1973 supplement to exploration geochemistry bibliography     

H.E. Hawkes  F.C. Canney  P.R. Donovan  G.H. Friedrich  C.F. Gleeson  M.B. Mehrtens  P. Lowenstein 《Journal of Geochemical Exploration》1974,3(1):89-128

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Surface features on glass spherules from the Luna 16 sample     

Jack B. Hartung  Friedrich Hörz  David S. McKay  Frank L. Baiamonte 《Earth, Moon, and Planets》1972,5(3-4):436-446

Two ellipsoidal spherules approximately 0.5 mm in diameter were studied in detail using a scanning electron microscope. A variety of surface features were observed: vesicles, mounds, dimples, streaks, ridges, grooves, accretion phenomena, and high-speed impact craters. The diameters of 27 glass-lined pits formed by impact on one spherule range from less than 1m to approximately 50m. Intermediate-sized glass-lined pits surrounded by concentric fractures demonstrate the transition between larger craters that have both a pit and a spall zone and generally smaller craters that have only a pit. Assuming all craters showing evidence of impact-related melting or flow are the result of primary impacts, the differential mass spectrum of impacting meteoroids in the range 10^–11 to 10^–10 g is in good agreement with a spectrum based on satellite-borne particle-detecting experiments.  相似文献   

Elektronenstrahl-Mikroanalyse des Meteoriten von Steinbach     

Gerhard Dörfler  Friedrich Hecht  Erwin Plöckinger 《Mineralogy and Petrology》1965,10(1-4):413-429

Zusammenfassung Eine uns vom Naturhistorischen Museum in Wien freundlicherweise zur Verfügung gestellte Probe des Meteoriten von Steinbach wurde mit einem Elektronenstrahl-Mikroanalysator vom Typ CAMECA qualitativ und quantitativ auf die chemische Zusammensetzung der einzelnen Phasen untersucht.Besonders eingehend wurde dabei die Metallphase analysiert, da diese sich durch die Anwesenheit einer gut ausgebildeten Widmanstättenschen Struktur in Gegenwart von Tridymit als Druckindikator auszeichnet.Die nichtmetallischen Phasen wurden ebenfalls quantitativ bestimmt und ergeben leicht abweichende Ergebnisse von den Analysen vonN. Story-Maskelyne, O. Winkler undF. Heide. Interessant sind vor allem der relativ hohe Mangangehalt in Bronzit und Chromit sowie der Chromgehalt des Troilits.Die Anwendung der neuen Berechnungen über die Abkühlungsgeschichte der Meteoritenmutterkörper vonWood auf unsere quantitativen Analysen ergab eine Abkühlungsgeschwindigkeit von 10°/Million Jahre, was einem Mutterkörper von ca. 50–90 km Durchmesser und einem Zentraldruck von 200 b entspricht.

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Summary A sample of the meteorite of Steinbach, made available by the Naturhistorisches Museum at Vienna, has been analyzed qualitatively and quantitatively by a CAMECA electron-beam microanalyzer.Detailed examination has been made on the structure of the metal phase, as the presence of a well-grown Widmanstätten-structure in contact with trydimite as a pressure-indicator is a direct proof for the formation of the Widmanstätten-structure without pressure.The nonmetallic phases have been analyzed quantitatively and the results are slightly different from those ofStory-Maskelyne, Winkler andHeide. Very interesting is the relatively high content of manganese in bronzite and chromite, also the chromium content of troilite.The application of the new computations ofWood, dealing with the cooling history of meteorite-parentbodies to our quantitative analyses indicate a cooling rate of 10° C/Million years, according to a parentbody of appr. 50–90 km diameter and a central pressure of appr. 200 b.

