Chlorinated hydrocarbons in fish-eating birds wintering in the Gdańsk Bay, 1981–82 and 1982–83     

Jerzy Falandysz  Piotr Szefer 《Marine pollution bulletin》1984,15(8):298-301

Seventy-four samples of adipose fat of 10 species of fisheating birds commonly wintering in Gdańsk Bay and one of little auk, a rare species in this area, have been analysed for residues of HCB, ΣBHC, ΣDDT and PCBs. Auks (guillemot, black guillemot and razorbill), which probably stay a whole year in the Baltic area, contained in their fat twice the level of PCBs as mergansers, and 5–6 times as much as in divers and grebes—birds which stay in the sea mainly after the breeding season. ΣDDT levels were somewhat higher but comparable in auks and grebes, and lower in mergansers and divers. ΣBHC and HCB levels were 3–4 times and 5–10 times higher, respectively, in auks than in birds from other families studied. When comparing residue levels found in adipose fat of birds taken during the wintering seasons of 1981–1982 and 1982–1983 with those taken in 1975–1976 or 1980–1981, an initially rapid, but in recent years a rather slow decline in ΣDDT level is detectable for grebes, mergansers and divers, and in the case of PCBs the residue levels fell slightly. In auks, the ΣDDT residue level fell by half, but remains rather stable in recent years, while there are only minor fluctuations in the residue level of PCBs.  相似文献   

Chlorinated hydrocarbons in fish-eating birds wintering in the Gdańsk Bay,Baltic Sea, 1980–1981     

Jerzy Falandysz  Piotr Szefer 《Marine pollution bulletin》1982,13(4):132-135

Further samples of the chlorinated hydrocarbon content in adipose tissue of fish-eating birds wintering in the South Baltic show high concentrations of PCB compared with ΣDDT, HCB, alpha- and gamma-BHC. The great crested grebe presently examined had approximately four times higher PCB/ΣDDT ratios than specimens taken during 1975–1976.  相似文献   

Isotope hydrological study of mean transit times in an alpine basin (Wimbachtal, Germany)     

Piotr Maloszewski  Werner Rauert  Peter Trimborn  Andreas Herrmann  Rolf Rau 《Journal of Hydrology》1992,140(1-4):343-360

Measurements of tritium and ¹⁸O concentrations in precipitation and runoff were used to provide further insight into the groundwater storage properties of the Wimbachtal Valley, a catchment area of 33.4 km², extending between 636 and 2713 m a.s.l. in the Berchtesgaden Alps. The catchment includes three aquifer types: a dominant porous aquifer; a fractured dolomite; a karstic limestone aquifer. Employing a simple hydrological model, information about mean transit times of environmental tracers is derived for the groundwater runoff component and several karst springs from the application of the exponential and dispersion flow models to the isotopic input and output data. The mean transit times calculated from a dispersion model with transit times of 4.1 years for ¹⁸O and 4.2 years for tritium, which agree well, allow calculation of total (mobile + stagnant) groundwater storage volume, which is equivalent to 6.6 m of water depth. Direct runoff appears negligible as in many other cases.  相似文献   

Some observations of bipolar flashes during summer thunderstorms near Warsaw     

Piotr Barański  Paweł Bodzak 《Acta Geophysica》2006,54(1):71-89

Lightning discharges monitored by the SAFIR network system in Poland have been additionally identified over the 100×100 km area near Warsaw by single-point independent recordings of electric field and Maxwell current rapid changes. The data collected in summer thunderstorm days of 2002 showed some untypical properties of the lightning discharges which are rarely observed. Especially remarkable was a number of ground multi-stroke flashes with the return strokes (RS) which transported to the earth charges of opposite signs. Bipolar flashes (BF) of this kind were mostly involved in the events in which the nearby intracloud (ic) and cloud-to-ground (c-g) discharges were very closely associated in time. Events of such a close collocation of two different types of lightning discharges, previously called the complex lightning discharge events (CLDE), were quite often observed during summer thunderstorms in Poland. The events of this kind, i.e. 8 flashes, identified by the SAFIR detection system as BF’s present the multiple stroke flashes of the mean horizontal separation distance between striking points of particular RS equal to (2.8 ± 2.1) km and of the mean time interval between strokes of (46.8 ± 74.4) ms. The time separation between the observed BF and the adjacent ic flashes was from 0.1 to 335 ms, and horizontal separation distance between them ranged from 1.8 to 14.5 km. The multiplicity of the recorded BF’s ranged from 2 to 4 strokes. Four of these BF’s followed the ic discharge, but the other three preceded the ic and one was alone with no close ic.  相似文献   

