检索结果-南通市图书馆

first Detailed Photometric Investigation on the Nature of Contact Binary System AA Cet

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2023年第7期 156-165页

作者： m.f.y?ld?r?m f.Soydugan ?anakkale Onsekiz mart University Astrophysics Research Center and Ulup?nar Observatory ?anakkale Onsekiz mart University Faculty of Sciences Department of Physics

The TESS light curve(LC) of the marginal contact binary A A Cet was analyzed simultaneously with the radial velocity and the orbital period(OP) change of the system was *** physical parameters of the system were obtained by analyzing the LC of A A Cet with the Wilson-Devinney method,and the absolute parameters of the components were calculated using the results *** the components of AA Cet,the masses and radii were calculated as m1=1.39±0.04 m⊙,m2=0.48±0.02 m⊙,and r1=1.64±0.03 r⊙,r2=1.01±0.04 r⊙,*** Cet is a marginal contact binary with a temperature difference of 1305 K between its components.A total of 14 eclipse times were obtained from the TESS data and used in the OP analysis together with those collected from the *** has been observed that the change in the OP of AA Cet is in the form of a decreasing *** mass transfer between the components has been interpreted as the reason for this *** OP decrease amount of A A Cet was obtained as dP/dt=0.0062±0.0006 s *** the reason for this decrease was attributed to a 3.3(9)×10-8m⊙.mass transfer per year from the more massive component to the less massive *** age of A A Cet has been estimated as 7 Gyr,as the age of contact systems helps us to understand their evolution.

关键词：

first Detailed Photometric Investigation on the Nature of Contact Binary System AA Cet

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2023年第7期23卷 154-163页

作者： m.f.yıldırım f.Soydugan Çanakkale Onsekiz mart University Astrophysics Research Center and Ulupınar Observatory17020ÇanakkaleTurkey Çanakkale Onsekiz mart University Faculty of SciencesDepartment of Physics17020ÇanakkaleTurkey

The TESS light curve(LC)of the marginal contact binary A A Cet was analyzed simultaneously with the radial velocity and the orbital period(OP)change of the system was *** physical parameters of the system were obtained by analyzing the LC of A A Cet with the Wilson-Devinney method,and the absolute parameters of the components were calculated using the results *** the components of AA Cet,the masses and radii were calculated as m_(1)=1.39±0.04 m_⊙,m_(2)=0.48±0.02 m_⊙,and r_(1)=1.64±0.03 r_⊙,r_(2)=1.01±0.04 r_⊙,*** Cet is a marginal contact binary with a temperature difference of 1305 K between its components.A total of 14 eclipse times were obtained from the TESS data and used in the OP analysis together with those collected from the *** has been observed that the change in the OP of AA Cet is in the form of a decreasing *** mass transfer between the components has been interpreted as the reason for this *** OP decrease amount of A A Cet was obtained as dP/dt=0.0062±0.0006 s yr^(-1).and the reason for this decrease was attributed to a 3.3(9)×10^(-8)m_⊙.mass transfer per year from the more massive component to the less massive *** age of A A Cet has been estimated as 7 Gyr,as the age of contact systems helps us to understand their evolution.

关键词： (stars:)binaries:eclipsing stars:fundamental parameters stars:individual(AA Cet)

A Collocation Technique via Pell-Lucas Polynomials to Solve fractional Differential Equationmodel for HIV/AIDS with Treatment Compartment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer modeling in Engineering & Sciences 2024年第10期141卷 281-310页

作者： Gamze yıldırım Suayip yüzbası Department of mathematics Faculty of ScienceAkdeniz UniversityAntalya07058Turkey Department of mathematics Faculty of Basic ScienceGebze Technical UniversityKocaeli41400Turkey Department of mathematics Faculty of ScienceBartın UniversityBartın74100Turkey