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Herrn Professor Dr.F. Machatschki zum 70. Geburtstag gewidmet.  相似文献   

Laboratory studies for beam plasma discharge experiments with rockets     

S.B. Lyakhov  A.D. Maiorov  G.G. Managadze  O.A. Povalyaev  A.I. Chmil  L.Yu. Kochmarev  E.G. Shustin  M.F. Friedrich  W.K. Riedler  A.N. Laliashvili  A. Kiraga  Z. Kłoss  Z. Kravchic  N.A. Leonov 《Planetary and Space Science》1982,30(4):347-357

Laboratory results of beam plasma discharge (BPD) (dimensions several metres) in a homogeneous atmosphere and a jet of neutral gas are presented. The beam was obtained by an electron gun of the same type as used in rocket experiments.The BPD parameters glow intensity, electromagnetic field and its spectrum, electron density as well as the flux of scattered electrons were measured. In addition, photographs of the BPD were taken. The threshold of BPD ignition was determined as a function of gas pressure and beam parameters. The initial stage of BPD formation as well as various types of oscillatory processes in the discharge were studied. A possible process of BPD initiation is presented.  相似文献   

Laudatio für Prof. Schreyer zur Verleihung der Steinmann-Medaille,Bochum, September 2003     

Friedrich?SeifertEmail author 《International Journal of Earth Sciences》2004,93(2):169-171

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Characterizing the severe turbulence environments associated with commercial aviation accidents. A real-time turbulence model (RTTM) designed for the operational prediction of hazardous aviation turbulence environments     

M. L. Kaplan  J. J. Charney  K. T. WaightIII  K. M. Lux  J. D. Cetola  A. W. Huffman  A. J. Riordan  S. D. Slusser  M. T. Kiefer  P. S. Suffern  Y.-L. Lin 《Meteorology and Atmospheric Physics》2006,94(1-4):235-270

Summary In this paper, we will focus on the real-time prediction of environments that are predisposed to producing moderate-severe (hazardous) aviation turbulence. We will describe the numerical model and its postprocessing system that is designed for said prediction of environments predisposed to severe aviation turbulence as well as presenting numerous examples of its utility. The purpose of this paper is to demonstrate that simple hydrostatic precursor circulations organize regions of preferred wave breaking and turbulence at the nonhydrostatic scales of motion. This will be demonstrated with a hydrostatic numerical modeling system, which can be run in real time on a very inexpensive university computer workstation employing simple forecast indices. The forecast system is designed to efficiently support forecasters who are directing research aircraft to measure the environment immediately surrounding turbulence. The numerical model is MASS version 5.13, which is integrated over three different grid matrices in real-time on a university workstation in support of NASA-Langley’s B-757 turbulence research flight missions. The model horizontal resolutions are 60, 30, and 15 km and the grids are centered over the region of operational NASA-Langley B-757 turbulence flight missions. The postprocessing system includes several turbulence-related products including four turbulence forecasting indices, winds, streamlines, turbulence kinetic energy, and Richardson numbers. Additionally there are convective products including precipitation, cloud height, cloud mass fluxes, lifted index, and K-index. Furthermore, soundings, sounding parameters, and Froude number plots are also provided. The horizontal cross section plot products are provided from 16,000–46,000 feet in 2,000 feet intervals. Products are available every three hours at the 60 and 30 km grid interval and every 1.5 hours at the 15 km grid interval. The model is initialized from the NWS ETA analyses and integrated two times a day.  相似文献   

Global Monsoon across timescales     

Pinxian Wang  Bin Wang  Thorsten Kiefer 《Climate Dynamics》2012,39(5):1043-1044

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Variations in stratigraphic and reservoir properties adjacent to the Mid-Paleocene sequence boundary, Campo section, Pyrenees, Spain     

A.-C. da Silva  C. Loisy  A. Cerepi  R. Toullec  E. Kiefer  L. Humbert  P. Razin 《Sedimentary Geology》2009,219(1-4):237-251

The Paleocene of the Campo section, Spain has different sedimentological characteristics above and below the Mid-Paleocene Unconformity. Beneath the unconformity sediments are dominated by evaporitic carbonates and collapse breccias. Above it they are characterized by continental detrital beds alternating with paleosols. Different subaerial features are observed and correspond to different porosity values, pore–throat sizes and micrite morphologies. Unexposed or intertidal facies have low porosity, low throat–pore size (mesoporosity) and well preserved rhombic crystals. Intermediate exposed facies (paleosols) possess medium porosity, medium pore–throat size (microporosity) and mainly micro-rhombic crystals. Finally, the facies corresponding to high exposure intensity and to evaporitic original facies presents high porosity, permeability, large pore–throat size and rounded micritic crystals. These observations show that the emersion phase caused important dissolution, especially when associated with an easily dissolved original lithofacies.  相似文献   

