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Chinese Journal of Polymer Science 2008年第6期26卷 669-678页

作者： R.Rajasekaran C.Karikalchozhan m.Alagar Department of Chemistry St.Joseph's College of EngineeringChennai-600 119.India Department of Chemical Engineering Anna UniversityChennai-600 025India

Organoclay-modified hydroxylterminated polysulfone (PSF)/epoxy interpenetrating network nanocomposites (om-PSF/EP nanocomposites) were prepared by adding organophilic montmorillonite (ommT) to interpenetrating polymer networks (IPNs) of polysulfone and epoxy resin (PSF/EP) using diaminodiphenylmethane (DDm) as curing *** mechanical properties like tensile strength,tensile modulus,flexural strength,flexural modulus and impact properties of the nanocomposites were studied as per ASTm ***...

关键词： Nanocomposites Glass transition temperature Impact strength Interpenetrating networks (IPN) Polysulfone.

Effect of storage conditions on long-term stability of Ag nanoparticles formed via green synthesis

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International Journal of minerals,metallurgy and materials 2017年第10期24卷 1177-1182页

作者： Oksana Velgosova Elena Cizmarova Jaroslav málek Jana Kavulicova Institute of materials Faculty of Metallurgy Technical University of Kosice Letna 9 042 00 Kosice Slovakia Department of materials Engineering Faculty of Mechanical Engineering Czech Technical University in Prague Karlovo nám. 13 121 32 Prague 2 Czech Republic Institute of metallurgy Faculty of Metallurgy Technical University of Kosice Letna 9 042 00 Kosice Slovakia

Spherical Ag nanoparticles(AgNPs) with a diameter of 20 nm or smaller were biologically synthesized using algae Parachlorella kessleri. The effect of storage conditions on the long-term stability of AgNPs was investigated. UV/Vis spectrophotometry, transmission electron microscopy, and dynamic light scattering measurements revealed that the long-term stability of AgNPs was influenced by light and temperature conditions. The most significant loss of stability was observed for the AgNPs stored in daylight at room temperature. The AgNPs stored under these conditions began to lose their stability after approximately 30 d; after 100 d, a substantial amount of agglomerated particles settled to the bottom of the Erlenmeyer flask. The AgNPs stored in the dark at room temperature exhibited better long-term stability. Weak particle agglomeration began at approximately the 100 th day. The AgNPs stored in the dark at about 5℃ exhibited the best long-term stability; the AgNPs stored under such conditions remained spherical, with a narrow size distribution, and stable(no agglomeration) even after 6 months. Zeta-potential measurements confirmed better dispersity and stability of AgNPs stored under these conditions.

关键词： silver nanoparticles stability storage conditions green synthesis Parachlorella kessleri

Evaluation of toxicity profiles of rare earth elements salts(lanthanides)

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Journal of Rare Earths 2021年第2期39卷 225-232页

作者： m.Rucki K.Kejlov A.Vlkov D.Jirova m.Dvorakova L.Svobodova H.Kandarova S.Letasiova H.Kolarova m.mannerstrom T.Heinonen National Institute of Public Health Srobarova 49/4810000 Prague.Czech Republic Centre of Experimental medicine SAS Slovak Academy of SciencesDubravska Cesta 984104 Bratislava.Slovakia matTek In Vitro Life Science Laboratories Mlynske Nivy 7382105 BratislavaSlovakia Department of medical Biophysics Faculty of Medicine and DentistryPalacky UniversityHnevotinska 377515 OlomoucCzech Republic FICAm Faculty of Medicine and Health TechnologyFI-33014 Tampere UniversityTampereFinland

The presented study aims to extend the knowledge of toxicological profile of rare earth elements salts(REEs).The basal toxicity test performed comprised assessment of cytotoxicity(3 T3 Balb/c Neutral Red Uptake Test)that allows for calculation of LD50(rats)on the basis of the concentration which leads to a50%reduction in cell growth(IC50).Environmental toxicity was addressed by the Tubifex tubifex(T.t.)express *** in vitro skin irritation(OECD TG 439)and skin corrosion tests(OECD TG 431)utilizing the 3 D in vitro reconstructed human epidermal model EpiDerm(matTek IVSL,SK)were used for assessment of skin irritation and corrosion potential hazard of *** effects were determined using the bacterial reverse mutation assay(Ames Test)on 5 Salmonella typhimurium strains with and without metabolic activation(OECD TG 471).Endocrine disruption was evaluated by means of a yeastbased assay YES/YAS(Xenometrix,CH).Skin sensitization was assessed using the LuSens assay,based on a genetically modified human keratinocyte cell line(OECD TG 442 D).The tested REEs have no potential of mutagenicity or skin sensitization,exhibit very weak endocrine disruption potential and only exceptional local irritation/corrosion effects for thulium(Ⅲ)chloride anhydrous,but have acute and chronic toxic effects on the aquatic environment.

