检索结果-南通市图书馆

Journal of Materials Science & Technology 2009年第5期25卷 597-602页

作者： H.keshmiri A.Momeni k.Dehghani G.R.Ebrahimi G.Heidari Esfarayen Steel Complex Department of Mining and Metallurgy Amir Kabir University of Technology Tarbiat Moalem University of Sabzevar

Duplex stainless steels （DSS） with ferritic-austenitic microstructures offer good combination of resistance to pitting corrosion and high strength that are not concomitantly attainable using conventional single phase austenitic or ferritic stainless steels, The DSS used in this investigation was 2205 alloy having a stable microstructure consisting of about 45% ferrite and 55% austenite at ambient temperature. In order to investigate aging behavior of this steel and the influences on mechanical properties, different aging treatments were conducted at temperatures of 350-950℃ for various aging time of 15, 30, 60 and 180 min. The aged specimens were subjected to impact testing and hardness measurements. Finally, the changes in microstructure due to aging were studied by optical and scanning electron microscopy. The results showed that aging at temperatures lower than 550℃ for different time had negligible effects on mechanical properties. Besides, no considerable changes in term of precipitation of harmful intermetallic particles were observed in microstructure below this temperature. However, a critical temperature range, 550-650 ℃, was introduced here. Aging in this range led to a significant decrease in toughness and notable increase in hardness. The formation of intermetallic phases such as CT was recognized as the major reason for the observed changes.

关键词： Duplex stainless steel Aging Toughness Sigma phase

Metal flow and die wear in semi-solid forging of steel using coated dies

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2010年第S3期20卷 954-960页

作者： L.kHIZHNYAkOVA M.EWERING G.HIRT k.BOBZIN N.BAGCIVAN Institute of Metal Forming RWTH Aachen UniversityAachenIntzestrasse 1052056 AachenGermany Surface Engineering Institute RWTH Aachen UniversityAachenAugustinerbach 4-2252056 AachenGermany

Thixoforging of steels is a potential forming technology,which aims at producing near-net-shaped components with good quality from high strength steels in one forging *** thixoforging process parameters such as billet temperature,temperature distribution after reheating,argon gas pressure,transportation time and forging load were investigated on the thixoforging of non axis-symmetric parts of steel grade *** experimental and numerical study of the material flow and tool temperature load reveal the areas of intensive tool wear,thus being useful for further tool *** hot working steel X38CrMoV5-1 as a tool bulk material with protecting thin films of TiAlN/γ-Al2O3 shows good experimental results at 170 forging cycles.

关键词： steel tool coating thixoforging process parameters tool life time

Fuzzy-Based Dynamic Distributed Queue Scheduling for Packet Switched Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2013年第2期28卷 357-365页

作者： Chollette C.Chude-Olisah Uche A.k.Chude-Okonkwo kamalrulnizam A.Bakar Ghazali Sulong Faculty of Computing Universiti Teknologi Malaysia Wireless Communication Center Universiti Teknologi Malaysia

Addressing the problem of queue scheduling for the packet-switched system is a vital aspect of congestion control. In this paper, the fuzzy logic based decision method is adopted for queue scheduling in order to enforce some level of control for traffic of different quality of service requirements using predetermined values. The fuzzy scheduler proposed in this paper takes into account the dynamic nature of the Internet traffic with respect to its time-varying packet arrival process that affects the network states and performance. Three queues are defined, viz low, medium and high priority queues. The choice of prioritizing packets influences how queues are served. The fuzzy scheduler not only utilizes queue priority in the queue scheduling scheme, but also considers packet drop susceptibility and queue limit. Through simulation it is shown that the fuzzy scheduler is more appropriate for the dynamic nature of Internet traffic in a packet-switched system as compared with some existing queue scheduling methods. Results show that the scheduling strategy of the proposed fuzzy scheduler reduces packet drop, provides good link utilization and minimizes queue delay as compared with the priority queuing （PQ）, first-in-first-out （FIFO）, and weighted fair queuing （WFQ）.

