Structural properties of the dynamics in flare fragmentation     

Heinz Isliker 《Solar physics》1992,141(2):325-334

Solar flares have a fragmented structure. Dynamical systems theory, for instance in its form of dimensional analysis, can analyze such structures. It answers the question whether the underlying process is deterministic or stochastic. If the process is deterministic, it provides a measure of how complicated the process is (the fractal dimension). In order to be reliable, the analysis has to be combined with the investigation of stationarity.We apply this method to ms-spikes, observed in the decimetric range, which are possibly a manifestation of flare fragmentation. We compare the system-theoretical properties - such as stationarity, stochasticity or deterministic behaviour - of the ms-spikes to the properties of several classes of suggested scenarios. This permits us to discuss different scenarios from a general point of view and to derive general properties of the source.Paper presented at the 4th CESRA Workshop in Ouranopolis (Greece) 1991.  相似文献   

The Flared Disc Project: RXTE and ASCA observations of X 1822−371     

S. Heinz  M. A. Nowak 《Monthly notices of the Royal Astronomical Society》2001,320(2):249-260

We present archival Rossi X-ray Timing Explorer ( RXTE ) and simultaneous Advanced Satellite for Cosmology and Astrophysics ( ASCA ) data of the eclipsing low mass X-ray binary (LMXB) X 1822−371. Our spectral analysis shows that a variety of simple models can fit the spectra relatively well. Of these models, we explore two in detail through phase-resolved fits. These two models represent the case of a very optically thick and a very optically thin corona. While systematic residuals remain at high energies, the overall spectral shape is well approximated. The same two basic models are fitted to the X-ray light curve, which shows sinusoidal modulations interpreted as absorption by an opaque disc rim of varying height. The geometry we infer from these fits is consistent with previous studies: the disc rim reaches out to the tidal truncation radius, while the radius of the corona (approximated as spherical) is very close to the circularization radius. Timing analysis of the RXTE data shows a time-lag from hard to soft consistent with the coronal size inferred from the fits. Neither the spectra nor the light curve fits allow us to rule out either model, leaving a key ingredient of the X 1822−371 puzzle unsolved. Furthermore, while previous studies were consistent with the central object being a 1.4 M_⊙ neutron star, which has been adopted as the best guess scenario for this system, our light curve fits show that a white dwarf or black hole primary can work just as well. Based on previously published estimates of the orbital evolution of X 1822−371, however, we suggest that this system contains either a neutron star or a low mass (≲2.5 M_⊙) black hole and is in a transitional state of duration shortward of 10⁷ yr.  相似文献   

Calcareous nannoplankton, planktonic foraminiferal, and carbonate carbon isotope stratigraphy of the Cenomanian–Turonian boundary section in the Ultrahelvetic Zone (Eastern Alps, Upper Austria)     

Michael Wagreich  Ana-Voica Bojar  Reinhard F. Sachsenhofer  Stephanie Neuhuber  Hans Egger 《Cretaceous Research》2008,29(5-6):965

Ultrahelvetic units of the Eastern Alps were deposited on the distal European continental margin of the (Alpine) Tethys. The Rehkogelgraben section (“Buntmergelserie”, Ultrahelvetic unit, Upper Austria) comprises a 5 m thick succession of upper Cenomanian marl-limestone cycles overlain by a black shale interval composed of three black shale layers and carbonate-free claystones, followed by lower Turonian white to light grey marly limestones with thin marl layers. The main biostratigraphic events in the section are the last occurrence of Rotalipora and the first occurrences of Helvetoglobotruncana helvetica and Quadrum gartneri. The thickest black shale horizon has a TOC content of about 5%, with predominantly marine organic matter of kerogen type II. Vitrinite reflectance and Rock-Eval parameter T_max (<424 °C) indicate low maturity. HI values range from 261 to 362 mg HC/g TOC. δ¹³C values of bulk rock carbonates display the well documented positive shift around the black shale interval, allowing correlation of the Rehkogelgraben section with other sections such as the Global Boundary Stratotype Section and Point (GSSP) succession at Pueblo, USA, and reference sections at Eastbourne, UK, and Gubbio, Italy. Sediment accumulation rates at Rehkogelgraben (average 2.5 mm/ka) are significantly lower than those at Pueblo and Eastbourne.  相似文献   

