检索结果-南通市图书馆

Feasibility of new ladle-treated Hadfield steel for mining purposes

在线全文

学校读者我要写书评

暂无评论

International Journal of minerals,metallurgy and materials 2018年第3期25卷 300-309页

作者： m.K. el Fawkhry Central metallurgical Research and Development Institute (CmRDI) Box 87 Helwan Egypt

A debate has arisen over the possibility of using a new ladle-treated Hadfield steel instead of conventional heat-treated Hadfield steel in mining applications. This debate might be solved by identifying the differences between the mechanical properties and strain-hardening properties of conventional heat-treated Hadfield steel and its counterpart ladle-treated Hadfield steel. Tensile and compression tests demonstrated that the ductility of ladle-treated Hadfield steel is similar to that of conventional heat-treated steel. However, the strain-hardening property of the ladle-treated Hadfield steel is almost two times higher than that of the heat-treated Hadfield steel. The results of this study demonstrate that the improvement of the strain-hardening behavior is attributable to the low stacking-fault energy of the main austenite matrix, which results from the high segregation coefficient of carbon and manganese solutes of the main austenite matrix into the new eutectic phase. Superior wear abrasion resistance is a potential consequence of different strain-hardening properties under low and high loads.

关键词： Hadfield steel ladle treatment process wear abrasion resistance strain hardening properties mechanical properties

Softζ-Rough Set and Its Applications in Decision making of Coronavirus

在线全文

学校读者我要写书评

暂无评论

Computers, materials & Continua 2022年第1期70卷 267-285页

作者： m.A.el Safty Samirah Al Zahrani m.K.el-Bably m.el Sayed Department of mathematics and Statistics College of ScienceTaif UniversityTaif21944Saudi Arabia Department of mathematics Faculty of ScienceTanta UniversityTantaEgypt Department of mathematics College of Science and ArtsNajran UniversityNajran66445Saudi Arabia

In this paper,we present a proposed method for generating a soft rough approximation as a modification and generalization of Zhaowen et *** were obtained between our approach and the previous study and ***,an application on Coronavirus(COVID-19)has been presented,illustrated using our proposed concept,and some influencing results for symptoms of Coronavirus patients have been ***,following these concepts,we construct an algorithm and apply it to a decision-making problem to demonstrate the applicability of our proposed ***,a proposed approach that competes with others has been obtained,as well as realistic results for patients with ***,we used mATLAB programming to obtain the results;these results are consistent with those of theWorld Health Organization and an accurate proposal competing with the method of Zhaowen et *** been ***,it is recommended that our proposed concept be used in future decision making.

关键词： Soft set soft rough set softζrough set COVID-19 intelligence discovery decision making

Adsorption properties of Rosmarinus officinalis oil as green corrosion inhibitors on C38 steel in 0.5 m H_2SO_4

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

Acta metallurgica Sinica(English Letters) 2010年第1期23卷 13-20页

作者： E.el Ouariachi J.Paolini m.Bouklah A.elidrissi A.Bouyanzer B.Hammouti J-m.Desjobert J.Costa Laboratoire de Chimie Appliqu'ee et Environnement Facult'e des SciencesUniversit'e Mohamed PremierBP71760000 OujdaMorocco UmR CNRS 6134 Laboratoire de Chimie des Produits NaturelsUniversit'e de CorseFrance

Rosmarinus officinalis essential oil obtained by hydrodistillation was tested as corrosion inhibitor of steel in 0.5 m H2SO4 using weight loss measurements, and electrochemical .polarisation methods. Results obtained indicate that the corrosion rate is reduced and R. officinalis oil adsorbs on the metal surface and then inhibits corrosion process. Its inhibition efficiency increases with oil increasing content to reach 61% at 1 g/L. Polarisation curves indicate that RO acts as a cathodic inhibitor. The inhibition efficiency of naturally oil remains slightly constant with the rise of temperature. Chemical analysis of R. officinalis essential oil was carried out using capillary GC and GC/mS. The oil composition was characterized by high amount of oxygenated monoterpene （77%） with 1,8-cineol （52.1%） as main component. Discussion of adsorption was investigated on the the isotherm adsorption of essential oil on basis of essential oil composition. Finally the steel has been also reported.