关键词： fuzzy logic based decision method priority queue limit queue scheduling

Some hydrodynamic aspects of 3-phase inverse fluidized bed

在线全文

学校读者我要写书评

暂无评论

China Particuology 2007年第5期5卷 351-356页

作者： krishna S.V.S.R. Bandaru D.V.S. Murthy k. krishnaiah Department of Chemical Engineering Indian Institute of Technology Madras

Hydrodynamics of 3-phase inverse fluidized bed is studied experimentally using low density particles for different liquid and gas velocities. The hydrodynamic characteristics studied include pressure drop, minimum liquid and gas fluidization velocities and phase holdups. The minimum liquid fluidization velocity determined using the bed pressure gradient, decreases with increase in gas velocity. The axial profiles of phase holdups shows that the liquid holdup increases along the bed height, whereas the solid holdup decreases down the bed. However, the gas holdup is almost uniform in the bed.

关键词： Inverse fluidization Inverse fluidized bed Hydrodynamics Phase holdup Axial holdup

Color-coded perfluorocarbon nanodroplets for multiplexed ultrasound and photoacoustic imaging

在线全文

学校读者我要写书评

暂无评论

Nano Research 2019年第4期12卷 741-747页

作者： Daniela Y. Santiesteban kristina A. Hallam Steven k. Yarmoska Stanislav Y. Emelianov Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA School of Electrical & Computer Engineering Georgia Institute of Technology Atlanta GA 30332 USA

Laser-activated perfluorocarb on n anodroplets are an emerging class of phase-cha nge, dual-c ontrast age nts that can be utilized in ultraso und and photoacoustic imaging. Through the ability to differe ntiate subpopulations of nano droplets via laser activatio n at differe nt wavelengths of n ear-infrared light, optically-triggered color-coded perfluorocarb on nano droplets prese nt themselves as an attractive tool for multiplexed ultrasound and photoacoustic imaging. In particular, laser-activated droplets can be used to provide quantitative spatiotemporal information regarding distinct biological targets, allowing for their potential use in a wide range of diagnostic and therapeutic applications. In the work prese nted, laser-activated color-coded perfluorocarb on nan odroplets are syn thesized to selectively resp ond to laser irradiati on at corresp on ding wavele ngths. The dyn amic ultraso und and photoacoustic signals produced by laser-activated perfluorocarbon nano droplets are evaluated in situ prior to implementation in a murine model. In vivo, these particles are used to distinguish unique particle trafficking mechanisms and are show n to provide ultraso und and photoacoustic contrast for up to 72 hours within lymphatics. Overall, the con ducted studies show that laser-activated color-coded perfluorocarbo n nano droplets are a promising agent for multiplexed ultraso und and photoacoustic imaging.

关键词： multiplexed imaging perfluorocarbon nanodroplets photoacoustic imaging ultrasound imaging molecular targets

Prediction of DOM removal of low specific UV absorbance surface waters using HPSEC combined with peak fitting

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 Environmental Sciences 2012年第7期24卷 1174-1180页

作者： Linan Xing Rolando Fabris W.k.Chow John van Leeuwen Mary Drikas Dongsheng Wang State key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of ScinecesBeijing 100085China Australian Water Quality Centre South Australian Water Corporation256 Victoria SquareAdelaideSouth Australia 5000Australia SA Water Centre for Water Management and Reuse University of South AustraliaMawson LakesSouth Australia 5095Australia

High performance size exclusion chromatography （HPSEC） is used in water quality research primarily to determine the molecular weight distribution of the dissolved organic matter （DOM）, but by applying peak fitting to the chromatogram, this technique can also be used as a tool to model and predict DOM removal. Six low specific UV absorbance （SUVA） source waters were treated using coagulation with alum and both the source and treated water samples were analysed using HPSEC. By comparing the molecular weight profiles of the source and treated waters, it was established that several DOM components were not effectively removed by alum coagulation even after high dosage alum treatment. A peak-fitting technique was applied based on the concept of linking the character （molecular weight profile） of the recalcitrant organics in the treated water with those of the source water. This was then applied to predict DOM treatability by determining the areas of the peaks which were assigned to removable organics from the source water molecular weight profile after peak fitting, and this technique quantified the removable and non-removable organics. The prediction was compared with the actual dissolved organic carbon （DOC） removal determined from jar testing and showed good agreement, with variance between 2% and 10%. This confirmed that this prediction approach, which was originally developed for high SUVA waters, can also be applied successfully to predict DOC removal in low SUVA waters.

