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  • 1
    Publication Date: 2014-10-10
    Description: The majority of ultraluminous X-ray sources are point sources that are spatially offset from the nuclei of nearby galaxies and whose X-ray luminosities exceed the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their X-ray luminosities in the 0.5-10 kiloelectronvolt energy band range from 10(39) to 10(41) ergs per second. Because higher masses imply less extreme ratios of the luminosity to the isotropic Eddington limit, theoretical models have focused on black hole rather than neutron star systems. The most challenging sources to explain are those at the luminous end of the range (more than 10(40) ergs per second), which require black hole masses of 50-100 times the solar value or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries, or both. Here we report broadband X-ray observations of the nuclear region of the galaxy M82 that reveal pulsations with an average period of 1.37 seconds and a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to an X-ray luminosity in the 3-30 kiloelectronvolt range of 4.9 x 10(39) ergs per second. The pulsating source is spatially coincident with a variable source that can reach an X-ray luminosity in the 0.3-10 kiloelectronvolt range of 1.8 x 10(40) ergs per second. This association implies a luminosity of about 100 times the Eddington limit for a 1.4-solar-mass object, or more than ten times brighter than any known accreting pulsar. This implies that neutron stars may not be rare in the ultraluminous X-ray population, and it challenges physical models for the accretion of matter onto magnetized compact objects.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bachetti, M -- Harrison, F A -- Walton, D J -- Grefenstette, B W -- Chakrabarty, D -- Furst, F -- Barret, D -- Beloborodov, A -- Boggs, S E -- Christensen, F E -- Craig, W W -- Fabian, A C -- Hailey, C J -- Hornschemeier, A -- Kaspi, V -- Kulkarni, S R -- Maccarone, T -- Miller, J M -- Rana, V -- Stern, D -- Tendulkar, S P -- Tomsick, J -- Webb, N A -- Zhang, W W -- England -- Nature. 2014 Oct 9;514(7521):202-4. doi: 10.1038/nature13791.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Universite de Toulouse, UPS-OMP, Institut de Recherche en Astrophysique et Planetologie, 9, Avenue du Colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France [2] CNRS, Institut de Recherche en Astrophysique et Planetologie, 9, Avenue du Colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France. ; Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA. ; MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. ; Physics Department, Columbia University, 538 West 120th Street, New York, New York 10027, USA. ; Space Sciences Laboratory, University of California, Berkeley, California 94720, USA. ; DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark. ; Lawrence Livermore National Laboratory, Livermore, California 94550, USA. ; Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK. ; Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA. ; NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA. ; Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada. ; Department of Physics, Texas Tech University, Lubbock, Texas 79409, USA. ; Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, Michigan 48109-1042, USA. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25297433" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 2
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Разложение изопропанола на V2O5 и бронзах: Li0,02V2O5, Na0,02V2O5, Na0,06V2O5, Li0,33V2O5 и Na0,33V2O5 было исследовано в области температур 186–300°C. Для первых четырех катализаторов основной реакцией оказалась дегидратация до пропена с незначительной дегидрогенизацией до ацетона. Дегидратация на этих катализаторах увеличивается с содержанием щелочного металла, а энергия активации остается неизменной. На последних двух катализаторах дегидратация и дегидрогенизация протекают при сравнимых скоростях. Исходя из влияния продуктов на начальную скорость, данных электропроводимости катализаторов и их ЭПР спектров, предлагается механизм дегидратации изопропанола.
    Notes: Abstract Decomposition of isopropanol on V2O5 and the bonzes Li0.02V2O5, Na0.02V2O5, Na0.06V2O5, Li0.33V2O5, and Na0.33V2O5 has been studied in the temperature range 168–300°C. The main reaction was found to be dehydration to propene with negligible dehydrogenation to acetone on the first four catalysts. Dehydration on these catalysts increased with the alkali metal content, but the energy of activation remained unchanged. On the last two catalysts, dehydration and dehydrogenation proceeded at comparable rates. A tentative mechanism for the dehydration of isopropanol is proposed, based on the effect of the product on the initial rate, the electric conductivity of the catalysts and their ESR spectra.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Рутениевые каталиэаторы на носителе Al2O3, приготовленные иэ Ru3(CO)12, были исследованы с помощью ИК и рентгеновской фотоэлектронной спектпоскопии (XPS). Триатомный кластер эадерживается на носителе, но при 150°C отщепляется. Для полного удаления карбонильных групп требуется наг⌕ев при 350°C в вакууме. XPS исследования укаэывают на то, что раэложившийся каталиэатор при дальнейшем восстановлении в H2 при 400°C уже не иэменяется. Атомы рутения остаются эахваченными в порах носителя.
