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Co-Doped ZnO nanoparticles:Structural,Morphological,Optical,Magnetic and Antibacterial Studies

journal of Materials Science & Technology 2014年第11期30卷 1108-1117页

作者： n.Mohamed Basith j.judith Vijaya l.john Kennedy M.Bououdina S.jenefar V.Kaviyarasan Catalysis & nanomaterials Research laboratory Department of ChemistryLoyola College (Autonomous) P.G.& Research Department of Chemistry The New College (Autonomous) Materials Division School of Advanced SciencesVellore Institute of Technology (VIT) UniversityChennai Campus nanotechnology Centre University of BahrainPO Box 32038Bahrain Department of Physics College of ScienceUniversity of BahrainPO Box 32038Bahrain Centre for Advanced Studies in Botany University of Madras

Un-doped and Co-doped ZnO nanoparticles （nPs） with different weight ratios （0.5, 1.0, 1.5, and 2.0 wt% of Co） were synthesized by a facile and rapid microwave-assisted combustion method using urea as a fuel. The prepared nPs were characterized by X-ray diffraction （XRD）, high resolution scanning electron microscopy （HR-SEM）, energy dispersive X-ray analysis （EDX）, diffuse reflectance spectroscopy （DRS）, photoluminescence （Pl） spectroscopy and vibrating sample magnetometry （VSM）. XRD patterns refined by the Rietveld method indicated that Co-doped ZnO had a single pure phase with wurtzite structure suggesting that Co^2＋ ions would occupy Zn^2＋ ionic sites within the ZnO crystal lattice. Interestingly, the morphology was found to convert substantially from grains to nanoparticles with close-packed periodic array of hexagonal-like shape and then into randomly distributed spherical nPs with the variation of Co-content. The optical band gap estimated using DRS was found to be red-shifted from 3.22 eV for the un-doped ZnO nPs then decrease up to 2.88 eV with increasing Co-content. Pl spectra showed a strong green emission band thus confirming the formation of pure single ZnO phase. Magnetic studies showed that Co-doped ZnO nPs exhibited room temperature ferromagnetism （RTFM） and that the saturation magnetization attained a maximum value of 2.203 × 10^-3 emu/g for the highest Co-content. The antibacterial studies performed against a set of bacterial strains showed that the 2.0 wt% Co-doped ZnO nPs possessed a greater antibacterial effect.

关键词： nanoparticles Optical properties Ferromagnetism Antibacterial activity

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leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris l. under different soil moisture levels near nairobi, Kenya

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journal of Environmental Sciences 1999年第4期11卷 449-456页

作者： M.M.Muniafu j.n.M.Macharia C.j.Stigter G.l.Coulson Department of Botany University of NairobiNairobiKenya TTMI-Project Department of MeteorologyWageningen Agricultural UniversityDuivendaal 26701 AP WageningenNetherlands T TMI-Project Departmen t of BotanyUniversi ty of Nai robiKenya

leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris l. cv GlP\|2 under two soil moisture levels in two contrasting seasons near nairobi, Kenya were investigated. The experiment confirms that dry weights and yields of Phaseolus vulgaris are limited by a drought induced decrease in leaf area, leading to less radiation interception as a source for assimilation. However, photosynthetic efficiency in Phaseolus vulgaris also appears to decrease and to contribute to these effects. Finally, an even larger decreases of economic efficiency as obtained in the second season, where stress lasted much later into the season, reveals that such a drought also limits considerably the partitioning and translocation of assimilates to the seeds of Phaseolus vulgaris. The efficiencies obtained are in line with the better literature data for other crops.

关键词： economic efficiency Phaseolus vulgaris l. photosynthetic efficiency radiation absorption/interception tube solarimeters

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Application of a new reagent for analysis of oxygen presence in a lowcarbon steel wire rod

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journal of Iron and Steel Research International 2021年第6期28卷 729-738页

作者： M.I.Dávila-Pérez H.j.Vergara-Hernández O.Vázquez-Gómez F.Reyes-Calderón E.lópez-Martínez j.M.Salgado-lópez national Technology of Mexico/T.I.of Morelia Morelia 58120MichoacanMexico national Council for Science and Technology COnACYT Mexico City 03940Mexico Isthmus University Santo Domingo TehuantepecOaxaca 70760Mexico Engineering and Industrial Development Center CIDESI Santiago de Queretaro 76125QueretaroMexico

