71,320 research outputs found
Ocyplanus megalops JACOBSON & KISTNER 1983
No full textOcyplanus megalops JACOBSON & KISTNER 1983 Ocyplanus megalops JACOBSON & KISTNER 1983: 33. M a t e r i a l:1, O. Afrika, Gomba, lux, leg. Inst. Amani (MNHUB). D i s t r i b u t i o n: Zaire, Gambia, Ivory Coast, Ghana.Published as part of Pace, R., 2012, New data and new species of Aleocharinae from Tropical Africa in the Natural History Museum of the Humboldt University, Berlin (Coleoptera, Staphylinidae), pp. 1331-1362 in Linzer biologische Beiträge 44 (2) on page 1342, DOI: 10.5281/zenodo.533529
Proper Ferroelectricity in the Dion?Jacobson Material CsBi2Ti2NbO10: Experiment and Theory
No full textA diverse range of materials and properties are exhibited by layered perovskites. We report on the synthesis, characterization, and computational investigation of a new ferroelectric?CsBi2Ti2NbO10, an n = 3 member of the Dion?Jacobson (DJ) family. Structural studies using variable temperature neutron powder diffraction indicate that a combination of octahedral rotations and polar displacements result in the polar structure. Density functional theory calculations reveal that the wider perovskite blocks in CsBi2Ti2NbO0 stabilize proper ferroelectricity, in contrast to the hybrid-improper ferroelectricity reported for all other DJ phases. Our results raise the possibility of a new class of proper ferroelectric materials analogous to the well-known Aurivillius phases
Diurnal variation of oceanic deep cumulus convection
No full textFebruary 1976.Sponsored by NOAA National Environmental Satellite Laboratory 04-3-158-51.Observational evidence / Jacobson, R. W. -- Physical hypothesis / Gray, W. M
Derelina nigriceps KISTNER & JACOBSON 1979
No full textDerelina nigriceps KISTNER 1979 Derelina nigriceps KISTNER & JACOBSON 1979: 329. M a t e r i a l: 6 specimens, O. Afrika, Gomba, lux, leg. Inst. Amani (MNHUB). D i s t r i b u t i o n: Kenya, Tanzania, Uganda, Zaire.Published as part of Pace, R., 2012, New data and new species of Aleocharinae from Tropical Africa in the Natural History Museum of the Humboldt University, Berlin (Coleoptera, Staphylinidae), pp. 1331-1362 in Linzer biologische Beiträge 44 (2) on page 1337, DOI: 10.5281/zenodo.533529
Direct, high-resolution measurement of furrow stiffening during division of adherent cells
No full textIt is unclear whether cell division is driven by cortical relaxation outside the equatorial region or cortical contractility within the developing furrow alone. To approach this question, a technique is required that can monitor spatially-resolved changes in cortical stiffness with good time resolution. We employed atomic force microscopy (AFM), in force-mapping mode, to track dynamic changes in the stiffness of the cortex of adherent cultured cells along a single scan-line during M phase, from metaphase to cytokinesis. Video microscopy, which we used to correlate the AFM data with mitotic events identified by light microscopy, indicated that the AFM force-mapping technique does not perturb dividing cells. Here we show that cortical stiffening occurs over the equatorial region about 160 seconds before any furrow appears, and that this stiffening markedly increases as the furrow starts. By contrast, polar relaxation of cells does not seem to be an obligatory event for cell division to occur
Finite rank operators in Jacobson radical {\scr R}\sb{{\scr N}\otimes{\scr M}}
No full textsummary:In this paper we investigate finite rank operators in the Jacobson radical of , where , are nests. Based on the concrete characterizations of rank one operators in and , we obtain that each finite rank operator in can be written as a finite sum of rank one operators in and the weak closure of equals if and only if at least one of , is continuous
The Jacobson Radical and Regular Modules
No full textLet A be an associative, but not necessarily commutative, ring with identity, and J = J(A) its Jacobson radical. A (unital) module is regular iff every submodule is pure (see (1)). The regular socle R(M) of a module M is the sum of all its submodules which are regular. These concepts have been introduced and studied in (2).</jats:p
Classification of rings with toroidal Jacobson graph
No full textsummary:Let be a commutative ring with nonzero identity and the Jacobson radical of . The Jacobson graph of , denoted by , is defined as the graph with vertex set such that two distinct vertices and are adjacent if and only if is not a unit of . The genus of a simple graph is the smallest nonnegative integer such that can be embedded into an orientable surface . In this paper, we investigate the genus number of the compact Riemann surface in which can be embedded and explicitly determine all finite commutative rings (up to isomorphism) such that is toroidal
On the Jacobson radical of strongly group graded rings
No full textsummary:For any non-torsion group with identity , we construct a strongly -graded ring such that the Jacobson radical is locally nilpotent, but is not locally nilpotent. This answers a question posed by Puczy{\l}owski
Thermal expansion anomalies of R(Fe, M)(12) (R=Y, Nd; M=Mo and Si)
No full textStructural and thermal-expansion anomaly studies on R(Fe,M)(12) (R=Nd and and Y, M=Mo and Si) compounds were performed by x-ray diffraction. Mo atoms occupy the 8i site. While Si atoms occupy the 8f and 8j sites but not the 8i site. Thermal-expansion anomaly shows only in ab plane in the Mo compounds, while becomes very weak and along with only the c axis in the Si compounds. The anomaly was attributed to the contribution of the interactions of short Fe-Fe distances similar to the previous explanation on other R-Fe intermetallics and that of other strongly positive interactions such as 8j-8j. (c) 2005 American Institute of Physics.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000230168300025&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)EICPCI-S(ISTP)
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