Analytical smoothing effect of solution for the boussinesq equations

In this paper, we study the analytical smoothing effect of Cauchy problem for the incompressible Boussinesq equations. Precisely, we use the Fourier method to prove that the Sobolev H 1-solution to the incompressible Boussinesq equations in periodic domain is analytic for any positive time. So the incompressible Boussinesq equation admet exactly same smoothing effect properties of incompressible Navier-Stokes equations

Nuclear symmetry energy and core-crust transition in neutron stars: a critical study

The slope of the nuclear symmetry energy at saturation density $L$ is pointed out as a crucial quantity to determine the mass and width of neutron-star crusts. This letter clarifies the relation between $L$ and the core-crust transition. We confirm that the transition density is soundly correlated with $L$ despite differences between models, and we propose a clear understanding of this correlation based on a generalised liquid drop model. Using a large number of nuclear models, we evaluate the dispersion affecting the correlation between the transition pressure $P_t$ and $L$. From a detailed analysis it is shown that this correlation is weak due to a cancellation between different terms. The correlation between the isovector coefficients $K_{\rm sym}$ and $L$ plays a crucial role in this discussion

Effective medium approximation and the complex optical properties of the inhomogeneous superconductor K_{0.8}Fe_{2-y}Se_2

The in-plane optical properties of the inhomogeneous iron-chalcogenide superconductor K_{0.8}Fe_{2-y}Se_2 with a critical temperature Tc = 31 K have been modeled in the normal state using the Bruggeman effective medium approximation for metallic inclusions in an insulating matrix. The volume fraction for the inclusions is estimated to be ~ 10%; however, they appear to be highly distorted, suggesting a filamentary network of conducting regions joined through weak links. The value for the Drude plasma frequency in the inclusions is much larger than the volume average, which when considered with the reasonably low values for the scattering rate, suggests that the transport in the grains is always metallic. Estimates for the dc conductivity and the superfluid density in the grains places the inclusions on the universal scaling line close to the other homogeneous iron-based superconductors.Comment: 6 pages, 3 figure

The role of phosphorylation and dephosphorylation of shell matrix proteins in shell formation : an in vivo and in vitro study

Protein phosphorylation is a fundamental mechanism regulating many aspects of cellular processes. Shell matrix proteins (SMPs) control crystal nucleation, polymorphism, morphology, and organization of calcium carbonate crystallites during shell formation. SMPs phosphorylation is suggested to be important in shell formation but the mechanism is largely unknown. Here, to investigate the mechanism of phosphorylation of SMPs in biomineralization, we performed in vivo and in vitro experiment. By injection of antibody against the anti-phosphoserine/threonine /tyrosine into the extrapallial fluid of the pearl oyster Pinctada fucata, phosphorylation of matrix proteins were significantly reduced after 6 days. Newly formed prismatic layers and nacre tablet were found to grow abnormally with reduced crystallinity and possibly changed crystal orientation shown by Raman spectroscopy. In addition, regeneration of shells is also inhibited in vivo. Then, protein phosphatase was used to dephosphorylate SMPs extracted from the shells. After dephosphorylation, the ability of SMPs to inhibiting calcium carbonate formation have been reduced. Surprisingly, the ability of SMPs to modulate crystal morphology have been largely compromised although phosphorylation extent remained to be at least half of the control. Furthermore, dephosphorylation of SMPs changed the distribution of protein occlusions and decreased the amount of protein occlusions inside crystals shown by confocal imaging, indicating interaction between phosphorylated SMPs and crystals. Taken together, this study provides insight into the mechanism of phosphorylation of SMPs during shell formation

The asymmetric structure of the Galactic halo

Using the stellar photometry catalogue based on the latest data release (DR4) of the Sloan Digital Sky Survey (SDSS), a study of the Galactic structure using star counts is carried out for selected areas of the sky. The sample areas are selected along a circle at a Galactic latitude of +60$^\circ$, and 10 strips of high Galactic latitude along different longitudes. Direct statistics of the data show that the surface densities of $\ell$ from $180^{\circ}$ to $360^{\circ}$ are systematically higher than those of $\ell$ from $0^{\circ}$ to $180^{\circ}$, defining a region of overdensity (in the direction of Virgo) and another one of underdensity (in the direction of Ursa Major) with respect to an axisymmetric model. It is shown by comparing the results from star counts in the $(g-r)$ colour that the density deviations are due to an asymmetry of the stellar density in the halo. Theoretical models for the surface density profile are built and star counts are performed using a triaxial halo of which the parameters are constrained by observational data. Two possible reasons for the asymmetric structure are discussed.Comment: 17 pages, 7 figures, 5 tables, MNRAS accepte

Evolution of Surface Deformations of Weakly-Bound Nuclei in the Continuum

We study weakly-bound deformed nuclei based on the coordinate-space Skyrme Hartree-Fock-Bogoliubov approach, in which a large box is employed for treating the continuum and surface diffuseness. Approaching the limit of core-halo deformation decoupling, calculations found an exotic "egg"-like structure consisting of a spherical core plus a prolate halo in $^{38}$Ne, in which the resonant continuum plays an essential role. Generally the halo probability and the decoupling effect in heavy nuclei are reduced compared to light nuclei, due to denser level densities around Fermi surfaces. However, deformed halos in medium-mass nuclei are possible with sparse levels of negative parity, for example, in $^{110}$Ge. The surface deformations of pairing density distributions are also influenced by the decoupling effect and are sensitive to the effective pairing Hamiltonian.Comment: 5 pages and 5 figure