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journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.jeong S.W.Lee W.j.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

A marathon,not a sprint:Increasing population physical activity as a legacy of sports mega-events

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journal of Sport and Health Science 2024年第6期13卷 732-735页

作者： Fiona C.Bull Paul j.Simpson Physical Activity Unit Department of Health PromotionWorld Health OrganizationGeneva CH-1211Switzerland The BMj London WC1H 9JPUK

*** matters The withdrawal of Australia as hosts for the Commonwealth Games in 2026 demonstrates that large international sporting events are more than just sporting mastery,medals,and *** also matters.1 The cost of hosting a major international tournament is eye-wateringly *** governments need to show that the billions of dollars of investment deliver a return beyond sporting glory to justify the resources that are spent.

关键词： return dollar sport

Physical activity with or without dietary intervention for the prevention of cardiovascular diseases

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journal of Sport and Health Science 2024年第6期13卷 753-755页

作者： Carl j.Lavie Salvatore Carbone Leandro Slipczuk The john Ochsner Heart and Vascular Institute Ochsner Clinical Schoolthe University of Queensland School of MedicineNew OrleansLA 70121USA Department of Kinesiology and Health Sciences College of Humanities and SciencesVirginia Commonwealth UniversityRichmondVA 23284USA Montefiore Health System/Albert Einstein College of Medicine BronxNY 10461USA

We and others have published extensively on the benefits of physical activity(PA),exercise training,and cardiorespiratory fitness(CRF)to decrease the prevalence of cardiovascular diseases(CVDs)and CVD and all-cause morbidity and mortality.^(1-5)Both PA and CRF are important;however,CRF,which is mostly obtained through PA,although there is a genetic component,seems to be even more important than PA for predicting prognosis.^(1,4-6)Certainly,the wealth of data from across the world has indicated that increasing PA to enhance CRF while mitigating sedentary behavior would go a long way to lessen the world-wide obesity epidemic and reduce CVD and all-cause mortality.

关键词： mortality prevention diseases

On the Trail of Self-Directed Online Learners

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ECNU Review of Education 2024年第2期7卷 406-419页

作者： Curtis j.Bonk 朱美娜 School of Education Indiana University201 N.Rose AvenueBloomingtonIN 4740lUSA Wayne State University

Purpose We describe a series of more than a dozen studies on self-directed online learning spanning over a ***/Approach/Methods We incorporated surveys,interviews,focus groups,and content analyses into these research studies,which initially targeted the goals,motivations,and challenges of learners using open educational resources and OpenCourseWare and then focused on learning from massive open online courses(MOOCs).This research accelerated after creating a database of over 3,000 MOOC instructors,through which we explored cultural sensitivity and personalization practices in MOOCs as well as instructional design considerations and challenges,MOOC instructor professional development and career development,instructor motivation and engagement,and student and instructor perceptions of self-directed *** This study reveals that self-directed online learners(SDOLs)seek learning environments offering freedom,choice,control,and a sense of autonomy and that both learners and instructors have intrinsic motivation for engaging in open online learning ***/Value Based on this research with both MOOC instructors and MOOC learners,we offer instructional design guidelines to address SDOLs’needs and assist in efforts to foster a new generation of SDOLs.

关键词： MOOCs motivation online learning self-directed learning self-management self-monitoring

CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and Pt)

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journal of Rare Earths 2024年第9期42卷 1669-1681,I0002页

作者： j.C.Martínez-Munuera M.P.Yeste A.García-García MCMA Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of AlicanteCarretera de San Vicente del Raspeig s/n03690San Vicente del RaspeigAlicanteSpain Solid Chemistry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of CádizAp.40E-11510Puerto RealCádizSpain

In this work,several ceria-zirconia based catalysts with very lo w(and equimolar) metal contents were prepared,characterised and tested for the CO oxidatio n reaction(under lean and stoichiometric conditions),trying to emulate those conditions found in a diesel oxidation catalyst(DOC) system from a diesel engine and those encountered under gasoline exhaust(λ=1).The metals chosen are Cu,Co,Ag and Pt(as a reliable benchmark).The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion(Ag-catalyst seems to present a low level of dispersion).This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H_(2)-TPR ***,the order in catalytic activity(Cu>Ag>Co≈Pt>>support) seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported metal catalysts is ***,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H_(2)-TPR measurements.

关键词： CO oxidation Low metal content Ceria-zirconia Copper species OSC parameter Rare earths

Effects of pyrethroid and organophosphate insecticides on reared black soldier fly larvae(Hermetia illucens)

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Insect Science 2024年第3期31卷 817-834页

作者： Nathan Meijer Lisa Zoet Theo de Rijk Paul Zomer Deborah Rjkers H.j.van der Fels-Klerx joop j.A.van Loon Wageningen Food Safety Research(WFSR) Part of Wageningen University and ResearchWageningenThe Netherlands Bestico B.V. Industrieweg 6Berkel en RodenrjsThe Netherlands Plant Sciences Group Laboratory of EntomologyWageningen UniversityWageningenTheNetherlands

