Information on effective interactions from experimental single-particle energies

1990 ◽  
Vol 41 (1) ◽  
pp. 386-389 ◽  
Author(s):  
B. J. Cole
Keyword(s):  
Single Particle ◽  
Effective Interactions

scholarly journals Single particle energies and nuclear g factors

2017 ◽  
Vol 26 (09) ◽  
pp. 1750053 ◽  
Author(s):  
Shadow Robinson ◽  
Larry Zamick
Keyword(s):  
Shell Model ◽  
Single Particle ◽  
Ground State ◽  
Particle State ◽  
Complex Interplay ◽  
Model Calculations ◽  
Effective Interactions ◽  
State Splitting ◽  
State Affect ◽  
Nuclear Shell

Adding one neutron to doubly magic [Formula: see text]Sn, we can associate the low lying states in[Formula: see text]Sn with single particle states. Thus, the [Formula: see text] and [Formula: see text] states are identified as the [Formula: see text] and [Formula: see text] single particle states, respectively. In [Formula: see text]Sn, these two low lying states are separated by an energy of 0.172[Formula: see text]MeV. Currently, there is a dispute as to the ordering of these states. We examine how the two scenarios, selecting [Formula: see text] as the ground state or [Formula: see text] as the ground state, affect spectra and nuclear [Formula: see text] factors of higher mass Sn isotopes in a variety of shell model situations. Significantly, this includes examining the complex interplay of the choice of single particle state splitting, effective interactions, and effective [Formula: see text]-factors in nuclear shell model calculations. Of particular importance is how the trends in the calculated results for [Formula: see text] factors diverge from recent experimental measurements for the higher mass isotopes of Sn.

scholarly journals Microscopic study of higher-order deformation effects on the ground states of superheavy nuclei around Hs-270

2021 ◽  
Author(s):  
Xiao-Qian Wang ◽  
Xiang-Xiang Sun ◽  
Shan-Gui 周善贵 Zhou
Keyword(s):  
Single Particle ◽  
Mean Field ◽  
Higher Order ◽  
Binding Energies ◽  
Superheavy Nuclei ◽  
Effective Interactions ◽  
Relativistic Mean Field ◽  
Order Deformation ◽  
Particle Spectra ◽  
Rmf Model

Abstract We study the effects of higher-order deformations βλ (λ = 4,6,8, and 10) on the ground state properties of superheavy nuclei (SHN) near the deformed doubly magic nucleus 270Hs by using the multidimensionally-constrained (MDC) relativistic mean-field (RMF) model with five effective interactions PC-PK1, PK1, NL3∗, DD-ME2, and PKDD. The doubly magic properties of 270Hs are featured by the large energy gaps at N = 162 and Z = 108 in the single-particle spectra. By investigating the binding energies and single-particle levels of270Hs in multidimensional deformation space, we find that the deformation β6 has the greatest impact on the binding energy among these higher-order deformations and influences the shell gaps considerably. Similar conclusions hold for other SHN near 270Hs. Our calculations demonstrate that the deformation β6 must be considered when studying SHN by using MDC-RMF.

scholarly journals Using DIRHB package to calculate the properties of some nuclei

2020 ◽  
Vol 3 (4) ◽  
pp. 252-258
Author(s):  
Nguyen Dien Quoc Bao
Keyword(s):  
Binding Energy ◽  
Single Particle ◽  
Energy Functional ◽  
Relativistic Case ◽  
Effective Interactions ◽  
Charge Radii ◽  
Hartree Fock ◽  
Calculation Results ◽  
Experimental Values ◽  
Short Range Correlations

In this work, the relativistic Hartree-Bogoliubov method is studied for calculating of nuclear properties such as binding energy per nucleon, charge radii, and single-particle energies of proton and neutron for some nuclei like O16, Ca40, Sn132 and Pb208. This method is the relativistic case of the Hartree-Fock-Bogoliubov method, which is a generalization of the Hartree-Fock method, and the method includes short-range correlations such as pairing force. In addition, the energy functional DD-ME2 is used to describe the effective interactions in equations of the relativistic Hartree-Bogoliubov method. The DIRHB package, which was written in Fortran, is utilized to calculate and get the results. The results are compared with experimental ones, except the single-particle energies of Ca40 due to the lack of data. The comparisons show well agreements between the calculation results and the experimental values of binding energy per nucleon as well as charge radii, for parameters of the DD-ME2 which were fitted based on the experimental data of nuclear mass. However, the results of single-particle levels do not agree with experimental ones in some cases. This means the relativistic Hartree-Bogoliubov method should be studied further in the future.

Localization of immunolabels by electron microscopy and image averaging

1983 ◽  
Vol 41 ◽  
pp. 282-283
Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Attachment Site ◽  
Uranyl Acetate ◽  
Limulus Polyphemus ◽  
Resolution Limit ◽  
Electron Microscopic ◽  
Image Averaging ◽  
Top View ◽  
Better Than

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.

Structural Studies on the Eukaryotic Ribosome

1990 ◽  
Vol 48 (1) ◽  
pp. 256-257
Author(s):  
Adriana Verschoor ◽  
Ronald Milligan ◽  
Suman Srivastava ◽  
Joachim Frank
Keyword(s):  
Chick Embryo ◽  
3D Reconstruction ◽  
Single Particle ◽  
Mass Density ◽  
Particle Surface ◽  
Uranyl Acetate ◽  
Electron Microscopic ◽  
Eukaryotic Ribosome ◽  
Negative Stain ◽  
Reconstruction Methods

We have studied the eukaryotic ribosome from two vertebrate species (rabbit reticulocyte and chick embryo ribosomes) in several different electron microscopic preparations (Fig. 1a-d), and we have applied image processing methods to two of the types of images. Reticulocyte ribosomes were examined in both negative stain (0.5% uranyl acetate, in a double-carbon preparation) and frozen hydrated preparation as single-particle specimens. In addition, chick embryo ribosomes in tetrameric and crystalline assemblies in frozen hydrated preparation have been examined. 2D averaging, multivariate statistical analysis, and classification methods have been applied to the negatively stained single-particle micrographs and the frozen hydrated tetramer micrographs to obtain statistically well defined projection images of the ribosome (Fig. 2a,c). 3D reconstruction methods, the random conical reconstruction scheme and weighted back projection, were applied to the negative-stain data, and several closely related reconstructions were obtained. The principal 3D reconstruction (Fig. 2b), which has a resolution of 3.7 nm according to the differential phase residual criterion, can be compared to the images of individual ribosomes in a 2D tetramer average (Fig. 2c) at a similar resolution, and a good agreement of the general morphology and of many of the characteristic features is seen.Both data sets show the ribosome in roughly the same ’view’ or orientation, with respect to the adsorptive surface in the electron microscopic preparation, as judged by the agreement in both the projected form and the distribution of characteristic density features. The negative-stain reconstruction reveals details of the ribosome morphology; the 2D frozen-hydrated average provides projection information on the native mass-density distribution within the structure. The 40S subunit appears to have an elongate core of higher density, while the 60S subunit shows a more complex pattern of dense features, comprising a rather globular core, locally extending close to the particle surface.

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