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Pseudo-Depth/Intercept-Time Monotonicity Requirements in the Inverse Scattering Algorithm for Predicting Internal Multiple Reflections

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Communications in Computational Physics 2009年第1期5卷 163-182页

作者： bogdan g.Nita Arthur b.Weglein Department of Mathematical Sciences Montclair State University1 Normal AvenueMontclairNJ 07043USA. Department of Physics University of Houston617 Science and Research Bldg.1HoustonTX 77004USA

In this paper we discuss the inverse scattering algorithm for predicting internal multiple reflections(reverberation artefacts),focusing our attention on the construction *** speaking,the algorithm combines amplitude and phase information of three different arrivals(sub-events)in the data set to predict one multiple *** three events are conditioned by a certain relation which requires that their pseudo-depths,defined as the depths of their turning points relative to the constant background velocity,satisfy a lower-higher-lower *** implicitly assumes a pseudo-depth monotonicity condition,i.e.,the relation between the actual depths and the pseudo-depths of any two sub-events is the *** study this relation in pseudo-depth and show that it is directly connected with a similar relation between the vertical or intercept times of the *** paper also provides the first multidimensional analysis of the algorithm(for a vertically varying acoustic model)with analytical *** show that the construction of internal multiples is performed in the plane waves domain and,as a consequence,the internal multiples with headwaves sub-events are also predicted by the *** we analyze the differences between the time monotonicity condition in vertical or intercept time and total travel time and show a 2D example which satisfies the former but not the *** we discuss one case in which the monotonicity condition is not satisfied by the sub-events of an internal multiple and discuss ways of lowering these restrictions and of expanding the algorithm to address these types of multiples.

关键词： Multiple reflections seismic imaging inverse scattering

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Numerical Investigation of Cavitation Interacting with Pressure Wave

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Numerical Mathematics(Theory,Methods and Applications) 2014年第4期7卷 524-536页

作者： J.g.Zheng b.C.Khoo Temasek Laboratories National University of SingaporeSingapore 117411 Department of Mechanical Engineering National University of SingaporeSingapore 119260 Singapore-MIT Alliance National University of SingaporeSingapore 117576

A computational fluid dynamics solver based on homogeneous cavitation model is employed to compute the two-phase cavitating *** model treats the two-phase regime as the homogeneous mixture of liquid and vapour which are locally assumed to be under both kinetic and thermodynamic *** our focus is on pressure wave formation,propagation and its impact on cavitation bubble,the compressibility effects of liquid water have to be accounted for and hence the flow is considered to be *** cavitating flow disturbed by the introduced pressure wave is simulated to investigate the unsteady features of cavitation due to the external *** is observed that the cavity becomes unstable,locally experiencing deformation or collapse,which depends on the shock wave intensity and freestream flow speed.

关键词： Isentropic cavitation model cavitating flow pressure wave

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EFFECT OF THE DEFECT STATES DENSITY ON OPTICAL bAND gAP OF CdIn_(2)O_(4)THIN FILM

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 403-410页

作者： H.S.San Z.g.Wu b.Li b.X.Feng KeyLaboratoryforMagnetismandMagneticMaterialofMinistryofEducation LanzhouUniversityLanzhou730000China ShanghaiInstituteofTechnicalPhysics TheChineseAcademyofSciencesShanghai200083China

Transparent conducting oxides CdIn2O4 thin films were prepared by radio-frequenc y reactive sputtering from a Cd-In alloy target in Ar+O2 atmosphere. by transmis sion spectrum and Hall measurement for different samples prepared at different s ubstrate temperatures, it could be found that the carrier concentration would in crease with the decrease of substrate temperature, but absorption edge showed an abrupt variation from a blue shift to a red shift. Theoretically, the paper for mulated the effect of high-density point defects on band structures; it embodied the formation of band tailing, burstein-Moss shift and band-gap narrowing. The density of holes will influence the magnitude of optical band gap and transmitta nce of light. Since extrapolation method does not fit degenerate semiconductor m aterials, a more accurate method of obtaining optical band gap is curve fitting. In addition, ionized impurities scattering is the main damping mechanism of the free electrons in CdIn2O4 films, the density of ionized impurities induced by a ltering substrate temperature will affect the carriers mobility.

