检索结果-南通市图书馆

Petrographic and sHRiMP studies of Zircons fromthe Caledonian Xiongdian Eclogite, NorthwesternDabie Mountains

在线全文

学校读者我要写书评

暂无评论

Acta Geologica sinica(English Edition) 2000年第4期74卷 766-773页

作者： i.s.WiLLiAMs Australian National University G.P.O Box 4 Canberra A.C.T. 2601 Australia

The Xiongdian eclogite occurring in the sujiahe tectonic melange zone at Luoshan County, Henan Province, in the western Dabie Mountains, is typical high-pressure (HP)-ultrahigh-pressure (UHP) and medium-temperature eclogite. The occurrence, internal texture and surface characteristics of zircons in eclogite were studied rather systematically petrographically combined with the cathodoluminescence (CL) and scanning electron microscope (sEM) methods. Zircons are mainly hosted in garnet and other metamorphic minerals with sharp boundaries, have a multifaceted morphology and are homogeneous or exhibit a metamorphic growth texture in the interior, thus indicating that they are the product of metamorphism. sHRiMP analyses give zircon 206Pb/238U ages of 335 to 424 Ma and show a certain degree of radiogenic Pb loss; therefore it may be inferred that the age of 424? Ma represents the minimum age of a HP-UHP metamorphic age. From the above analyses coupled with previous sm-Nd, 40Ar-39Ar, U-Pb and 207Pb/206Pb age data, it is suggested that the peak metamorphic age of the Xiongdian eclogite should be between 424 and 480 Ma. This study further validate the view of the existence of a Caledonian HP-UHP metamorphic event in the western Dabie Mountains.

关键词： Dabie Mountains Caledonian eclogite sHRiMP analysis

Enhanced acetone sensing performance of nanostructured sm2O3 doped snO2 thick films

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2017年第8期35卷 813-823页

作者： F.i.shaikh L.P.Chikhale J.Y.Patil i.s.Mulla s.s.suryavanshi school of Physical sciences Solapur University Solapur 413255 (M.S.) lndia Council of scientific and industrial Research Pashan Pune 411008 India

in the present work, we synthesized sm2O3 doped snO2 in order to prepare a selective acetone sensor with fast response, quick recovery and good repeatability. Pure as well as 2 mol.%, 4 mol.%, 6 mol.% and 8 mol.% sm2O3 doped snO2 nanostructured samples were synthesized by using a co-precipitation method. The characterization of the samples was done by thermogravimetric and differential thermo-gravimetric analysis（TG-DTA）, X-ray diffraction（XRD）, field emission gun-scanning electron microscopy（FEG-sEM）, energy dispersive analysis by X-rays（EDAX）, high resolution scanning electron microscopy（HR-TEM）, selected area X-ray diffraction（sAED）, Brunauer-Emmet-Teller（BET） and ultraviolet-visible-near infrared（UV-Vis-NiR） spectroscopy techniques. The gas response studies of liquid petroleum gas, ammonia, ethanol and acetone vapor were carried out. The results showed that sm doping systematically lowered operating temperature and enhanced the gas response and selectivity for acetone. The response and recovery time for 6 mol.% sm2O3 doped snO2 thick film at the operating temperature of 250 °C were 15 and 24 s, respectively.

关键词： tin oxide samarium oxide screen printing thick film acetone sensor rare earths

A theoretical justification of the slip index concept in fretting analysis

在线全文

学校读者我要写书评

暂无评论

Friction 2023年第7期11卷 1265-1275页

作者： ivan i.ARGATOV Young s.CHAi institut für Mechanik Technische Universität Berlin10623 BerlinGermany school of Mechanical Engineering Yeungnam UniversityGyeongsan 712-749Republic of Korea

Fretting in the partial-slip and gross-slip regimes under a constant normal load is *** tangential force-displacement relations for the forward and backward motions are described based the generalized Cattaneo-Mindlin theory of tangential contact and Masing's hypothesis on modelling the force-displacement hysteretic *** the critical force and displacement parameters(characterizing the triggering of sliding),the model includes one dimensionless fitting parameter that tunes the tangential contact stiffness of the friction-contact *** expressions are derived for the main tribological parameters of the fretting loop,including the slip index and the signal *** presented phenomenological modelling approach has been applied to the analysis of two sets of experimental data taken from the *** has been shown that the experimentally observed simple relation of a rational type between the slip index and the slip ratio corresponds to the gross-slip asymptotics of the corresponding model-based predicted *** known quantitative criteria for the transition from the partial slip regime to the gross slip regime are expressed in terms of the stiffness parameter,and a novel geometric transition criterion is formulated.