Solute Transport Processes in a Highly Permeable Fault Zone of Lindau Fractured Rock Test Site (Germany)   总被引：2，自引：0，他引：2  

Thomas Himmelsbach  Heinz Hbtzl  Piotr Maloszewski 《Ground water》1998,36(5):792-800

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An attempt to test Ambartsumian's idea of the origin of the galaxy . II. location of galaxies within clusters and galaxy position angles     

H. A. Harutynyan  Monica Biernacka  Piotr Flin 《Astrophysics》2010,53(1):42-49

The location of galaxies in 377 rich Abell galaxy clusters is discussed. We compared the distributions of galaxies in the sample containing all galaxies with the sample compiled from the 20 brightest objects. Counts in circular sectors with angle width equal to 30î show isotropy. Only in the case of BM I clusters and the coordinate system related to the cluster major axis did we find anisotropic distributions. We investigated also the distributions of galaxy position angles within clusters exhibiting isotropy. The structure position angles for both samples have been studied as well. They appeared to be different. The difference in location of galaxies in the case of cD clusters, as well as the more elliptical shape and different position angles of samples containing bright galaxies is observed.  相似文献   

HydroCube: an entity-relationship hydrogeological data model   总被引：1，自引：1，他引：0  

Piotr Wojda  Serge Brouyère  Johan Derouane  Alain Dassargues 《Hydrogeology Journal》2010,18(8):1953-1962

Managing, handling and accessing hydrogeological information depends heavily on the applied hydrogeological data models, which differ between institutions and countries. The effective dissemination of hydrogeological information requires the convergence of such models to make hydrogeological information accessible to multiple users such as universities, water suppliers, and administration and research organisations. Furthermore, because hydrogeological studies are complex, they require a wide variety of high-quality hydrogeological data with appropriate metadata in clearly designed and coherent structures. A need exists, therefore, to develop and implement hydrogeological data models that cover, as much as possible, the full hydrogeological domain. A new data model, called HydroCube, was developed for the Walloon Region in Belgium in 2005. The HydroCube model presents an innovative holistic project-based approach which covers a full set of hydrogeological concepts and features, allowing for effective hydrogeological project management. The model stores data relating to the project locality, hydrogeological equipment, and related observations and measurements. In particular, it focuses on specialized hydrogeological field experiments such as pumping and tracer tests. This logical data model uses entity-relationship diagrams and it has been implemented in the Microsoft Access environment. It has been enriched with a fully functional user interface.  相似文献   

Simulation of an uncertain emission market for greenhouse gases using agent-based methods     

Zbigniew Nahorski  Jarosław Stańczak  Piotr Pałka 《Climatic change》2014,124(3):647-662

The paper presents the problem of a simulation of the greenhouse gases emission permits market where only low accuracy emission amounts are known. An organization of the market with uncertain emissions is proposed and trading rules for individual market participants are discussed. Simulation of the market is based on a multi-agent system. Negotiation of purchase/sale prices between the parties are introduced, where the trading parties adopt one of two options: (i) bilateral negotiations, and (ii) sealed bid reverse auctions. Results of simulation runs show trajectories of transaction prices, as well as probability distributions of learning agents’ bidding prices.  相似文献   

Averaging spectral shapes     

Piotr Lubi&#;ski 《Monthly notices of the Royal Astronomical Society》2004,350(2):596-608

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The statistical effects of galactic tides on the Oort cloud     

Piotr A. Dybczyński  Halina Pretka 《Earth, Moon, and Planets》1996,72(1-3):13-18

This report is a comment on two papers by Matese and Whitman (1989, 1992). We discuss here the applicability of uniform probability densities for the orbital parameters of the Oort cloud comets.  相似文献