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A comparison study of Ce/La and Ca microalloying on the bio-corrosion behaviors of extruded Mg-Zn alloys

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journal of Magnesium and Alloys 2020年第4期8卷 1269-1280页

作者： j.H.Chu L.B.Tong Z.H.jiang D.N.Zou Q.j.Wang S.F.Liu H.j.Zhang School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055China State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Key Lab of Automobile Materials College of Materials Science and EngineeringJilin UniversityNanling CampusChangchun 130025China

The influences of Ca and Ce/La microalloying on the microstructure evolution and bio-corrosion resistances of extruded Mg-Zn alloys have been systematically investigated in the current *** with single Ca or Ce/La addition,the Ca-Ce/La cooperative microalloying results in an outstanding grain refinement,because the fine secondary phase particles effectively hinder the recrystallized grain *** coarse Ca2Mg6Zn3 phases promote the formation of Ca3(PO4)2 or hydroxyapatite particles during the immersion process and accelerate the dissolution of the corrosion product film,which destroys its integrity and results in the deterioration of anti-corrosive *** Ce/La elements can be dispersed within the conventional Mg7Zn3 phases,which reduce the internal galvanic corrosion between Mg matrix and the secondary phases,leading to an obvious improvement of corrosion ***,the Ca-Ce/La cooperative microalloying achieves a homogenous fine-grained microstructure and improves the protective ability of surface film,which will pave a new avenue for the design of biomedical Mg alloys in the coming future.

关键词： Extruded Mg-Zn alloy Ca and Ce/La microalloying Microstructure evolution Bio-corrosion behaviors

Influence of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H_(2)O nanofluid on a flat surface in a porous medium:A stability analysis

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Chinese Physics B 2022年第4期31卷 404-413页

作者： Astick Banerjee Krishnendu Bhattacharyya Sanat Kumar Mahato Ali j.Chamkha Department of Mathematics Sidho-Kanho-Birsha UniversityPurulia 723104India Department of Mathematics Institute of ScienceBanaras Hindu UniversityVaranasi 221005India Faculty of Engineering Kuwait College of Science and TechnologyDoha DistrictKuwait

The nanofluid and porous medium together are able to fulfill the requirement of high cooling rate in many engineering ***,here the impact of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H_(2)O nanofluid on a flat surface in a porous medium is ***,the thermal radiation and viscous dissipation effects are *** problem governing partial differential equations are converted into self-similar coupled ordinary differential equations and those are numerically solved by the shooting *** computed results can reveal many vital findings of practical ***,dual solutions exist for decelerating unsteady flow and for accelerating unsteady and steady flows,the solution is *** presence of nanoparticles affects the existence of dual solution in decelerating unsteady flow only when the medium of the flow is a porous *** different shapes of nanoparticles are not disturbing the dual solution existence range,though it has a considerable impact on thermal conductivity of the *** shapes of nanoparticles act differently to enhance the heat transfer characteristics of the base fluid,i.e.,the water *** the other hand,the existence range of dual solutions becomes wider for a larger permeability parameter related to the porous *** the cooling rate of the heated surface,it rises with the permeability parameter,shape factor(related to various shapes of Cu-nanoparticles),and radiation *** surface drag force becomes stronger with the permeability ***,with growing values of nanoparticle volume fraction,the boundary layer thickness(BLT)increases and the thermal BLT becomes thicker with larger values of shape *** decelerating unsteady flow,the nanofluid velocity rises with permeability parameter in the case of upper branch solution and an opposite trend for the lower branch is *** thermal BLT is thicker with radiation *** to the ex

关键词： Cu-H_(2)O nanofluid various shapes of nanoparticles unsteady stagnation-point flow dual solutions stability analysis

Mid-infrared-perturbed molecular vibrational signatures in plasmonic nanocavities

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Light(Science & Applications) 2022年第1期11卷 127-135页

作者： Rohit Chikkaraddy Angelos Xomalis Lukas A.jakob jeremy j.Baumberg NanoPhotonics Centre Cavendish LaboratoryDepartment of PhysicsJJ Thompson AvenueUniversity of CambridgeCambridge CB30HEUK Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Mechanics of Materials and NanostructuresThunSwitzerland

