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Synthesis of some new fused coumarin derivatives

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Chinese Journal of Chemistry 2000年第4期18卷 590-595页

作者： EL-DEEN ibrahim Mohey ibrahim H.k. MAHMOUD F.F. Faculty of Education Suez Canal University Port-Said EgyptFaculty of Science Suez Canal University Ismailia EgyptFaculty of Science (for Girls) Al-Azhar University Nasr City Egypt

2-Hydrazino-4-hydroxy-5H-[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (3) was prepared via condensation of 2 with hydrazine hydrate. Treatment of 3 with methylene chloride, ethyl chloroformate, ethyl chloroacetate and benzaldehyde yielded the corresponding 2 - ( substituted ) hydrazino - 4 -hydro-xy-5H-[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (4, 5, 6, and 10), followed by cyclization of 4, 5 and 6 with dimethyl formamide and fused sodium acetate under reflux, while compound 10 was cyclized with bromine and sodium acetate in acetic acid. Compound 3 reacted with β-(toloyl) acrylic acid, ethyl α-cyano-p-methoxycinnamate, diethyl malonate and acetyl chloride affording the corresponding 2-(substituted) hydrazino-4-hydroxy-5H-[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (12, 13, 14, 15 and 16).

关键词： Synthesis fused coumarin derivatives cyclization

Ballistic resistance and energy dissipation of woven-fabric composite targets:Insights on the effects of projectile shape and obliquity angle

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Defence Technology（防务技术） 2023年第3期21卷 14-32页

作者： ibrahim Goda UniversitéBourgogne Franche-Comté FEMTO-ST InstituteDépartement Mécanique Appliquée24 Rue de L’Épitaphe25000BesançonFrance

This study aims at investigating the ballistic resistance and energy absorption in woven E-glass composite panels,considering different projectile nose shapes and oblique incidence *** that scope,three-dimensional finite element(FE)models of both projectiles and the laminated target are developed and numerical investigations are carried out using Abaqus Explicit *** composite damage model’s constitutive law encompasses nonlinear material response,material properties degradation,progressive failure,and an element deletion *** cohesive surface technique is used to represent the interface between two adjacent plies in the laminate,and the traction-separation law is used to characterize the behaviors of interlaminar degradation and *** responses attributable to fiber rupture,matrix cracking,and plasticity caused by micro-matrix cracking due to shear loading are taken into account with suitable damage evolution *** computational framework is first validated against the experimental results reported in the literature by performing ballistic impact tests on the target laminate with conical,hemispherical and blunt-ended projectile,and the numerical results showed a good comparison in terms of residual *** the framework is explored in simulating more complex failure mechanisms,with particular emphasis on the influence of the impact angle of obliquity,a parameter that is not usually analyzed in the *** that regard,the effects of normal and oblique impact on the damage morphologies and ballistic behavior of the fabric composite target in terms of energy absorption,impact contact force,and projectile residual velocity are conducted and analyzed,*** findings showed that the ballistic impact behavior of target composite is substantially influenced by projectile nose shape and incidence angle obliquity.

关键词： resistance cracking composite

Effect of Aging on the Toughness of Austenitic and Duplex Stainless Steel Weldments

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Journal of Materials Science & Technology 2010年第9期26卷 810-816页

作者： Omyma Hassan ibrahim ibrahim Soliman ibrahim Tarek Ahmed Fouad khalifa Metallurgy Dept. Nuclear Research CentreAtomic Energy Authority(Egypt) Nuclear Safety Centre Atomic Energy Authority(Egypt) Shoubra Faculty of Engineering Benha University

In the present study,the effect of aging heat treatment at 650,750,and 850？C on the impact toughness of 316L austenitic stainless steel,2205 duplex stainless steel and their weldments has been *** process was conducted using the TIG（tungsten inert gas） welding *** impact testing,at room temperature,was employed to determine the effect of aging treatment on the impact properties of investigated *** treatment resulted in degradation in the impact toughness as demonstrated by the reduction in the impact fracture energy and deformation parameters（strain hardening capacity,fracture deffection,and crack initiation and propagation energy）.The degree of embrittlement was more noticeable in duplex stainless steel parent and weld-metal than in 316L stainless steel and became greater with the increase of aging *** degradation in impact toughness was discussed in relation to the observed precipitation of the intermetallic sigma phase in the microstructure of the stainless steel weldments and the corresponding fracture surface morphology.

