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Imaging of target with complicated motion using ISAR system based on IPHAF-TVA

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chinese Journal of Aeronautics 2021年第2期34卷 252-264页

作者： Abdelkader ALI cherif Yong WANG Algerian Space Agency Satellite Development CenterOran 31000Algeria Research Institute of Electronic Engineering Technology Harbin Institute of TechnologyHarbin 150001China

The technique of imaging a target with a complicated motion using an Inverse Synthetic Aperture Radar(ISAR) system is an effective tool in the field of radar signal processing. After the translational compensation, the received signal reflected from the target can take the form of a multi-component Polynomial Phase Signal(m-PPS), and the high quality ISAR image can be provided via the combination between the estimated parameters of the m-PPS and the Range Instantaneous-Doppler technique(RID). For a target with a high maneuvrability, the occurrence of scatterers Migration Through Resolution Cell(MTRC), caused by the rotational movement could be appearing. That is why the variation in the amplitude of the echo during the time of observation cannot be neglected. The purpose of this study is the parameters estimation of the m-PPS signal with order three in the case of the Time Varying Amplitude(TVA). The Improved-version of the Product High-order Ambiguity Function(IPHAF) with TVA is proposed to improve the quality of the ISAR image compared with traditional techniques based on a constant amplitude;the experimental outcomes confirm that the new IPHAF-TVA method presented in this study is an effective technique to make the ISAR image very clear.

关键词： Inverse Synthetic Aperture Radar(ISAR) Maneuvering target Multi-component Polynomial Phase Signal(m-PPS) Product High-Order Ambiguity Function(IPHAF) Time Varying Amplitude(TVA)

New results for a Lasota-Wazewska model

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International Journal of Biomathematics 2019年第2期12卷 143-162页

作者： Farouk cherif Mohsen Miraoui MaPSFA LR11ES35ISSATUniversity of Sousse4002 SousseTunisia IPEIK University of Kairouan3100 KairouanTunisia LR11ES53Faculty of Sciences of Sfax University of SfaxTunisia

In nature there is no phenomenon that is purely periodic,and this gives the idea to consider the measure pseudo almost periodic *** this paper,by employing a suitable fixed point theorem,the proper ties of the measure pseudo almost periodic functions and differential inequality,we investigate the existence and uniqueness of the measure pseudo almost periodic solutions for some models of Lasota-Wazewska equation with measure pseudo almost periodic coefficients and mixed *** suppose that the linear part has almost periodic and the nonlinear part is assumed to be measure pseudo almost ***,the global attractivity and the exponential stability of the measure pseudo almost periodic solutions are also considered for the *** application,an illustrative numerical example is given to demonstrate the effectiveness of the obtained results.

关键词： Lasota Wazewska model measure pseudo almost periodic function fixed point theorem

Thermal performance of lightweight concrete applications in building envelopes in Lebanon

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Building Simulation 2021年第5期14卷 1359-1375页

作者： Emilio Sassine Elias Kinab Yassine cherif Emmanuel Antczak Michel Nasrallah Lebanese University Habitat and Energy UnitGroup of Thermal and Renewable Energies-Laboratory of Applied Physics(LPA-GMTER)Faculty of SciencesFanar CampusLebanon Lebanese University Faculty of EngineeringRoumiehEl MetnLebanon Univ.Artois ULR4515Laboratoire de Genie Civil et geo-Environnement(LGCgE)BethuneF-62400France CC Technique Memari StreetHamraBeirutLebanon

Innovative building materials are being used in building envelopes for reducing their heating and cooling *** paper aims to assess the thermal impact of using lightweight concrete in Lebanese building constructions by pouring an 8 cm thickness of lightweight concrete on the roof and the slab and replacing traditional hollow concrete block by lightweight concrete *** properties of two different samples were experimentally determined:the first one(558 kg/m^(3))used for the roof and the slab and the second one(1074 kg/m^(3))used for the *** numerical simulations were carried out for a Lebanese traditional detached house using the characteristics of these two *** thermally improved Light Weight Concrete building(LWC)was compared to a traditional Lebanese house base case(BC)using a dynamic building energy simulation tool in the four different Lebanese climate zones:coastal,mid-mountain,mountain,and inland *** results highlight the effectiveness of integrating LWC to building envelopes by reducing energy consumption and improving thermal comfort in both winter and summer climate conditions and in the different Lebanese climatic *** paper demonstrates that the use of LWC in the vertical walls replacing the traditional hollow blocks can reduce the heating needs by up to 9%and by up to 13%for cooling *** the other hand,adding a LWC roof screed has a very high impact on cooling and heating energy consumption,which can reach up to 74%in cooling energy savings and up to 24%in heating energy savings.