Recent developments in surface-enhanced Raman scattering(SERS)enable observation of single-bond vibrations in real time at room *** contrast,mid-infrared(MIR)vibrational spectroscopy is limited to inefficient slow *** we develop a new method for MIR sensing using *** method utilizes nanoparticle-on-foil(NPoF)nanocavities supporting both visible and MIR plasmonic hotspots in the same nanogap formed by a monolayer of *** SERS signals from individual NPoF nanocavities are modulated in the presence of MIR *** strength of this modulation depends on the MIR wavelength,and is maximized at the 6–12μm absorption bands of SiO_(2) or polystyrene placed under the *** a single-photon lock-in detection scheme we time-resolve the rise and decay of the signal in a few 100 *** observations reveal that the phonon resonances of SiO_(2) can trap intense MIR surface plasmons within the Reststrahlen band,tuning the visible-wavelength localized plasmons by reversibly perturbing the localized few-nm-thick water shell trapped in the nanostructure *** suggests new ways to couple nanoscale bond vibrations for optomechanics,with potential to push detection limits down to single-photon and single-molecule regimes.

关键词： visible signature utilize

The impact of salps(Salpa thompsoni)on the Antarctic krill population(Euphausia superba): an individual-based modelling study

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Ecological Processes 2023年 680-695页

作者： Bruno Walter Pietzsch Aaron Schmidt jürgen Groeneveld Dominik Bahlburg Bettina Meyer Uta Berger Faculty of Environmental Sciences Institute of Forest Growth and Forest Computer Sciences Technische Universit?t Dresden Department of Ecological Modelling Helmholtz Centre for Environmental Research-UFZ Section Polar Biological Oceanography Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Institute for Chemistry and Biology of the Marine Environment (ICBM) Carl-Von-Ossietzky University Helmholtz Institute for Marine Functional Biodiversity (HIFMB)

Background Krill（Euphausia superba） and salps（Salpa thompsoni） are key macrozooplankton grazers in the Southern Ocean ecosystem. However, due to differing habitat requirements, both species previously exhibited little spatial overlap. With ongoing climate change-induced seawater temperature increase and regional sea ice loss, salps can now extend their spatial distribution into historically krill-dominated areas and increase rapidly due to asexual reproduction when environmental conditions are favorable. Understanding the potential effects on krill is crucial, since krill is a species of exceptional trophic significance in the Southern Ocean food web. Negative impacts on krill could trigger cascading effects on its predators and prey. To address this question, we combined two individual-based models on salps and krill, which describe the whole life cycle of salp individuals and the dynamic energy budget of individual krill. The resulting new model PEKRIS（PErformance of KRIll vs. Salps） simulates a krill population for 100 years under varying chlorophyll-a concentrations in the presence or absence of *** All of the investigated krill population properties（abundance, mean length, and yearly egg production）were significantly impacted by the presence of salps. On the other hand, salp density was not impacted if krill were present. The medians of krill population properties deviated during variable maximum chlorophyll-a density per year when salps were introduced by-99.9%（-234 individuals per 1000 m3） for krill density,-100%（-22,062 eggs per 1000 m3） for krill eggs and-0.9%（-0.3 mm） for mean length of *** If both species compete for the same food resource in a closed space, salps seem to inhibit krill populations. Further simulation studies should investigate whether this effect prevails if different phytoplankton sizes and consumption preferences of krill are implemented. Furthermore, direct predation of the two species or consumption of krill fe

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Principal Component Analysis of Ground Level Enhancement of Cosmic Ray Events

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Research in Astronomy and Astrophysics 2023年第3期23卷 155-169页

作者： R.E.Ugwoke A.A.Ubachukwu j.O.Urama O.Okike j.A.Alhassan A.E.Chukwude Department of Physics Federal University of Technology OwerriImo StateNigeria Department of Physics and Astronomy University of Nigeria.NsukkaNigeria Department of Industrial Physics Ebonyi State UniversityAbakalikiNigeria

We applied principal component analysis(PCA)to the study of five ground level enhancements(GLEs)of cosmic ray(CR)*** nature of the multivariate data involved makes PCA a useful tool for this study.A subroutine program written and implemented in the R software environment generated interesting principal *** of the results shows that the method can distinguish between neutron monitors(NMs)that observed Forbush decreases from those that observed GLEs at the same *** PCA equally assigned NMs with identical signal counts with the same correlation factor(r)and those with close r values equally have a close resemblance in their CR *** results further indicate that while NMs that have the same time of peak may not have the same r,most NMs that had the same r also had the same time of *** the second principal components yielded information on the differences between NMs having opposite but the same or close values of *** that had the same r equally had the tendency of being close in latitude.