关键词： Lanthanides Rare earth elements Local toxicity Systemic toxicity Ecotoxicity

Symmetric and Anti-Symmetric Lamb Waves in a Two-Dimensional Phononic Crystal Plate

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Chinese Physics Letters 2010年第7期27卷 165-168页

作者：李勇侯志林傅秀军 Badreddine m Assouar Department of Physics South China University of Technology Guangzhou 510640 Institut Jean Lamour (UHP-CNRS) UmR 7198 Deartement Physique de la Matiere et des Materiaux (P2M) France

It is weft known that Lamb waves in a plate with a mirror plane can be separated into two uncoupled sets： symmetric and anti-symmetric modes. Based on this property, we present a revised plane wave expansion method （PWE） to calculate the band structure of a phononie crystal （PC） plate with a mirror plane. The developed PWE method can be used to calculate the band structure of symmetric and anti-symmetric modes separately, by which the depending relationship between the partial acoustic band gap （PABG）, which belongs to the symmetric and anti-symmetric modes alternatively, and the position of the scatterers can be determined. As an example of its application, the band structure of the Lamb modes in a two-dimensional PC plate with two layers of void circular inclusions is investigated. The results show that the band structure for the symmetric and anti-symmetric modes can be changed by the position of the scatterers drastically, and larger PABGs will be opened when the scatterers are inserted into the area of the plate, where the elastic potential energy is concentrated.

关键词： Separators Platanus Separating Lambs Parturition Computers methods Broadcasting

magnetohydrodynamic Activity During Limiter Biasing on the CT-6B Tokamak

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Chinese Physics Letters 2001年第3期18卷 393-395页

作者： KHORSHID Pejman WANG Long YANG Xuan-Zong FENG Chun-Hua ZHANG Peng-Yun QI Xia-Zhi ROUHANI Shahriar RAHImITABAR m.Reza AGHAmIR m.Farzin GHORANNEVISS mahmud HANTEZADEH m.Reza Institute of Physics Chinese Academy of SciencesBeijing 100080 Plasma Physics Research Centre Azad UniversityTehranIran Institute for Studies in Theoretical Physics and mathematics TehranIran

magnetohydrodynamic phenomena in the CT-6B Tokamak based on mirnov oscillations have been investigated by applying the limiter biasing potentials and changing the vacuum chamber gas pressure and plasma *** results show that setting up a radial electric field at the plasma edge could drive electromagnetic instabilities in the tokamak *** oscillation frequency upon application of a positive bias decreases about 10-15%and then after a delay time,τ_(d)=2.5-3 ms increases about 20-25%with respect to their value without *** the negative bias regime the oscillation frequency increases about 10%in 1 ms after the application of the bias *** poloidal rotation velocity changes during two steps are related to its link with the radial electric field and the time scale of the density *** frequency of oscillations increases with the increasing chamber gas pressure and decreases with the increasing the outward plasma displacement.

关键词： Tokamak oscillation tokamak

Annealing Effects on the Structural, Optical, and UV Photoresponse Properties of ZnO Nanostructures Prepared by RF-magnetron Sputtering at Different Deposition Temperatures

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Acta metallurgica Sinica(English Letters) 2015年第2期28卷 230-242页

作者： Husam S.Al-Salman m.J.Abdullah School of Physics University Sains Malaysia Department of Physics College of Science University of Basrah

Undoped ZnO nanostructures were deposited on SiO2/Si substrates via radio 11：equency magnetron sputtenng at different deposition temperatures （room temperature, 200, 300, and 400 ℃）. The prepared samples were annealed at 500 ℃ for 2 h under an N2 flow. The structural, surface morphological, optical, and photoresponse characteristics of ZnO nanostructures as deposited and after annealing were then investigated. The energy bandgaps of all samples after annealing （3.22-3.28 eV） decreased compared with those of the as-deposited specimens. The barrier height increased when the deposition temperature increased and reached 0.77 eV at 400 ℃ after annealing with a leakage current of 0.17 gA at a 5 V bias. The UV photodetector device which was deposited at the optimal temperature of 300 ℃, has 12.51 × 10^3% pho- tosensitivity, 2.259 pA dark current, 0.508 s response time, and 0.466 s recovery time. The dark current significantly decreased for all samples after annealing. The proposed UV photodetectors exhibit high performance, high photosensi- tivity, shorter response and recovery times, and excellent stability at lower bias voltages of 5 and 2 V.