关键词： lightweight concrete thermal properties building energy simulation thermal insulation climatic conditions

Interactions of zinc and cadmium toxicity in their effects on growth and in antioxidative systems in tomato plants (Solanum lycopersicum)

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Journal of Environmental Sciences 2011年第5期23卷 837-844页

作者： Jaouhra cherif chamseddine Mediouni Wided Ben Ammar Fatma Jemal Unit of Research "Nitrogenized Nutrition and Metabolism and Stress Proteins" UR 99/09-20 Department of BiologyFaculty of Science University of Tunis Tunis 2092 Tunisia Unit of Research "Nitrogenized Nutrition and Metabolism and Stress Proteins" UR 99/09-20 Department of BiologyFaculty of ScienceUniversity of Tunis Tunis 2092 Tunisia

The interaction between zinc and cadmium was investigated in tomato plants （Solanum lycopersicum）. Ten-day-old seedlings were treated with 10 μmol/L CdC12 associated to different concentrations of ZnC12 （10, 50, 100, and 150 μmol/L）. Zn supply clearly reduced Cd accumulation in leaves and simultaneously increased Zn concentration. Cd induced oxidative stress in leaves as indicated by an increase in thiobarbituric acid-reactive substances （TBARS） level and chlorophyll breakdown. Furthermore, compared with control, Cd- treated plants had significantly higher activities of superoxide dismutase （SOD, EC 1.***.1.1）, whereas, catalase （CAT, EC 1.***.1.6）, ascorbate peroxidase （APX, EC 1.***.1.11）, and glutathione reductase （GR, EC 1.***.4.2） activities were significantly suppressed by Cd addition. Zn supplementation, at low level, restored and enhanced the functional activity of these enzymes （SOD, CAT, APX and GR） as compared to Cd-alone-treated plants. The beneficial effect of adequate Zn level on Cd toxicity was confirmed by a significant decrease in TBARS level and restoration of chlorophyll content. However, when Zn was added at high level in combination with Cd there was an accumulation of oxidative stress, which was higher than that for Cd or excess Zn alone treatments. These results suggested that higher Zn concentrations and Cd are synergistic in their effect on plant growth parameters and oxidative stress.

关键词： Solanum lycopersicum cadmium zinc oxidative stress antagonism synergism.

Extracts from Marine Macroalgae and Opuntia ficus-indica Cladodes Enhance Halotolerance and Enzymatic Potential of Diazotrophic Rhizobacteria and Their Impact on Wheat Germination Under Salt Stress

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Pedosphere 2018年第2期28卷 241-254页

作者： Abdelwahab RAI Ameur cherif Cristina CRUZ Elhafid NABTI Département de Microbiologie Faculté des Sciences de la Nature et de la Vie Université Ferhat Abbas Sdtif-1 19000 (Algdrie) Universitg de Béjaia FSNV Laboratoire de Maitrise des Energies Renouvelables (LMER) Equipe de Biomasse et Environnement Targa Ouzemmour Béaia 06000 (Algérie) LR Biotechnology and Bio-Geo Resources Valorization Higher Institute for Biotechnology University of Manouba Sidi Thabet Biotechpole 2020 Sidi Thabet Ariana 2080 (Tunisia) cE3c-Centre for Ecology Evolution and Environmental Changes Campo Grande Bloco C-2 Piso 5 Sala 03 Lisboa 1749-016 CPor- tugal)

Soil salinity, which affects more than 6% of the earth’s land surface and more than 20% of its irrigated areas, is a major threat to agriculture. Diazotrophic bacteria are among the functional groups of soil microbiota that are threatened by this abiotic stress, as their activity is mostly inhibited by salt stress. Seventy bacterial strains with distinct characteristics were isolated from soils by using N-free Jensen’s selective medium. Based on their ability to produce metabolites of agricultural interest, four strains were selected and identified as Flavobacterium johnsoniae, Pseudomonas putida, Achromobacter xylosoxidans, and Azotobacter chroococcum. The selected strains were grown at different NaCl concentrations (0–600 mmol L^(-1) in N-free broth and 0–2 000 mmol L^(-1) in Luria-Bertani medium) in the presence and absence of glycine betaine (GB), aqueous and hydro-alcoholic extracts from marine macroalgae, Ulva lactuca and Enteromorpha intestinalis, and Opuntia ficus-indica cladodes. The selected bacterial strains, GB, and the aforementioned extracts were tested for their ability to promote the germination of wheat (Triticum durum) seeds at 0–300 mmol L^(-1) NaCl. Compared with the results obtained with the synthetic osmoprotectant GB, the extracts from O. ficus-indica, U. lactuca, and E. intestinalis significantly promoted bacterial growth and seed germination under salt stress.