关键词： sputtering CdIn2O4 thin film electrical property optical property

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Investigation of Total Absorption of Radio Waves in High Latitude Ionosphere

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Plasma Science and Technology 2014年第9期16卷 833-836页

作者：史建魁王铮陶伟 g.A.ZHEREbTSOV E.b.ROMANOVA K.g.RATOVSKY State Key Laboratory of Space Weather NSSC/CAS Institute of Solar-Terrestrial Physics SB/RAS Irkutsk 664033 Russia

Using the digisonde data observed at ionospheric station Norilsk （Dip lat. 60~N） in 2006, a statistical study on the characteristics of the ionospheric plasma total absorption of radio waves （IPTAR） was performed. In the winter and some months of equinox, the IPTAR mainly occurred in the nighttime and the highest occurrence rate could be up to 90%. In the summer, the occurrence was relatively low and the differences between nighttime and daytime occurrence reduced. The total duration of IPTAR seemed longer around the winter than that around the summer. The occurrence of IPTAR events ascended as the Kp index increased. The frequent precipitation of energetic particles into the ionospheric plasma in the auroral belt may be the main cause of the IPTAR events.

关键词： ionosphere radio waves total absorption

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Simultaneous Effects of Hydrostatic Pressure and Conduction band Non-parabolicity on binding Energies and Diamagnetic Susceptibility of a Hydrogenic Impurity in Spherical Quantum Dots

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Communications in Theoretical Physics 2011年第8期56卷 377-381页

作者： g.Rezaei N.A.Doostimotlagh b.Vaseghi Department of Physics College of SciencesYasouj University Young Research Club Islamic Azad University

Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in typical gaAs/Alx- ga1-x As spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolieity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the diamagnetic susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows： the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the diamagnetic susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the diamagnetic susceptibility reduces with increasing pressure.

关键词： non-parabolic conduction band hydrostatic pressure quantum dots hydrogenic impurity diamagnetic susceptibility

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Nonlinear corrections for the nuclear gluon distribution in eA processes

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Chinese Physics C 2024年第3期48卷 52-64页

作者： g.R.boroun b.Rezaei F.Abdi Department of Physics Razi UniversityKermanshah 67149Iran.

An analytical study with respect to the nonlinear corrections for the nuclear gluon distribution function in the next-to-leading order approximation at small x is *** consider the nonlinear corrections to the nuclear gluon distribution functions at low values of x and Q^(2) using the parametrization F_(2)(x,Q^(2))and the nuclear modification factors obtained from the Khanpour-Soleymaninia-Atashbar-Spiesberger-guzey *** CT18 gluon distribution is used for the baseline proton gluon density at Q^(2)_(0)=*** discuss the behavior of the gluon densities in the next-to-leading order and the next-to-next-to-leading order approximations at the initial scale Q^(2)_(0),as well as the modifications due to the nonlinear *** find that the QCD nonlinear corrections are more significant for the next-to-leading order accuracy than the next-to-next-to-leading order for light and heavy *** results of the nonlinear gLR-MQ evolution equation are similar to those obtained with the Rausch-guzey-Klasen gluon upward and downward evolutions within the *** magnitude of the gluon distribution with the nonlinear corrections increases with a decrease in x and an increase in atomic number A.

关键词： gluon distribution nonlinear corrections light and heavy nuclei low x physics

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Truncated States Obtained by Iteration

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Chinese Physics Letters 2008年第2期25卷 517-520页

作者： W. b. Cardoso N. g. de Almeida Instituto de Física Universidade Federal de Goiás 74.001-970 Goiania (GO) Brazil Núcleo de Pesquisas em Física Universidade Católica de Goiá s 74.605-220 Goiania (GO) Brazil

We introduce the concept of truncated states obtained via iterative processes （TSI） and study its statistical features, making an analogy with dynamical systems theory （DST）. As a specific example, we have studied TSI for the doubling and the logistic functions, which are standard functions in studying chaos. TSI for both the doubling and logistic functions exhibit certain similar patterns when their statistical features are compared from the point of view of DST.

