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Chinese Journal of Aeronautics 2021年第1期34卷 327-335页

作者： Roholah VAHDANI Hossein KHALEGHI BIZAKI mohsen FALLAH JOSHAGHANI Department of Electrical arid Computer Engineering Maleke Ashtar University of TechnologyTehran 1774-15875Iran

In this paper,a new correlated covariance matrix for Multi-Input Multi-Output(MIMO)radar is proposed,which has lower Side Lobe Levels(SLLs)compared to the new covariance matrix designs and the well-known multi-antenna radar designs including phased-array,MIMO radar and phased-MIMO radar *** is shown that Binary Phased-Shift Keying(BPSK)waveforms that have constant envelope can be used in a closed-form to realize the proposed covariance ***,there is no need to deploy different types of radio amplifiers in the transmitter which will reduce the cost,*** proposed design allows the same transmit power from each antenna in contrast to the phased-MIMO ***,the proposed covariance matrix is full-rank and has the same capability as MIMO radar to identify more targets,*** of the proposed transmit covariance matrix including receive beampattern and output Signal-to-Interference plus Noise Ratio(SINR)is simulated,which validates analytical results.

关键词： Beampattern Correlated MIMO radar Covariance matrix design Sidelobe level Signal-to-Interference Plus Noise Ratio(SINR)

Optimal control of a fractional-order model for the HIV/AIDS epidemic

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International Journal of Biomathematics 2018年第7期11卷 59-81页

作者： Hossein Kheiri mohsen Jafari Faculty of Mathematical Sciences University of Tabriz TabrizIran

In this paper,we present a general formulation for a fractional optimal control problem (FOCP),in which the state and co-state equations are given in terms of the left fractional *** develop the forward-backward sweep method (FBSM)using the Adamstype predictor-corrector method to solve the *** present a fractional model for transmission dynamics of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS)with treatment and incorporate three control efforts (effective use of condoms,ART treatment and behavioral change control)into the model aimed at controlling the spread of HIV/AIDS *** necessary conditions for fractional optimal control of the disease are derived and *** numerical results show that implementing all the control efforts increases the life time and the quality of life those living with HIV and decreases significantly the number of HIV-infected and AIDS ***,the maximum levels of the controls and the value of objective functional decrease when the derivative order a limits to 1(0.7≤a <1).In addition,the effect of the fractional derivative order a (0.7≤a <1)on the spread of HIV/AIDS epidemic and the treatment of HIV-infected population is *** results show that the derivative order a can play the role of using ART treatment in the model.

关键词： Fractional optimal control diseases modeling numerical simulation HIV/AIDS dynamics

Quantification of grain boundary effects on the geometrically necessary dislocation density evolution and strain hardening of polycrystalline Mg-4Al using in situ tensile testing in scanning electron microscope and HR-EBSD

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Journal of Magnesium and Alloys 2024年第5期12卷 1815-1829页

作者： Eunji Song mohsen Taheri Andani Amit Misra Department of Materials Science and Engineering University of MichiganAnn ArborMI 48109USA Department of Mechanical Engineering University of MichiganAnn ArborMI 48109USA Department of Mechanical Engineering Texas A&M UniversityCollege StationTX 77843USA

In situ tensile testing in a scanning electron microscope(SEM)in conjunction with high-resolution electron backscatter diffraction(HR-EBSD)under load was used to characterize the evolution of geometrically necessary dislocation(GND)densities at individual grain boundaries as a function of applied strain in a polycrystalline Mg-4Al *** increase in GND density was investigated at plastic strains of 0%,0.6%,2.2%,3.3% from the area including 76 grains and correlated with(i)geometric compatibility between slip systems across grain boundaries,and(ii)plastic *** develop expressions for the grain boundary GND density evolution as a function of plastic strain and plastic incompatibility,from which uniaxial tensile stress-strain response of polycrystalline Mg-4Al are computed and compared with experimental *** findings in this study contribute to understanding the mechanisms governing the strain hardening response of single-phase polycrystalline alloys and more reliable prediction of mechanical behaviors in diverse microstructures.

关键词： Mg-Al alloys Grain boundaries Geometrically necessary dislocations Strain gradient plasticity HR-EBSD

Loss of offsite power (LOOP) accident analysis by integration of deterministic and probabilistic approaches in Bushehr-1 VVER-1000/V446 nuclear power plant

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Nuclear Science and Techniques 2022年第5期33卷 39-52页

作者： mohsen Esfandiari Gholamreza Jahanfarnia Kamran Sepanloo Ehsan Zarifi Department of Nuclear Engineering Science and Research BranchIslamic Azad UniversityTehranIran Reactor and Nuclear Safety School Nuclear Science and Technology Research Institute(NSTRI)TehranIran

The results of an accident analysis for the loss of offsite power(LOOP)scenario in a reference Bushehr-1 VVER-1000/V446 nuclear power plant(NPP)are presented in this *** study attempted to provide a better analysis of LOOP accident management by integrating deterministic and probabilistic *** RELAP5 code was used to investigate the occurrence of specific thermal–hydraulic *** probabilistic safety assessment of the LOOP accident is presented using the SAPHIRE *** accident data were extracted from the Bushehr NPP final safety analysis reports and probabilistic safety analysis reports.A deterministic approach was used to reduce the core damage frequency in the probabilistic analysis of LOOP *** probabilistic approach was used to better observe the philosophy of defense in depth and safety margins in the deterministic analysis of the LOOP *** results show that the integration of the two approaches in LOOP accident investigations improved accident control.

