检索结果-南通市图书馆

Chinese Journal of Polymer science 2013年第8期31卷 1074-1086页

作者： n. Rajini J.t. Winowlin Jappes s. Rajakarunakaran C. Bennet Centre for Composite Materials Department of Mechanical Engineering Kalasalingam University Center for Advanced Materials Department of Mechanical Engineering Cape Institute of Technology Levengipuram

studies on the behavior of molecular transport properties such as thermal conductivity, gas permeability, volume and surface resistivity have been carried out for the naturally woven coconut sheath （Cs） fiber reinforced composites with the addition of nanoclay and chemical treatment of fiber. the compression molding technique was used to fabricate the coconut sheath/clay reinforced hybrid composites. the morphological studies such as X-ray diffractogram （XRD）, transmission electron microscopy （tEM） and scanning electron microscopy （sEM） have been carried out for polyester nanocomposites and coconut sheath fiber. the decreased gas permeability, thermal conductivity and volume and surface resistivity have been observed with increasing the weight percentage of nanoclay in polyester matrix. In chemical modifications, the alkali and silane treated coconut sheath reinforced composites have shown great influence on the transport properties due to the increasing hydrophilic nature by the topographical changes at the fiber surface. Dielectric strength has also been reported in this paper for all types of composites. Infra-red （IR） spectra have also been taken to study the physical and chemical structural changes of treated coconut sheath.

关键词： nanoclay Coconut sheath Gas permeability tEM sEM FtIR.

On the modified(G′/G^(2))-expansion method for finding some analytical solutions of the traveling waves

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and science 2022年第4期7卷 313-320页

作者： s.Behera n.h.Aljahdaly J.P.s.Virdi Department of Physics Veer Surendra Sai University of TechnologyOdishaIndia Department of Mathematics Faculty of Sciences and Arts-Rabigh CampusKing Abdulaziz UniversityJeddahSaudi Arabia

this work investigates three nonlinear equations that describe waves on the oceans which are the Kadomtsev Petviashvili-modified equal width(KP-MEW)equation,the coupled Drinfel’d-sokolov-Wilson(DsW)equation,and the Benjamin-Ono(BO)equation using the modified(G′/G^(2))-expansion *** solutions of proposed equations by modified(G′/G^(2))-expansion approach can be trigonometric,hyperbolic,or rational *** a result,some new exact solutions are obtained and plotted.

关键词： nonlinear physical models nLEEs Modified(G′/G^(2))-expansion approach KP-MEW equation Drinfeld and soklov and Wilson equation Benjamin-Ono equation

Development of a high-strength Mg alloy with superior ductility through a unique texture modification from equal channel angular pressing

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

Journal of Magnesium and Alloys 2021年第3期9卷 1007-1018页

作者： L.B.tong J.h.Chu W.t.sun Z.h.Jiang D.n.Zou s.F.Liu s.Kamado M.Y.Zheng school of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055China school of Materials science and Engineering Harbin Institute of TechnologyHarbin 150001China school of Materials science and Engineering Jilin UniversityChangchun 130025China Department of Mechanical Engineering Nagaoka University of TechnologyNagaoka 940-2188Japan

In the current study,a homogenous ultra-fine grained microstructure with average grain size of 1.0μm is achieved in the Mg-Zn-Ca-Mn alloy through the reduplicative equal channel angular pressing(ECAP)at 300℃,and the mechanical properties are remarkably improved,with room-temperature yield strength of 269.6 MPa and elongation of 22.7%.the twinning deformation results in a discontinuous recrystallization behavior in the initial stage of *** further deformation,the continuously dynamic recrystallization contributes to an obvious grain refinement *** activation of non-basal slip system leads to the formation of a unique basal texture,which is related to the elevated ECAP temperature and the decreased grain *** grain refinement and texture modification derived from ECAP process result in the increase of yield strength,while the cracked secondary phase particles are beneficial to the enhanced ductility,through reducing the stress concentration and hindering premature failure.