In this study,a numerical method based on the Pell-Lucas polynomials(PLPs)is developed to solve the fractional order HIV/AIDS epidemic model with a treatment *** HIV/AIDS mathematical model with a treatment compartment is divided into five classes,namely,susceptible patients(S),HIV-positive individuals(I),individuals with full-blown AIDS but not receiving ArV treatment(A),individuals being treated(T),and individuals who have changed their sexual habits sufficiently(r).According to the method,by utilizing the PLPs and the collocation points,we convert the fractional order HIV/AIDS epidemic model with a treatment compartment into a nonlinear system of the algebraic ***,the error analysis is presented for the Pell-Lucas approximation *** aim of this study is to observe the behavior of five populations after 200 days when drug treatment is applied to HIV-infectious and full-blown AIDS *** demonstrate the usefulness of this method,the applications are made on the numerical example with the help of *** addition,four cases of the fractional order derivative(p=1,p=0.95,p=0.9,p=0.85)are examined in the range[0,200].Owing to applications,we figured out that the outcomes have quite decent ***,we understand that the errors decrease when the value of N *** figures in this study are created in *** outcomes indicate that the presented method is reasonably sufficient and correct.

关键词： Collocation method fractional differential equations HIV/AIDS epidemic model Pell-Lucas polynomials

Logical Image Acquisition and Analysis of Android Smartphones

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 Computer and Communications 2024年第4期12卷 139-152页

作者： Nursel yalçın Tayfun yıldırım Department of Computer and Instructional Technologies Education Faculty of Education Gazi University Ankara T&#252rkiye Department of Computer forensics Institute of Informatics Gazi University Ankara T&#252rkiye

Android smartphones largely dominate the smartphone market. for this reason, it is very important to examine these smartphones in terms of digital forensics since they are often used as evidence in trials. It is possible to acquire a physical or logical image of these devices. Acquiring physical and logical images has advantages and disadvantages compared to each other. Creating the logical image is done at the file system level. Analysis can be made on this logical image. Both logical image acquisition and analysis of the image can be done by software tools. In this study, the differences between logical image and physical image acquisition in Android smartphones, their advantages and disadvantages compared to each other, the difficulties that may be encountered in obtaining physical images, which type of image contributes to obtaining more useful and effective data, which one should be preferred for different conditions, and the benefits of having root authority are discussed. The practice of getting the logical image of the Android smartphones and making an analysis on the image is also included. Although root privileges are not required for logical image acquisition, it has been observed that very limited data will be obtained with the logical image created without root privileges. Nevertheless, logical image acquisition has advantages too against physical image acquisition.

关键词： Android Smartphone forensics Data Acquisition Data Analysis root Privileges Digital forensics

fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

matter and radiation at Extremes 2024年第3期9卷 11-18页

作者： y.X.Wang X.L.Zhu S.m.Weng P.Li X.f.Li H.Ai H.r.Pan Z.m.Sheng Key Laboratory for Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IfSA Shanghai Jiao Tong UniversityShanghai 200240China research Center of Laser fusion of China Academy of Engineering Physics MianyangSichuan 621900China State key Laboratory of High field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-Ir)to terahertz(THz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-Ir or THz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-Ir or THz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength Ir and THz spectral ranges.

关键词： laser ultrashort photon

Influence of erbium on structural,and charged particles,photons,and neutrons shielding properties of Ba_(1-x)Er_(x)SnO_(3) perovskite ceramics

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 2024年第4期42卷 724-732页

作者： m.K.h.Hamad Nidal Dwaikat m.H.A.mhareb m.I.Sayyed r.m.Hamad y.S.m.Alajerami m.A.Almessiere Gameel Saleh Ahmad Hussein Alomari K.A.Ziq Department of Basic Sciences School of Social and Basics SciencesAl Hussein Technical UniversityKing Abdullah II St 242Amman11831Jordan Department of Physics College of Engineering and PhysicsInterdisciplinary Research Center for Advanced MaterialsKing Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia Basic and Applied Scientific research Center Imam Abdulrahman Bin Faisal UniversityP0.Box 1982Dammam31441Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmman11622Jordan Department of Nuclear medicine research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Arabia medical Imaging Department Applied Medical Sciences FacultyAl Azhar University-Gaza CityPo.Box 1277Palestine Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box1982Dammam 31441Saudi Arabia Department of Biomedical Engineering College of EngineeringImam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Energy&minerals regulatory Commission Amman11821Jordan

