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Dry Sliding Oxidative Wear in Plain Carbon Dual Phase Steel

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Journal of Iron and Steel Research International 2007年第4期14卷 43-48页

作者： V Abouei H Saghafian sh Kheirandish Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyNarmak 16844TehranIran

To investigate the tribological potential of the dual phase （DP） steel as a wear resistant material, the wear and the friction characteristics of this steel, which consists of hard martensite islands embedded in a ductile ferrite matrix, have been investigated and compared with those observed in plain carbon hardened （H） steel that has the same carbon content of 0.2%. Dry sliding wear tests have been carried out using a pin-on-disk wear testing machine at different normal loads of 21.3 N, 28. 5 N, 35.7 N, and 42.6 N and at a constant sliding velocity of 1.20 m/s. The analysis of surface and wear debris of samples showed that the wear mechanism was mainly mild oxidative. The friction and the wear rate of the H steel and the DP Steel have been explained with respect to the microstructure and the wear mechanism.

关键词： dual phase steel wear microstructure heat treatment

Evaluation of Four Coals for Blast Furnace Pulverized Coal Injection

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Journal of Iron and Steel Research International 2010年第3期17卷 8-12,20页

作者： sh Raygan H Abdizadeh A Eskandari Rizi School of Metallurgy and Materials Engineering University of Tehran

One of the effective methods of reducing coke consumption is pulverized coal injection. The most important problems encountered in this method are reduced permeability, unburned and high ash content. To select the best coal for injection, suitable tests can be used. Therefore, experiments such as proximate and ultimate analysis, Rock- Eval and combustion tests were performed on four kinds of coals from different mines, including Sarakhs, Sangrood, Karmozd, and Tabas. The results of proximate and ultimate analysis indicated that although the sulfur content and ash content of selected coals were a little high, they were suitable for coal injection. The results of combustion experiments and Rock-Eval tests showed that Karmozd coal was the best one to be injected into blast furnace. The result indicated that the mixing of coals could improve the combustion properties of pulverized coals.

关键词： pulverized coal blast furnace non-coking coal

Optimum Environmental Load Design Criterion for Marine Structures Based on Investment and Benefit Analysis

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China Ocean Engineering 1998年第2期13卷 235-242页

作者： Zhang, sh Yu, YF Li, BX Ocean Univ Qingdao Qingdao 266003 Peoples R China

Marine structures operating in natural ocean environment are subjected to various stochastic loads. For design of the marine structures, the most important task is to determine environmental load design criterion. This paper presents a method to determine the optimum environmental load design criterion for marine structures. This method is based on the investment and benefit analysis and it can reach the design purpose of decreasing total costs during the service life of the structures and increasing economic benefits.

关键词： marine structures investment-benefit analysis optimum environmental load design criterion

EIGENFUNCTION EXPANSION FOR STURM-LIOUVILLE PROBLEMS WITH TRANSMISSION CONDITIONS AT ONE INTERIOR POINT

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Acta Mathematica Scientia 2015年第3期35卷 639-649页

作者： Oktay sh.MUKHTAROV Kadriye AYDEMIR Institute of Mathematics and Mechanics Azerbaijan National Academy of Sciences Department of Mathematics Faculty of ScienceGaziosmanpasa University

The purpose of this article is to extend some spectral properties of regular Sturm- Liouville problems to the special type discontinuous boundary-value problem, which consists of a Sturm-Liouville equation together with eigenparameter-dependent boundary conditions and two supplementary transmission conditions. We construct the resolvent operator and Green＇s function and prove theorems about expansions in terms of eigenfunctions in modified Hilbert space L2[a, b].

关键词： Boundary-value problems transmission conditions resolvent operator

Essential commutant of analytic Toeplitz operators

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Chinese Science Bulletin 1997年第7期42卷 548-552页

作者： Ding, XH Sun, sh Department of Mathematics Sichuan Union University Chengdu China

LET Bn be the unit ball of Cn. The n-dimensional vector space over the complex field C, Sn=（?）Bn is the boundary of Bn. We use σ to denote the unique rotation-invariant probability measure on Sn. The Lebesgue space... 详细信息

关键词： Toeplitz operators inner function essential commutant.

