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Berry‘’s Phase in Noncommutative spaces

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Chinese Physics Letters 2003年第5期20卷 605-607页

作者： s.a.alavi HighEnergyPhysicsDivision DepartmentofPhysicsUniversityofHelsinkiFinlandHelsinkiInstituteofPhysicsFIN-00014HelsinkiFinland

We discuss the perturbative aspects of noncommutative quantum mechanics. Then we study Berry's phase within the framework of noncommutative quantum mechanics. The results show deviations from the usual quantum mechani... 详细信息

关键词：贝里相位量子力学非交换空间扰动

General Noncommuting Curvilinear Coordinates and Fluid Mechanics

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Chinese Physics Letters 2006年第10期23卷 2637-2639页

作者： s.a.alavi Department of Physics Sabzevar University of Tarbiat Moallem Sabzevar PO Box 397 Iran Sabzevar House of Physics Asrar Laboratories of Physics Laleh Square Sabzevar Iran

We show that restricting the states of a charged particle to the lowest Landau level introduces noncommutativity between general curvilinear coordinate operators. The Cartesian, circular cylindrical and spherical polar coordinates are three special cases of our quite general method. The connection between U（1） gauge fields defined on a general noncommuting curvilinear coordinates and fluid mechanics is explained. We also recognize the seiberg-Witten map from general noncommuting to commuting variables as the quantum correspondence of the Lagrange-to-Euler map in fluid mechanics.

关键词： sCATTERING sPACEs

Empirical formulas for proton decay half-lives:Role of nuclear deformation and Q-value

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Chinese Physics C 2018年第10期42卷 95-102页

作者： V.Dehghani s.a.alavi Department of Physics University of Sistan and Baluchestan

Two empirical formulas for the proton decay half-lives including nuclear deformation are proposed. The formula with parameter set I gives the logarithm of the proton decay half-lives as an explicit function of the orbital angular momentum with eight adjustable parameters, whereas that with set II represents the logarithm of the reduced half-lives as an implicit function of the angular momentum with seven adjustable parameters. Experimental data for the half-lives of 44 proton emitters in the ground state or isomeric state were used to obtain the parameters. The experimental and calculated Q values were used. Different sets of parameters were obtained for the ground state transition, isomeric state transition, and all transitions for both deformed and spherical nuclei. The best agreement with experimental data was observed for set I for deformed proton emitters with exr）erimental Q values.

关键词： proton emission deformation empirical formula

Influence of the shell effects on evaporation residue cross section of superheavy nuclei

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Nuclear science and Techniques 2018年第11期29卷 229-237页

作者： D.Naderi s.a.alavi Department of Physics Faculty of Basic SciencesRazi University Department of Physics University of Sistan and Baluchestan

In order to study the influence of the shell effects on the formation and fission of superheavy elements, we applied multidimensional Langevin equations. The evaporation residue cross sections have been calculated for 3n, 4n, and 5n evaporation channels using three(K = 0)-and four(K ≠ 0)-dimensional Langevin equations. Calculations were done for ^(48)Ca + ^(238)U and ^(48)Ca + ^(244)Pu hot fusion reactions with 3n, An evaporation channels and ^(70)Zn+ ^(208)Pb, and ^(54)Cr + ^(209)Bi cold fusion reactions with In and 2n evaporation channels. The calculations were performed for An and 5n evaporation channels of the ^(26)Mg+ ^(238)U reaction, as well. Our results show that with increasing dimension of Langevin equations the residue cross section increases, whereas the fission cross section decreases. The obtained results with four-dimensional Langevin and considering shell effects are in better agreement with experimental data in comparison with three-and four-dimensional Langevin equations without shell effects.

关键词： superheavy Langevin equations Cross section

Alpha-induced reaction cross-section for sm, U, Np targets： influence of hexadecapole deformation and deformed surface diffuseness

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Chinese Physics C 2017年第6期41卷 85-92页

作者： s.a.alavi V.Dehghani Department of Physics University of Sistan and Baluchestan Zahedan 98135-674 Iran

Alpha-induced reactions on 154^sm,233,235,236,238^U, and 237^Np deformed nuclei are studied *** effects of hexadecapole deformation, deformed surface diffuseness parameter, and orientation on barrier height and position, fusion cross-section at any angle, and fusion cross-section have been investigated. Both hexadecapole deformation and deformed surface diffuseness can affect barrier characteristics and enhance fusion cross-section. Good agreement between experimental data and theoretical calculations with quadrupole and hexadecapole deformation and deformed surface diffuseness were observed for the 4^He＋^154^sm,235^U,237^Np reactions.