关键词： Rosmarinus officinalis oil Adsorption Corrosion Inhibition Steel 1,8-cineol

Targeting harmful effects of non-excitatory amino acids as an alternative therapeutic strategy to reduce ischemic damage

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2454-2463页

作者： Victoria Jiménez Carretero IrisÁlvarez-merz Jorge Hernández-Campano Sergei A.Kirov Jesús m.Hernández-Guijo Department of Pharmacology and Therapeutic School of MedicineUniv.Autónoma de MadridMadridSpain Ramón y Cajal Institute for Health Research(IRYCIS) Neurobiology-Research ServiceHospital Ramón y CajalMadridSpain Institute of Neurobiology Faculty of Mathematics and Natural SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany Department of Neuroscience and Regenerative medicine&Department of Neurosurgery Medical College of Georgia at Augusta UniversityAugustaGAUSA

The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is ***,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely *** release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the *** findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma *** amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate *** N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during *** is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor ***,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain *** these pathways co uld highlight new therapeutic targets to mitigate brain injury.

关键词： cell swelling N-methyl-D-aspartate receptor non-excitatory amino acids stroke synaptic transmission

Water equivalence of some 3D dosimeters:a theoretical study based on the effective atomic number and effective fast neutron removal cross section

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2017年第12期28卷 170-181页

作者： A.m.el-Khayatt Department of Physics College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU) Reactor Physics Department NRC Atomic Energy Authority

Effective atomic numbers for photon energy absorption(ZPEA_(eff)) and their corresponding electron numbers (NPEA_(eff)), and effective macroscopic removal cross sections of fast neutrons(RR) were calculated for 27 different types of three-dimensional dosimeters, four types of phantom.m.terials, and water. The values of ZPEA_(eff) and NPEA_(eff) were obtained using the direct method for energies ranging from 10 keV to 20 meV. Results are presented relative to water, for direct comparison over the range of examined energies. The effect of monomers that are used in polymer gel dosimeters on the water equivalence is discussed. The relation between Σ_R and hydrogen content was studied. micelle gel dosimeters are highly promising because our results demonstrate perfect matching between the effective atomic number, electron density number, and fast neutron attenuation coefficient of water.

关键词： 3D dosimeters Water equivalence Effective atomic number Photon energy absorption Removal cross section Fast neutrons

Diffusion coefficient of vacancies and jump length of electrons in Co_(1-x)Zn_(x)Fe_(2)O_(4)ferrites

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2012年第2期1卷 144-149页

作者： m.el-SAADAWY Physics Department Faculty of ScienceKafrelsheikh UniversityKafrelsheikh CityEgypt

A series of polycrystalline samples of Co_(1-x)Zn_(x)Fe_(2)O_(4)where(x=0.1,0.2,0.3,0.4,0.5 and 0.6)were prepared by the usual ceramic technique.X-ray diffraction patterns confirmed the spinel cubic *** diffusion coefficients of oxygen vacancies were estimated from dc conductivity *** was noticed that the diffusion coefficient decreases with increasing Zn^(2+)*** increase of temperature increases the diffusion of lattice *** Curie temperature,lattice parameter and jump length of electrons were studied as a function of Zn^(2+)*** the correlation between the ionic radius and the radii of octahedral and tetrahedral sites,the theoretical lattice parameters were calculated and suggested cation distribution for the given ferrites was determined.