关键词： QUANTUM CRYPTOgRAPHY DECOHERENCE gENERATION COLLAPSE REVIVAL OPTICS FIELD

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Linear and Nonlinear Optical Properties of Spherical Quantum Dots:Effects of Hydrogenic Impurity and Conduction band Non-Parabolicity

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Communications in Theoretical Physics 2012年第3期57卷 485-489页

作者： g.Rezaei b.Vaseghi N.A.Doostimotlagh Department of Physics College of SciencesYasouj University Young Researchers Club Yasooj BranchIslamic Azad University

Simultaneous effects of an on-center hydrogenic impurity and band edge non-parabolicity on intersubband optical absorption coefficients and refractive index changes of a typical gaAs/Alxga1-xAs spherical quantum dot are theoretically investigated, using the Luttinger-Kohn effective mass equation. So, electronic structure and optical properties of the system are studied by means of the matrix diagonalization technique and compact density matrix approach, respectively. Finally, effects of an impurity, band edge non-parabolicity, incident light intensity and the dot size on the linear, the third-order nonlinear and the total optical absorption coemcients and refractive index changes are investigated. Our results indicate that, the magnitudes of these optical quantities increase and their peaks shift to higher energies as the influences of the impurity and the band edge non-parabolicity are considered. Moreover, incident light intensity and the dot size have considerable effects on the optical absorption coefficients and refractive index changes.

关键词： hydrogenic impurity non-parabolic conduction band quantum dots absorption coefficient refractive index

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Circuit breakers in HVDC systems: state-of-the-art review and future trends

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Protection and Control of Modern Power Systems 2023年第3期8卷 16-31页

作者： Erfan Taherzadeh Hamid Radmanesh Shahram Javadi g.b.gharehpetian Department of Electrical Engineering Islamic Azad University Central Tehran BranchTehranIran Electrical Engineering Department Amirkabir University of Technology(Tehran Polytechnic)Tehran ***Iran

High voltage direct current(HVDC)systems are efficient solutions for the integration of large-scale renewable energy sources with the main power *** rapid development of the HVDC grid has resulted in a growing interest in DC circuit breakers(DCCbs).A fast and reliable circuit breaker is a necessary requirement in the development of large scale HVDC *** paper provides a comprehensive review and survey of the HVDC Cbs and discusses potential research *** principles and the main features of various DCCbs are described and their merits and shortcomings are also highlighted.

关键词： DC circuit breakers(DCCbs) High voltage direct current(HVDC)system Multi-terminal HVDC(MT-HVDC) Fault current isolation Renewable energies Voltage clamping

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Real-time wavelength routing based on bragg reflection with integrated forward Raman for long-reach networks

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Optoelectronics Letters 2020年第1期16卷 40-44页

作者： g.M.Isoe T.b.gibbon South African Radio Astronomy Observatory(SARAO) Cape Town 7925South Africa Centre for broadband Communication Nelson Mandela UniversityPort Elizabeth 6031South Africa

We experimentally demonstrate the all-optical efficient technique for dynamic full-duplex wavelength routing and reach extension through adoption of passive fibre bragg grating(Fbg),energy efficient vertical cavity surface emitting lasers(VCSELs)and high gain forward Raman *** this study,two VCSEL channels at 1549.62 nm and 1550.01 nm are directly modulated with a 8.5 gbit/s data signal each,and transmitted over 25.5 km fibre to a passive single mode Fbg-based wavelength routing *** precise wavelength selectivity of the Fbg is exploited to achieve all-optical real-time wavelength routing of the 1549.62 nm VCSEL channel with a maximum insertion loss of 22.1 *** 1550.01 nm channel is transmitted through the Fbg with a maximum penalty of 1.03 *** utilizing the 7.2 db flat gain of a forward Raman pump,the routed 1549.62 nm VCSEL channel is transmitted over 76.7 km fibre with a maximum penalty of 3.84 db at bit error rate(bER)of *** technique is all-optical,power efficient as it employs passive Fbg and circulators and has low cross talk allied to precise wavelength selectivity of the technique.

关键词： passive pump fibre

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