A microstructural analysis was performed to determine the presence of oxygen in a wire rod section of AISI 1008 steel with a surface mechanical failure produced during wire *** failure zone was analyzed by comparison using three different attack reagents:alkaline sodium chromate(ASC),ASC with hydrogen peroxide and amyl alcohol,and a solution of nitric acid in ethyl *** reagents were applied in samples in the failure zone,showing different types of zones in regions with internal and superficial defects such as carbides,pores,cracks,deformation,and detachment zones,indicating the possible presence of *** areas identified were observed by means of an optical microscope and were correlated with the content of elements that were present in the region using a scanning electron microscope and a scattered X-ray energy spectrometer,which determined that the areas identified by chromate sodium correspond to regions with a high concentration of oxygen and slag-forming elements such as silicon,aluminum,and iron;this is associated with the presence of oxygen in the oxide *** was also observed that the ASC and the modified ASC solution with hydrogen peroxide and amyl alcohol could identify areas with a high presence of oxides,while the nitric acid solution only identified the steel *** modified ASC solution is an alternative to identify the presence of chemical variants of oxygen because the conventional formulation is unstable and has a too short shelf life,and therefore,its application must be carried out at the time of preparation.

关键词： Etching Alkaline sodium chromate Oxide presence Internal defect

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Multi-isotope and geochemical approach to the magma source and tectonic setting of Proterozoic anorthosite massifs and AnorthositeMangerite-Charnockite-Granite(AMCG)suites

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Geoscience Frontiers 2024年第6期15卷 2-21页

作者： l.A.Elizondo-Pacheco l.A.Solari R.González-Guzmán H.l.He E.Becerra-Torres j.A.Ramírez-Fernández R.Maldonado Posgrado en Ciencias de la Tierra Instituto de GeocienciasUniversidad Nacional Autónoma de MéxicoSantiago de Querétaro 76230Mexico Instituto de Geociencias Universidad Nacional Autónoma de MéxicoSantiago de Querétaro 76230Mexico Departamento de Geología División de Ciencias de la TierraCICESEEnsenada 22860Mexico School of Earth Sciences Yunnan UniversityKunming 650500PR China Yunnan International joint laboratory of Critical Mineral Resource Kunming 650500PR China Escuela nacional de Estudios Superiores Unidad juriquilla Universidad Nacional Autónoma de MéxicoSantiago de Querétaro 76230México Facultad de Ciencias de la Tierra Universidad Autónoma de Nuevo LeónLinares 67700Mexico Instituto de Geología Universidad Nacional Autónoma de MéxicoCiudad de México 04510Mexico

The occurrence of massif-type anorthosite intrusions is a widespread Proterozoic *** are usually associated with gabbroic,charnockitic,and granitic rocks,comprising the so-called anorthositemangerite-charnockite-granite(AMCG)*** these rocks have been extensively studied worldwide,several aspects concerning their formation remain *** them,the magma source and the tectonic setting are the most *** evaluate these issues,we first compiled geochemical and isotopic data of Proterozoic anorthosite massifs and AMCG suites worldwide and stored it in a database named *** plethora of data allows us to make some important *** argue that the wide-ranging multi-isotopic composition of this group of rocks reflects varying proportions of juvenile mantle-derived melts and crustal *** interpret that the precursor magmas of most massive anorthosite bodies and associated mafic rocks have a mantle-dominated ***,we highlight that a crustal component is indispensable to generate these *** variable amounts of this material during succeeding multi-stage assimilation-fractional crystallization(AFC)processes gives these intrusions their typical mantle-crustal hybrid isotopic *** contrast,a crustaldominant origin with a complementary mantle component is interpreted for most MCG *** summary,the isotopic information in datAMCG indicates that both sources are necessary to generate AMCG ***,we suggest that hybridized magmas with different mantle-crust proportions originate these *** interpretation might offer a more nuanced and accurate depiction of this phenomenon in future work instead of choosing a single-sourced model as in the past ***,tectonomagmatic diagrams suggest that the rocks under study were likely generated in a tectonic environment that transitioned between collision and post-collisional extension,sometimes involving subduction-modified ma

关键词： Massif-type anorthosite Anorthosite-granite suite Magmatic sources Hybridized magmas Tectonic setting Post-orogenic extension

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Organic light Emitting Diodes with lithium Contained Alq3 as Electron Injection layer

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Chemical Research in Chinese Universities 2002年第2期18卷 121-123页

