evading backaction noise,reducing the mechanical thermal noise,and enhancing the external signal,which can be an alternative design for sensitive devices.

关键词： force sensing optical parametric amplifier quantum non-demolition measurement optomechanical system

Deep bed filtration model for cake filtration and erosion

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 355-372页

作者： l.I.KUZMINA Y.V.OSIPOV A.R.PESTEREV Department of Applied Mathematics HSE UniversityMoscow 101000Russia Department of Computer Science and Applied Mathematics Moscow State University of Civil EngineeringMoscow 129337Russia

Many phenomena in nature and technology are associated with the filtration of suspensions and colloids in porous media. Two main types of particle deposition,namely, cake filtration at the inlet and deep bed filtration throughout the entire porous medium, are studied by different models. A unified approach for the transport and deposition of particles based on the deep bed filtration model is proposed. A variable suspension flow rate, proportional to the number of free pores at the inlet of the porous medium, is considered. To model cake filtration, this flow rate is introduced into the mass balance equation of deep bed filtration. For the cake filtration without deposit erosion,the suspension flow rate decreases to zero, and the suspension does not penetrate deep into the porous medium. In the case of the cake filtration with erosion, the suspension flow rate is nonzero, and the deposit is distributed throughout the entire porous medium. An exact solution is obtained for a constant filtration function. The method of characteristics is used to construct the asymptotics of the concentration front of suspended and retained particles for a filtration function in a general form. Explicit formulae are obtained for a linear filtration function. The properties of these solutions are studied in detail.

关键词： deep bed filtration cake filtration porous medium particle deposition and erosion analytical solution concentration front

Modelling of the elastoplastic behaviour of the bio-cemented soils using an extended Modified Cam Clay model

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2184-2197页

作者： Xuerui Wang Christian b.Silbermann Thomas Nagel Udo Nackenhorst Institute of Mechanics and Computational Mechanics Leibniz UniversitätHannoverAppelstr.9aHannover30167Germany Gesellschaft für Anlagen-und Reaktorsicherheit(GRS)gGmbH Theodor-Heuss-Straße 4Braunschweig38122Germany Geotechnical Institute Technische Universität BergakademieFreibergGustav-Zeuner-Str.1Freiberg09599Germany

An elastoplastic constitutive model based on the Modified Cam Clay(MCC)model is developed to describe the mechanical behaviour of soils cemented via microbially induced calcite precipitation(MICP).It considers the increase of the elastic stiffness,the change of the yield surface due to MICP cementation and the degradation of calcium carbonate bonds during ***,to capture the typical contraction-dilation transition in MICP soils,the original volumetric hardening rule in the MCC model is modified to a combined deviatoric and volumetric hardening *** model could reproduce a series of drained triaxial tests on MICP-treated soils with different calcium carbonate ***,we carry out a parametric study and observe numerical instability in some *** combination with an analytical analysis,our numerical modelling has identified the benefits and limitations of using MCCbased models in the simulation of MICP-cemented soils,leading to suggestions for further model development.

关键词： Microbially induced calcite precipitation(MICP) Elastoplasticity Modified cam clay(MCC) OpenGeoSys MFront Contraction-dilation transition

Association between fundamental motor skills and physical activity in the early years:A systematic review and meta-analysis

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Journal of Sport and Health Science 2020年第6期9卷 542-552页

作者： Dan Jones Alison Innerd Emma l.giles liane b.Azevedo School of Health and life Sciences Teesside UniversityMiddlesbrough TS13BXUK

background:Physical activity(PA)in the early years is associated with a range of positive health *** motor skill(FMS)competence is associated with PA and is theorized to be driven by PA in the early years and vice versa in mid to late ***,to date,no studies have meta-analyzed the association between PA and FMS in the early ***:Six electronic databases were searched for articles published up to April ***-sectional and longitudinal studies were included if they targeted children(ages 3-6 year)as the population of the study and assessed the association between objectively measured PA and *** FMS,total physical activity(TPA),and moderate-to-vigorous physical activity(MVPA)data were meta-analyzed using a random effects ***:We identified 24,815 titles and *** total,19 studies met the inclusion criteria,including 14 cross-sectional and 4 longitudinal studies,as well as 1 study with cross-sectional and longitudinal *** was a significant but small positive association between FMS and MVPA(r=0.20,95%confidence interval(CI):0.13-0.26)and TPA(r=0.20,95%CI:0.12-0.28).Findings from longitudinal studies revealed that PA drives FMS in early *** was explored in 1 study,which found that perceived motor competence did not mediate the association between FMS and ***:Using a meta-analysis,this study is the first to show a positive association between FMS,MVPA,and TPA in the early years of childhood,suggesting that the association begins at an early *** evidence from longitudinal studies supports the theory that PA drives FMS in the early years of *** evidence is needed from large studies to track PA and FMS until mid to late childhood and to explore the mediators of this association.

关键词： Early years Fundamental motor skills Physical activity