关键词： nuclear potential fusion cross section deformation alpha induced reaction.

Proton radioactivity half-lives with nuclear asymmetry factor

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Chinese Physics C 2021年第4期45卷 335-343页

作者： A.soylu F.Koyuncu G.Gangopadhyay V.Dehghani s.a.alavi Department of physics nigde omer halisdemir universitynigde 51240turkey program of opticianry golhisar voeational school of health servicesburdur mehmet akif ersoy university15400golhisarburdurturkey department of physics university of calcuttakolkata 700009india department of physics university of sistan and baluchestanzahedaniran

The dependence of proton emission half-lives on the nuclear asymmetry parameter is investigated using the WKB method and two types of empirical *** the single-folding formalism with asymmetry-depend-ent nuclear radius and surface diffuseness of nuclear matter,the nuclear potential and consequently the half-life are functions of the asymmetry *** small values of asymmetry in neutron-deficient proton emitters,notice-able changes in the half-lives are *** addition of an asymmetry parameter term to the two forms of empir-ical formulas leads to a reduction in the rms error for ground state and isomeric transitions.A noticeable reduction of about 43%is obtained for isomeric transitions in the second form of the empirical *** ground state transitions in two categories,odd-even and odd-odd emitters,and adopting deformation and asymmetry-dependent empirical formulas,the rms decreases *** low est values of rms errors,viz.0.1492,0.2312,and 0.1999,are obtained for the aforementioned empirical formulas for ground state transitions of odd-even and odd-odd emit-ters and for all isomeric transitions,respectively.

关键词： proton emission asymmetry parameter empirical formula

Cluster decay half-lives using asymmetry dependent densities

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Chinese Physics C 2022年第4期46卷 131-140页

作者： V.Dehghani s.a.alavi R.Razavi A.soylu F.Koyuncu Department of Physics University of Sistan and BaluchestanZahedanIran Physics Department Faculty of ScienceImam Hossein Comprehensive UniversityTehranIran Department of Physics Nigdeomer Halisdemir UniversityNigde 51240Turkey Program of Opticianry Golhisar Vocational School of Health ServicesBurdur Mehmet Akif Ersoy University15400GolhisarBurdurTurkey

By adopting different neutron and proton density distributions,cluster decay half-lives were investigated using double-folding potentials with constant and nuclear asymmetry dependent sets of nuclear density *** adopted asymmetry dependent sets of parameters were fitted based on microscopic calculations,and they were calculated based on the neutron skin/halo-type nuclei assumption and by employing experimental rms charge radii.A bulk agreement between theory and experiment was obtained for all sets of parameters using a calculated cluster preformation *** differences were observed between the skin and halo-type ***,the notable role of the asymmetry parameter was observed in the relatively large differences between the skin and skintype with zero thickness.

关键词： cluster decay double-folding charge radii density

Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

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Journal of Rare Earths 2024年第1期42卷 66-75页

作者： s.W.Wi Y.s.Lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of Li + Photoluminescence sensitizer Rare earths

First evidence for chiral wobbling of triaxial nuclei

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Nuclear science and Techniques 2024年第7期35卷 4-7页

作者： s.Frauendorf Department of Physics and Astronomy University of Notre DameNotre DameIN 46556USA

Chirality(Greek“handiness”)is a property of many com-plex *** molecules exist in two forms,one being the mirror image of the *** for our hands,it is impossible to make the images identical by a suitable *** two forms are called left-handed and *** have the same binding energy,because the electro-magnetic interaction,which holds the molecule together,does not change under a *** properties that are insensitive to the geometry are also the *** different geometry is the reason why the left-handed form turns the polarization plane of transmitted light in one direction by some angle while the right-handed form turns it in the oppo-site direction by the same ***,the geometrical differences between the two species may have other *** two species of the carvon molecule shown in Fig.1 taste quite differently.

关键词： turns Chiral mirror