Functional Molecular Biodiversity: Assessing the Immune Status of Two Sponge Populations (Suberites domuncula) on the Molecular Level     

Heinz C. Schröder  Vladislav A. Grebenjuk  Michael Binder  Alexander Skorokhod  Renato Batel  Hamdy Hassanein  & Werner E. G. Müller 《Marine Ecology》2004,25(2):93-108

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Continental slope sedimentation adjacent to an ice margin I. Seismic facies of Labrador Slope   总被引：1，自引：0，他引：1  

Reinhard Hesse 《Geo-Marine Letters》1992,12(4):189-199

Sleeve-gun, 3.5-kHz, and 12-kHz profiles from the Labrador Slope provide the basis for an analysis of sedimentary facies, processes, and evolution of a continental slope adjacent to an ice margin. The upper slope is deeply incised by numerous canyons reflecting headward canyon branching. The less rugged middle-slope topography has fewer canyons and large slide and slump scars followed downslope by debris-flow deposits. Echo character of seismic profiles reflects the difference in sediment types supplied from mud-dominated sources and sand-, gravel- and till-dominated sources. On the rise, debris-flow deposits are largely confined to canyons. Intercanyon areas are dominated by spill-over turbidites alternating with hemipelagic sediments, which on some of the southern to southwestern levees occur in sediment-wave fields formerly attributed to bottom-current activity.  相似文献   

Channelized and hillslope sediment transport and the geomorphology of mountain belts     

Heinz Schneider  Marco Schwab  Fritz Schlunegger 《International Journal of Earth Sciences》2008,97(1):179-192

This paper uses the results of landscape evolution models and morphometric data from the Andes of northern Peru and the eastern Swiss Alps to illustrate how the ratio between sediment transport on hillslopes and in channels influences landscape and channel network morphologies and dynamics. The headwaters of fluvial- and debris-flow-dominated systems (channelized processes) are characterized by rough, high-relief, highly incised surfaces which contain a dense and hence a closely spaced channel network. Also, these systems tend to respond rapidly to modifications in external forcing (e.g., rock uplift and/or precipitation). This is the case because the high channel density results in a high bulk diffusivity. In contrast, headwaters where landsliding is an important sediment source are characterized by a low channel density and by rather straight and unstable channels. In addition, the topographies are generally smooth. The low channel density then results in a relatively low bulk diffusivity. As a consequence, response times are greater in headwaters of landslide-dominated systems than in highly dissected drainages. The Peruvian and Swiss case studies show how regional differences in climate and the litho-tectonic architecture potentially exert contrasting controls on the relative importance of channelized versus hillslope processes and thus on the overall geomorphometry. Specifically, the Peruvian example illustrates to what extent the storminess of climate has influenced production and transport of sediment on hillslopes and in channels, and how these differences are seen in the morphometry of the landscape. The Swiss example shows how the bedding orientation of the bedrock drives channelized and hillslope processes to contrasting extents, and how these differences are mirrored in the landscape. An erratum to this article can be found at  相似文献   

Recommended Values of ²³⁹Pu, ²⁴⁰Pu and ^239+240Pu Concentrations in Reference Material IAEA-315 (Marine Sediment) Estimated by Thermal Ionisation Mass Spectrometry, Inductively Coupled Plasma-Mass Spectrometry and Alpha Spectrometry     

Taeko Shinonaga  Helmuth Aigner  Dilani Klose  Peter Spinder  Heinz Fröschl  David Donohue 《Geostandards and Geoanalytical Research》2008,32(1):93-101