Black soldier fly larvae(Hermetia illucens)receive growing interest as a potential alternative animal feed *** insects may be exposed to insecticide residues in the rearing *** study aimed to investigate the effects of six different pyrethroid and organophosphate insecticides on this insect species'*** toxicity of two"model"substances for each of these classes(cypermethrin;pirimiphosmethyl)was quantified,with and without the synergist piperonyl butoxide(PBO).Critical effect doses corresponding to 10%yield(CED10)for cypermethrin(0.4 mg/kg)and pirimiphos-methyl(4.8 mg/kg)were *** addition of PBO to cypermethrin enhanced its relative potency with a factor *** data were compared against the relative toxicity of two analogue substances in each class(permethrin,deltamethrin;chlorpyrifosmethyl,malathion).Results suggest that exposure to concentrations complying with legal limits can cause significant reductions in *** to multiple substances at lower concentrations resulted in negative additive and synergistic *** the tested substances,deltamethrin was most toxic,causing 94%yield at 0.5 mg/*** results suggested that transfer of tested substances to the larval biomass was substance-and concentration-specific,but appeared to be correlated to reduced yields and the presence of *** of organophosphates was overall low(justing legally allowed maximum residue levels in insect feed.

关键词： feed insects pesticides rearing substrate

Interpretation and compensation of backlash error data in machine centers for intelligent predictive maintenance using ANNs

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Advances in Manufacturing 2015年第2期3卷 97-104页

作者： Ke-Sheng Wang Zhe Li jФrgen Braaten Quan Yu Knowledge Discovery Laboratory Department of Production and Quality EngineeringNorwegian University of Science and Technology Key Laboratory of Intelligent Manufacturing and Robotics Shanghai University

It is especially significant for a manufacturing company to select a proper maintenance policy because maintenance impacts not only on economy, reliability and availability but also on personnel safety. This article re- ports on research in the backlash error data interpretation and compensation for intelligent predictive maintenance in machine centers based on artificial neural networks （ANNs）. The backlash error, measurement system and prediction methods are analyzed in detail. The result indicates that it is possible to predict and compensate for the backlash error in both forward and backward directions in machine centers.

关键词： Backlash error Artificial neural network(ANN) Machine centers Predictive maintenance

Fecal tumor M2 pyruvate kinase is not a specific biomarker for colorectal cancer screening

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World journal of Gastroenterology 2007年第19期13卷 2768-2769页

作者： Yogesh M Shastri jürgen M Stein Department of Medicine I-ZAFES Division of Gastroenterology and Clinical Nutrition Johann Wolfgang Goethe-University Hospital Frankfurt am Main Germany

TO THE EDITORWe read with great interest and a bit of surprise the article by Tonus et al. We would share herein our comments about it. The specificity of the fecal tumor M2 pyruvate kinase 0VI2-PK） reported by Tonus et al for diagnosing colorectal cancer （CRC） is 93%. This is considerably higher than in any of the previously published studies. In our work, the maximum specificity of fecal M2- PK is 78% （Table 1）. There is a vast difference of 15% between the previous studies and the current study of Tonus et al, which is difficult to explain. We are skeptical about such a high specificity reported by the authors.

关键词： Gastroenterology

Background removal from global auroral images:Data-driven dayglow modeling

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Earth and Planetary Physics 2024年第1期8卷 247-257页

作者： A.Ohma M.Madelaire K.M.Laundal j.P.Reistad S.M.Hatch S.Gasparini S.j.Walker Birkeland Centre for Space Science Department of Physics and TechnologyUniversity of BergenBergenNorway

Global images of auroras obtained by cameras on spacecraft are a key tool for studying the near-Earth ***,the cameras are sensitive not only to auroral emissions produced by precipitating particles,but also to dayglow emissions produced by photoelectrons induced by *** emissions and scattered sunlight can contribute to the background *** fully utilize such images in space science,background contamination must be removed to isolate the auroral *** we outline a data-driven approach to modeling the background intensity in multiple images by formulating linear inverse problems based on B-splines and spherical *** approach is robust,flexible,and iteratively deselects outliers,such as auroral *** final model is smooth across the terminator and accounts for slow temporal variations and large-scale asymmetries in the *** demonstrate the model by using the three far ultraviolet cameras on the Imager for Magnetopause-to-Aurora Global Exploration(IMAGE)*** method can be applied to historical missions and is relevant for upcoming missions,such as the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.

关键词： aurora dayglow modeling global auroral images far ultraviolet images dayglow removal

Spectral Gap of the Largest Eigenvalue of the Normalized Graph Laplacian

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Communications in Mathematics and Statistics 2022年第3期10卷 371-381页

作者： jürgen jost Raffaella Mulas Florentin Münch Max Planck Institute for Mathematics in the Sciences LeipzigGermany

We offer a new method for proving that the maxima eigenvalue of the normalized graph Laplacian of a graph with n vertices is at least n+1/n−1 provided the graph is not complete and that equality is attained if and only if the complement graph is a single edge or a complete bipartite graph with both parts of size n−1/*** the same method,we also prove a new lower bound to the largest eigenvalue in terms of the minimum vertex degree,provided this is at most n−1/2.

关键词： Spectral graph theory Normalized Laplacian Largest eigenvalue Sharp bounds