Enigma of ultraluminous X-ray sources may be resolved by 3D-spectroscopy (MPFS data)

The ultraluminous X-ray sources (ULXs) were isolated in external galaxies for the last 5 years. Their X-ray luminosities exceed 100-10000 times those of brightest Milky Way black hole binaries and they are extremely variable. There are two models for the ULXs, the best black hole candidates. 1. They are supercritical accretion disks around a stellar mass black hole like that in SS433, observed close to the disk axes. 2. They are Intermediate Mass Black Holes (of 100-10000 solar masses). Critical observations which may throw light upon the ULXs nature come from observations of nebulae around the ULXs. We present results of 3D-spectroscopy of nebulae around several ULXs located in galaxies at 3-6 Mpc distances. We found that the nebulae to be powered by their central black holes. The nebulae are shocked and dynamically perturbed probably by jets. The nebulae are compared with SS433 nebula (W50).Comment: Proceedings of the ESO and Euro3D Workshop "Science Perspectives for 3D Spectroscopy", Garching (Germany), October 10-14, 2005. M. Kissler-Patig, M.M. Roth and J.R. Walsh (eds.

Antarctic meteorites: MIL 07687 and ALHA 77307 - A novel approach of in-situ micro-XRD study of the matrix

第6回極域科学シンポジウム[OA] 南極隕石11月16日（月）　国立国語研究所 2階 講

Non-kin ties as a source of support amongst older adults ‘left behind’ in Poland

In the transition to democracy and a market economy, the Central and Eastern European countries experienced rapid and fundamental changes. Large-scale emigration flows and pronounced reductions in previously universal welfare systems increased the phenomenon of ‘left behind’ older adults. We examine this phenomenon in the case of Poland, a rather family-oriented society which in recent years sent most emigrants to Western Europe in absolute terms. Employing a support system framework and representative survey data, we enquire into older adults’ support patterns. Our results suggest that older adults in Poland rely predominantly on family support, although this varies greatly across living arrangements. We also find a positive association between distance separating parents and their closest child, and support from at least one non-kin. Yet, our findings reveal differences between practical and emotional support, with the latter being more likely to be provided by non-kin, but with distance mattering to a lesser degree. Parents with very distant child(ren) are few and differ only from parents with very proximate child(ren), a finding prompting the question as to what is the difference between being ‘left behind’ by international and by internal migration. We conclude that the phenomenon of ‘left behind’ in Poland, at least in terms of support, is less a matter of children's migration and more an issue of household and regional context

Population dynamics of the freshwater clam Galatea paradoxa (Donacidae) in the Cross River, Nigeria

Population dynamics, Growth, Mortality, Clam fisheries, Freshwater molluscs, Cross River, Nigeria, Galatea paradoxa

First-principles study of (BiScO3){1-x}-(PbTiO3){x} piezoelectric alloys

We report a first-principles study of a class of (BiScO3)_{1-x}-(PbTiO3)_x (BS-PT) alloys recently proposed by Eitel et al. as promising materials for piezoelectric actuator applications. We show that (i) BS-PT displays very large structural distortions and polarizations at the morphotropic phase boundary (MPB) (we obtain a c/a of ~1.05-1.08 and P_tet of ~1.1 C/m^2); (ii) the ferroelectric and piezoelectric properties of BS-PT are dominated by the onset of hybridization between Bi/Pb-6p and O-2p orbitals, a mechanism that is enhanced upon substitution of Pb by Bi; and (iii) the piezoelectric responses of BS-PT and Pb(Zr_{1-x}Ti_x)O3 (PZT) at the MPB are comparable, at least as far as the computed values of the piezoelectric coefficient d_15 are concerned. While our results are generally consistent with experiment, they also suggest that certain intrinsic properties of BS-PT may be even better than has been indicated by experiments to date. We also discuss results for PZT that demonstrate the prominent role played by Pb displacements in its piezoelectric properties.Comment: 6 pages, with 3 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/ji_bi/index.htm

Controllability and universal three-qubit quantum computation with trapped electron states

We show how to control and perform universal three-qubit quantum computation with trapped electron quantum states. The three qubits are the electron spin, and the first two quantum states of the cyclotron and axial harmonic oscillators. We explicitly show how the universal gates can be performed. As an example of a non-trivial quantum algorithm, we outline the implementation of the Deutsch-Jozsa algorithm in this system.Comment: 4 pages, 1 figure. Typos corrected. The original publication is available at http://www.springerlink.co

Epitaxially strained [001]-(PbTiO3_3)1_1(PbZrO3_3)1_1 superlattice and PbTiO3_3 from first principles

The effect of layer-by-layer heterostructuring and epitaxial strain on lattice instabilities and related ferroelectric properties is investigated from first principles for the [001]-(PbTiO$_3$)$_1$(PbZrO$_3$)$_1$ superlattice and pure PbTiO$_3$ on a cubic substrate. The results for the superlattice show an enhancement of the stability of the monoclinic r-phase with respect to pure PbTiO$_3$. Analysis of the lattice instabilities of the relaxed centrosymmetric reference structure computed within density functional perturbation theory suggests that this results from the presence of two unstable zone-center modes, one confined in the PbTiO$_3$ layer and one in the PbZrO$_3$ layer, which produce in-plane and normal components of the polarization, respectively. The zero-temperature dielectric response is computed and shown to be enhanced not only near the phase boundaries, but throughout the r-phase. Analysis of the analogous calculation for pure PbTiO$_3$ is consistent with this interpretation, and suggests useful approaches to engineering the dielectric properties of artificially structured perovskite oxides.Comment: 8 pages, 5 figure

Cluster Masses Accounting for Structure along the Line of Sight

Weak gravitational lensing of background galaxies by foreground clusters offers an excellent opportunity to measure cluster masses directly without using gas as a probe. One source of noise which seems difficult to avoid is large scale structure along the line of sight. Here I show that, by using standard map-making techniques, one can minimize the deleterious effects of this noise. The resulting uncertainties on cluster masses are significantly smaller than when large scale structure is not properly accounted for, although still larger than if it was absent altogether.Comment: 5 pages, 5 figure

Anomalous enhancement of tetragonality in PbTiO3 induced by negative pressure

Using a first-principles approach based on density-functional theory, we find that a large tetragonal strain can be induced in PbTiO3 by application of a negative hydrostatic pressure. The structural parameters and the dielectric and dynamical properties are found to change abruptly near a crossover pressure, displaying a ``kinky'' behavior suggestive of proximity to a phase transition. Analogous calculations for BaTiO3 show that the same effect is also present there, but at much higher negative pressure. We investigate this unexpected behavior of PbTiO3 and discuss an interpretation involving a phenomenological description in terms of a reduced set of relevant degrees of freedom.Comment: 9 pages, with 9 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/st_pbti/index.htm

Lattice instabilities of PbZrO3/PbTiO3 [1:1] superlattices from first principles

Ab initio phonon calculations for the nonpolar reference structures of the (001), (110), and (111) PbZrO_3/PbTiO_3 [1:1] superlattices are presented. The unstable polar modes in the tetragonal (001) and (110) structures are confined in either the Ti- or the Zr-centered layers and display two-mode behavior, while in the cubic (111) case one-mode behavior is observed. Instabilities with pure oxygen character are observed in all three structures. The implications for the ferroelectric behavior and related properties are discussed.Comment: 12 pages, 2 figures, 7 tables, submitted to PR