关键词： routine equally identical

The mechanical behavior of nanoscale metallic multilayers:A survey

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Acta Mechanica Sinica 2015年第3期31卷 319-337页

作者： Q.Zhou j.Y.Xie F.Wang P.Huang K.W.Xu T.j.Lu State-Key Laboratory for Mechanical Behavior of Material Xi’an Jiaotong University State-Key Laboratory for Mechanical Structure Strength and Vibration Xi’an Jiaotong University

The mechanical behavior of nanoscale metallic multilayers （NMMs） has attracted much attention from both scientific and practical views. Compared with their monolithic counterparts, the large number of interfaces existing in the NMMs dictates the unique behavior of this special class of structural composite materials. While there have been a number of reviews on the mechanical mechanism of micro- laminates, the rapid development of nanotechnology brought a pressing need for an overview focusing exclusively on a property-based definition of the NMMs, especially their size- dependent microstructure and mechanical performance. This article attempts to provide a comprehensive and up-to-date review on the microstructure, mechanical property and plas- tic deformation physics of NMMs. We hope this review could accomplish two purposes：（1） introducing the basic concepts of scaling and dimensional analysis to scientists and engi- neers working on NMM systems, and （2） providing a better understanding of interface behavior and the exceptional qual- ities the interfaces in NMMs display at atomic scale.

关键词： Multilayer Interface Microstructure Mechanical behavior

Hydrogen production by catalytic decomposition of methane using a Fe-based catalyst in a fluidized bed reactor

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journal of Natural Gas Chemistry 2012年第4期21卷 367-373页

作者： D.Torres S.deLlobet j.L.Pinilla M.j.Lzaro I.Suelves R.Moliner Instituto de Carboquímica CSICMiguel Luesma Castn 450018 ZaragozaSpain

Catalytic decomposition of methane using a Fe-based catalyst for hydrogen production has been studied in this work. A Fe/Al2O3 catalyst previously developed by our research group has been tested in a fluidized bed reactor （FBR）. A parametric study ot the effects of some process variables, including reaction temperature and space velocity, is undertaken. The operating conditions strongly affect the catalyst performance. Methane conversion was increased by increasing the temperature and lowering the space velocity. Using temperatures between 700 and 900℃ and space velocities between 3 and 6 LN/（gcat·h）, a methane conversion in the range of 25%-40% for the gas exiting the reactor could be obtained during a 6 h run. In addition, carbon was deposited in the form of nanofilaments （chain like nanofibers and multiwall nanotubes） with similar properties to those obtained in a fixed bed reactor.

关键词： hydrogen production fluidized bed reactor metal catalysts

American government The Essentials james Q. Wilson, john j. Dilulio 8th ed.; postinaugural ed.

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American government The Essentials James Q. Wilson, John J. ...

Assembly and electrochemical testing of renewable carbon-based anodes in SIBs:A practical guide

2001年

作者： james Q. Wilson john j. Dilulio

来源：畅想之星图书光盘版（南... 评论

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journal of Energy Chemistry 2022年第12期75卷 457-477,I0012页

作者： Darío Alvira Daniel Antorán joan jManyà Aragón Institute of Engineering Research(I3A) Thermochemical Processes GroupUniversity of ZaragozaEscuela Politécnica Superior22071 HuescaSpain

Sodium-ion batteries(SIBs)are considered as a promising candidate to replace lithium-ion batteries(LIBs)in large-scale energy storage *** sodium resources and similar working principles make this technology attractive to be implemented in the near ***,the development of high-performance carbon anodes is a focal point to the upcoming success of SIBs in terms of power density,cycling stability,and *** knowledge in electrochemical and physicochemical techniques is required to properly evaluate the anode performance and move it in the right *** review aims at providing a comprehensive guideline to help researchers from different backgrounds(e.g.,nanomaterials and thermochemistry)to delve into this *** main components,lab configurations,procedures,and working principles of SIBs are ***,a detailed description of the most used electrochemical and physicochemical techniques to characterize electrochemically active materials is provided.

关键词： Sodium-ion battery Anode Hard carbon Electrochemical techniques Carbon characterization