检索结果-南通市图书馆

Strain Hardening and Strain rate Sensitivity Behaviors of Advanced High Strength Steels

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 Iron and Steel research International 2013年第6期20卷 68-74页

作者： F Ozturk A Polat S Toros r c Picu Department of Mechanical Engineering Nigde University Department of Mechanical Aerospace and Nuclear Engineering Rensselaer Polytechnic InstituteTroy 12180 New York USA

The mechanical properties of commercial dual phase （DP）, transformation induced plasticity （TrIP）, and high strength low alloy （HSLA-340） steel sheets are investigated and compared at various strain rates ranging from 0.001 7to 0.17 s-1 at ambient *** steel outperforms the other two materials , having comparable ductility and twice as large strength relative to DP *** has larger strength and much larger ductility than *** exceuent ductility of TrIP800is due to its high strain hardening capability , which promotes stable plastic *** is observed that the strain hardening rate in TrIP800does not decrease to zero at failure , as common in most materials in which failure is preceded by necking.

关键词： steel advanced high strength steel HSLA DP TrIP hardening

The influence of aspect ratio on the properties of cobalt nanowire-based magnetorheological fluids

在线全文

学校读者我要写书评

暂无评论

International Journal of Smart and Nano Materials 2022年第4期13卷 626-642页

作者： r.c Bell N.M Wereley Department of chemistry The Pennsylvania State UniversityAltoona CollegeAltoonaPAUSA Department of Aerospace Engineering University of MarylandCollege ParkMdUSA

The yield stress of magnetorheological(Mr)fluids has been shown to depend on particle morphology,but the exact nature of this contribution is still not fully *** this study,Mr fluids containing 4 vol.%cobalt particles(spherical particles ***-wires)suspended in silicone oil were *** influence of the aspect ratio on the rheological properties of suspensions that contained cobalt nanowires with aspect ratios ranging from 10 to 101 in increments of~6 is *** cobalt nanowires were fabricated using alumina template-based electrodeposition,produ-cing wires with 305±66 nm *** shear stress was measured as a function of shear rate for increasing applied mag-netic *** apparent yield stress and viscosity as a function of changing aspect ratio of the nanowire suspensions were *** a saturated magnetic flux density,the yield stress was found to increase linearly up to an aspect ratio of 23(7.1μm long wires)at which time the yield stress reached a plateau of 3.7 kPa even as the aspect ratio was further *** a comparison,suspensions containing 4 vol.%1.6μm spherical cobalt particles only reached a maximum yield stress of 1.6 kPa.

关键词： Magnetorheological fluids nanowires size dependence

Age-hardening behavior,corrosion mechanisms,and passive film structure of nanocrystalline Al-V supersaturated solid solution

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 Materials Science & Technology 2023年第4期135卷 1-12页

作者： J.christudasjustus M.r.Felde c.S.Witharamage J.Esquivel A.A.Darwish c.Winkler r.K.Gupta Department of Materials Science and Engineering North Carolina State UniversityRaleighNC 27606United States Department of chemical Biomolecular and Corrosion EngineeringThe University of AkronAkronOH 44325United States

The effect of age-hardening on microstructure,hardness,and corrosion of an Al-5at.%V alloy,produced us-ing high-energy ball milling and subsequent cold compaction,has been *** alloy exhibited a grain size below 100 nm and extremely high solid solubility of V in Al(3.1 at.%).The age-hardening was carried out at 150,200,and 250℃.The peak-aged condition of 150℃ demonstrated the highest hardness-transpired from grain refinement,precipitation,and solid solution *** corrosion re-sistance of the Al-5at.%V alloy was studied as a function of aging *** peak-aged condition retained the corrosion resistance while it deteriorated in the over-aged ***,the cor-rosion resistance of the ball-milled Al alloys in all the aging conditions was superior to that of pure *** passive film structure and origin of corrosion were studied using scanning/transmission electron mi-croscopy(S/TEM).The high corrosion resistance of the alloy was attributed to the V enrichment at the film/metal interface and deposition of V on the cathodic phases,which suppresses the dissolution of Al within the pit and therefore promotes repassivation in the early stages of corrosion.

