We present an analysis of a recent approach for determining the average pairing matrix elements within a specified interval of single-particle(sp)states around the Fermi level,denoted asλ.This method,known as the uni...We present an analysis of a recent approach for determining the average pairing matrix elements within a specified interval of single-particle(sp)states around the Fermi level,denoted asλ.This method,known as the uniform gap method(UGM),highlights the critical importance of the averaged sp level density.The pairing matrix elements within the UGM approach are deduced from microscopically calculated values of and gaps obtained from analytical formulae of a semi-classical nature.Two effects generally ignored in similar fits are addressed:(a)a correction for a systematic bias introduced by fitting pairing gaps corresponding to equilibrium deformation solutions,as discussed by Möller and Nix[Nucl.Phys.A 476,1(1992)],and(b)a correction for a systematic spurious enhancement of for protons in the vicinity ofλ,caused by the local Slater approximation commonly employed in treating Coulomb exchange terms(e.g.,[Phys.Rev.C 84,014310(2011)]).This approach has demonstrated significant efficiency when applied to Hartree-Fock+Bardeen-Cooper-Schrieffer(BCS)calculations(including the seniority force and self-consistent blocking for odd nuclei)of a large sample of well and rigidly deformed even-even rare-earth nuclei.The experimental moments of inertia for these nuclei were reproduced with an accuracy comparable to that achieved through direct fitting of the data[Phys.Rev.C 99,064306(2019)].In this study,we extended the evaluation of our method to the reproduction of three-point odd-even mass differences centered on odd-N or odd-Z nuclei in the same region.The agreement with experimental data was found to be comparable to that obtained through direct fitting,as reported in[Phys.Rev.C 99,064306(2019)].展开更多
A flow past two side-by-side identical circular cylinders was numerically investigated with the unstructured spectral element method. From the computational results at various non-dimensional distances between cylinde...A flow past two side-by-side identical circular cylinders was numerically investigated with the unstructured spectral element method. From the computational results at various non-dimensional distances between cylinder centers T/D and the Reynolds number Re, a total of nine kinds of wake patterns were observed： four steady wake patterns, including single bluff-body steady pattern, separated double-body steady pattern and transition steady pattern for sub-critical Reynolds numbers and biased steady pattern for super-critical Reynolds numbers, and five unsteady wake patterns, including single bluff-body periodic pattern, biased quasi-steady pattern, quasi-periodic （flip-flopping） pattern, in-phase-synchronized pattern and anti-phase-synchronized pattern. Time evolution of lift and drag coefficients corresponding to each unsteady wake pattern was given.展开更多
We construct a new stabilized finite volume method on rectangular grids for the Stokes equations. The lowest equal-order conforming finite element pair （piecewise bilinear veloc- ities and pressures） and piecewise c...We construct a new stabilized finite volume method on rectangular grids for the Stokes equations. The lowest equal-order conforming finite element pair （piecewise bilinear veloc- ities and pressures） and piecewise constant test spaces for both the velocity and pressure are employed in this method. We show the stability of this method and prove first optimal rate of convergence for the velocity in the H1 norm and the pressure in the L2 norm. In addition, a second order optimal error estimate for the velocity in the L2 norm is derived. Numerical experiments illustrating the theoretical results are included.展开更多
基金support by the Hue University under the Core Research Program,(NCM.DHH.2018.09)Universiti Teknologi Malaysia for its UTMShine grant(Q.J130000.2454.09G96)。
文摘We present an analysis of a recent approach for determining the average pairing matrix elements within a specified interval of single-particle(sp)states around the Fermi level,denoted asλ.This method,known as the uniform gap method(UGM),highlights the critical importance of the averaged sp level density.The pairing matrix elements within the UGM approach are deduced from microscopically calculated values of and gaps obtained from analytical formulae of a semi-classical nature.Two effects generally ignored in similar fits are addressed:(a)a correction for a systematic bias introduced by fitting pairing gaps corresponding to equilibrium deformation solutions,as discussed by Möller and Nix[Nucl.Phys.A 476,1(1992)],and(b)a correction for a systematic spurious enhancement of for protons in the vicinity ofλ,caused by the local Slater approximation commonly employed in treating Coulomb exchange terms(e.g.,[Phys.Rev.C 84,014310(2011)]).This approach has demonstrated significant efficiency when applied to Hartree-Fock+Bardeen-Cooper-Schrieffer(BCS)calculations(including the seniority force and self-consistent blocking for odd nuclei)of a large sample of well and rigidly deformed even-even rare-earth nuclei.The experimental moments of inertia for these nuclei were reproduced with an accuracy comparable to that achieved through direct fitting of the data[Phys.Rev.C 99,064306(2019)].In this study,we extended the evaluation of our method to the reproduction of three-point odd-even mass differences centered on odd-N or odd-Z nuclei in the same region.The agreement with experimental data was found to be comparable to that obtained through direct fitting,as reported in[Phys.Rev.C 99,064306(2019)].
基金the National Natural Science Foundation of China (Grant Nos. 10432020 and 10602056)the Fund for Foreign Scholars in University Research and Teaching programs (Grant No. B07033).
文摘A flow past two side-by-side identical circular cylinders was numerically investigated with the unstructured spectral element method. From the computational results at various non-dimensional distances between cylinder centers T/D and the Reynolds number Re, a total of nine kinds of wake patterns were observed： four steady wake patterns, including single bluff-body steady pattern, separated double-body steady pattern and transition steady pattern for sub-critical Reynolds numbers and biased steady pattern for super-critical Reynolds numbers, and five unsteady wake patterns, including single bluff-body periodic pattern, biased quasi-steady pattern, quasi-periodic （flip-flopping） pattern, in-phase-synchronized pattern and anti-phase-synchronized pattern. Time evolution of lift and drag coefficients corresponding to each unsteady wake pattern was given.
文摘We construct a new stabilized finite volume method on rectangular grids for the Stokes equations. The lowest equal-order conforming finite element pair （piecewise bilinear veloc- ities and pressures） and piecewise constant test spaces for both the velocity and pressure are employed in this method. We show the stability of this method and prove first optimal rate of convergence for the velocity in the H1 norm and the pressure in the L2 norm. In addition, a second order optimal error estimate for the velocity in the L2 norm is derived. Numerical experiments illustrating the theoretical results are included.
