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41.
Lucien Jeanmaire Michel Masson Francois Patti Pierre Germain Liliane Cappellini 《Marine pollution bulletin》1981,12(1):29-32
Analyses for 99Tc in some marine biological samples taken near the outlet of the low level radioactive effluent pipeline of the nuclear reprocessing plant of La Hague, France, gave positive results. From 500 to 3500 pCi kg?1 wet weight of 99Tc were observed in brown algae; Fucus sp. appeared to be a good indicator of this long-lived radionuclide in a marine environment. 相似文献
42.
Jean-Yves Boisson Lucien Bertrand Jean-François Heitz Yann Golvan 《Hydrogeology Journal》2001,9(1):108-123
In the context of a research and development program on waste disposal, an experimental site (Tournemire tunnel, Aveyron,
France) was selected by the French Institute for Nuclear Protection and Safety (IPSN) in order to undertake studies on potential
fluid flow at different scales of space and time within a 250-m-thick argillaceous formation. The argillite has a low natural
water content (~3–5%) and very low radii access porosity. Diffusion (tritiated water) coefficients (1×10–12 to 2×10–11 m2/s) and hydraulic conductivities derived from different types of laboratory tests (10–14 to 10–13 m/s) are characteristics of a very low-permeable rock. In situ hydraulic tests (including long-term hydraulic-head measurements)
were used to obtain values for hydraulic head and hydraulic conductivity at a scale of 1–10 m (10–13 to 10–11 m/s). Despite uncertainties on these data (due to a scale factor, presence of fissures, and possible artefacts due to hydro-chemo-mechanical
coupling), it is expected that fluid flow is essentially governed by diffusion processes. Identification of possible natural
flows at larger scales of time and space was investigated using natural isotopic tracers from interstitial fluids. Modelling,
based on the deuterium profile along the clay formation and assuming pure diffusion processes, provides estimations of possible
flow times. However, lack of knowledge concerning the past geological evolution of the site and the possible role of a fracture
network do not permit reduction of uncertainties on these estimations at this stage.
Electronic Publication 相似文献
43.
Lucien Brush 《Coastal Engineering》1986,10(4)
44.
Lucien Leclaire Yannis Bassias Micheline Denis-Clocchiatti Hugh Davies Isabelle Gautier Bernard Gensous Pierre-Jean Giannesini Philippe Patriat Jacques Segoufin Michel Tesson Jacques Wannesson 《Geo-Marine Letters》1987,7(4):169-176
Geological samples from the southern Kerguelen Plateau include Lower Cretaceous basalt and lava breccia, probable Lower Cretaceous conglomerate and shelf limestone, Upper Cretaceous chert with dolomite, Upper Cretaceous-Eocene ooze, and Tertiary conglomerate. Neogene sediments are only a few hundred m thick, and include foraminiferal and diatomaceous ooze, and ice-rafted debris. In conjunction with seismic reflection profiles, the samples indicate Early Cretaceous near-shore volcanism, followed by erosion, sedimentation, and subsidence through Cretaceous; arching of the plateau at the end of Cretaceous; subsidence through Paleogene; widespread emergence in mid-Tertiary; and slow subsidence through Neogene. 相似文献
45.
Andreas Krein Holger Klinck Michael Eiden Wolfhard Symader Reinhard Bierl Lucien Hoffmann Laurent Pfister 《地球表面变化过程与地形》2008,33(1):152-163
This article deals with the following two questions. Are acoustic measurements in running waters appropriate for a highly resolved investigation of the bedload transport? Which characterizations of the bedload regarding mass and shape are possible via the acoustic signals? The signals were recorded by means of data recorders (Tascam Inc. DAP1 Portable Data Recorder) and hydrophones (International Transducer Corp. ITC‐4001 A). The ITC‐4001 is a shallow water omnidirectional transducer containing a flexural disc transducer utilizing Channelite‐5400 ceramics mounted in a rugged corrosion‐resistant housing. These hydrophones were screwed onto the bottom side of stainless steel plates, serving as a contact surface for the bedload in motion above them. After more than 100 series of tests in the laboratory, which indicated the basic relations between the dimension, shape and weight of the bedload and the resulting signal, field tests of the measuring system were conducted. By artificially produced flood waves in the small brooks Riverisbach, Olewiger Bach and by a winter flood wave in the River Moselle, it is possible to elaborate similar structures of the signal course of the bedload movement. The highest transport rates can be observed at the beginning of the increasing limbs and behind the peaks of the waves. At the beginning of the waves, the increasing transport power of the water and the loose material can be considered as the cause for this result. The high stream velocity behind the wave peaks explains the increase in the bedload transport so that material from the channel beds is unfastened and will be mobilized. The characterization of the bedload regarding the shape and mass is still limited regarding the field measurements and could be solved only for homogeneous grain sizes and single stones under laboratory conditions. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
46.