作者： Zugang liu j.l.Pinto Department of Materials University of OxfordParks RoadOxford OX13PFUK Departamento de Física Universidade de Aveiro3810194 AveiroPortuga

lnovel lithium doped tris 8 hydroxylquinoline aluminium(Alq3:li) layer is deposited between emission layer and electron injection aluminium electrode as an electron injection assistant layer in different organic light emitting diodes(OlED) to lower the electron injection barrier. In these devices, Alq3 is used as emission layer, and a bilayer film of n,n bis (1 naphhyl) n,n diphenyl 1,1 biphenyle 4,4' diamine(nPB) and 4,4,4' tris(3 methyl phenylphenylamino) triphenylamine( m MTDATA) used as hole transport layer(HTl). The electroluminescent performance of devices with different thicknesses of Alq3∶li shows that the insertion of the lithium doped Alq3 layer can reduce the turn on voltage by at least 2 volts, and the stability of devices with this lithium doped Alq3 layer is improved too. It can also change the efficiency of devices. Compared with an ultra thin lithium fluoride(liF) layer, Alq3∶li sheet gives similar effects but higher efficiency and can be much thicker and hence it is easier to control the deposition.

关键词： Organic light emitting diodes lithium layer Alq3 EI

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PHYSICAl SIMUlATIOn BASED InTEllIGEnT SYSTEM FOR THE PREDICTIOn OF SHEET METAl DRAWInG CAPABIlITY

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Acta Metallurgica Sinica(English letters) 2000年第2期13卷 451-458页

作者： D.lv D.n.He X.j.Bao Y.Q.Zhang X.Y.Ruan j.l.Cheng j.Y.jiang national Die&Mold CAD Engineering Research Center Shanghai Jiaotong UniversityShanghai 200030China Shanghai Volkswagen Automotive Company limited Shanghai 201805China

With the combination of a new theoretical formula, physical simulation experiments, the technology of artificial neural network and database, an intelligent system for the prediction of sheet metal drawing capability is constructed for the first time. A modified criterion for sheet metal drawing capability is proposed in this paper, namely, the Technological limiting Drawing Ratio, TlDR = f(R, n, s, t, F, μ,r_d,r_p…). Based on the studies of other scholars, a new formula is derived to predict the TlDR in this paper. Then a series of orthogonal physical simulation experiments are designed to investigate the effect of technological parameters on the TlDR, and the results are analyzed in the paper. Then the predicting system is constructed with the combination of the theoretical formula, orthogonal experiments, the technology of artifocial neural network and database. The predicted results show good agreements with experimental data, so it can be used to avoid the blindness in the selection of sheet metal before stamping. The system operates under the Windows operating system, and it supports the mechanism of Client/Server as well as Intranet, so the system has high engineering value.

关键词： TlDR theoretical analysis physical simulation orthogonal experiments neural network database predicting system

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ElECTROCHEMICAl nOISE FEATURES OF PURE AlUMInUM DURInG PITTInG CORROSIOn In nEUTRAl naCl SOlUTIOn

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Acta Metallurgica Sinica(English letters) 2003年第1期16卷 20-30页

作者： F.H.Cao Z.Zhang Y.l.Cheng j.F.li j.Q.Zhang j.M.Wang C.n.Cao Department of Chemistry Zhejiang UniversityHangzhou 310027China State Key laboratory for Corrosion and Protection of Metals Institute of Metal ResearchThe Chinese Academy of SciencesShenyang 110016China

Spontaneous electrochemical noise (En) can be a rich source of information concerning the processes simultaneously occurring at a corroding interface. Potential noise fluctuations during the free corrosion of pure aluminum in different concentration of neutral sodium chloride solution are investigated, and the breakdown and restoration of passive metal's film are studied using potentiodynamic scanning (PDS) measurements and electrochemical impedance spectroscopy (EIS) technique. Two capacitance loops are observed in the nyquist plots in two kinds of concentration, and the corrosion process is under activation control at first, then become diffusion control within the oxide film and corrosion products of (Al(OH)p-mCl-m) accumulated on the surface of the corroding electrode. It is suggested that the pitting corrosion is much easier to occur for pure aluminum in 7.0wt% than in 2.0wt% naCl solution, and the high concentration of chloride ion in solution inhibits the repassivation of a metastable pit. The corrosion rate deterministic step does not involve Cl-.

