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Journal of materials Science & Technology 2013年第10期29卷 898-902页

作者： C.S.Naveen m.l.dinesha H.S.Jayanna Department of PG Studies and Research in Physics Kuvempu University

ZnO nanoparticles of different sizes were prepared by varying the molar ratio of glycine and zinc nitrate hexahydrate as fuel and oxidizer （0.1, 0.8, 1.11, 1.3, 1.5, 1.7, 2.0） by simple solution combustion method. UV-Visible spectrophotometry studies show that, the band gap of the prepared ZnO nanoparticles increases with increasing fuel to oxidant （F/O） molar ratio up to 1.7 revealing the formation of ZnO nanoparticles. The decrease in band gap for the sample of F/O molar ratio 2.0 is due to an increase in particle size. Powder X-ray diffraction patterns of the prepared samples show the formation of single phase ZnO nanoparticles and the particle size decreases with increasing F/O molar ratio up to 1.7. Surface morphology of the prepared samples was studied by scanning electron microscopy and it was observed that, the porosity increases with increasing F/O molar ratio. DC electrical conductivity at room temperature and in the temperature range of 303-563 K was studied for all the samples and the results revealed that, the sample of F/O molar ratio 1.7 has low electrical conductivity at room temperature and high EAR （high temperature activation energy） compared to other samples.

关键词： ZnO nanoparticles Structural characterization Electrical conductivity

low-Frequency Dependence of Conductivity and Dielectric Properties of Polyaniline/ZnFe_(2)O_(4) Nanocomposites

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Chinese Physics letters 2011年第11期28卷 218-221页

作者： G.D.Prasanna H.S.Jayanna Ashok R lamani m.l.dinesha C.S.Naveen G.J.Shankaramurthy Department of PG Studies and Research in Physics Kuvempu UniversityShankarghatta-577451KarnatakaIndia Bapuji Institute of Engineering and Technology Davangere-577004KarnatakaIndia

Conducting polyaniline/ZnFe_(2)O_(4) nanocomposites are synthesized by using a simple and inexpensive one-step in-situ polymerization method in the presence of ZnFe2O4 nanoparticles.The structural,morphological and electrical properties of the samples are characterized by x-ray diffraction,Fourier transform infrared spectra and scanning electron microscopy.These results reveal the formation of polyaniline/ZnFe2O4 nanocomposites.The morphology of these samples is studied by scanning electron microscopy.Further,the ac conductivity(σac)of these composites is investigated in the frequency range of 1 kHz–10 mHz.The presence of polarons and bipolarons are responsible for the frequency dependence of ac conductivity in these nanocomposites.The ac conductivity is found to be constant up to 1mHz and thereafter it increases steeply.The ac conductivity of 0.695 S・cm^(−1) at room temperature is observed as the maxima for the polyaniline with 40wt%of the ZnFe2O4 nanocomposite.

关键词： composites ZnFe2O4 conductivity

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

In search of a pan-coronavirus vaccine:next-generation vaccine design and immune mechanisms

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Cellular & molecular Immunology 2024年第2期21卷 103-118页

作者： S.Cankat m.U.Demael l.Swadling Division of Infection and Immunity Institute of Immunity and TransplantationUniversity College LondonPears BuildingLondon NW32PPUK

members of the coronaviridae family are endemic to human populations and have caused several epidemics and pandemics in recent history.In this review,we will discuss the feasibility of and progress toward the ultimate goal of creating a pan-coronavirus vaccine that can protect against infection and disease by all members of the coronavirus family.We will detail the unmet clinical need associated with the continued transmission of SARS-CoV-2,mERS-CoV and the four seasonal coronaviruses(HCoV-OC43,Nl63,HKU1 and 229E)in humans and the potential for future zoonotic coronaviruses.We will highlight how first-generation SARS-CoV-2 vaccines and natural history studies have greatly increased our understanding of effective antiviral immunity to coronaviruses and have informed next-generation vaccine design.We will then consider the ideal properties of a pan-coronavirus vaccine and propose a blueprint for the type of immunity that may offer cross-protection.Finally,we will describe a subset of the diverse technologies and novel approaches being pursued with the goal of developing broadly or universally protective vaccines for coronaviruses.

关键词： Vaccine Coronavirus Cross-reactive immunity Cross-protection Universal

Effect of radiative loss mechanisms on FIR thermometric parameters of Nd3+-doped lithium tellurite glasses

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Journal of Rare Earths 2024年第7期42卷 1250-1257页

作者： C.Y.morassuti A.P.l Silva l.A.O.Nunes S.m.lima l.H.C.Andrade Optical and Photothermal Spectroscopy Group (GEOF) Center for Studies in Natural Resources (CERNA)State University of Mato Grosso do Sul(UEMS) Renato Archer Information Technology Center Institute of Physics of Sao Carlos University of S?o Paulo

Nd3+-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio（FIR） technique.Nevertheless,at high Nd3+concentrations,energy transfer（ET） processes such as optical reabsorption and cross-relaxation can affect the Nd3+emission,which has been little explored in the literature.Therefore,the present work investigated the use of Nd3+-doped tellurite glass(samples doped with Nd3+at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%) in fluorescence thermometers,in the temperature range from 299 to 371 K.The results indicate a strong dependence of the FIR parameters on the Nd3+concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd3+emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio4F5/2→4I9/2/4F3/2→4I9/2is observed for samples doped with higher amounts of Nd3+.The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd3+ions.

