Rapid and efficient geological mapping     

T.J.G. Francis 《Marine Policy》1985,9(3):237-242

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V792 Her=HD 155638: A totally eclipsing RS CVn binary     

Charles H. Nelson  Douglas S. Hall  Francis C. Fekel  Robert E. Fried  Richard E. Lines  Helen C. Lines 《Astrophysics and Space Science》1991,182(1):1-17

Photometry of HD 155638=V792 Her has been analyzed to determine the elements of this totally eclipsing RS CVn binary. The light variation outside eclipse was found to have a period of 27^d.07±0^d.07, which is slightly different from the 27^d.5384±0^d.0045 orbital period. Analysis of the eclipses was achieved by a modification of the Russell-Merrill technique. With the aid of radial velocity measures, absolute elements were obtained for the hot and cool stars, respectively;R _h=2.58R ,R _c=12.28R ,M _h=1.40M ,M _c=1.46M ,i=80^o.61 and velocity semi-amplitudesK _c=48.36 km s^–1±0.79 km s^–1, andK _h=50.50 km s^–1±0.33 km s^–1. The apparent magnitudes areV _h=9 ^m .73 andV _c=8 ^m .48. The distance to HD 155638 was estimated to be 310 parsecs.  相似文献   

Georadiochemical evidence to weathering of mining residues of the Mansfeld mining district,Germany   总被引：1，自引：0，他引：1  

N. Müller  K. Franke  P. Schreck  D. Hirsch  H. Kupsch 《Environmental Geology》2008,54(4):869-877

Mining heaps are used as archives for the investigation of weathering processes. Aim of this work was to investigate the different weathering behavior of heap materials derived from Kupferschiefer mining with respect to environmental hazard. For this purpose, Kupferschiefer and slag material of two heaps of different age were examined regarding to the radionuclide distribution and geochemical composition. By measuring of the local dose rate, performing digital autoradiography and gamma spectrometry the radiological load of the heaps and the heap materials was determined. The geochemical characterization of the samples was performed by XRF, ICP–OES and ICP–MS. The results show a clear higher radionuclide load of the younger slag heap. A depletion of chalcophile and lithophile elements in the older slag was determined. Apart from a homogeneous radionuclide distribution, considerable radionuclide enrichments in fossil fragments could be proven. The results reveal a different weathering behavior of slag material in comparison to the Kupferschiefer depending on the chemical binding of the elements on organic and inorganic species. Natural organic matter as well as apatite in Kupferschiefer act as retention barrier for some metals.  相似文献   

Controls on porphyroblast size along a regional metamorphic field gradient     

David M. Hirsch 《Contributions to Mineralogy and Petrology》2008,155(4):401-415

Garnet-bearing schists from the Waterville Formation of south-central Maine provide an opportunity to examine the factors governing porphyroblast size over a range of metamorphic grade. Three-dimensional sizes and locations for all garnet porphyroblasts were determined for three samples along the metamorphic field gradient spanning lowest garnet through sillimanite grade, using high-resolution X-ray computed tomography. Comparison of crystal size distributions to previous data sets obtained by stereological methods for the same samples reveals significant differences in mode, mean, and shape of the distributions. Quantitative textural analysis shows that the garnets in each rock crystallized in a diffusion-controlled nucleation and growth regime. In contrast to the typical observation of a correlation between porphyroblast size and position along a metamorphic field gradient, porphyroblast size of the lowest-grade specimen is intermediate between the high- and middle-grade specimens’ sizes. Mean porphyroblast size does not correlate with peak temperatures from garnet-biotite Fe-Mg exchange thermometry, nor is post-crystallization annealing (Ostwald Ripening) required to produce the observed textures, as was previously proposed for these rocks. Robust pseudosection calculations fail to reproduce the observed garnet core compositions for two specimens, suggesting that these calc-pelites experienced metasomatism. For each of these two specimens, Monte Carlo calculations suggest potential pre-metasomatism bulk compositions that replicate garnet core compositions. Pseudosection analyses allow the estimation of the critical temperatures for garnet growth: ∼481, ∼477, and ∼485°C for the lowest-garnet-zone, middle-garnet-zone, and sillimanite-zone specimens, respectively. Porphyroblast size appears to be determined in this case by a combination of the heating rate during garnet crystallization, the critical temperature for the garnet-forming reaction and the kinetics of nucleation. Numerical simulations of thermally accelerated, diffusion-controlled nucleation, and growth for the three samples closely match measured crystal size distributions. These observations and simulations suggest that previous hypotheses linking the garnet size primarily to the temperature at the onset of porphyroblast nucleation can only partially explain the observed textures. Also important in determining porphyroblast size are the heating rate and the distribution of favorable nucleation sites.  相似文献   

