The Two Center Oscillator Potential with Finite Depth

1975 ◽  
Vol 30 (4) ◽  
pp. 406-412 ◽  
Author(s):  
Piet-Tjing Ong ◽  
Werner Scheid
Keyword(s):  
Shell Model ◽  
Finite Depth ◽  
Hamilton Operator ◽  
Oscillator Potential ◽  
The Individual

Abstract It is suggested to diagonalize the Hamilton operator of a two-or more center shell model in terms of oscillator functions concentrated around the individual centers. The method is applied to the case of a two center oscillator with finite depth.

scholarly journals Energy levels of an electron in a circular quantum dot in the presence of spin-orbit interactions

Doklady BGUIR ◽  
2022 ◽  
Vol 19 (8) ◽  
pp. 20-25
Author(s):  
A. V. Baran ◽  
V. V. Kudryashov
Keyword(s):  
Quantum Dot ◽  
Energy Levels ◽  
Approximate Expression ◽  
Finite Depth ◽  
Energy Splitting ◽  
Spin Orbit ◽  
Axially Symmetric ◽  
The Individual ◽  
Spin Orbit Interactions ◽  
Potential Parameters

The two-dimensional circular quantum dot in a double semiconductor heterostructure is simulated by a new axially symmetric smooth potential of finite depth and width. The presence of additional potential parameters in this model allows us to describe the individual properties of different kinds of quantum dots. The influence of the Rashba and Dresselhaus spin-orbit interactions on electron states in quantum dot is investigated. The total Hamiltonian of the problem is written as a sum of unperturbed part and perturbation. First, the exact solution of the unperturbed Schrödinger equation was constructed. Each energy level of the unperturbed Hamiltonian was doubly degenerated. Further, the analytical approximate expression for energy splitting was obtained within the framework of perturbation theory, when the strengths of two spin-orbit interactions are close. The numerical results show the dependence of energy levels on potential parameters.

Calculations of Gamow–Teller Transition Strengths in fp-Shell Nuclei Using Shell Model

2020 ◽  
pp. 1-5
Author(s):  
Fouad A. Majeed ◽  
Sarah M. Obaid
Keyword(s):  
Shell Model ◽  
Theoretical Calculations ◽  
Model Space ◽  
Exchange Reactions ◽  
Model Calculations ◽  
Effective Interactions ◽  
Mechanisms Of Formation ◽  
Nuclear Structures ◽  
The Individual ◽  
Gamow Teller

The Gamow–Teller (GT) strength transitions in nuclear structures and astrophysical processes proved to be very important to understand the mechanisms of formation of neutron stars and black holes, therefore the GT transitions in the 46Ti→46V, 47Ti→47V, 48Ti→48V, and 50Cr→50Mn charge-exchange reactions have been studied. The shell model calculations have been carried out in the fp-model space without any restrictions using the GXFP1A, KB3G, and FPD6 effective interactions. The calculation of the GT distribution is compared with recent available experimental data. The theoretical calculations are in reasonably good agreement with the experimental GT distributions and with the summed transition strengths B(GT). For the individual transformations we have reached a qualitative agreement, while the measured cumulative transformation strengths are closely matched by the observed ones.

Multiharmonic nuclear Hamiltonian

1992 ◽  
Vol 70 (5) ◽  
pp. 361-364 ◽  
Author(s):  
G. S. Anagnostatos
Keyword(s):  
Shell Model ◽  
Ground State ◽  
Binding Energies ◽  
Oscillator Potential ◽  
Central Potential ◽  
Direct Treatment ◽  
Independent Particle

The present study successfully extends the independent-particle shell model by employing a multiharmonic oscillator potential for nuclei from 16O to 208Pb. Specifically, this study assumes a separate and different central potential for the nucleons of each shell, instead of a common central potential for all nucleons in a nucleus as is usually assumed by the conventional shell model. The present extension of the shell model leads to a simultaneous direct treatment of ground-state radii and binding energies for a sample of nuclei, i.e., 16O,28Si, 36Ar, 40Ar, 40Ca, 56Fe, 58Ni, 90Ni, 90Zr, 104Pd, 110Pd, 120Sn, 126Te,136Ba, 138Ba, 142Nd, 202Hg, and 208Pb.

Collective motion in the nuclear shell model. I. Classification schemes for states of mixed configurations

1958 ◽  
Vol 245 (1240) ◽  
pp. 128-145 ◽  
Keyword(s):  
Shell Model ◽  
Collective Motion ◽  
Wave Functions ◽  
Coupling Scheme ◽  
Nuclear Shell Model ◽  
Model Framework ◽  
Oscillator Potential ◽  
Harmonic Oscillator Potential ◽  
Classification Schemes ◽  
Nuclear Shell

To understand how collective motion can develop in the shell-model framework it is necessary to study configuration interaction. With this in mind, group-theoretical methods are used to investigate the possible classification schemes for a number of nucleons in m xed configurations. One particular coupling scheme, which is associated with the degeneracy of a harmonic oscillator potential and which, in a following paper, will be shown to have collective properties is described in detail. The wave functions in this scheme are seen to be very similar to those resulting from an actual shell-model calculation with configurational mixing.