关键词： Fluorescence intensity ratio Judd-Ofelt Nd3+-doped tellurite glass Optical thermometry Rare earths

A comprehensive review on the processing-property relationships of laser strengthened magnesium

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Journal of magnesium and Alloys 2024年第1期12卷 1-34页

作者： Alessandro m.Ralls Aaksheta Agnel Pradeep l.menezes Department of mechanical Engineering University of Nevada RenoRenoNV 89557United States

Among the existing series of softer metals,magnesium(mg)has attracted much attention due to its impressive strength-to-weight ratio.However,due to its ease of deformability,mg tends to suffer from rapid degradation in a wide variety of abrasive and electrochemical environments.One method of improving its surface properties is through surface modification techniques.Among the existing techniques,laser shock peening(lSP)has been one of the most widely utilized processes due to its surface-hardening-like effects.Despite this understanding,a comprehensive review has yet to exist that encapsulates the strengthening mechanism of lSP for mg and its influence in degradation environments.This review aims to encapsulate the existing research around the lSP field for mg.Specifically,an understanding of the surface-strengthening effects in relation to its mechanical,tribological,corrosion,and tribo-corrosion characteristics is elucidated.Additionally,the feasibility of lSP for mg materials in critical industries is also discussed.Through this work,a novel understanding of lSP for mg can be understood,which can provide a future direction for research in this field.

关键词： laser shock peening magnesium Surface deformation Tribology microstructure

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 manufacturing.In the SPS process,interparticle diffusion of compressed particles is rapidly achieved due to the concept of Joule heating.Compared to traditional and additive manufacturing(Am)techniques,SPS gives unique control of the structural and microstructural features of mg components.By doing so,their mechanical,tribological,and corrosion properties can be tailored.Although great advancements in this field have been made,these pieces of knowledge are scattered and have not been contextualized into a single work.The motivation of this work is to address this scientific gap and to provide a groundwork for understanding the basics of SPS manufacturing for mg.To do so,the existing body of SPS mg literature was first surveyed,with a focus on their structural formation and degradation mechanisms.It was found that successful mg SPS fabrication highly depended on the processing temperature,particle size,and particle crystallinity.The addition of metal and ceramic composites also affected their microstructural features due to the Zener pinning effect.In degradative environments,their performance depends on their structural features and whether they have secondary phased composites.In industrial applications,SPS'd mg was found to have great potential in biomedical,hydrogen storage,battery,automotive,and recycling sectors.The 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 components.Despite these findings,the interactions of multi-composites on the processing-structure-property relationships of SPS mg is not well understood.In 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

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied mathematics and mechanics(English Edition) 2024年第1期45卷 197-216页

作者： C.G.PAVITHRA B.J.GIREESHA m.l.KEERTHI Department of PG Studies and Research in mathematics Kuvempu UniversityShankaraghatta 577451India Department of mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTm) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTm) trihybrid nanofluid magnetic field

Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

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Earth and Planetary Physics 2024年第1期8卷 204-214页

作者： A.m.Jorgensen TianRan Sun Y.Huang l.li R.Xu l.Dai Chi Wang New mexico Institute of mining and Technology SocorroNMUSA National Space Science Center Chinese Academy of SciencesBeijing 100190China Tsinghua University Beijing 100084China

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few spacecraft.This work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch analysis.If the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution reconstructions.In this paper we explore the reconstruction using,two,three,and four spacecraft.We show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.

关键词： magnetosheath tomography soft X-ray imaging SmIlE

Epidemiology of insertional and midportion Achilles tendinopathy in runners:A prospective cohort study

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Journal of Sport and Health Science 2024年第2期13卷 256-263页

作者： Wenbo Chen Kyra l.A.Cloosterman Sita m.A.Bierma-Zeinstra marienke van middelkoop Robert-Jan de Vos Department of Orthopaedic Surgery and Sports medicine Erasmus MC University Medical CenterRotterdam 3015GDthe Netherlands Department of General Practice Erasmus MC University Medical CenterRotterdam 3015GDthe Netherlands Department of Sports medicine Huashan HospitalFudan UniversityShanghai 200040China

Background:Achilles tendinopathy(AT)is a common problem among runners.There is only limited evidence for risk factors for AT,and most studies have not defined the AT subcategories.No study has compared the incidence and risk factors between insertional AT and midportion AT,though they are considered distinct.This study aimed to assess incidence and risk factors of AT based on data from a large prospective cohort.The secondary aim was to explore differences in risk factors between insertional and midportion AT.methods:Participants were recruited from among registered runners at registration for running events.Questionnaires were completed at baseline,1 month before the event,1 week before the event,and 1 month after the event.Information concerning demographics,training load,registered events,and running-related injuries were collected at baseline.The follow-up questionnaires collected information about new injuries.A pain map was used to diagnose midportion and insertional AT.The primary outcome was the incidence of AT.multivariable logistic regression analysis was applied to identify risk factors for the onset.Results:We included 3379 participants with a mean follow-up of 20.4 weeks.The incidence of AT was 4.2%.The proportion of insertional AT was 27.7%and of midportion AT was 63.8%;the remaining proportion was a combined type of insertional and midportion AT.men had a significantly higher incidence(5%,95%confidence interval(95%CI):4.1%-6.0%)than women(2.8%,95%CI:2.0%-3.8%).AT in the past12 months was the most predominant risk factor for new-onset AT(odds ratio(OR)=6.47,95%CI:4.27-9.81).This was similar for both subcategories of AT(insertional:OR=5.45,95%CI:2.51-11.81;midportion:OR=6.96,95%CI:4.24-11.40).Participants registering for an event with a distance of 10/10.55 km were less likely to develop a new-onset AT(OR=0.59,95%CI:0.36-0.97)or midportion AT(OR=0.47,95%CI:0.23-0.93).Higher age had a significant negative association with insertional AT(OR=0.97,95%CI:0.94-1.00).Conclusion:The incidence of new-onset AT

关键词： Achilles tendon injury Incidence Risk factor Running-related injury