关键词： diffusion coefficient lattice parameter jump length and jump rate of vacancies Curie temperature cation distribution

CO oxidation and 4-nitrophenol reduction over ceria-promoted platinum nanoparticles impregnated with ZSm-5 zeolite

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 Rare Earths 2022年第8期40卷 1247-1254页

作者： Zeinhom.m.el-Bahy mohammed T.Alotaibi Salah m.el-Bahy Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt Department of Chemistry Turabah University CollegeTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

Active new ceria-promoted platinum supported on ZSm-5 catalysts were prepared and characterized by X-ray diffraction(XRD),Fourier transform infrared spectra(FTIR),transform electron microscopy(TEm),temperature programmed desorption(TPD),and FTIR of CO *** samples were prepared by the incipient wetness impregnation method and calcined at 500℃.The XRD patterns and FTIR spectra prove that the zeolite framework is kept unaltered after metal *** images prove the presence of Pt nanoparticles with particle size starting from 14 to 27 *** FTIR data suggest the formation of Pt-O-Ce ***-situ FTIR of CO adsorption over reduced samples proves the presence of Pt~0 only,and no Pt^(n+)-CO species are *** prepared catalysts were tested in both oxidation reaction(CO oxidation) in the gas phase and in reduction reaction(4-nitrophenol reduction) in the aqueous ***,CO oxidation by O_(2) results in the formation of a CO_(2) peak at 2347 cm^(-1) as the only CO oxidation product in the studied frequency *** intensity of the CO_(2) peak increases after the addition of Ce,and it is 4 times higher in Pt_(1) Ce_(0.5)ZSm-5 than that in the Ce-free *** to the FTIR data and previous reports,the increase in the catalytic activity may be due to the formation of Pt-O-Ce ***,Ce-promoted Pt_(1) ZSm5 also exhibits enhanced catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol by NaBH_(4) in the aqueous *** first-order rate constant of the reduction increases ≈13 times after incorporating equal ratios of Pt and Ce(Pt_(1) Ce_(1)ZSm-5),and the activation energy(E_(a)) decreases to 40% of that in the reaction over Pt_(1) ZSm-5.

关键词： 4-Nitrophenol CO oxidation TPD-CO Platinum-cerium ZSm-5 Rare earths

Physical and Dielectric Properties of Some Nonionic Surfactants

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 1998年第4期14卷 361-367页

作者： el-Anwar, I.m. el-Henawii, S.A. National Research Center Dokki Cairo Egypt Faculty of Science Helwan University Egypt

Fatty acid esters have been prepared by reacting the acid C//1//8 with polyethylene glycols having varying numbers of oxyethylene units (4-88 units) by the direct esterification reaction method. Surface and interfacial tensions were studied at various experimental conditions, including, concentration, temperature and chemical constitution of the surfactant. Critical micelle concentrations (CmC), surface excess and residual area occupied by each surface active agent molecule A have been calculated by using Gibb's equations. CmC values range from 10 to 55 multiplied by 10** minus **5 mole/L for all studied agents, while the residual area occupied by each molecule varies from 0.6 to 1.5 nm**2. Variation of CmC of some of these agents with temperature have been also examined and the obtained data were used to calculate the heat of micellization delta H//m and the entropy change during micellization delta S//m. Values of delta H//m vary from 14.63 kJ/mole to 2.717 kJ/mole depending on the chemical constitution of the agent under consideration. The apparent dipole m.m.nts mu of three surfactant were measured following the Headstrand's method. (Edited author abstract) 23 Refs.

关键词： Surface active agents

Neutron and Ion Beams Emitted from Plasma Focus (112.5 J) Device

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2010年第1期12卷 1-5页

作者： G.m.el-ARAGI Plasma Physics and Nuclear Fusion Department Nuclear Research Center

Preliminary results of recent experiments performed within the mather-type 112.5 J plasma focus device are presented. The ion beams from the focus device operated with deuterium filling at 1 mbar were registered using CR-39 solid state nuclear track detectors （SSNTD） and a Faraday cup detector for time-resolved measurements. The time-resolved neutron emission from the focus region measurements was detected with a photomultiplier tube （IP-28） optically coupled with a plastic scintillator NE 102.

关键词： plasmas neutron scintillator detectors photomultiplier Faraday