关键词： Mg alloy ECAP Microstructural evolution high strength superior ductility

Luminescence characteristics of Dy^(3+) doped Gd_2O_3-CaO-siO_2-B_2O_3 scintillating glasses

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2016年第6期34卷 583-589页

作者： J.Kaewkhao n.Wantana s.Kaewjaeng s.Kothan h.J.Kim Center of Excellence in Glass technology and Materials science (CEGM) Nakhon Pathom Rajabhat University Department of Radiologic technology Faculty of Associated Medical Sciences Chiang Mai University Department of Physics Kyungpook National University

Glasses were prepared from the compositions of 25Gd_2O_3-10 CaO-10 siO_2-（55–x）B_2O_3-xDy_2O_3（where x is 0.0 mol.%–1.0 mol.%） by the conventional melt-quenching technique at 1400 oC. the results demonstrated the increase in the glass density with respect to the increase in the doping concentrations of Dy_2O_3. nine absorption bands were observed. the emission spectra of the developed glass showed two strong peaks at 577 nm（~4F_（9/2）→~6h_（13/2）） and 482 nm（~4F_（9/2）→~6h_（15/2））. the highest emission intensity was observed from the developed glass prepared at 0.4 mol.% of Dy_2O_3, as the efficient energy transfer took place from Gd^（3＋） to Dy^（3＋）. From the X-ray induced optical luminescence, the emission spectra were identical to those from PL measurements, but with the highest intensity observed from the glass quenched at 0.45 mol.% of Dy_2O_3. Finally, the integral scintillation efficiency of the developed glass was determined at 27% of that of the commercially available BGO crystal.

关键词： amorphous materials glasses oxides optical properties luminescence rare earths

Investigation of Charge transport in Percolating network of PdCu nanoclusters

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 2014年第1期27卷 156-160页

作者： A.I.Ayesh s.t.Mahmoud n.Qamhieh Z.A.Karam Department of Physics United Arab Emirates University

transport of charge carriers in percolating nanocluster devices based on bimetallic PdCu nanoclusters was investigated in this work. the device was fabricated by self-assembly of the nanoclusters between electrical electrodes inside an ultra-high vacuum compatible system. the average size of the produced nanoclusters was 7.3 nm, and the composition was Pdo.77Cuo.23. systematic in situ current-voltage measurements as a function of temperature were per- formed which provide a conductance-temperature profile. the results are explained in terms of the charge carriers＇ tunneling through small potential barriers at the junctions between nanoclusters. the results predict the size of the nanoclusters as well as the magnitude of the potential difference of the tunneling barriers. this investigation helps understanding the nature of the interface between the nanoclusters and the charge carrier transport within those devices to be utilized for optimizing gas sensing properties of PdCu nanocluster devices.

关键词： PdCu Bimetallic nanoclusters nanocluster devices Inert-gas condensation tunneling Charpe transvort

Ion heat transport in electron cyclotron resonance heated L-mode plasma on the t-10 tokamak

在线全文

学校读者我要写书评

暂无评论

Plasma science and technology 2024年第4期26卷 52-60页

作者： V.A.KRUPIn M.R.nURGALIEV A.R.nEMEts I.A.ZEMtsOV s.D.sUntsOV t.B.MYALtOn D.s.sERGEEV n.A.sOLOVEV D.V.sARYChEV D.V.RYJAKOV s.n.tUGARInOV n.n.nAUMEnKO national Research Centre“Kurchatov Institute” Moscow 123182Russia Bauman Moscow state technical University Moscow 105005Russia Institution“Project Center ItER” Moscow 123098Russia JsC“sOLAR” Minsk 220034Belarus

Anomalous ion heat transport is analyzed in the t-10 tokamak plasma heated with electron cyclotron resonance heating(ECRh) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRh plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. to study this effect two scans are presented: over the EC resonance position and over the ECRh power. the EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. the scan over the heating power is presented with on-axis and mixed ECRh regimes. Discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. the high ion heat transport regimes are distinguished by three parameters: the ratio te/ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. the combination of high te/ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak L-mode electron cyclotron resonance heating ion heat transport

tunable passively Q-switched ytterbium-doped fiber laser with mechanically exfoliated Gase saturable absorber

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2018年第2期16卷 93-97页

作者： h.Ahmad s.n.Aidit s.I.Ooi Z.C.tiu Photonics Research Centre University of Malaya

A tunable passively Q-switched ytterbium-doped fiber laser using few-layer gallium selenide（Gase） as a saturable absorber（sA） is *** few-layer Gase sA,which is fabricated by the mechanical exfoliation method,is able to generate a Q-switched fiber laser that has a maximum repetition rate of 92.6 khz and a minimum pulsed width of 2.3 μ*** highest pulse energy exhibited by the generated pulse is 18.8 nJ with a signal to noise ratio of ~40 *** tunability of the proposed laser covers from 1042 to 1082 nm,giving a tuning range of 40 nm.