Sorption of certain lanthanides by kieselguhr loaded with Cyanex 572 from sulfate medium

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Journal of Rare Earths 2020年第3期38卷 299-305页

作者： sh.sh.Emam M.S.Gasser N.E.El-Hefny W.H.Mahmoud H.F.Aly Hot Laboratories Centre Atomic Energy AuthorityCairo 13759Egypt Department of Chemistry Faculty of ScienceAin Shams UniversityCairoEgypt

Kieselguhr for chromatography was loaded with Cyanex 572 extractant and characterized using X-ray diffraction(XRF),scanning electron microscopy(SEM),Fourier transform infra-red(FT-IR),and thermal *** of some heavy lanthanides together with yttrium by the prepared kieselguhr/Cy-572 sorbent was investigated by batch experiment in terms of initial metal ions concentrations,volume to solid mass ratio(V/m),sulfuric acid concentration as well as *** sorption equilibrium of Cy-572 loaded kieselguhr was satisfactorily explained by the pseudo second-order kinetic model and Langmuir isotherm ***,the values of thermodynamic parameters △G°,△H°,and △S°at25℃of the studied metal ions show that the process is spontaneous and endothermic in nature.2.0 mol/L HNO3 is promising to desorb these metal ions.

关键词： Sorption Cyanex 572 Lanthanides Kieselguhr Sulfate medium Rare earths

Methanol-to-propylene process: Perspective of the most important catalysts and their behavior

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Chinese Journal of Catalysis 2016年第3期37卷 325-339页

作者： M.Khanmohammadi sh.Amani A.Bagheri Garmarudi A.Niaeib 霍梅尼国际大学科学学院化学系大不里士大学化工与应用化学系

The methanol-to-propylene （MTP） process is a route of methanol conversion to hydrocarbons, which is in high demand because of limited oil resources. The present paper discusses the effect of catalyst structure on the MTP process conditions, and the role of different zeolite factors, such as acidity, crystal size, mesoporosity, and topology, on the activity and selectivity of the MTP reaction.

关键词： Methanol-to-propylene process ZSM-5 zeolite Catalysis

Asymmetric Meerwein-Ponndorf-Verley reduction catalyzed by a new type of chiral binaphthol-samarium complex

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Chinese Journal of Chemistry 1996年第6期14卷 561-564页

作者： Ding, ZB Cheng, KJ Wu, sh FUDAN UNIV DEPT CHEMSHANGHAI 200433PEOPLES R CHINA

A new type of chiral 1,1'-binaphthol(BINOL) derived samarium complex, prepared from (R)- or (S)-BINOL and SmCl3, serves as an enantioselective catalyst for the Meerwein-Ponndorf-Verley (MPV) reduction in the presence of Molecular Sieves 4 Angstrom(MS 4 Angstrom). Moderate enantioselectivity was obtained. Kinetic studies show slight decrease of the enantiomeric excess with the conversion.

关键词： asymmetric synthesis reduction samarium reagent

Effects of Silicon Content and Intercritical Annealing on Manganese Partitioning in Dual Phase Steels

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Journal of Iron and Steel Research International 2010年第5期17卷 44-50页

作者： A Nouri H Saghafian sh Kheirandish Department of Metallurgy and Materials Engineering Iran University of Science and Technology

Steels of constant manganese and carbon contents with silicon content of 0.34 %- 2.26% were cast. The as-cast steels were then hot rolled at 1 100 ℃ in five passes to reduce the cast ingot thickness from 80 to 4 mm, air cooled to room temperature and cold rolled to 2 mm in thickness. Dual phase microstructures with different volume fraction of martensite were obtained through the intercritical annealing of the steels at different temperatures for 15 min followed by water quenching. In addition to intercritical annealing temperature, silicon content also altered the volume fraction of martensite in dual phase steels. The partitioning of manganese in dual phase silicon steels was investigated using energy-dispersive spectrometer （EDS）. The partitioning coefficient, defined as the ratio of the amounts of alloying element in the austenite to that in the adjacent ferrite, for manganese increased with increasing intercritieal annealing temperature and silicon content of steels. It was also found that the solubility of manganese in ferrite and austenite decreased with increasing intereritical temperature. The results were discussed by the diffusivity and the solubility of manganese in ferrite and austenite existed in dual phase silicon steels.

关键词： partitioning dual phase steel intercritical annealing temperature silicon manganese