95,563 research outputs found
Octupole degree of freedom for the critical-point candidate nucleus Sm in a reflection-asymmetric relativistic mean-field approach
The potential energy surfaces of even-even Sm are investigated in
the constrained reflection-asymmetric relativistic mean-field approach with
parameter set PK1. It is shown that the critical-point candidate nucleus
Sm marks the shape/phase transition not only from U(5) to SU(3)
symmetry, but also from the octupole-deformed ground state in Sm to the
quadrupole-deformed ground state in Sm. By including the octupole
degree of freedom, an energy gap near the Fermi surface for single-particle
levels in Sm with is found, and the
important role of the octupole deformation driving pair and is demonstrated.Comment: 11 pages, 3 figure
Discussion on Event Horizon and Quantum Ergosphere of Evaporating Black Holes in a Tunnelling Framework
In this paper, with the Parikh-Wilczek tunnelling framework the positions of
the event horizon of the Vaidya black hole and the Vaidya-Bonner black hole are
calculated respectively. We find that the event horizon and the apparent
horizon of these two black holes correspond respectively to the two turning
points of the Hawking radiation tunnelling barrier. That is, the quantum
ergosphere coincides with the tunnelling barrier. Our calculation also implies
that the Hawking radiation comes from the apparent horizon.Comment: 8 page
Pressure Dependence of Wall Relaxation in Polarized He Gaseous Cells
We have observed a linear pressure dependence of longitudinal relaxation time
() at 4.2 K and 295 K in gaseous He cells made of either bare pyrex
glass or Cs/Rb-coated pyrex due to paramagnetic sites in the cell wall. The
paramagnetic wall relaxation is previously thought to be independent of He
pressure. We develop a model to interpret the observed wall relaxation by
taking into account the diffusion process, and our model gives a good
description of the data
Robust optimization for energy transactions in multi-microgrids under uncertainty
Independent operation of single microgrids (MGs) faces problems such as low self-consumption of local renewable energy, high operation cost and frequent power exchange with the grid. Interconnecting multiple MGs as a multi-microgrid (MMG) is an effective way to improve operational and economic performance. However, ensuring the optimal collaborative operation of a MMG is a challenging problem, especially under disturbances of intermittent renewable energy. In this paper, the economic and collaborative operation of MMGs is formulated as a unit commitment problem to describe the discrete characteristics of energy transaction combinations among MGs. A two-stage adaptive robust optimization based collaborative operation approach for a residential MMG is constructed to derive the scheduling scheme which minimizes the MMG operating cost under the worst realization of uncertain PV output. Transformed by its KKT optimality conditions, the reformulated model is efficiently solved by a column-and-constraint generation (C&CG) method. Case studies verify the effectiveness of the proposed model and evaluate the benefits of energy transactions in MMGs. The results show that the developed MMG operation approach is able to minimize the daily MMG operating cost while mitigating the disturbances of uncertainty in renewable energy sources. Compared to the non-interactive model, the proposed model can not only reduce the MMG operating cost but also mitigate the frequent energy interaction between the MMG and the grid
Evaluation of the EMC environment generated by a static var compensator
Describes an evaluation of the EMC environment generated by a static var compensator
Impact of pairing correlations on the orientation of the nuclear
For the first time, the tilted axis cranking covariant density functional
theory with pairing correlations has been formulated and implemented in a fully
self-consistent and microscopic way to investigate the evolution of the spin
axis and the pairing effects in rotating triaxial nuclei. The measured energy
spectrum and transition probabilities for the Nd-135 yrast band are reproduced
well without any ad hoc renormalization factors when pairing effects are taken
into account. A transition from collective to chiral rotation has been
demonstrated. It is found that pairing correlations introduce additional
admixtures in the single-particle orbitals, and, thus, influence the structure
of tilted axis rotating nuclei by reducing the magnitude of the proton and
neutron angular momenta while merging their direction.Comment: 13 pages, 5 figure
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