The daily solar radio flux values at 9400, 3750, 2000 and 1000 MHz and at 2800 MHz observed since 1957 at Toyokawa and Ottawa, respectively, have been used to provide new information on the solar radio fluxes as indices of solar activity. After an examination of the yearly mean values at each frequency, another investigation based on mean ratios during periods of 18 or 6 months indicates that a close connection is observed between the radio fluxes in the cm region and that anomalies related to calibration problems can be detected. The regression analysis of the daily values of the fluxes during at least 25 years and a special test on the sensitivity may provide final information on the stability of the data with respect to time and solar activity. The method is capable of detecting long-term trends corresponding to instrumental drifts. Such information is essential to our understanding of anomalies detected in the observations of u.v. and X-ray irradiances. However, such a method is based on a linear relationship. When a quadratic form, as it is observed in the decimeter region, is adopted, the effect of the various levels of activity in a solar cycle must be considered. 相似文献
47.
Lucien Bossy 《Planetary and Space Science》1983,31(9):977-985
Solar radio fluxes, Zurich relative sunspot number Rz, and Solar Call plage indexes daily values for the period 1957–1980 are analyzed in order to test the stability of the series with respect to time and solar activity. It is found that between the series of the 3,8 and 10 cm radio fluxes and the series of Rz no significant trend with time, solar activity or solar cycle exists when mean values for periods of the order of one year are considered.Then, the daily solar u.v.-irradiances measured since 1969 for H-Lyman-alpha and-beta, the Hel-resonance line and HeII-Lyman-alpha are compared with the 10.7 cm radio fluxes and adjusted. After adjustment, the behaviour of the four series of irradiances with respect to the 10.7 cm flux shows a similar structure as the behaviour typical for the series of the 3 cm or the 8 cm fluxes.This adjustment allows the determination of the slope of the mean variation of the u.v.-irradiances with solar activity. The increases from solar minimum to solar maximum related to the minimum values are respectively : 60% for H-Lyman-alpha, 80% for H-Lyman-beta and 90% for Hel and Hell. 相似文献
48.
Istvan Bogardi Lucien Duckstein Antal Schmieder Ferenc Szidarovszky 《Advances in water resources》1980,3(1):3-8
An event-based stochastic forecasting approach is used to model water inrushes into underground works under karstic water hazard. The stochastic properties of inrushes are related to the statistical properties of fissures in the karstic rock. The probability distributions (DF) of five random variables of interest in design are estimated; namely, inrush yield q, number N of inrushes per unit area, distance L between inrushes, maximum qmax in N events and total yield Q. The phenomenological hypotheses of log normal DF of q and Poisson DF of N are reinforced by observation data. On the basis of these DF, a Monte Carlo simulation of a spatial Poisson process of inrushes is run to estimate the DF of qmax and Q. The derivation of Bayesian DF to account for parameter uncertainty is discussed. The stochastic model is used for design and operation of minewater control facilities in the Transdanubian karstic region of Hungary. 相似文献
49.
Yan Chen Bernard Henry Michel Faure Jean-François Becq-Giraudon Jean-Yves Talbot Lucien Daly Maxime Le Goff 《International Journal of Earth Sciences》2006,95(2):306-317
In order to assess the structural evolution of the Brive basin and the Paleozoic activity of surrounding major faults in the French Massif Central, we carried out a paleomagnetic study on Early Permian rocks from this basin. Positive-fold tests and solely reversed polarities indicate that the characteristic remanent magnetization is likely to be primary. Early Permian tilt-corrected site mean declinations vary from 207°–167° indicating that the Brive basin experienced internal vertical-axis rotations. On the contrary, Late Permian paleomagnetic site means exhibit a circular Fisherian distribution showing no relative rotations. Detailed analyses of Permian paleomagnetic data from five contemporaneous basins of the French Massif Central reveal that these basins share the same equatorial paleolatitude with stable Europe throughout the Permian. However, in Early Permian, three of the five basins experienced differential rotations. The Saint-Affrique basin not only suffered internal deformation during the Early Permian, but the basin as a whole underwent a full-scale counterclockwise vertical-axis block rotation with respect to stable Europe. As a consequence, paleomagnetic data from similar late orogenic basins have to be thus carefully considered for establishment of Apparent Polar Wander paths. 相似文献