关键词： Al alloys Nanocrystalline alloy Age-hardening Ball milling corrosion Hardness

Thermal Efficiency for Each Zone of a Solar Pond

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

chinese Physics Letters 2011年第10期28卷 281-283页

作者： BEZİr cİcEK Nalan ŞAHİNŞENcAN Arzu Department of Physics Faculty of ScienceSuleyman Demirel UniversityTurkey Department of Mechanical Education Technical Education FacultySüleyman Demirel UniversityTurkey

A salt gradient solar pond with a surface area of 3.5×3.5 m^(2) and a depth of 2 m is *** collapsible covers are used to reduce thermal energy loss from the surface of the solar pond during the night and to increase the thermal efficiency of the pond solar energy harvesting during *** covers can be rotated between 0 and 180°by a controlled electric motor and has insulation and reflection *** thermal efficiency for each solar pond zone is investigated theoretically and experimentally.

关键词： properties insulation harvesting

Biomass torrefaction in a slot-rectangular spouted bed reactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2019年第1期17卷 154-162页

作者： Ziliang Wang c. Jim Lim John r. Grace Department of chemical and Biological Engineering. University of British columbia Vancouver. Canada

Sawdust was subjected to torrefaction in a "semi-batch" slot-rectangular spouted bed (SrSB) reactor at temperatures from 240 to 330℃ and biomass feed rates from 220 to 710g/*** spouting of the sawdust was achieved in the slot-rectangular spouted bed,although the pressure drop across the reactor was observed to *** to the biomass feed rate,the temperature had a greater effect on the biomass weight loss and energy *** in temperature were found to promote weight loss of the sawdust while decreasing the energy *** main solid product was the torrefied sawdust,which remained in the SrSB reactor and was captured by a *** ratio of the torrefied biomass removed by the cyclone to the total torrefied biomass increased along with both the feed rate and *** undergoing torrefaction,6.7%-39.2% of the original sawdust mass was lost while 67.4%-98.7% of its energy was *** torrefied sawdust had a higher carbon content but less oxygen,hydrogen and volatiles,along with a greater higher heating value and increased density compared to the raw *** size of the sawdust particles also decreased markedly during the torrefaction process.

关键词： Torrefaction Slot-rectangular spouted bed reactor Temperature Biomass feed rate Torrefied sawdust property

rapid Identification of rice Samples Using an Electronic Nose

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 Bionic Engineering 2009年第3期6卷 290-297页

作者： John Westbrook W.c.Hoffmann r.E.Lacey USDA-ArS College Station Department of Biological and Agricultural Engineering Texas A&M UniversityCollege Station

Four rice samples of long grain type were tested using an electronic nose (cyranose-320).Samples of 5 g of each variety of rice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer *** cyranose-320 was able to differentiate between varieties of *** chemical composition of the rice odors for differentiating rice samples needs to be *** optimum parameter settings should be considered during the cyranose-320 training process especially for multiple samples,which are helpful for obtaining an accurate training model to improve identification ***,it is necessary to investigate the E-nose sensor selection for obtaining better classification accuracy.A re- duced number of sensors could potentially shorten the data processing time,and could be used to establish an application pro- cedure and reduce the cost for a specific electronic *** research is needed for developing analytical procedures that adapt the cyranose-320 as a tool for testing rice quality.

关键词： rice grain identification electronic nose data analysis pattern recognition

Dipole and generalized oscillator strength derived electronic properties of an endohedral hydrogen atom embedded in a Debye-Huckel plasma

在线全文

学校读者我要写书评

暂无评论

Matter and radiation at Extremes 2018年第5期3卷 227-242页

作者： c.Martínez-Flores r.cabrera-Trujillo Instituto de ciencias Físicas Universidad Nacional Autonoma de MexicoAp.Postal 43-8CuernavacaMorelos62251Mexico