The recommended concentrations of ²³⁹Pu, ²⁴⁰Pu and ^239+240Pu in reference material IAEA‐315 (marine sediment) were estimated by three analytical methods: isotope dilution thermal ionisation mass spectrometry (TIMS), isotope dilution inductively coupled plasma‐mass spectrometry (ICP‐MS) and alpha spectrometry. The determination of ²³⁹Pu and ²⁴⁰Pu (^239+240Pu by alpha spectrometry) was carried out with samples from randomly selected bottles using each method. Plutonium‐238 was also measured by alpha spectrometry. A plutonium‐242 reference material was used as a spike for the quantitative analysis. The influence of ²⁴²Pu in the samples was therefore calculated; however, this contribution was less than the range of uncertainty and did not influence the final results. The obtained data were statistically analysed using variance component analysis and paired comparison. The combined standard uncertainties from “method/measurement”, “bottle” and “sub‐sample” were in the order of 3 to 6%. The main contributions to the uncertainty were from the material heterogeneity and from systematic differences between methods. Based on this study with twenty‐seven analyses using 10–14 g sample mass, concentrations of (38 ± 3) Bq kg^?1, (28 ± 3) Bq kg^?1 and (66 ± 4) Bq kg^?1 are proposed as recommended values for ²³⁹Pu, ²⁴⁰Pu and ^239+240Pu, respectively, and (9.5 ± 0.4) Bq kg^?1 for ²³⁸Pu as an information value in reference material IAEA‐315. In mass concentration units, these amount to (16.4 ± 1.2) ng kg^?1, (3.3 ± 0.4) ng kg^?1 and (0.015 ± 0.003) ng kg^?1 for ²³⁹Pu, ²⁴⁰Pu and ²³⁸Pu, respectively. The certified reference materials NIST 4350B and NIST 4354 were also analysed by TIMS for quality assurance of the method used in this study.  相似文献   

Phosphine absorption in the 5-μm window of Jupiter     

Reinhard Beer  Fredric W. Taylor 《Icarus》1979,40(2):189-192

Since the original suggestion by Gillett et al. (1969) it has generally been assumed that the region of partial transparency near 5 μm in Jupiter's atmosphere (the 5-μm window) is bounded by the v₄ NH₃ at 6.1 μm and the v₃ CH₄ band at 3.3 μm. New measurements of Jupiter and of laboratory phosphine (PH₃) samples show that PH₃ is a significant contributor to the continuum opacity in the window and in fact defines its short-wavelength limit. This has important implications for the use of 5-mu;m observations as a means to probe the deep atmospheric structure of Jupiter. The abundance of PH₃ which results from a comparison of Jovian and laboratory spectra is about 3 to 5 cm-am. This is five to eight times less than that found by Larson et al. [Astrophys. J. (1977) 211, 972–979] in the same spectral region, but is in good agreement with the result of Tokunaga et al. [Astrophys. J. (1979) 232, 603–615] from 10-μm observations.  相似文献   

Coalification and thermal histories of Tertiary basins in relation to late Alpidic evolution of the Eastern Alps     

Dr. Reinhard F. Sachsenhofer 《International Journal of Earth Sciences》1992,81(2):291-308

The thermal histories of Tertiary basins situated around and within the Eastern Alps are examined using coalification data.Waples' method is used to estimate paleogeothermal conditions. The data suggest that the basins' thermal histories are intimately related to late Alpidic geodynamics of the Eastern Alps.Basins situated near the thrust front (Eastern Alpine foredeep, Vienna basin) are characterized by hypothermal histories and low coalification gradients. This is a consequence of relatively thick crust, high paleosedimentation rates in the Alpine foredeep, and Oligocene to Early Miocene stacking of cool sediments along the southern margin of the Eastern Alpine foredeep. Extension in the Vienna basin region is restricted mainly to shallow crustal levels and did not change the thermal pattern beneath the Alpine nappes. Major hyperthermal events of Oligocene age and local coalification maxima in the central Slovenian basin date from magmatic activity along the Periadriatic lineament, caused by Oligocene subduction. In Miocene times subduction migrated eastward and magmatic activity shifted to the northern Slovenian and Styrian basins, resulting in a strong hyperthermal phase of Ottnangian to Lower Badenian age in these basins.Rapid uplift of the Tauern window in the central part of the Eastern Alps, due to buoyancy, is related to E-W directed crustal stretching and resulted in raised heat flow in Miocene times in the Tauern window region, and in relatively high rank in adjacent Tertiary basins (Wagrain, Tamsweg).Present geothermal patterns are controlled primarily by raised heat flow along the south-eastern margin of the Alps, a consequence of thinned crust beneath the Pannonian basin.

