177 research outputs found
Effects of tensor forces in nuclear spin-orbit splittings from ab initio calculations
A systematic and specific pattern due to the effects of the tensor forces is
found in the evolution of spin-orbit splittings in neutron drops. This result
is obtained from relativistic Brueckner-Hartree-Fock theory using the bare
nucleon-nucleon interaction. It forms an important guide for future microscopic
derivations of relativistic and nonrelativistic nuclear energy density
functionals.Comment: 14 pages, 3 figure
Relativistic Brueckner-Hartree-Fock theory for neutron drops
Neutron drops confined in an external field are studied in the framework of
relativistic Brueckner-Hartree-Fock theory using the bare nucleon-nucleon
interaction. The ground state energies and radii of neutron drops with even
numbers from to are calculated and compared with results
obtained from other nonrelativistic \textit{ab initio} calculations and from
relativistic density functional theory. Special attention has been paid to the
magic numbers and to the sub-shell closures. The single-particle energies are
investigated and the monopole effect of the tensor force on the evolutions of
the spin-orbit and the pseudospin-orbit splittings is discussed. The results
provide interesting insight of neutron rich systems and can form an important
guide for future density functionals.Comment: 31 pages, 12 figure
Fully self-consistent relativistic Brueckner-Hartree-Fock theory for finite nuclei
Starting from the relativistic form of the Bonn potential as a bare
nucleon-nucleon interaction, the full Relativistic Brueckner-Hartree-Fock
(RBHF) equations are solved for finite nuclei in a fully self-consistent basis.
This provides a relativistic ab initio calculation of the ground state
properties of finite nuclei without any free parameters and without three-body
forces. The convergence properties for the solutions of these coupled equations
are discussed in detail at the example of the nucleus O. The binding
energies, radii, and spin-orbit splittings of the doubly magic nuclei He,
O, and Ca are calculated and compared with the earlier RBHF
calculated results in a fixed Dirac Woods-Saxon basis and other
non-relativistic ab initio calculated results based on pure two-body forces.Comment: 22 pages, 13 figure
Pseudospin symmetry: Recent progress with supersymmetric quantum mechanics
It is an interesting and open problem to trace the origin of the pseudospin
symmetry in nuclear single-particle spectra and its symmetry breaking mechanism
in actual nuclei. In this report, we mainly focus on our recent progress on
this topic by combining the similarity renormalization group technique,
supersymmetric quantum mechanics, and perturbation theory. We found that it is
a promising direction to understand the pseudospin symmetry in a quantitative
way.Comment: 4 pages, 1 figure, Proceedings of the XX International School on
Nuclear Physics, Neutron Physics and Applications, Varna, Bulgaria, 16-22
September, 201
Predicting miRNA-disease associations based on multi-view information fusion
MicroRNAs (miRNAs) play an important role in various biological processes and their abnormal expression could lead to the occurrence of diseases. Exploring the potential relationships between miRNAs and diseases can contribute to the diagnosis and treatment of complex diseases. The increasing databases storing miRNA and disease information provide opportunities to develop computational methods for discovering unobserved disease-related miRNAs, but there are still some challenges in how to effectively learn and fuse information from multi-source data. In this study, we propose a multi-view information fusion based method for miRNA-disease association (MDA)prediction, named MVIFMDA. Firstly, multiple heterogeneous networks are constructed by combining the known MDAs and different similarities of miRNAs and diseases based on multi-source information. Secondly, the topology features of miRNAs and diseases are obtained by using the graph convolutional network to each heterogeneous network view, respectively. Moreover, we design the attention strategy at the topology representation level to adaptively fuse representations including different structural information. Meanwhile, we learn the attribute representations of miRNAs and diseases from their similarity attribute views with convolutional neural networks, respectively. Finally, the complicated associations between miRNAs and diseases are reconstructed by applying a bilinear decoder to the combined features, which combine topology and attribute representations. Experimental results on the public dataset demonstrate that our proposed model consistently outperforms baseline methods. The case studies further show the ability of the MVIFMDA model for inferring underlying associations between miRNAs and diseases
Tris(ethylenediamine-κ2 N,N′)cobalt(III) aquatris(oxalato-κ2 O 1,O 2)indate(III)
In the cation of the title compound, [Co(C2H8N2)3][In(C2O4)3(H2O)], the CoIII atom is coordinated by six N atoms from three ethylenediamine molecules. The CoIII—N bond lengths lie in the range 1.956 (4)–1.986 (4) Å. In the anion, the InIII atom is seven-coordinated by six O atoms from three oxalate ligands and by a water molecule. The cations and anions are linked by extensive O—H⋯O and N—H⋯O hydrogen bonds, forming a supermolecular network
Numerical simulation analysis for the effect of water content on the intelligent compaction quality of roadbed
In the process of intelligent compaction of roadbeds, the water content of the roadbed is one of the important influencing factors of compaction quality. In order to analyze the effect of water content on the compaction quality of roadbeds, this paper is developed by secondary development of Abaqus finite element numerical simulation software. At the same time, the artificial viscous boundary was set to eliminate the influence of boundary conditions on the results in the finite element modeling process, so that the numerical simulation can be refined to model. On this basis, the dynamic response analysis of the roadbed compaction process is performed on the finite element numerical simulation results. This paper established the correlation between compaction degree and intelligent compaction index CMV (Compaction Meter Value) and then analyzed the effect of water content on the compaction quality for the roadbed. The results of this paper show that the amplitude of the vertical acceleration is almost independent of the moisture content, and the vertical displacement mainly occurs in the static compaction stage. The vertical displacement changes sharply in the first 0.5 s when the vibrating wheel is in contact with the roadbed. The main stage of roadbed compaction quality increase is before the end of the first compaction. At the end of the first compaction, the roadbed compaction degree increased rapidly from 80% to 91.68%, 95.34% and 97.41%, respectively. With the increase in water content, the CMV gradually increased. At the end of the second compaction, CMV increased slightly compared with that at the end of the first compaction and stabilized at the end of the second compaction. The water content of the roadbed should be considered to be set slightly higher than the optimal water content of the roadbed by about 1% during the construction of the roadbed within the assumptions of this paper
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