关键词： fretting wear slip index signal index partial slip energy ratio

Anomalous reactivity of thermo-bioconvective nanofluid towards oxytactic microorganisms

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第5期41卷 711-724页

作者： s.i.ABDELsALAM M.M.BHATTi Basic science Department Faculty of EngineeringThe British University in EgyptAl-Shorouk CityCairo 11837Egypt instituto de Matemáticas-Juriquilla Universidad Nacional Autónoma de MéxicoBlvd.Juriquilla 3001Quer´etaro 76230M´exico College of Mathematics and systems science Shandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina

The peristaltic flow of a non-Newtonian nanofluid with swimming oxytactic microorganisms through a space between two infinite coaxial conduits is investigated. A variable magnetic field is applied on the flow. The bioconvection flow and heat transfer in the porous annulus are formulated, and appropriate transformations are used, leading to the non-dimensionalized ruling partial differential equation model. The model is then solved by using the homotopy perturbation scheme. The effects of the germane parameters on the velocity profile, temperature distribution, concentration distribution, motile microorganism profile, oxytactic profile, pressure rise, and outer and inner tube friction forces for the blood clot and endoscopic effects are analyzed and presented *** is noticed that the pressure rise and friction forces attain smaller values for the endoscopic model than for the blood clot model. The present analysis is believed to aid applications constituting hemodynamic structures playing indispensable roles inside the human body since some blood clotting disorders, e.g., haemophilia, occur when some blood constituents on the artery wall get confined away from the wall joining the circulation system.

关键词： oxytactic swimming microorganism swimming variable magnetic field blood clotting endoscopy non-Newtonian fluid

Multifunctional A356 alloy/PKsAnp composites:Microstructure and mechanical properties

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第3期16卷 731-736页

作者： V.s.Aigbodion i.C.Ezema Department of Metallurgical and Materials Engineering University of NigeriaNsukkaNigeria

Mechanical properties and microstructure of multifunctional composites produced with palm kernel shell ash nano particle(PKsAnp)-A356 alloy composites was *** composites were produced using Double layer feeding stir casting method(DLF-sCM) by adding 1 wt%-4 wt.% *** microstructure,density,electrical and mechanical properties were *** results shows that there was a uniform distribution of the PKsAnp in A356 *** mismatch at the interface between the PKsAnp and A356 alloy was 4.26%.improvement of 30.47%,41.91%,49.52%,40.90% and 65.09% were obtained for hardness values,tensile,yield strength,%elongation and impact energy at 4 wt% *** work has established that the developed composites can be used for multifunctional applications where combination of toughness and strength is vital.

关键词： PKsAnp A356 alloy Microstructure Electrical and mechanical properties

Morphology,structure and magnetic behavior of orthorhombic and hexagonal HoFeO_(3)synthesized via solution combustion approach

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第2期40卷 296-301,I0004页

作者： K.D.Martinson i.s.Kondrashkova M.i.Chebanenko A.s.Kiselev T.Yu Kiseleva V.i.Popkov ioffe institute 26 PoliteknicheskayaSL Petersburg194021Russia saint Petersburg state institute of Technology 26 MoskovskySt.Petersburg190013Russia Faculty of Physics M.V.Lomonosov State UniversityLeninskie CoryMoscow119991Russia

Nanostructured HoFeO_(3)powders were obtained by solution combustion method at various glycinenitrate ratios(G/N=0.2,0.4,...,1.4).According to X-ray powder diffractometry data,the presence of two modifications of HoFeO_(3)in the synthesized samples was established:orthorhombic(Pbnm)and hexagonal(P63/mmc).The crystallite size of the obtained compositions varies from 62±6 to 29±3 nm,depending on the G/N *** magnetic structure studies,it is found that HoFeO_(3)obtained with a stoichiometric amount of glycine in the reaction solution is in the magnetically ordered state and is represented by a sextet with quadrupole splitting(Qs)=0 mm/s,isomeric shift(is)=0.36 mm/s and effective field strength(Heff)=497 *** to the results of vibrational magnetometry,it is found that the orthoferrites obtained have a ferromagnetic structure,the main parameters of which(Ms,Mr and Hc)systematically change with a change in the redox ratio of the reaction mixture and,as a consequence,their phase composition,and reach maximum values at a G/N ratio=*** the samples obtained with a significant excess and lack of glycine(G/N=0.2 and 1.4),despite their amorphous nature,hysteresis loops characteristic of the ferromagnetic state of the substance is *** is hopeful to obtain a pure hexagonal modification of HoFeO_(3)via heat treatment on amorphous products of glycine-nitrate combustion.