关键词： Austenitic and duplex stainless steels Aging Instrumented impact Toughness

NEW POLY(METHACRYLATE)S CONTAINING OXIME ESTERS MOIETIES BASED ON CYCLOHEXANON AND CYCLOPENTANON

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Chinese Journal of Polymer Science 2008年第4期26卷 443-454页

作者： ibrahim Erol Afyon kocatepe Universty Faculty of Science and Arts Department of ChemistryAfyonkarahisarTurkey

The synthesis of two new methacrylates such as 2-[(cyclohexylideneamino)oxy]-2-oxoethyl methylacrylate (CHOEMA)and 2-[(cyclopentylideneamino)oxy]-2-oxoethyl methylacrylate(CPOEMA)are *** monomers produced from the reaction of corresponding cyclohexanone O-(2-chloroacetyl)oxime and cyclopentanone O-(2- chloroacetyl)oxime with sodium methacrylate was polymerized in 1,4-dioxane solution at 65℃using AIBN as an initiator. The monomers and their polymers were characterized by IR,~1H- and ^(13)C-NMR spec...

关键词： Methacrylate Oxime esters Activation energy Thermal decompositionv Biological activitiy

Wear Behaviour of Plasma Paste Boronized of AISI 8620 Steel with Borax and B_2O_3 Paste Mixtures

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Journal of Materials Science & Technology 2013年第7期29卷 662-668页

作者： ibrahim Gunes Department of Metallurgical and Materials Engineering Faculty of TechnologyAfyon Kocatepe UniversityAfyonkarahisar 03200Turkey

In the present study, AlSl 8620 steel was plasma paste boronized （PPB） by using paste mixtures with different borax and B2O3 percentages. The PPB process was carried out in a DC plasma system at 973, 1023 and 1073 k for 5 h in a gas mixture with 70% H2-30% Ar under a constant pressure of 103 Pa （10 mbar）. The thickness of boride layers ranged from 15.9 to 53.6 tim depending on the temperature and process time. The hardness of the borides formed on the surface of the steel substrate and unborided steel substrate were 1648-1924 HV0.05 and 226 HV0.05, respectively. X-ray diffraction analysis of the boride layers on the surface of the samples were obtained for FeB and Fe2B phases. The wear tests on the steel were performed by using a ball-on-disc test device at room temperature with applied load of 10 N and with a shear velocity of 0.2 m/s. Wear test results showed that the highest value of wear rate was observed in the unborided sample while the lowest wear rate was observed in the PPB samples with 30% borax ＋ 70% B4C paste at 1073 k for 5 h.

关键词： Coating Borax B2O3 Wear Coefficient of friction

Recent advances on flexible electrodes for Na-ion batteries and Li–S batteries

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Journal of Energy Chemistry 2019年第5期28卷 15-44页

作者： Mohammed-ibrahim Jamesh Department of Physics and Materials Science City University of Hong Kong Applied and Plasma Physics School of Physics (A28) University of Sydney CSIR-Central Electrochemical Research Institute-Chennai Unit CSIR Madras Complex

Flexible energy storage devices are essential for emerging flexible electronics. The existing state-of-the-art Li-ion batteries are slowly reaching their limitation in terms of cost and energy density. Hence, flexible Na-ion batteries (SIBs) with abundanee Na resources and Li-S batteries with high energy density become the alternative for the Li-ion batteries in future. This review summarizes the recent advances in the development of flexible electrode materials for SIBs with metallic matrix and carb on aceous matrix such as carb on nano-tubes, carbon nano-fiber, graphene, carbon cloth, carbon fiber cloth, and cotton textiles. Then, the potential prototype flexible full SIBs are discussed. Further, the recent progress in the development of flexible electrode materials for Li-S batteries based on carb on nano-fiber, carb on nano-tubes, graphene, and cotton textiles is reviewed. Moreover, the design strategies of suitable interlayer, separator, electrolyte, and electrodes to prevent the dissolution and shuttle effect of polysulfides in flexible Li-S batteries are provided. Finally some prospective investigation trends towards future research of flexible SIBs and Li-S batteries are also proposed and discussed. The scientific and engineering knowledge gained on flexible SIBs and Li-S batteries provides conceivable development for practical application in near future.