关键词： Loss of offsite power Deterministic Probabilistic Integration RELAP5 SAPHIRE

Efficient one-pot synthesis of 14-substituted-14H-dibenzo[a,j]xanthenes using boric acid under solvent-free conditions

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Chinese Chemical Letters 2010年第5期21卷 547-549页

作者： Zahed Karimi-Jaberi mohsen Keshavarzi Department of Chemistry Islamic Azad University of FiroozabadP.O.Box 74715-117 FiroozabadFarsIran

Boric acid efficiently catalysed the one-pot reaction of alkyl or aryl aldehydes with 2-naphthol to afford the corresponding 14- alkyl-or aryl-14H-dibenzo[a,j]xanthenes in good yields under solvent-free conditions.

关键词： Boric acid 2-Naphthol Dibenzoxanthenes Solvent-free synthesis

Complementary Inequalities to Improved AM-GM Inequality

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Acta Mathematica Sinica,English Series 2017年第12期33卷 1609-1616页

作者： Hamid Reza MORADI mohsen Erfanian OMIDVAR Department of Mathematics Mashhad Branch Islamic Azad University Mashhad Iran

Following an idea of Lin, we prove that if A and B are two positive operators such that 0 〈 mI 〈 A 〈 m＇I ≤ M＇I ≤B 〈 MI, then Ф^2（A＋B/2）≤K^2（h）/（1＋（logM＇/m＇）^2/8）^2Ф^2（A#B）,and Ф^2（A＋B/2）≤K^2（h）/（1＋（logM＇/m＇）^2/8）^2（Ф（A）#Ф（B））^2,where K（h） = （h＋1）2 /4h and h = M and Ф is a positive unital linear map.

关键词： Operator inequalities positive linear maps operator norm Kantorovich inequality Wielandt inequality

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

Effects of modified graphene oxide(GO) nanofluid on wettability and IFT changes: Experimental study for EOR applications

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Petroleum Science 2022年第4期19卷 1779-1792页

作者： Ehsan Jafarbeigi Farhad Salimi Ehsan Kamari mohsen Mansouri Department of Chemical Engineering Kermanshah BranchIslamic Azad UniversityKermanshahIran Department of Petroleum Engineering Research Institute of Petroleum IndustryTehranIran Department of Chemical Engineering llam UniversityllamIran

The application of nanoparticles(NPs) in enhanced oil recovery(EOR) offers a practical approach to resolving some surface-related problems encountered in contemporary technological processes. In this study, graphene oxide nanosheets(GONs) were synthesized by Hummer's method and, then, were subjected to surface modification by hexamethyldisilazane(HMDS) and diazonium sulfonic(DS) compounds. The new combination was known as GO-Su-HMDS. The potential stability of GO-Su-HMDS nanofluids(NFs) was investigated using the zeta(ζ) potential test. A comparative study of the effect of the synthesized NFs on wettability alteration of the reservoir rock was performed using interfacial tension(IFT) and contact angle experiments. According to the results of this study, the contact angle decreased from the initial value of 161.(oil wet) to 35.(water wet). In addition, IFT decreased from18.45 mN/m for deionized(DI) water to 8.8 mN/m for 500 ppm GO-Su-HMDS NF. Moreover, the results of flooding experiments showed that the NPs of a GO-Su-HMDS concentration of 400 and 500 ppm could increase the oil recovery by 20% and 19%, respectively. The experimental results showed that GO-SuHMDS NFs with a concentration of 500 ppm have the best efficiency in terms of altering the wettability of the rock from oil wet to water wet. Thus, it can be said that this nanofluid can reduce the contact angle and IFT and also increase the sweeping efficiency of oil.

关键词： Wettability alteration Graphene oxide Contact angle Interfacial tension Zeta potential

The effect of water spreading system on the functionality of rangeland ecosystems

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Journal of Arid Land 2012年第3期4卷 292-299页

作者： Mohammad Rahim FOROUZEH mohsen SHARAFATMANDRAD PhD Student of Rangeland Science Gorgan University of Agricultural Sciences and Natural Resources Gorgan 49138-15739 Iran

In recent decades, the control of floods is an efficient management practice for the rehabilitation of rangelands in most arid and semiarid areas. To evaluate the benefits, we used the Landscape Function Analysis （LFA） method to assess the function of patches and qualitative capability of a rangeland ecosystem in Gareh By- gone region, Fars province, southwestern Iran. Landscape functionality depends on soil, water and nutrient （col- lectively called ＂resources＂） conservation and use within a given ecosystem. Many landscapes are naturally het- erogeneous in terms of resource control and possess patches, where resources tend to accumulate, and in- ter-patches. Assessing rangeland health and function of landscape patches in response to environment and man- agement can give rise to correct management decisions for qualitative improvement of the ecosystem. Therefore, our study area was divided into two parts, i.e. water spreading and control parts, and sampling was done using LFA method in each part separately. Structural parameters, including the number, length and width of patches, and the mean length of inter-patches, were determined by the method to characterize the functional status of the monitoring sites. For each patch/inter-patch type identified in the transect organization log, we recorded its soil surface proper- ties classified according to the Soil Surface Assessment Method. The density, canopy cover and composition of plants were then assessed. The results showed that the number of ecological patches and their dimensions were significantly increased in the water spreading site. Soil stability and the values of nutrient cycling indices were in- creased but the infiltration values were decreased in the water spreading site. It could be related to the effect of suspended materials transported by floods to the soils in the study area. The improvement of ecological patches and rangeland ecosystem was achieved where water spreading systems were practiced. Theref

关键词： ecological patch landscape function analysis water spreading arid lands