关键词： DOM high performance size exclusion chromatography peak fitting water treatment

Doubly periodic patterns of modulated hydrodynamic waves:exact solutions of the Davey-Stewartson system

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2011年第5期27卷 620-626页

作者： J.-H. Li S.-Y. Lou k.-W. Chow Department of Mechanical Engineering University of Hong Kong Pokfulam Road Hong Kong China Department of Physics Shanghai Jiao Tong University200030 Shanghai China

Exact doubly periodic standing wave patterns of the Davey-Stewartson （DS） equations are derived in terms of rational expressions of elliptic *** fluid mechanics,DS equations govern the evolution of weakly nonlinear,free surface wave packets when long wavelength modulations in two mutually perpendicular,horizontal directions are *** functions with two different moduli （periods） are necessary in the two *** relation between the moduli and the wave numbers constitutes the dispersion relation of such *** the long wave limit,localized pulses are recovered.

关键词： Free surface waves · Periodic patterns · DaveyStewartson equations

A review of effective strides in amelioration of the biocompatibility of PEO coatings on Mg alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第9期10卷 2354-2383页

作者： Arash Fattah-alhosseini Razieh Chaharmahali kazem babaei Meisam Nouri Mohsen k.keshavarz Mosab kaseem Department of Materials Engineering Bu-Ali Sina UniversityHamedan 65178-38695Iran Department of Mechanical and Mechatronics Engineering University of WaterlooWaterlooON N2L 3G1Canada Department of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul 05006Republic of Korea

Recently,developing bioactive and biocompatible materials based on Mg and Mg-alloys for implant applications has drawn attention among researchers owing to their suitable body *** Mg and its alloys reduces the risk of long-term incompatibility with tissues because of their close mechanical properties and no need for re-operation to remove the ***,the degradation rate of the implant needs to be controlled because production of hydrogen gas and accumulation of its bubbles increases local pH around the *** confine the integrity of implants and the body,the corrosion concern in the body fluid requires to be *** modification as one of the effective strategies can improve corrosion ***,it creates a suitable surface for bone grafting and cell *** development of proper surface-coated implants needs appropriate techniques and *** electrolytic oxidation(PEO)coating can provide long-term protection by providing a ceramic layer and improving the implant’s ***,a general review of in-vivo and in-vitro evaluation of PEO coatings on Mg and Mg-alloys has been carried *** advances in surface modification on Mg and Mg-alloys have been discussed,however,the need for reliable laboratory models to predict in-vivo degradation is still valid.

关键词： Mg alloys Biodegradation Surface modification In-vivo In-vitro PEO coatings

在线全文

学校读者我要写书评

暂无评论

当代英国作家作品选析

当代英国作家作品选析

Ionic liquid-assisted hydrothermal synthesis of SnS nanoparticles:Electrode materials for lithium batteries,photoluminescence and photocatalytic activities

作者： P.k.·泰森(P.k. Tyson)

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2018年第3期27卷 806-812页

作者： k.N.Manukumar G.Nagaraju Brij kishore C.Madhu N.Munichandraiah Department of Chemistry Siddaganga Institute of TechnologyTumkurKarnatakaIndia Department of Inorganic and Physical Chemistry Indian Institute of ScienceBangaloreKarnatakaIndiac Department of Physics.Siddaganga Institute of Technology.Tumkur KarnatakaIndia

Tin mono-sulphide（Sn S） nanoparticles（Nps） have been successfully synthesised through ionic liquid assisted hydrothermal method using hydrated tin（II） chloride as a precursor, thiourea as sulphur source precursors using 2-Methoxy ethyl methyl imidazolium methane sulfonate ionic liquid as co-solvent. The Reitveld refinement on powder X-ray diffraction（PXRD） confirmed the presence of orthorhombic Sn S structure as major phase along with traces amount of Sn S2 and Sn2 S3. Diffuse reflectance spectrum studies revealed the energy band gap around 1.38 e V. TEM images confirmed the Sn S Nps with average particle size of 40 nm and HRTEM suggest good crystallinity. The electrochemical property for lithium storage behaviour shows an initial discharge capacity of 658 m Ah/g and it retains discharge capacity of 426 m Ah/g for 16 cycles, at current density 100 m A/g. The obtained results indicate that Sn S Nps to be one of the possible promising anode materials for next generation Lithium batteries. Photoluminescence study of Sn S Nps shows a strong green emission at 530 nm. Sn S Nps were also tested for the photocatalytic adsorption of methylene blue and Rhodamine B.

关键词： Nanoparticles Lithium-ion batteries Ionic liquids Ionothermal