关键词： Undoped ZnO UV photoresponse Deposition temperatures Annealing effect

A cavitation aggressiveness index within the Reynolds averaged Navier Stokes methodology for cavitating flows

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Journal of Hydrodynamics 2015年第4期27卷 579-586页

作者： KOUKOUVINIS P. BERGELES G. GAVAISES m. Department of Engineering and mathematical Science City University London

The paper proposes a methodology within the Reynolds averaged Navier Stokes（RANS） solvers for cavitating flows capable of predicting the flow regions of bubble collapse and the potential aggressiveness to material damage. An aggressiveness index is introduced, called cavitation aggressiveness index（CAI） based on the total derivative of pressure which identifies surface areas exposed to bubble collapses, the index is tested in two known cases documented in the open literature and seems to identify regions of potential cavitation damage.

关键词： cavitation aggressiveness index(CAI) cavitation erosion multiphase cavitating flows

A review of hydrogen technologies and engineering solutions for railway vehicle design and operations

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Railway Engineering Science 2021年第3期29卷 212-232页

作者： Yan Sun m.Anwar N.m.S.Hassan maksym Spiryagin Colin Cole Centre for Railway Engineering Central Queensland UniversityRockhamptonQLDAustralia

Interest in hydrogen-powered rail vehicles has gradually increased worldwide over recent decades due to the global pressure on reduction in greenhouse gas emissions,technology availability,and multiple options of power *** the past,research and development have been primarily focusing on light rail and regional trains,but the interest in hydrogen-powered freight and heavy haul trains is also *** review shows that some technical feasibility has been demonstrated from the research and experiments on proof-of-concept *** rail vehicles powered by hydrogen either are currently operating or are the subject of experimental *** paper identifies that fuel cell technology is well developed and has obvious application in providing electrical traction power,while hydrogen combustion in traditional IC engines and gas turbines is not yet well *** need for on-board energy storage is discussed along with the benefits of energy management and control systems.

关键词： Hydrogen Fuel cells Hybrid power Rail vehicles Greenhouse gas emissions

ImPLICITY LINEAR COLLOCATION mETHOD AND ITERATED ImPLICITY LINEAR COLLOCATION mETHOD FOR THE NUmERICAL SOLUTION OF HAmmERSTEIN FREDHOLm INTEGRAL EQUATIONS ON 2D IRREGULAR DOmAINS

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Journal of Computational mathematics 2020年第4期38卷 624-637页

作者： H.Laeli Dastjerdi m.Nili Ahmadabadi Department of mathematics Farhangian UniversityTehranIran Department of mathematics Najafabad BranchIslamic Azad UniversityNajafabadIran

In this work,we adapt and compare implicity linear collocation method and iterated implicity linear collocation method for solving nonlinear two dimensional Fredholm integral equations of Hammerstein type using ImQ-RBFs on a non-rectangular *** show to be the most promising RBFs for this kind of *** proposed methods are mesh-free and they are independent of the geometry of *** analysis of the proposed methods together with some benchmark examples are provided which support their reliability and numerical stability.

关键词： Two dimensional equations Irregular domain Fredholm integral equations mesh-less method Numerical treatment

PVC nanocomposites for cable insulation with enhanced dielectric properties,partial discharge resistance and mechanical performance

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High Voltage 2020年第4期5卷 463-471页

作者： Nagat m.K.Abdel-Gawad Adel Z.El Dein Diaa-Eldin A.mansour Hanaa m.Ahmed mohamed m.F.Darwish matti Lehtonen Department of Electrical Power and machines Engineering Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of High Voltage Networks Faculty of Energy EngineeringAswan UniversityAswanEgypt High Voltage and Superconductivity Laboratory Department of Electrical Power and Machines EngineeringFaculty of EngineeringTanta UniversityTantaEgypt Department of mathematics and Engineering Physics Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of Electrical Engineering and Automation School of Electrical EngineeringAalto UniversityEspooFinland

The current study aims to develop polyvinyl chloride(PVC)nanocomposites with enhanced electrical and mechanical properties by incorporating titanium oxide(TiO_(2))nanoparticles within PVC *** loading of nanoparticles and different nanoparticle surface states were *** surface states are unfunctionalised,functionalised using vinyl silane and functionalised using amino *** choice of a most suitable surface state was a critical factor that guarantees a good dispersion of nanoparticles and consequently enhances the compatibility between TiO_(2)and PVC *** process followed in the PVC/TiO_(2)nanocomposites preparation,loaded with different wt.%of TiO_(2)nanoparticles,was the solvent *** dielectric properties measured here were the relative permittivity(ɛr),dielectric loss(tanδ),breakdown strength(AC and DC under uniform field)and the internal partial discharges(PDs)within insulation *** measurements have been performed under room temperature and at frequency ranged from 20 to 1.0 ***,the mechanical properties of the samples like elongation,elasticity modulus and tensile strength were also *** silane showed better improvements in both electrical and mechanical performances compared to the amino silane,especially in cases of high weight fractions of TiO_(2).This is because of the improvement in the PVC-TiO_(2)interfacial region arise from the similarity of polarity and surface tension values of vinyl silane with that of PVC matrix and TiO_(2)nanoparticles.

关键词： dielectric insulation resistance