关键词： tunable passively Q-switched ytterbium-doped fiber laser with mechanically exfoliated Gase saturable absorber sA

three-dimensional free vibration analysis of multi-directional functionally graded piezoelectric annular plates on elastic foundations via state space based differential quadrature method

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2015年第4期36卷 439-464页

作者： M.h.YAs n.MOLOUDI Department of Mechanical Engineering Razi University

the three-dimensional free vibration analysis of a multi-directional func- tionally graded piezoelectric （FGP） annular plate resting on two parameter （Pasternak） elastic foundations is investigated under different boundary conditions. the material properties are assumed to vary continuously along the radial and thickness directions and have exponent-law distribution. A semi-analytical approach named the state space based differential quadrature method （ssDQM） is used to provide an analytical solution along the thickness using the state space method （ssM） and an approximate solution along the radial direction using the one-dimensional differential quadrature method （DQM）. the influence of the Winkler and shear stiffness of the foundation~ the material property graded variations, and the circumferential wave number on the nomdimensional natural frequency of multi-directional FGP annular plates is studied.

关键词： multi-directional functionally graded piezoelectric annular plate freevibration

towards defining soil quality of Mediterranean calcareous agricultural soils:Reference values and potential core indicator set

在线全文

学校读者我要写书评

暂无评论

International soil and Water Conservation Research 2024年第1期12卷 145-155页

作者： Germán A.Durán Daniel sacristán Edelweis Farrús Jaume Vadell Institut de Recerca i FormacióAgrària i Pesquera de les Illes Balears C/Eusebi Estada14507009PalmaSpain Plant Biology Department University of Valencia46100BurjassotValenciaSpain soil and Environmental Quality Department Centro de Investigaciones sobre Desertificación-CIDE(CSIC-Universitat de València-Generalitat Valenciana)Carretera Moncada-Náquera km 4.546113MoncadaValenciaSpain Universitat de les Illes Balears Cra.De Valldemossakm 7507122PalmaSpain

to avoid soil degradation,adapt to climate change and comply with the sustainable Development goals 2030(Un General Assembly),establishing the quality/fertility of the agricultural soils of the Mediterranean region and evaluate how these evolve with time is *** enables adequate management practices to be *** Mediterranean calcareous region has received little attention in this sense,in spite its soil ***,24 different representative calcareous agricultural soils of the Mediterranean region,including the main management strategies of agricultural soils(rainfed and irrigated),were sampled from the island of Mallorca;and their physical,chemical and biological properties *** values obtained for most of the soil characteristics allowed to establish an initial approach to the reference values for the type of calcareous agricultural soils considered,and to clearly distinguish the effect of rainfed or irrigation management practices on soils properties and *** enzyme activities were not stimulated by the irrigation conditions assayed or they were only in dry conditions,suggesting optimum enzyme activities could be obtained when alternating dry and humid soil *** organic carbon,calcium carbonate and active lime revealed of significant importance in the collection of ***,the results obtained clearly indicate the heterogeneity of the region and its implications on the different soil ***,this study could serve as a starting point to adequately establish the quality(fertility)for Mediterranean calcareous agricultural soils and their reference values by conducting further research in this region and including more type of soils.

关键词： soil fertility Mediterranean agricultural soils Calcareous soils soil enzymes soil management

numerical assessment of spacing–burden ratio to effective utilization of explosive energy

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

International Journal of Mining science and technology 2015年第2期25卷 291-297页

作者： sazid Mohd singh t.n. Mining Engineering Department King Abdulaziz University Department of Earth sciences Indian Institute of Technology-Bombay

the spacing–burden(s/B) ratio plays significant role on rock fragmentation and proper utilization of explosive energy to minimize the undesirable *** s/B ratio generates fine fragments due to pressure rings coalescence of two blast holes,whereas boulder generations were observed above optimum s/B *** conditions are not acceptable because of wastage of explosive ***,to resolve this issue,a numerical model study was conducted to optimize the s/B ratio and to envisage its effect on rock fragmentation based on utilization of explosive *** element simulation tool was used to see the extent of two blast hole influence area variation with varying s/B *** better results were obtained at s/B ratio of 1:2 with optimum utilization of peak explosive *** performance was observed based on peak kinetic energy,peak pressure,radial and hoop stresses on centre of the two blast holes,where pressure rings coalescence.

关键词： Rock blasting spacing-burden ratio (s/B)Rock fragmentation numerical modelling Pressure rings