关键词： Na-ion batteries Lithium-sulfur batteries Flexible Free-standing High performance energy storage Long cycle life

Super Gaussian enhancers in the Schwinger mechanism

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Communications in Theoretical Physics 2020年第1期72卷 81-88页

作者： ibrahim Akal Theory Group DESY 22607 HamburgGermany

We study the Schwinger mechanism in the presence of an additional uniformly oriented,weak super Gaussian of integer order 4 N+*** the worldline approach,we determine the relevant critical points to compute the leading order exponential factor *** show that increasing the parameter N gives rise to a strong dynamical *** N=2,this effect turns out to be larger compared to a weak contribution of the Sauter *** higher orders,specifically,for the rectangular barrier limit,i.e.N→∞,we approach the Lorentzian case as an upper *** the mentioned backgrounds significantly differ in Minkowski spacetime,we show that the found coincidence applies due to identical reflection points in the Euclidean instanton *** addition,we also treat the background in perturbation theory following recent *** doing so,we show that the parameter N determines whether the weak contribution behaves perturbatively or nonperturbatively with respect to the field strength ratio,and,hence,reveals an interesting dependence on the background *** particular,we show that for backgrounds,for which higher orders in the field strength ratio turn out to be relevant,a proposed integral condition is not *** view of these findings,the latter may serve as an indicator for the necessity for higher-order contributions.

关键词： quantum field theory nonperturbative phenomena instantons Schwinger effect semiclassics

Microstructure,Properties and Wear Behaviors of (Ni_3Al)_p Reinforced Cu Matrix Composites

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Journal of Materials Science & Technology 2011年第10期27卷 937-943页

作者： ibrahim elikyrek Nese .krpe Tugba ler Remzi Grler Metallurgical and Materials Engineering Department Faculty of Engineering and ArchitectureEski sehir Osmangazi University Institute of Metallurgy Eski sehir Osmangazi University

Pure copper and its composites reinforced with Ni3Al particles were produced by powder metallurgy （PM）. Ni3Al powders were produced by mechanical ball milling from vacuum arc melted compounds. The Ni3Al powders were characterized by X-ray diffraction （XRD）. The microscopy examinations revealed that the Ni3Al particles were distributed uniformly in the matrix. The effects of the particle fraction on the density, electrical conductivity, strength and dry sliding wear resistance of composite were investigated. It was found that the density and electrical conductivity of the composites decrease while the compression yield strength and wear resistance of composites increase with an increase in the particle fraction. The dry sliding wear tests were performed with pin-on-disk geometry. After sliding wear tests, the worn surfaces were examined by scanning electron microscopy （SEM） equipped with an energy dispersive X-ray spectrometer （EDS）. Results have shown that the wear mechanism is oxidative and adhesive.

关键词： Metal matrix composites Powder metallurgy Wear Intermetallics

Analytical Investigation of Soliton Solutions to Three Quantum Zakharov-kuznetsov Equations

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Communications in Theoretical Physics 2018年第10期70卷 405-412页

作者： Rahmatullah ibrahim Nuruddeen khalid Suliman Aboodh khalid k. Ali Department of Mathematics Federal University Dutse Department of Mathematics Faculty of Science & Technology Omdurman Islamic University Department of Mathematics Faculty of Science & Arts University of Bisha Mathematics Department Faculty of Science Al-Azhar University

In the present paper, the two-dimensional quantum Zakharov-kuznetsov(QZk) equation, three-dimensional quantum Zakharov-kuznetsov equation and the three-dimensional modified quantum Zakharov-kuznetsov equation are analytically investigated for exact solutions using the modified extended tanh-expansion based method. A variety of new and important soliton solutions are obtained including the dark soliton solution, singular soliton solution, combined dark-singular soliton solution and many other trigonometric function solutions. The used method is implemented on the Mathematica software for the computations as well as the graphical illustrations.

关键词： two-dimensional QZk equation three-dimensional QZk equations soliton solutions