    Notes: Abstract A supported ruthenium catalyst on alumina prepared from Ru3(CO)12 has been studied by infrared and X-ray photoelectron spectroscopy (XPS). The triatomic cluster is retained on the support but breaks down at 150°C. Complete elimination of the carbonyl groups requires heating at 350°C under vacuum. XPS studies show that the decomposed catalyst does not change on further reduction in H2 at 400°C. The ruthenium atoms remain trapped within the pores of the support.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Каталитическое окисление CO исследовано на Nd1−xBaxCoO3 и LnCoO3 (Ln=La, Sm, Nd, Dy). Каталитическую активность сравнивали с изменением х, кхслородных дефектов и со структурнями изменениями. Найдено, что соединехия с кубической структурой дают максимальную активность, которая уменьшается в направлении от кубической структуры. Это объясняют лучшей делокализацией d-электронов кобальта кубических соединений.
    Notes: Abstract Catalytic oxidation of CO has been studied on Nd1−xBaxCoO3 and LnCoO3 (Ln=La, Sm, Nd, Dy). Catalytic activity was compared with changing x, oxygen defects and structural changes. It has been found that compounds with cubic structure show maximum activity, which decreases with deviation from cubic structure. This has been explained as due to better delocalization of the d-electrons of cobalt in the cubic compounds.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Были приготовлены образцы окиси никеля, насышенные литием и индием, с содержанием допанта до 3 ат.%-ов. Были исследованы электрические свойства этих образцов. Для всех образцов была обнаружена проводимость типа р, которая возрастает с литиевым насыщением и уменышается с индиевым насыщением. Дегидрирование 2-пропанола на этих катаизаторах уменьшается с увеличением концетрации дырок в твердом веществе. Ступенью, лимитирующей скорость процесса, является десорбция ацетона. Предлагается вероятный менанизм протекания процесса.
    Notes: Abstract Lithium and indium doped nickel oxide samples have been prepared with up to 3 at. % of dopant. The electrical properties of these samples have been studied. All the samples exhibit p-type conductivity which increases with lithium doping and decreases upon doping with indium. Dehydrogenation of 2-propanol on these catalysts increases with the hole concentration in the solid. Desorption of acetone appears to be the rate-determining step. A possible mechanism for the reaction is proposed.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract РФЭС спектры LaCoO3 были сняты перед и после обработки in situ окисью углерода при комнатной температуре и 200°C. Доказано, что газовая CO реагирует с хемосорбированным кислородом, давая CO2.
    Notes: Abstract XPS spectra of LaCoO3 have been studied before and after in situ treatment with carbon monoxide at room temperature and at 470 K. It has been concluded that gaseous CO reacts with chemisorbed oxygen to form CO2.
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  • 7
    ISSN: 1439-0426
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Thirty-two glass jars (3 L each) in the laboratory and outdoor tanks (300 L) were used to examine the influence of common carp (Cyprinus carpio L.) in increasing the fertilizer value of phoshate rock in eight treatment combinations in quadruplicate. Input of water soluble hosphate was determined to quantify the effects of bioturbation, fish excrements and soil. The level of orthophosphate in water was always lowest in the control series. Introduction of common carp fry resulted in a net increase of 0.1 to 0.114 mg. L-1 of orthophosphate attributable to the effect of fish excrement. Bioturbation caused by common carp resulted in as high as a 72 to 100 % influx of phosphate from bottom soil in the presence of phosphate rock but only about 7 to 8 % in the absence of phosphate rock.〈section xml:id="abs1-2"〉〈title type="main"〉Zusammenfassung Die Bedeutung eingesetzter Karpfen (Cyprinus carpio L.) zur Steigerung des Düngerwertes von Phosphatgestein32 Glasgefäße (3 L Volumen) wurden im Labor und 4 Behälter (300 L) im Freien aufgestellt urn den Einfluß zunehmender Düngung durch Phosphatgestein auf Karpfen (Cyprinus carpio L.) in 8 unterschiedlichen Applikationen mit jeweils 4 Replikaten zu testen. Der Eintrag wasserloslichen Phosphats wurde bestimmt, urn die Wirkung von Bioturbation, Fischexkrementen und Bodensubstrat zu prüfen. Die Konzentration an Orthophosphat war in den Kontrollen am niedrigsten. Das Einsetzen von Karpfen-Jungfischen erhöhte die Nertozunahme des Orrhophosphats auf 0,1 bis 0,114 mg. -1 und diese Zunahme muß den Ausscheidungen der Fische zugeschrieben werden. Die durch die Karpfen verursachte Bioturbation resultiene in einer 72 bis 100% igen Zunahme des Influx des Phosphats aus dem Bodensubstrat wenn Phosphatgestein dem Boden zugegeben wurde, wahrend dieser Wert nur 7–8%) ohne Phosphatgestein betrug.
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  • 8
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The relativistic plasma flows onto neutron stars that are accreting material from stellar companions can be used to probe strong-field gravity as well as the physical conditions in the supra-nuclear-density interiors of neutron stars. Plasma inhomogeneities orbiting a few kilometres above the ...
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  • 9
    ISSN: 0022-328X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0022-328X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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