关键词： pure aluminum pitting corrosion electrochemical noise electrochemical impedance spectroscopy potentiodynamic scanning

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EFFECT OF QUEnCHInG TEMPERATURE On SHAPE MEMORY EFFECT OF Fe-18Mn -5Si-8Cr-4ni AllOY

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Acta Metallurgica Sinica(English letters) 1999年第5期12卷 739-742页

作者： Wen, Y.H. li, n. Xu, Y.G. Tu, M.j. li, Y.l. Ma, Y.l. Sichuan Univ Chengdu China

The effects of quenching temperature on shape memory effect and microstructure of Fe 18Mn 5Si 8Cr 4ni shape memory alloy have been studied. The results show that both the shape recovery ratio and the recovery strain increased as quenching temperature increased, the amount of stress induced ε martensite in the process of cold work decreased with the increase of quenching temperature, the shape recovery ratio and the recovery strain reached maximum at 650℃, and then decreased rapidly with the further increase of quenching temperature,the stress induced ε martensite wholly disappeared at 1023K. But when the quenching temperature is higher than 1023K, the further increase of quenching temperature had little effect on shape recovery ratio, the amount and size of thermal induced ε martensite would increased with the further increase in quenching temperature. The shape memory effect can be improved by the moderate amount of pre exist ε martensite in the matrix before deforming.

关键词： shape memory alloy shape recovery ratio ,martensite transformation

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Optical prediction of single muscle fiber force production using a combined biomechatronics and second harmonic generation imaging approach

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light(Science & Applications) 2018年第1期7卷 289-302页

作者： Dominik Schneidereit Stefanie nübler Gerhard Prölß Barbara Reischl Sebastian Schürmann Oliver j Müller Oliver Friedrich Institute of Medical Biotechnology Friedrich-Alexander-University(FAU)Erlangen-NürnbergPaul-Gordan-Str.391052 ErlangenGermany Erlangen Graduate School in Advanced Optical Technologies(SAOT) FAU Erlangen-NürnbergPaul-Gordan-Str.791052 ErlangenGermany Muscle Research Center Erlangen(MURCE) Friedrich-Alexander-University Erlangen-NürnbergErlangenGermany Department of Internal Medicine III University of KielArnold-Heller-Str.324105 KielGermany DZHK(German Center for Cardiovascular Research)Partner Site Hamburg/Kiel/lübeck KielGermany

Skeletal muscle is an archetypal organ whose structure is tuned to match *** magnitude of order in muscle fibers and myofibrils containing motor protein polymers determines the directed force output of the summed force vectors and,therefore,the muscle’s power performance on the structural *** and function can change dramatically during disease states involving chronic *** remodeling of the cytoarchitecture has been pursued using noninvasive and label-free multiphoton second harmonic generation(SHG)***,structure parameters can be extracted as a measure of myofibrillar order and thus are suggestive of the force output that a remodeled structure can still ***,to date,the parameters have only been an indirect measure,and a precise calibration of optical SHG assessment for an exerted force has been elusive as no technology in existence correlates these *** engineered a novel,automated,high-precision biomechatronics system into a multiphoton microscope allows simultaneous isometric Ca2+-graded force or passive viscoelasticity measurements and SHG *** this MechaMorph system,we studied force and SHG in single EDl muscle fibers from wt and mdx mice;the latter serves as a model for compromised force and abnormal myofibrillar *** present Ca2+-graded isometric force,pCa-force curves,passive viscoelastic parameters and 3D structure in the same fiber for the first ***,we provide a direct calibration of isometric force to morphology,which allows noninvasive prediction of the force output of single fibers from only multiphoton images,suggesting a potential application in the diagnosis of myopathies.

关键词： structure harmonic fibers

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light-weighting in aerospace component and system design

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Propulsion and Power Research 2018年第2期7卷 103-119页

作者： l.Zhu n.li P.R.n.Childs Imperial College london London SW72AZUnited Kingdom

light-weighting involves the use of advanced materials and engineering methods to enable structural elements to deliver the same,or enhanced,technical performance while using less *** concept has been extensively explored and utilised in many industries from automotive applications to fashion and packaging and offers significant potential in the aviation *** implementations of light-weighting have involved use of high performance materials such as composites and optimisation of structures using computational aided engineering approaches with production enabled by advanced manufacturing methods such as additive manufacture,foam metals and hot *** paper reviews the principal approaches used in light-weighting,along with the scope for application of light-weighting in aviation applications from power-plants to airframe components.A particular area identified as warranting attention and amenable to the use of lightweighting approaches is the design of solar powered aircraft *** high aspect ratio typically used for these can be associated with insufficient stiffness,giving rise to non-linear deformation,aileron reversal,flutter and rigid-elastic *** applications considered include ultralight aviation components and sub-systems,UAVs,and *** optimisation approaches can be applied to optimise the layout of structural elements,as well as geometrical parameters in order to maximise structural stiffness,minimise mass and enable incorporation of energy storage *** use of additive manufacturing technologies,some capable of producing composite or multi-material components is an enabler for light-weighting,as features formally associated with one principal function can be designed to fulfil multiple functionalities。

关键词： light-weighting aviation High performance lightweight materials numerical structural optimization Advanced manufacturing

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