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Journal of Central South university 2016年第11期23卷 2984-2998页

作者： Mohammad Vaghefi Yaser Safarpoor Maryam Akbari Department of Civil Engineering Persian Gulf University

Spur dike is one of the river training structures. This work presented a numerical simulation of flow field and three-dimensional velocity around a T-shaped spur dike located in bend using SSIIM model. The main objective of this work is to investigate the three-dimensional velocities and streamlines at transverse and longitudinal sections and plan views around the T-shaped spur dike in different submergence ratios(0, 5%, 15%, 25% and 50%). It is concluded that by increasing the submergence ratio from 5% to 50%, the maximum of scour is reduced; the maximum of longitudinal velocity increases by 7.7% and occurs at the water surface in spur dike axis. Near the bed, the maximum of vertical velocity occurs at the end of spur wing. By analyzing the streamlines at transverse sections, the followings were deduced for different submergence ratios: different dimensions and different positions of vortices around the spur dike.

关键词： T-shaped spur dike flow pattern submergence ratio SSIIM model

Study of different features offission dynamics of ^(224)Th produced in fusion reactions within a stochastic approach

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Chinese Physics C 2015年第5期39卷 20-27页

作者： H.Eslamizadeh Department of Physics Persian Gulf University

The evaporation residue cross section anisotropy of the fission fragment angular distribution, pre-scission neutron multiplicity and the pre-saddle and post-saddle contributions of the pre-scission neutron multiplicity were analyzed within a stochastic approach based on one-, two- and three-dimensional Langevin equations for the compound nucleus ^224Th formed via a complete fusion. In these calculations, dissipation was generated through the chaos weighted wall and window friction formula. Comparison of the theoretical results with the experimental data showed that three-dimensional Langevin equations with dissipation generated through the chaos weighted wall and window friction formula make it possible to reproduce satisfactorily the above-mentioned experimental data.

关键词： fission evaporation residue cross section pre-scission neutron multiplicity

Two-dimensional Langevin modeling of fission dynamics of the excited compound nuclei ^(188)Pt,^(227)Pa and ^(251)Es

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Chinese Physics C 2016年第2期40卷 33-39页

作者： H.Eslamizadeh Department of Physics Persian Gulf University

A stochastic approach based on one-and two-dimensional Langevin equations is applied to calculate the pre-scission neutron multiplicity,fission probability,anisotropy of fission fragment angular distribution,fission cross section and the evaporation cross section for the compound nuclei ^188Pt,^227Pa and ^251Es in an intermediate range of excitation *** chaos weighted wall and window friction formula are used in the Langevin *** elongation parameter,c,is used as the first dimension and projection of the total spin of the compound nucleus onto the symmetry axis,K,considered as the second dimension in Langevin dynamical calculations.A constant dissipation coefficient of K,γk=0.077（MeV zs）^-1/2）,is used in two-dimensional calculations to reproduce the above mentioned experimental *** of the theoretical results of the pre-scission neutron multiplicity,fission probability,fission cross section and the evaporation cross section with the experimental data shows that the results of two-dimensional calculations are in better agreement with the experimental ***,it is shown that the two-dimensional Langevin equations together with a dissipation coefficient of K,γk=0.077（MeV zs）^-1/2,can satisfactorily reproduce the anisotropy of fission fragment angular distribution for the heavy compound nucleus^***,a larger value of γk=0.250（MeV zs）^-1/2is needed to reproduce the anisotropy of fission fragment angular distribution for the lighter compound nucleus^227Pa.

关键词： Langevin fission dynamics mean neutron multiplicity nuclear viscosity

Study of shape isomer yields of ^(240)Am in the framework of a dynamical-statistical model

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Chinese Physics C 2010年第11期34卷 1714-1716页

作者： Hadi Eslamizadeh Department of Physics Persian Gulf University

A dynamical statistical model is used to analyze the experimental shape isomer yields data in the reaction d＋240Pu at E=20–29 *** possibility of determining the nuclear dissipation is *** of the experimental data wi... 详细信息

关键词： fission fission barrier reduced dissipation coeffcient

DIRECT IMPLEMENTATION OF TIKHONOV REGULARIZATION FOR THE FIRST KIND INTEGRAL EQUATION

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Journal of Computational Mathematics 2022年第3期40卷 335-353页

作者： Meisam Jozi Saeed Karimi Department of Mathematics Persian Gulf UniversityBushehrIran

A common way to handle the Tikhonov regularization method for the first kind Fredholm integral equations,is first to discretize and then to work with the final linear *** unavoidably inflicts discretization errors which may lead to disastrous results,especially when a quadrature rule is *** propose to regularize directly the integral equation resulting in a continuous Tikhonov *** Tikhonov problem is reduced to a simple least squares problem by applying the Golub-Kahan bidiagonalization(GKB)directly to the integral *** regularization parameter and the iteration index are determined by the discrepancy principle ***,we study the discrete version of the proposed method resulted from numerical evaluating the needed *** on the nodal values of the solution results in a weighted version of GKB-Tikhonov method for linear systems arisen from the Nystr¨om ***,we use numerical experiments on a few test problems to illustrate the performance of our algorithms.