关键词： Crystal structure Rare earth compounds Perovskites Nanomaterials Magnetic materials

Anticorrosion properties and thin film composite deposition of ZnsiC-Cr_3C_2 coating on mild steel

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第1期15卷 106-110页

作者： A.A.Ayoola O.s.i.Fayomi A.P.i.Popoola Chemical Engineering Department Covenant University Chemical Metallurgical and Materials Engineering DepartmentTshwane University of Technology Mechanical Engineering Department Covenant University

This work considered the influence of Cr3 C2 particle loading on microstructure and mechanical properties of Zn-siC-Cr3 C2 nanocomposite produced via electrocodeposition are investigated. The surface nature of the nanocomposite coatings were characterized using scanning electron microscope(sEM)coupled with the energy dispersive spectrometer(EDs). Abrasive wear behaviour and hardness property of Zn-siC-Cr3 C2 nanocomposite produced were investigated using CERT UMT-2 multi-functional tribological tester and Dura scan hardness tester. The corrosion property was evaluated through linear polarization approach. The result showed that the coatings exhibited good stability and Cr_3 C_2 nanocomposite loading significantly improved the micro structural performance, hardness property,wear resistance as well as corrosion resistance of the coatings.

关键词： Zn-siC-Cr3C2 Electrodeposition Coatings Corrosion resistance Hardness

Performance enhancement of a DC-operated micropump with electroosmosis in a hybrid nanofluid:fractional Cattaneo heat flux problem

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2022年第6期43卷 931-944页

作者： A.M.ALsHARiF A.i.ABDELLATEEF Y.A.ELMABOUD s.i.ABDELsALAM Department of Mathematics and statistics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Applied Mathematics and science Faculty of EngineeringNational University of Science and TechnologySeeb 111Sultanate of Oman Department of Mathematics College of Science and Arts at KhulisUniversity of JeddahJeddah 21589Saudi Arabia Department of Mathematics Faculty of ScienceAl-Azhar University(Assiut Branch)Assiut 71254Egypt Department of Basic science Faculty of EngineeringThe British University in EgyptCairo 11837Egypt

The purpose of this investigation is to theoretically shed some light on the effect of the unsteady electroosmotic flow(EOF)of an incompressible fractional secondgrade fluid with low-dense mixtures of two spherical nanoparticles,copper,and *** flow of the hybrid nanofluid takes place through a vertical micro-channel.A fractional Cattaneo model with heat conduction is *** the DC-operated micropump,the Lorentz force is responsible for the pressure difference through the *** Debye-H¨ukel approximation is utilized to linearize the charge *** semianalytical solutions for the velocity and heat equations are obtained with the Laplace and finite Fourier sine transforms and their numerical *** addition to the analytical procedures,a numerical algorithm based on the finite difference method is introduced for the given domain.A comparison between the two solutions is *** variations of the velocity heat transfer against the enhancements in the pertinent parameters are thoroughly investigated *** is noticed that the fractional-order parameter provides a crucial memory effect on the fluid and temperature *** present work has theoretical implications for biofluid-based microfluidic transport systems.

关键词： hybrid nanofluid fractional Cattaneo heat flux Caputo-Fabrizio derivative

structural, vibrational, optical, photoluminescence, thermal,dielectric, and mechanical studies on zinc(tris) thiourea sulfate single crystal: A noticeable effect of organic dye

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第5期27卷 304-312页

作者： Mohd shkir V Ganesh s AlFaify i s Yahia Mohd Anis Advanced Functional Materials & Optoelectronic Laboratory Department of PhysicsFaculty of ScienceKing Khalid University Department of Physics Sant Gadge Baba Amravati University

in this work, uranine-dyed zinc（tris） thiourea sulfate（ZTs） monocrystals, 26 mm×15 mm×10 mm in size, were synthesized by the solution method at ambient temperature. Their purity, crystallinity, lattice parameters, and functional modes were studied by x-ray diffraction, Fourier transform-infrared spectroscopy（FT-iR）, and FT-Raman spectroscopy analyses. The sodium ion content of the crystals from the dye was confirmed by elemental analysis. The diffused reflectance spectral analysis of the dyed crystal revealed a characteristic absorption band at 490 nm attributed to the presence of the dye. The calculated band gaps of the non-dyed and dyed crystals were 4.53 and 4.57 e V, respectively. A green emission peak at ～（512 ± 4） nm was observed in the photoluminescence spectrum of the uranine-dyed crystals. A differential scanning calorimetry study confirmed that the thermal stability improved owing to the addition of the dye. Dielectric and microhardness studies were conducted to examine the significant improvements in the corresponding properties of dyed crystals. The results demonstrated the competency of the dyed ZTs crystals for applications in optoelectronic devices.

关键词： crystal growth dielectric properties luminescence thermal properties mechanical properties