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Journal of Arid Land 2011年第3期3卷 174-183页

作者： samir Mohammad Ali Alredaisy Department of Geography Faculty of EducationUniversity of Khartoum

The climatic, geomorphic, hydrologic and aquifer characteristics of the torrential Gash River across mountainous areas, in far eastern Sudan, were analyzed in order to mitigate its recurring catastrophic impacts. Hydrologic and climatic data and interpretation of Gash River satellite images were from relevant research works carried out in Gash Basin from 1985 to 2008. The results indicated that the total catchment area of Gash River is about 21,000 km2, and the basin area is 31,000 km2. The total length of Gash River is 450 km and the average slope is 200 cm/km. The width of the catchment varies from 30 m to 90 m and that of the basin is from 100 m to 800 m, and the course of the river is varied. During the period of 1980？2008, the mean annual rainfall was 250 mm and the mean annual discharge was 6.8 ×10~8 m^3, and the flooding is approximately one time per 5 years. Torrential floods measured at Kassala town since 1907 showed that an absolute maximum discharge was 876 m3/s and a mean maximum discharge was 365 m3/s. These characteristics differ widely between catchment and basin areas. The author proposes that, by analyzing the climatic, geomorphic, hydrologic and aquifer characteristics of the Gash River and considering the role of community, a concise database could be provided to formulate the aquifer, geomorphic, hydrologic and climatic （AQUIGEOHYCLIM） regional approach to mitigate Gash River recurring catastrophic impacts.

关键词： AQUIGEOHYCLIM Gash River basin climate geomorphology hydrology mitigation water management

Vibration-based crack prediction on a beam model using hybrid butterfly optimization algorithm with artificial neural network

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Frontiers of Structural and Civil Engineering 2022年第8期16卷 976-989页

作者： Abdelwahhab KHATIR Roberto CAPOZUCCA samir KHATIR Erica MAGAGNINI Structural Section DICEA Polytechnic University of MarcheAncona 60131Italy Faculty of Civil Engineering Ho Chi Minh City Open UniversityHo Chi Minh City 700000Vietnam

Vibration-based damage detection methods have become widely used because of their advantages over traditional *** paper presents a new approach to identify the crack depth in steel beam structures based on vibration analysis using the Finite Element Method(FEM)and Artificial Neural Network(ANN)combined with Butterfly Optimization Algorithm(BOA).ANN is quite successful in such identification issues,but it has some limitations,such as reduction of error after system training is complete,which means the output does not provide optimal *** paper improves ANN training after introducing BOA as a hybrid model(BOA-ANN).Natural frequencies are used as input parameters and crack depth as *** data are collected from improved FEM using simulation tools(ABAQUS)based on different crack depths and locations as the first ***,data are collected from experimental analysis of cracked beams based on different crack depths and locations to test the reliability of the presented *** proposed approach,compared to other methods,can predict crack depth with improved accuracy.

关键词： damage prediction ANN BOA FEM experimental modal analysis

ON THE SUPERSTABILITY OF THE PEXIDER TYPE GENERALIZED TRIGONOMETRIC FUNCTIONAL EQUATIONS

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Acta Mathematica Scientia 2014年第6期34卷 1749-1760页

作者： Driss ZEGLAMI Ahmed CHARIFI samir KABBAJ Department of Mathematics E.N.S.A.M Moulay Ismail University Department of Mathematics Faculty of SciencesIbn Tofail University

The aim of this paper is to investigate the superstability problem for the pexiderized trigonometric functional equation∑ v∈Φ∫Kf（xkv（y）k^-1）dwK（k）= Φ g（x）h（y）, x, y ∈ G,where G is any topological group, K is a compact subgroup of G, ωK is the normalized Haar measure of K, Φ is a finite group of K-invariant morphisms of G and f, g, h are continuous complex-valued ***, we have generalized the results of stability for d＇Alembert＇s and Wilson＇s equations by R. Badora, J. Baker, B. Bouikhalene, P. Gavruta, S. Kabbaj, Pl. Kannappan, G. ***, J.M. Rassias, A. Roukbi, L. Sz′ekelyhidi, D. Zeglami, etc.

关键词： superstability generalized Pexider d'Alembert equation Wilson's functional equation group of morphisms

GLOBAL EXISTENCE AND ASYMPTOTIC BEHAVIOR OF SOLUTIONS FOR SOME COUPLED SYSTEMS VIA A LYAPUNOV FUNCTIONAL

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Acta Mathematica Scientia 2019年第6期39卷 1538-1550页

作者： Lamia DJEBARA Salem ABDELMALEK samir BENDOUKHA Department of Mathematics and Computer Science ICOSI LaboratoryUniversity of KhenchelaKhenchela04000Algeria Department of Mathematics and Informatics Faculty of Exact Sciences and Natural Sciences and LifeUniversity of Larbi TebessiTebessa12002Algeria Electrical Engineering Department College of Engineering at YanbuTaibah UniversitySaudi Arabia

The purpose of this work is to study the global existence and asymptotic behavior of solutions to a coupled reaction-diffusion system describing epidemiological or chemical situations. Our analytical proofs are based ... 详细信息

关键词： epidemic model reaction-diffusion global existence of solutions asymptotic stability

Spectral lags of flaring events in LS I+61°303 from RXTE Observations

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Research in Astronomy and Astrophysics 2016年第7期16卷 29-38页

作者： Tamal Sarkar samir Sarkar Arunava Bhadra High Energy&Cosmic Ray Research Centre University of North BengalSiliguriWB 734013India University Science Instrumentation Centre University of North BengalSiliguriWB 734013India

This work reports the first discovery of（negative） spectral lags in X-ray emission below 10 ke V from the gamma ray binary LS I＋61？303 during large flaring episodes using Rossi X-ray Timing Explorer（RXTE） observations. It is found from the RXTE data that during the flares, low energy（3–5 ke V） variations lead the higher energy（8–10 ke V） variations by a few tens of seconds whereas no significant time lag is observed during the non-flaring states. The observed spectral lag features for flaring events suggest that inverse Compton scattering may be operating, at least in some part of the system. Another possibility is that the sites of particle acceleration may be different for flaring and non-flaring events such as in the microquasar model, in which the flaring radiation may come from hot spots sitting above the black hole while steady state emissions are due to the jets.