The Ultrastructure of Monkey Gingival Epithelium

1967 ◽  
Vol 25 ◽  
pp. 16-17
Author(s):  
C.N. Sun
Keyword(s):  
Epithelial Cells ◽  
Macaca Nemestrina ◽  
Stratum Granulosum ◽  
Solution Ph ◽  
Gingival Epithelial Cells ◽  
Stratum Spinosum ◽  
Cell Layers ◽  
Gingival Epithelium ◽  
The Individual ◽  
Different Thickness

The present study demonstrates the ultrastructure of the gingival epithelium of the pig tail monkey (Macaca nemestrina). Specimens were taken from lingual and facial gingival surfaces and fixed in Dalton's chrome osmium solution (pH 7.6) for 1 hr, dehydrated, and then embedded in Epon 812.Tonofibrils are variable in number and structure according to the different region or location of the gingival epithelial cells, the main orientation of which is parallel to the long axis of the cells. The cytoplasm of the basal epithelial cells contains a great number of tonofilaments and numerous mitochondria. The basement membrane is 300 to 400 A thick. In the cells of stratum spinosum, the tonofibrils are densely packed and increased in number (fig. 1 and 3). They seem to take on a somewhat concentric arrangement around the nucleus. The filaments may occur scattered as thin fibrils in the cytoplasm or they may be arranged in bundles of different thickness. The filaments have a diameter about 50 A. In the stratum granulosum, the cells gradually become flatted, the tonofibrils are usually thin, and the individual tonofilaments are clearly distinguishable (fig. 2). The mitochondria and endoplasmic reticulum are seldom seen in these superficial cell layers.

A Study of the Ultrastructure of Visual Cell Outer Segment Membranes, Using a Water-Miscible Embedding Medium and Differential Staining

1972 ◽  
Vol 30 ◽  
pp. 50-51
Author(s):  
Anthony J. Godfrey
Keyword(s):  
Outer Segment ◽  
Protein Denaturation ◽  
Uranyl Acetate ◽  
Differential Staining ◽  
Visual Cell ◽  
Lead Citrate ◽  
Chick Retina ◽  
Dark Staining ◽  
Embedding Medium ◽  
The Individual

Aldehyde-fixed chick retina was embedded in a water-containing resin of glutaraldehyde and urea, without dehydration. The loss of lipids and other soluble tissue components, which is severe in routine methods involving dehydration, was thereby minimized. Osmium tetroxide post-fixation was not used, lessening the amount of protein denaturation which occurred. Ultrathin sections were stained with 1, uranyl acetate and lead citrate, 2, silicotungstic acid, or 3, osmium vapor, prior to electron microscope examination of visual cell outer segment ultrastructure, at magnifications up to 800,000.Sections stained with uranyl acetate and lead citrate (Fig. 1) showed that the individual disc membranes consisted of a central lipid core about 78Å thick in which dark-staining 40Å masses appeared to be embedded from either side.

The Red Neuronal Pigment in the Nervous System of the Mussel, Mytilus Edulis: Localization and Its Effect on Lateral Ciliary Activity with Spectral and Analytical Changes

1981 ◽  
Vol 39 ◽  
pp. 494-495
Author(s):  
Anthony A. Paparo ◽  
Judith A. Murphy
Keyword(s):  
Nervous System ◽  
Mytilus Edulis ◽  
Neuronal Cell ◽  
Ciliary Activity ◽  
Neuronal Cell Bodies ◽  
The Central Nervous System ◽  
Intracellular Organelles ◽  
The Common ◽  
The Individual ◽  
Cryostat Sections

The purpose of this study was to localize the red neuronal pigment in Mytilus edulis and examine its role in the control of lateral ciliary activity in the gill. The visceral ganglia (Vg) in the central nervous system show an over al red pigmentation. Most red pigments examined in squash preps and cryostat sec tions were localized in the neuronal cell bodies and proximal axon regions. Unstained cryostat sections showed highly localized patches of this pigment scattered throughout the cells in the form of dense granular masses about 5-7 um in diameter, with the individual granules ranging from 0.6-1.3 um in diame ter. Tissue stained with Gomori's method for Fe showed bright blue granular masses of about the same size and structure as previously seen in unstained cryostat sections.Thick section microanalysis (Fig.l) confirmed both the localization and presence of Fe in the nerve cell. These nerve cells of the Vg share with other pigmented photosensitive cells the common cytostructural feature of localization of absorbing molecules in intracellular organelles where they are tightly ordered in fine substructures.

Some Effects of Oxidant Air Pollutants (Ozone and Peroxyacetyl Nitrate) on the Ultrastructure of Leaf Tissues

1972 ◽  
Vol 30 ◽  
pp. 360-361
Author(s):  
William W. Thomson ◽  
Elizabeth S. Swanson
Keyword(s):  
Air Pollutants ◽  
Electron Microscopic Examination ◽  
Peroxyacetyl Nitrate ◽  
Electron Microscopic ◽  
Growth Physiology ◽  
Physiology And Biochemistry ◽  
Entire Plant ◽  
Leaf Tissues ◽  
Gaseous Hydrocarbons ◽  
The Individual

The oxidant air pollutants, ozone and peroxyacetyl nitrate, are produced in the atmosphere through the interaction of light with nitrogen oxides and gaseous hydrocarbons. These oxidants are phytotoxicants and are known to deleteriously affect plant growth, physiology, and biochemistry. In many instances they induce changes which lead to the death of cells, tissues, organs, and frequently the entire plant. The most obvious damage and biochemical changes are generally observed with leaves.Electron microscopic examination of leaves from bean (Phaseolus vulgaris L.) tobacco (Nicotiana tabacum L.) and cotton (Gossipyum hirsutum L.) fumigated for .5 to 2 hours with 0.3 -1 ppm of the individual oxidants revealed that changes in the ultrastructure of the cells occurred in a sequential fashion with time following the fumigation period. Although occasional cells showed severe damage immediately after fumigation, the most obvious change was an enhanced clarity of the cell membranes.

Sign in / Sign up

Export Citation Format

Share Document