关键词： First kind integral equation Golub-Kahan bidiagonalization Tikhonov regularization Quadrature Discretization

Simulation of the fission dynamics of the excited compound nuclei ^206Po and ^168Yb produced in the reactions ^12C＋^194Pt and ^18O＋^150Sm

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Chinese Physics C 2017年第4期41卷 69-74页

作者： H. Eslamizadeh F. Bagheri Department of Physics Persian Gulf University *** Bushehr Iran

A two-dimensional dynamical model based on the Langevin equation was used to study the fission dynamics of the compound nuclei ^206Po and ^168Yb produced in the reactions ^12C＋^194Pt and ^18O＋^150Sm,*** fission cross section and average pre-scission neutron multiplicity were calculated for the compound nuclei ^206Po and ^168Yb,and results of the calculations compared with the experimental *** elongation coordinate was used as the first dimension and the projection of the total spin of the compound nucleus onto the symmetry axis,K,considered as the second dimension in the Langevin dynamical *** the two-dimensional calculations,a constant dissipation coefficient of K and a non-constant dissipation coefficient have been used to reproduce the abovementioned experimental *** is shown that the two-dimensional Langevin equation can satisfactorily reproduce the fission cross section and average pre-scission neutron multiplicity for the compound nuclei ^206Po and ^168Yb by using constant values of the dissipation coefficient of K equal to γκ=0.18（MeV zs）^-1/2 and γκ= 0.20（MeV zs）^-1/2for the compound nuclei ^206Po and ^168Yb,respectively.

关键词： dissipation coefficient Langevin model fission cross section

Silica-bonded S-sulfonic acid a recyclable catalyst for the synthesis of coumarins

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Chinese Chemical Letters 2009年第12期20卷 1444-1448页

作者： Khodabakhsh Niknam Dariush Saberi Mojtaba Baghernejad Department of Chemistry Faculty of SciencesPersian Gulf University

Silica-bonded S-sulfonic acid （SBSSA） was prepared by the reaction of 3-mercaptopropylsilica （MPS） and chlorosulfonic acid in chloroform. This solid acid has been employed as a recyclable catalyst for the synthesi... 详细信息

关键词： Silica-bonded S-sulfonic acid Coumarins Solvent-free Phenols -Keto-esters

Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

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Chinese Chemical Letters 2010年第4期21卷 399-402页

作者： Khodabakhsh Niknam Alireza Hasaninejad Madihe Arman Department of Chemistry Faculty of SciencesPersian Gulf University

Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing *** solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.

关键词： Silica-supported tin chloride Silica-supported titanium tetrachloride Bis-3 4-dihydropyrimidin-2(1H)-one Solvent-free 1 3-Dicarbonyl compounds

Study of pre-scission particle emissions and fission probability of the ^(178)W produced in fusion reactions

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Chinese Physics C 2014年第6期38卷 35-39页

作者： H.Eslamizadeh M.Pirpour Department of Physics Persian Gulf University 75169 Bushehr Iran

A dynamical model based on one-dimensional Langevin equations was used to calculate the average pre-fission multiplicities of neutrons, light charged particles, and the fission probability for compound nucleus 17Sw produced in fusion reactions. The pre-seission multiplicities of particles and fission probability are calculated and compared with the experimental data over a wide range of excitation energy. A modified wall and window dissipation with a reduction coefficient, ks, has been used in the Langevin equations for reproducing experimental data. It was shown that the results of the calculations are in good agreement with the experimental data by using values of ks in the range 0.24〈 ks 〈0.47.

关键词： fission pre-scission particle multiplicity fission probability

Seismic bearing capacity of strip footings on rock masses using the Hoeke Brown failure criterion

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第2期8卷 170-177页

作者： Amin Keshavarz Abdoreza Fazeli Siavosh Sadeghi School of Engineering Persian Gulf University

In this paper,the bearing capacity of strip footings on rock masses has been studied in the seismic *** stress characteristics or slip line method was used for *** problem was analyzed in the plane strain condition using the Hoeke Brown failure ***,the equilibrium equations along the stress characteristics were obtained and the rock failure criterion was ***,the equations were solved using the finite difference method.A computer code has been provided for *** the footing and rock parameters,the code can calculate the stress characteristics network and obtain the stress distribution under the *** seismic effects have been applied as the horizontal and vertical pseudo-static *** results of this paper are very close to those of the other *** seismic bearing capacity of weightless rock masses can be obtained using the proposed equations and graphs without calculating the whole stress characteristics network.

关键词： Rock mass Bearing capacity Strip footings Stress characteristics Hoeke Brown failure criterion