关键词： X-rays:binaries X-rays:individual(LS I+61?303)

Shear reinforcement effect of reinforced concrete tie-columns on the lateral resistance of confined masonry walls

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 313-324页

作者： samir Bouhedja Abdelkrim Bourzam Ahmed Boukhaled Ammar Nechnech University of Sciences and Technology Houari Boumediene(USTHB)Faculty of Civil EngineeringLaboratory of EnvironmentWaterGeomechanics and Structures(LEEGO)BP 32 El AliaBab EzzouarAlgiers16111Algeria University of Sciences and Technology Houari Boumediene(USTHB)Faculty of Civil EngineeringLaboratory of Built Environment Research(LBE)BP 32 El AliaBab EzzouarAlgiers16111Algeria

Tie-columns improve significantly the lateral resistance of masonry bearing walls against persistent, transient and accidental loads. The research work described herein has been carried out to assess the lateral resistance of confined masonry walls, where contribution of the masonry panel is evaluated according to material mechanics and tie-columns effect is estimated by a proposed analytical formulation based on a model reported on previously. This approach takes into account the effect of dowel support on the reaction of its adjacent shear reinforcement： the conditions for the various contributions of transverse reinforcements are better defined following a clear evaluation of the participation ratio of these reinforcements. Lateral resistances of confined masonry walls measured in full-scale tests and gleaned from the literature are compared and checked with resistances calculated using the present approach.

关键词： reinforcement columns confined reinforced walls Shear formulation panel participation herein

The xanthate route to all-carbon quaternary centers

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Science China Chemistry 2019年第11期62卷 1450-1462页

作者： Béatrice Quiclet-Sire samir Z.Zard Laboratoire de Synthèse Organique Ecole Polytechnique

This review discusses the numerous routes to all-carbon quaternary centers based on the unique radical chemistry of xanthates. Itsummarizes the various approaches to the synthesis of tertiary xanthates then describes the intra- and intermolecular radicaladditions and combinations thereof that have so far been used to construct quaternary centers.

关键词： xanthates quaternary centers radical addition cyclization tandem reactions

Microstructure of coupled Al/gray cast iron obtained by molding and its effect on mass loss

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China Foundry 2018年第5期15卷 378-383页

作者： Mohamed Bouitna Naima Boutarek-Zaourar samir Mansour samir Mourad Chentouf Eric Mossang Laboratory of Materials Technology Faculty of Mechanical Engineering and Process EngineeringUniversity of Science and Technology Houari BoumedieneB.P.32 El Alia16111 AlgiersAlgeria Department of Mechanical Engineering School of Technology Superior1100 Notre-Dame Street WestMontrealQuebec H3C 1K3Canada NEEI Institute National Center for Scientific Research25rue des MartyrsBO 16638042Grenoble CedexFrance

This study aims to consolidate the surface of gray cast iron with aluminum deposition by developing a method that combines the preparation and surface treatment in a single operation. The effect of the wall thickness of the castings on the microstructure of the formed layers was studied, and two thicknesses, 8 mm and 25 mm, were studied. The formation of a continuous and homogeneous rich aluminum layer on the surface of the cast iron was observed. The formed layer is composed of two successive zones identified as two proeutectoid phases FeAl+FeAl/FeAl2 and single-phase FeAl, which significantly increases the surface hardness. Furthermore, this change in surface composition makes it possible to reduce the mass of the immersed samples in a 1 M hydrochloric acid solution during different exposure times(1 to 4 days). Consequently, a clear improvement in the corrosion resistance of the treated layers is highlighted.

关键词： gray cast iron aluminum coating treatment in the mold mass loss

Existence Results for a Class of Periodic Evolution Variational Inequalities

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Chinese Annals of Mathematics,Series B 2007年第6期28卷 629-650页

作者： samir ADLY Daniel GOELEVEN Michel THRA DMI-XLIM UMR-CNRS 6172Université de Limoges123 Avenue A.Thomas87060 Limoges CedexFrance. IREMIA Université de La Réunion97400 Saint-DenisFrance.

In this paper, using the Brouwer topological degree, the authors prove an existence result for finite variational inequalities. This approach is also used to obtain the existence of periodic solutions for a class of e... 详细信息

关键词： Variational inequalities Differential inclusions Topological degree Guiding functions Periodic solutions

Periodic Solutions of Evolution Variational Inequalities—a Method of Guiding Functions

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Chinese Annals of Mathematics,Series B 2009年第3期30卷 261-272页

作者： samir ADLY Daniel GOELEVEN Michel THRA Département de Math'ematiques et Informatique Laboratoire XLIM(Unité Mixte 6172 du CNRS)Université de Limoges123 Avenue A.Thomas87060 Limoges CedexFrance. Laboratoire d' Informatique et de Mathématiques Université de La Réunion97400 Saint-DenisFrance.

This paper focuses on a part of the presentation given by the third author at the Shanghai Forum on Industrial and Applied Mathematics(Shanghai 2006).It is related to the existence of a periodic solution of evolution ... 详细信息

关键词： Variational inequality Differential inclusion Topological degree Guiding function Periodic solution