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Zusammenfassung Die Inkohlungsbilder von tertiären Sedimentbecken, die im Bereich der Ostalpen situiert sind, werden hinsichtlich der thermischen Geschichte diskutiert. In einigen Becken erfolgt eine Abschätzung der paläogeothermischen Verhältnisse mit Hilfe derWaples-Methode. Die Inkohlungsbilder der Tertiärbecken belegen eine enge Beziehung zwischen der thermischen Geschichte dieser Becken und der jungalpidischen Geodynamik der Ostalpen.In der Nähe der Überschiebungsfront gelegene Becken (Molassebecken, Wiener Becken) werden durch hypothermische Verhältnisse und geringe Inkohlung charakterisiert. Dies ist eine Folge relativ dicker Kruste, hoher Paläo-Sedimentationsraten in der alpinen Vortiefe und des Übereinanderstapelns kühler Sedimente am Südrand des Molassebeckens während Oligozän und frühem Miozän. Die Extension im Wiener Becken war auf den obersten Krustenabschnitt beschränkt und hat die thermischen Verhältnisse unterhalb der alpinen Decken nicht beeinflußt.Die magmatische Aktivität entlang der Periadriatischen Naht steht in Zusammenhang mit der oligozänen Subduktion und ist für hyperthermische Ereignisse und lokale Inkohlungsmaxima in oligozänen Sedimenten des zentralen Slowenischen Beckens verantwortlich. Im Miozän wanderte die Subduktion ostwärts und die magmatische Aktivität verlagerte sich in das nördliche Slowenische und Steirische Becken. Dadurch wurde in diesen Becken eine starke hyperthermische Phase während Ottnang bis Unterbaden initiiert.Der rasche isostatische Aufstieg des Tauernfensters in den zentralen Ostalpen steht mit miozäner, E-W gerichteter Dehnungstektonik in Zusammenhang. Er ist für erhöhten Wärmefluß im Miozän im Bereich des Tauernfensters und für die relativ hohe Inkohlung des Wagrainer und Tamsweger Beckens verantwortlich.Die heutigen geothermischen Verhältnisse werden vor allem durch erhöhten Wärmefluß am Südostrand der Alpen geprägt. Dieser ist eine Folge der Krustenausdünnung unter dem Pannonischen Becken.

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Résumé La houillification des bassins sédimentaires tertiaires des Alpes orientales est discutée dans la perspective de leur histoire thermique. Les conditions paléogéothermiques sont estimées au moyen de la méthode deWaples. L'étude de la houillification de ces bassins montre une relation étroite entre leur histoire thermique et la géodynamique des Alpes orientales à la fin du Tertiaire.Ces bassins, situés à proximité du front de charriage — il sagit du Bassin molassique et du Bassin viennois —, se caractérisent par leur condition «hypothermique» et leur faible gradient de houillification; cette propriété provient de l'épaississement de la croute terrestre due à une sédimentation rapide en avant des Alpes et à l'empilement tectonique des sédiments froids les uns sur les autres le long de la bordure méridionale du Bassin molassique au cours de l'Oligocène et du Miocène inférieur. L'extension, dans la région du Bassin viennois, s'est limitée à un niveau crustal peu profond et n'a pas influencé la situation thermique dans les nappes alpines.L'activité magmatique le long du linéament périadriatique, due à la subduction oligocène, est contemporaine des événements «hyperthermiques» et des maxima locaux de houillification dans les sédiments oligocènes du bassin central de Slovénie.Pendant le Miocène, la subduction progressa vers l'est et l'activité magmatique se déplaça vers les bassins de Slovénie septentrionale et de Styrie, avec comme conséquence, dans ces bassins, une phase «hyperthermique» marquée à l'Ottnangien et au Badenien inférieur.La montée isostatique rapide de la Fenêtre des Tauern dans la partie centrale des Alpes orientales est en relation avec l'extension tectonique est-ouest au Miocène; elle est responsable d'un flux thermique élevé dans la région de la Fenêtre et d'une houillification relativement importante dans les bassins tertiaires adjacents de Wagrain et de Tamsweg.La géothermie actuelle de la bordure sud-est des Alpes est régie par un flux thermique élevé, conséquence de l'amincissement crustal sous le bassin Pannonique.

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Guest Editors’ Foreword     

Miran Veselič  Heinz Hoetzl  Božidar Biondič  Jože Pezdič 《Environmental Geology》2006,49(6):795-795

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