Genetic history of the population of Atlantic salmon, Salmo salar L., under restoration in the Connecticut River, USA     

Ayllon  Fernando; Martinez  Jose L.; Juanes  Francis; Gephard  Stephen; Garcia-Vazquez  Eva 《ICES Journal of Marine Science》2006,63(7):1286-1289

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Metabolism of perylene by monooxygenases of the skin and liver of Ambystoma tigrinum     

Robert S Anderson  Marilyn A Angel  Francis L Rose 《Marine environmental research》1988,24(1-4)

The prevalence of dermal neoplasia among neotenic tiger salamanders (Ambystoma tigrinum) collected from the Reese Air Force Base sewage lagoon far exceeded that among salamanders from nearby uncontaminated lagoons. Perylene was the predominant pglycyclic aromatic hydrocarbon contaminant in this lagoon. Perylene was shown to be a substrate for monooxygenases in skin and liver homogenates and formed DNA-binding metabolites. Perylene exposure appeared to augment subsequent perylene metabolism by dermal enzymes but it was not a strong inducer of hepatic monooxygenases. Aroclor 1254 induced benzo(a)pyrene and perylene metabolism by both skin and liver enzymes. However, perylene apparently was not activated by salamander enzymes, as suggested by its lack of in vitro mutagenicity and failure to induce tumors.  相似文献   

Determination de l'Age par la Lecture des Otolithes chez deuxEspeces de Sciaenides Ouest-Africains: (Pseudotolithus senegalensis C. V. et Pseudotolithus typus Blkr.)     

Troadec  Francis Poinsard et Jean-Paul 《ICES Journal of Marine Science》1966,30(3):291-307

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Effects of crustacean traps on benthic fauna     

Eno  N. Clare; MacDonald  David S.; Kinnear  Jim A. M.; Amos  S. Chris; Chapman  Colin J.; Clark  Robin A.; Bunker  Francis St P.D.; Munro  Colin 《ICES Journal of Marine Science》2001,58(1):11-20

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Hydrodynamic optimization of ship hull forms     

Scott Percival  Dane Hendrix  Francis Noblesse   《Applied Ocean Research》2001,23(6):1429

An extremely simple CFD tool is used to compare the calm-water drags of a series of hull forms and to define ‘optimized’ monohull ships for which the total (friction+wave) calm-water drag is minimized. The friction drag is estimated using the classical ITTC formula. The wave drag is predicted using the zeroth-order slender-ship approximation. Comparisons of theoretical predictions and experimental measurements for a series of eight hull forms show that—despite the extreme simplicity of the method that is used here to estimate the friction drag and the wave drag—the method is able to rank the drags of a series of hull forms roughly in accordance with experimental measurements. Thus, the method may be used, with appropriate caution, as a practical hull form design and optimization tool. For purposes of illustration, optimized hull forms that have the same displacement and waterplane transverse moment of inertia as the classical Wigley hull, taken as initial hull in the optimization process, are determined for three speeds and for a speed range.  相似文献   

A daily egg production method estimate of snapper biomass in Hauraki Gulf, New Zealand   总被引：2，自引：0，他引：2  

Zeldis  J. R.; Francis  R. I. C. C. 《ICES Journal of Marine Science》1998,55(3):522-534

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