We report electronic properties of a hydrogen atom encaged by an endohedral cavity under the influence of a weak plasma interaction. Weimplement a finite-difference approach to solve the Schrodinger equation for a hydrogen atom embedded in an endohedral cavity modeled by theWoods-Saxon potential with well depth V0, inner radius r0, thickness D, and smooth parameter g. The plasma interaction is described by aDebye-Hu¨ckel screening potential that characterizes the plasma in terms of a Debye screening length lD. The electronic properties of theendohedral hydrogen atom are reported for selected endohedral cavity well depths, V0, and screening lengths, lD, that emulate differentconfinement and plasma conditions. We find that for low screening lengths, the endohedral cavity potential dominates over the plasma interaction by confining the electron within the cavity. For large screening lengths, a competition between both interactions is observed. We assessand report the photo-ionization cross section, dipole polarizability, mean excitation energy, and electronic stopping cross section as function of lD and V0. We find a decrease of the Generalized Oscillator Strength (GOS) when the final excitation is to an s state as the plasma screeninglength decreases. For a final excitation into a p state, we find an increase in the GOS as the endohedral cavity well-depth increases. For the caseof the electronic stopping cross section, we find that the plasma screening and endohedral cavity effects are larger in the low-to-intermediateprojectile energies for all potential well depths considered. Our results agree well to available theoretical and experimental data and are afirst step towards the understanding of dipole and generalized oscillator strength dependent properties of an atom in extreme conditions encagedby an endohedral cavity immersed in a plasma medium.

关键词： Oscillator strengths Debye-Huckel plasma cavities Endohedral Energy loss Stopping power

Damage detection on framed structures: modal curvature evaluation using Stockwell Transform under seismic excitation

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2015年第2期14卷 265-274页

作者： r.Ditommaso F.c.Ponzo G.Auletta Department of Structures Geotechnics Engineering Geology University of Basilicata School of Engineering University of Basilicata

The key parameters for damage detection and localization are eigenfrequencies, related equivalent viscous damping factors and mode shapes. The classical approach is based on the evaluation of these structural parameters before and after a seismic event, but by using a modern approach based on time-frequency transformations it is possible to quantify these parameters throughout the ground shaking phase. In particular with the use of the S-Transform, it is possible to follow the temporal evolution of the structural dynamics parameters before, during and after an earthquake. In this paper, a methodology for damage localization on framed structures subjected to strong motion earthquakes is proposed based on monitoring the modal curvature variation in the natural frequency of a structure. Two examples of application are described to illustrate the technique: computer simulation of the nonlinear response of a model, and several laboratory(shaking table) tests performed at the University of Basilicata(Italy). Damage detected using the proposed approach and damage revealed via visual inspections in the tests are compared.

关键词： damage detection S-transform band-variable fi lter

Bionics and Structural Biology:A Novel Approach for Bio-energy Production

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2008年第1期5卷 25-32页

作者： c.Karthikeyan r.Krishnan S.Adline Princy School of chemical and Biotechnology SASTRA UniversityThanjavur 613402India School of Electrical and Electronics Engineering SASTRA UniversityThanjavur 613402India

cellular metabolism is a very complex process. The biochemical pathways are fundamental structures of biology. These pathways possess a number of regeneration steps which facilitate energy shuttling on a massive scale. This facilitates the biochemical pathways to sustain the energy currency of the cells. This concept has been mimicked using electronic circuit components and it has been used to increase the efficiency of bio-energy generation. Six of the carbohydrate biochemical pathways have been chosen in which glycolysis is the principle pathway. All the six pathways are interrelated and coordinated in a complex manner. Mimic circuits have been designed for all the six biochemical pathways. The components of the metabolic pathways such as enzymes, cofactors etc., are substituted by appropriate electronic circuit components. Enzymes are related to the gain of transistors by the bond dissociation energies of enzyme-substrate molecules under consideration. cofactors and coenzymes are represented by switches and capacitors respectively. resistors are used for proper orientation of the circuits. The energy obtained from the current methods employed for the decomposition of organic matter is used to trigger the mimic circuits. A similar energy shuttle is observed in the mimic circuits and the percentage rise for each cycle of circuit functioning is found to be 78.90. The theoretical calculations have been made using a sample of domestic waste weighing 1.182 kg. The calculations arrived at finally speak of the efficiency of the novel methodology employed.

关键词： bionics structural biology carbohydrate metabolism bio-chemical pathways mimic circuits transistors