APEX and ATCA observations of the southern hot core G327.3-0.6 and its environs     

Friedrich Wyrowski  Per Bergman  Karl Menten  Jürgen Ott  Peter Schilke  Sven Thorwirth 《Astrophysics and Space Science》2008,313(1-3):69-72

There is no generally accepted evolutionary scheme for high mass star formation yet. A simple approach to address this problem is to cover several of the known stages during the formation of massive stars in the same cloud and then investigate their properties trying to construct an evolutionary sequence. Here we present such a project conducted with complementary APEX and ATCA observations. These observations show a compact and bright single hot core in the G327.3-0.6 region on a 0.03 pc scale with a mass of 500 M_⊙ and 0.5–1.5 10⁵ L_⊙. Additionally a clumpy filament is seen in N₂H⁺. Together with cm continuum observations, the data reveal like pearls on a string several stages of massive star formation, with likely the youngest stages hiding in the cold N₂H⁺ cores analysed with a multilevel study of the APEX and ATCA observations.  相似文献   

Experimental impacts into chondritic targets,part I: Disruption of an L6 chondrite by multiple impacts     

Mark J. CINTALA  Friedrich HöRZ 《Meteoritics & planetary science》2008,43(4):771-803

Abstract— A fragment of an L6 chondrite (Allan Hills [ALH] 85017,13) with an initial mass (M₀) of 464.1 g was the target in a series of experimental impacts in which the largest remaining fragment (M_R) after each shot was impacted by a 3.18 mm ceramic sphere at a nominal speed of 2 km s^?1. This continued until the mass of the largest remaining piece was less than half the mass of the target presented to that shot (M_S). Two chunks of Bushveldt gabbro with similar initial masses were also impacted under the same conditions until M_R was less than half M₀. The two gabbro targets required a total of 1.51 × 10⁷ and 1.75 × 10⁷ erg g^?1 to attain 0.27 and 0.33 M_R/M₀, respectively; the chondrite, however, was considerably tougher, reaching 0.40 and 0.21 M_R/M₀ only after receiving 2.37 × 10⁷ and 3.10 × 10⁷ erg g^?1, respectively. The combined ejecta and spallation products from the gabbro impacts were coarser than those from the chondrite and in sufficient quantities that the new surface areas exceeded those from the meteorite until the fifth shot in the chondrite series, which was the number of impacts required to disrupt each gabbro target (i.e., M_R/M₀ ≤ 0.5). Unlike the behavior shown in previous regolith‐evolution series, neither gabbro target produced an enhancement in the size fraction reflecting the mean size of the crystals composing the rock (about 3 mm), an effect possibly related to the width of the shock pulse. The original chondrite was so fine‐grained and fractured, and the variance in its grain‐size distribution so large, that effects related to grain size were relegated to the<63 μm fraction. Impacts into ALH 85017 produced abundant, fine‐grained debris, but otherwise the slopes of its size distributions were comparable to those from other experiments involving natural and fabricated terrestrial targets. The characteristic slopes of the chondrite's size distributions, however, were notably more constant over the entire nine‐impact series than those from any of the terrestrial targets, a testament to the control over comminution apparently exerted by pre‐existing fractures and other, microscopic damage in the meteorite. The enhancement in the finer fraction of debris from ALH 85017 indicates that ordinary chondrites in solar orbit would be very efficient contributors to the cosmic‐dust complex. At the same time, the greater resistance to disruption displayed by ordinary chondrites relative to that exhibited by igneous rocks indicates that a selection effect could be operative between the annealed, ordinary‐chondritic breccias and relatively weaker, differentiated meteorites. Preferential survival from their time in the regoliths of their parent bodies through their transit to Earth and passage through the atmosphere suggests that meteorite collections could be biased in favor of the ordinary chondrites.  相似文献