Beyond-mean-field study of the possible "bubble" structure of 34Si

Recent self-consistent mean-field calculations predict a substantial depletion of the proton density in the interior of 34Si. In the present study, we investigate how correlations beyond the mean field modify this finding. The framework of the calculation is a particle-number and angular-momentum projected Generator Coordinate Method based on Hartree-Fock-Bogoliubov+Lipkin-Nogami states with axial quadrupole deformation. The parametrization SLy4 of the Skyrme energy density functional is used together with a density-dependent pairing energy functional. For the first time, the generator coordinate method is applied to the calculation of charge and transition densities. The impact of pairing correlations, symmetry restorations and shape mixing on the density profile is analyzed step by step. All these effects significantly alter the radial density profile, and tend to bring it closer to a Fermi-type density distribution.Comment: 9 pages, 7 figure

Tensor coupling effects on spin symmetry in anti-Lambda spectrum of hypernuclei

The effects of $\bar\Lambda\bar\Lambda\omega$-tensor coupling on the spin symmetry of $\bar{\Lambda}$ spectra in $\bar{\Lambda}$-nucleus systems have been studied with the relativistic mean-field theory. Taking $^{12}$C+$\bar{\Lambda}$ as an example, it is found that the tensor coupling enlarges the spin-orbit splittings of $\bar\Lambda$ by an order of magnitude although its effects on the wave functions of $\bar{\Lambda}$ are negligible. Similar conclusions has been observed in $\bar{\Lambda}$-nucleus of different mass regions, including $^{16}$O+$\bar{\Lambda}$, $^{40}$Ca+$\bar{\Lambda}$ and $^{208}$Pb+$\bar{\Lambda}$. It indicates that the spin symmetry in anti-lambda-nucleus systems is still good irrespective of the tensor coupling.Comment: 12 pages, 3 figures

Spectral properties of 1D extended Hubbard model from bosonization and time-dependent variational principle: applications to 1D cuprate

Recent ARPES experiments on doped 1D cuprates revealed the importance of effective near-neighbor (NN) attractions in explaining certain features in spectral functions. Here we investigate spectral properties of the extended Hubbard model with the on-site repulsion $U$ and NN interaction $V$, by employing bosonization analysis and the high-precision time-dependent variational principle (TDVP) calculations of the model on 1D chain with up to 300 sites. From state-of-the-art TDVP calculations, we find that the spectral weights of the holon-folding and $3k_F$ branches evolve oppositely as a function of $V$. This peculiar dichotomy may be explained in bosonization analysis from the opposite dependence of exponent that determines the spectral weights on Luttinger parameter $K_{\rho}$. Moreover, our TDVP calculations of models with fixed $U=8t$ and different $V$ show that $V\approx -1.7t$ may fit the experimental results best, indicating a moderate effective NN attraction in 1D cuprates that might provide some hints towards understanding superconductivity in 2D cuprates.Comment: 9 pages, 4 figure

Core Polarization and Tensor Coupling Effects on Magnetic Moments of Hypernuclei

The effects of core polarization and tensor coupling on the magnetic moments in $^{13}_\Lambda$C, $^{17}_\Lambda$O, and $^{41}_\Lambda$Ca $\Lambda$-hypernuclei are studied in the Dirac equation with scalar, vector and tensor potentials. It is found that the effect of core polarization on the magnetic moments is suppressed by $\Lambda$ tensor coupling. The $\Lambda$ tensor potential reduces the spin-orbit splitting of $p_\Lambda$ states considerably. However, almost the same magnetic moments are obtained using the hyperon wave function obtained via the Dirac equation either with or without the $\Lambda$ tensor potential in the electromagnetic current vertex. The deviations of magnetic moments for $p_\Lambda$ states from the Schmidt values are found to increase with nuclear mass number.Comment: 10 pages, 2 figures, 2 table

tert-Butyl 6-amino-3,4-dihydro-2H-1,4-benzoxazine-4-carboxyl­ate

The title mol­ecule, C13H18N2O3, contains a benzene ring fused to an oxazine ring and one tert-but­oxy­carbonyl group bound to the N atom of the oxazine ring. A weak intra­molecular C—H⋯O inter­action occurs. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds stack the mol­ecules down the b axis. Weak C—H⋯N contacts connect the stacks, generating a three-dimensional network

Hexaaqua­cobalt(II) bis­{[N-(4-meth­oxy-2-oxidobenzyl­idene)glycyl­glycinato]copper(II)} hexa­hydrate

In the crystal structure of the title compound, [Co(H2O)6][Cu(C12H11N2O5)]2·6H2O, the CoII atom is located on an inversion center and coordinated by six water mol­ecules in a slightly distorted octa­hedral geometry. The CuII atom is chelated by the Schiff base ligand in a distorted CuN2O2 square-planar geometry. An extensive O—H⋯O hydrogen-bonding network is present in the crystal structure

Research on Computing Efficiency of MapReduce in Big Data Environment

The emergence of big data has brought a great impact on traditional computing mode, the distributed computing framework represented by MapReduce has become an important solution to this problem. Based on the big data, this paper deeply studies the principle and framework of MapReduce programming. On the basis of mastering the principle and framework of MapReduce programming, the time consumption of distributed computing framework MapReduce and traditional computing model is compared with concrete programming experiments. The experiment shows that MapReduce has great advantages in large data volume