关键词： glycine betaine Ulva lactuca Enteromorpha intestinalis plant growth-promoting rhizobacteria (PGPR) seed germi-nation Triticum durum

DYNAMICS OF NEW CLASS OF HOPFIELD NEURAL NETWORKS WITH TIME-VARYING AND DISTRIBUTED DELAYS

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Acta Mathematica Scientia 2016年第3期36卷 891-912页

作者： Adnene ARBI Farouk cherif chaouki AOUITI Abderrahmen TOUATI Department of Mathematics Facultd des Sciences de BizerteUniversity of CarthageJarzouna 7021BizerteTunisia Department of Computer Science ISSATSLaboratory of Math PhysicsUniversity of SousseSpecials Functions and Applications LR11ES35ecole suprieure des sciences et de technologieSousse 4002Tunisia

In this paper, we investigate the dynamics and the global exponential stability of a new class of Hopfield neural network with time-varying and distributed delays. In fact, the properties of norms and the contraction principle are adjusted to ensure the existence as well as the uniqueness of the pseudo almost periodic solution, which is also its derivative pseudo almost periodic. This results are without resorting to the theory of exponential dichotomy. Furthermore, by employing the suitable Lyapunov function, some delayindependent sufficient conditions are derived for exponential convergence. The main originality lies in the fact that spaces considered in this paper generalize the notion of periodicity and almost periodicity. Lastly, two examples are given to demonstrate the validity of the proposed theoretical results.

关键词： delayed functional differential equations neural networks pseudo-almost peri- odic solution global exponential stability time-varying and distributed delays fixed point theorem

Milk losses due to bovine tropical theileriosis(Theileria annulata infection) in Algeria

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Asian Pacific Journal of Tropical Biomedicine 2016年第9期6卷 801-802页

作者： Ouarda Ayadi Mohamed Gharbi Mohamed cherif Benchikh Elfegoun Laboratory of Parasitology Institute of Veterinary Science El KhroubUniversity of Mentouri Brothers Laboratory of Parasitology National School of Veterinary MedicineInstitution of Agricultural Research and Higher EducationUniv.

The authors studied the impact of tropical theileriosis onset on milk yield decrease in 10 local bred cows in Skikda(Northern Algeria) during 2015 summer *** milk yield decrease estimated weekly during two months was 2.76 L/day/cow corresponding to31.92% of the total milk *** decrease corresponds to 110.5 Algerian Dinars(1.02US$)/day/diseased *** relative variation of milk yield showed a dramatic decrease from 82.72% to 0.76% at Day 21 then became *** studies are needed to improve these estimations of financial losses due to bovine tropical theileriosis in Algeria.

关键词： Theileria annulata Milk Cattle Local breed

On a Hybrid Preamble/Soft-Output Demapper Approach for Time Synchronization for IEEE 802.15.6 Narrowband WBAN

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china Communications 2015年第2期12卷 1-10页

作者： Imen Nasr Leila Najjar Atallah Sofiane cherif YANG Jianxiao WANG Kunlun Unité d'Informatique et d'Ingènierie des Systemes(U2IS) Ecole Nationale Supérieure de Techniques Avancées(ENSTA Paris Tech) Communication Signal and Image(COSIM) LaboratoryHigher School of Communications of Tunis(Sup'Com) Network Coding and Transmission Laboratory Shanghai Jiao Tong University

In this paper,we present a maximum likelihood(ML) based time synchronization algorithm for Wireless Body Area Networks(WBAN).The proposed technique takes advantage of soft information retrieved from the soft demapper for the time delay *** algorithm has a low complexity and is adapted to the frame structure specified by the IEEE 802.15.6standard[1]for the narrowband *** results have shown good performance which approach the theoretical mean square error limit bound represented by the Cramer Rao Bound(CRB).

关键词： WBAN IEEE 802.15.6 time synchronization ML estimation soft demapping

Electronic factor in electron self-exchange reaction of hydrated redox ion pairs from thermodynamic data

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chinese Journal of chemistry 1997年第3期15卷 201-210页

作者： Bu, YX Deng, ch SHANDONG UNIV INST THEORET CHEMSHANDONG 250100PEOPLES R CHINA

An accurate scheme for determining the electronic factor of the electron self-exchange reaction in solution is presented in this paper. The used various activation parameters and slopes of potential energy surfaces are obtained in terms of an improved activation model and the accurate potential function determined from the vibrational spectroscopic and thermodynamic data. The coupling matrix elements are determined using numerical integral method over the perturbed double-zeta Slater type state functions. Theoretical results of electronic factor in this work are found in close agreement with those extracted from experimental rate constant data and to be less than unity. Results indicate that outer-sphere electron transfer reactions in solution involving hydrated transition metal ions are nonadiabatic in nature.

关键词： electronic factor Landau-Zener probability activation model hydrated transition metal ions