five perovskite ceramics samples of Ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction *** prepared samples were characterized by X-ray diffraction(XrD),fourier transforms infrared(fTIr),and UV-Vis *** shielding properties against ionizing radiation were also *** XrD analysis shows the perovskite cubic structure as the major phase in all *** fTIr reveals a distinctive band around 614-620 cm^(-1) ascribed to the antisymmetric O-Sn-O ***-Vis spectroscopy was used to determine the bandgap according to diffuse reflectance,and the results display a fixed enhancement in the bandgap from 3.2 to 3.3 eV for all ***-ray shielding properties of the synthesized samples were experimentally measured and compared with XCOm computational *** relative differences(Δ,%)between experimental and theo retical values are low and fall within the 0.446%-7.10%*** addition of Er leads to the enhanced density,neutron,and gamma shielding *** contrast,charged particles’shielding parameters gradually reduce with rising Er *** results suggest that Ba_(1-x)Er_(x)SnO_(3) samples can be used in different radiation shielding applications.

关键词： Perovskite Ceramics Gamma ray shielding mass stopping power rare earths

维普期刊数据库

Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABBASI GAVArI m.r.HOmAEINEZHAD faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis

维普期刊数据库

Growth of rB Population in the Conversion Phase of Chlamydia Life Cycle

在线全文

学校读者我要写书评

暂无评论

Communications on Applied mathematics and Computation 2024年第1期6卷 90-112页

作者： frederic y.m.Wan Department of mathematics University of CaliforniaIrvineCA92697-3875USA

Upon infecting a host cell,the reticulate body(rB)form of the Chlamydia bacteria simply proliferates by binary fission for an extended *** data show only rB units in the infected cells 20 hours post infection(hpi),spanning nearly half way through the development *** data collected every 4 hpi,conversion to the elementary body(EB)form begins abruptly at a rapid rate sometime around 24 *** modeling proliferation and conversion as simple birth and death processes,it has been shown that the optimal strategy for maximizing the total(mean)EB population at host cell lysis time is a bang-bang control qualitatively replicating the observed conversion ***,the simple birth and death model for the rB proliferation and conversion to EB deviates in a significant way from the available data on the evolution of the rB population after the onset of rB-to-EB *** working with a more refined model that takes into account a small size threshold eligibility requirement for conversion noted in the available data,we succeed in removing the deficiency of the previous models on the evolution of the rB population without affecting the optimal bang-bang conversion strategy.

关键词： Chlamydia Life cycle Optimal control maximal infectious spread Specie competitive survival

The viscous strip approach to simplify the calculation of the surface acoustic wave generated streaming

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2024年第4期45卷 711-724页

作者： f.JAZINI DOrCHEH m.GHASSEmI fuel Cells and Nano Systems(fCNS)Laboratory Department of Mechanical EngineeringK.N.Toosi University of TechnologyTehran 19697Iran

In recent decades,the importance of surface acoustic waves,as a biocompatible tool to integrate with microfluidics,has been proven in various medical and biological *** numerical modeling of acoustic streaming caused by surface acoustic waves in microchannels requires the effect of viscosity to be considered in the equations which complicates the *** this paper,it is shown that the major contribution of viscosity and the horizontal component of actuation is concentrated in a narrow region alongside the actuation *** the inviscid equations are considerably easier to solve,a division into the viscous and inviscid domains would alleviate the computational load *** particles'traces calculated by this approximation are excellently alongside their counterparts from the completely viscous *** is also shown that the optimum thickness for the viscous strip is about 9-fold the acoustic boundary layer thickness for various flow patterns and amplitudes of actuation.

关键词： surface acoustic wave microfluidics numerical simulation particle tracing acoustic streaming

维普期刊数据库