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21.
The Silesia–Cracow district in Poland has been one of the world’s principal sources of zinc from nonsulfide zinc ore (Polish: galman). The still remaining nonsulfide ore resources can be estimated at 57 Mt at 5.6% Zn and 1.4% Pb. Nonsulfide mineralization is mainly hosted by Lower Muschelkalk (Triassic) limestone and is associated with different generations of the hydrothermal ore-bearing dolomite (OBD I, II, III). A fundamental ore control is believed to have been exerted by the basement faults, which were repeatedly reactivated during the Alpine tectonic cycle, leading to the formation of horst-and-graben structures: these dislocations may have caused short periods of emersion and the circulation of meteoric waters during the Cenozoic. Nonsulfide ores show a wide range of morphological characteristics and textures. They occur as earthy masses, crystalline aggregates, and concretions in cavities. Breccia and replacement textures are also very common. The most important mineral phases are: smithsonite, Fe–smithsonite, Zn–dolomite, goethite, and Fe–Mn(hydr)oxides. Minor hemimorphite and hydrozincite have also been detected. Two distinct nonsulfide ore types occur: the predominant red galman and the rare white galman. In the white galman, Fe–smithsonite and Zn–dolomite are particularly abundant. This ore type is commonly considered as a peripheral hydrothermal alteration product related to the same fluids that precipitated both the OBD II–III and the sulfides. In contrast, a supergene origin is commonly assumed for the red galman. Evidence of the petrographic and mineralogical difference between white and red galman is also found in stable isotope data. Smithsonite from red galman shows a limited range of δ 13CVPDB values (−10.1 to −11.4‰), and δ 18OVSMOW values (25.3‰ to 28.5‰, mean 26.8 ± 0.3‰). The uniform and low carbon isotope values of red galman smithsonite are unusual for supergene carbonate-hosted deposits and indicate the predominance of a single organic carbon source. Smithsonite from white galman has a more variable, slightly more positive carbon isotope (−2.9‰ to −7.4‰), but broadly similar oxygen isotope composition (26.8‰ to 28.9‰). The relationship of the white galman ore with the hydrothermal system responsible for OBD II and sulfide generation is still uncertain. The most important paleoweathering events took place in both Lower and Upper Silesia during Late Cretaceous up to Paleogene and early Neogene time. During this period, several short-lasting emersions and intense weathering episodes facilitated the formation of sinkholes in the Triassic carbonate rocks and the oxidation of sulfide orebodies through percolating meteoric waters. These phenomena may have lasted until the Middle Miocene.  相似文献   
22.
Human activities in cities affect properties of urban soils. In particular, urban soils often contain high contents of harmful metals even in deeper horizons added to them from diverse sources over centuries of the city development. This is reflected in complex distribution of metals in bulk soils with depth and the complex metal fractionation, but the exact sources of the metals are difficult to identify. This is also the situation in soils from Wroclaw, one of the largest cities in Poland. Potentially harmful elements Pb, Cd and Hg were examined in six profiles located along the major communication route and compared to two non-urban soils profiles located close to the same route. In all of the urban profiles, Pb and Cd exceeded the element contents observed in non-urban profiles and showed an erratic distribution compared to the more predictable one in non-urban soils. The differences between urban and non-urban profiles were explained as the result of contamination coming from more pollution sources in the case of urban soils, the conclusion supported by Pb isotope analyses. In fact, Pb isotopes showed that the contamination sources in urban soils included leaded petrol, coal combustion, smelting and possibly old pre-industrial ore processing, whereas leaded petrol and pre-industrial lead were the only possible anthropogenic sources in non-urban soils. The comparison of Wrocöaw soils with those from cities of comparable size Kraków and Poznań show similar ranges of metal contents with implication that urban pollution oversteps diverse geogenic chemical background. On the other hand, the comparison with other European cities show large variability in metal contents and suggest that urban soils contamination is time integrated and reflects long-term industrial evolution of each country.  相似文献   
23.
Ray Riley  Maria Tkocz 《GeoJournal》1999,48(4):279-290
It is argued that the emphasis of much recent research into coalmining has been placed on international and national scale influences which affect coalfields as a whole; change at the intra-coalfield scale has received less attention. After providing a background to events in Poland during communism, attention focuses on developments since 1989, commencing with coalfield-wide influences. There follows an examination of the work of the state body Państwowa Agencja Węgla Kamiennego, which executes government policy at the local level, and whose membership is drawn from the coalfield region. This agency recommends the closure and amalgamation of mines, but otherwise rationalisation measures are left to the seven mining companies and the colliery managers. The restructuring which has been carried out is considered under five heads: organisational change within the collieries, employment, production and technical change, and ecological adjustment. While recognising the importance of the socioeconomic and political environment and geology, there is much evidence to suggest that intra-coalfield patterns are strongly determined by local decision-makers. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
24.
The 160 km long Sudetic Marginal Fault (SMF) of Middle Silesia, southwestern Poland, is a main Alpine fault oriented NW–SE. This paper provides evidence of possible neotectonic activity in front of the SMF. The data are based on three exposures in the Roztoka–Mokrzeszow Graben near the city of Swidnica. Morphotectonic evidence in front of the SMF is also examined. Two sets of extensional deformation features are exposed and analysed. The main one includes gently inclined normal faults and flexures, with displacements in the bedrock of at least several metres. Based on the Quaternary stratigraphy of the region, the age of deformation is most probably Lower Saalian (Upper Pleistocene). The trigger for the deformation was probably the re-reactivation of the SMF and other faults due to the advance of the Lower Saalian Scandinavian ice-sheet into the Sudetic Mountains. The secondary deformation system includes sub-vertical, often conjugate faults with displacements up to 0·5 m superimposed on former structures. Its dominant normal faulting mode suggests an extensional stress regime that apparently coincides with the post-glacial glacioisostatic rebound. © 1997 John Wiley & Sons, Ltd.  相似文献   
25.
In 1990 the Polish Geological Institute initiated geochemical mapping of the country aimed at determining the actual conditions of chemistry in the Earth's surficial environments (soils, water sediments, and surficial waters as well) and sea-floor deposits in the Polish economic sector of the Baltic Sea. The geochemical mapping on different scales covered the entire area of the country and selected more important urban agglomerations and industrial districts. Approximately 15,100 samples of soils, 16,200 samples of fresh water sediments, 14,600 samples of surface waters and 467 samples of marine deposits were collected and analysed. A list of geochemical atlases published by the Polish Geological Institute is presented. Investigation of the distribution of radionuclides (natural and artificial) has been done since 1992. Concentrations of U, Th, K, post-Chernobyl Cs and γ dose rate were measured. Approximately 20,000 points covering the whole country were measured. More detailed mappings were executed in the areas polluted by Cs.  相似文献   
26.
Abstract

Discharge in the Warta River in Poland has been analysed based on long series of measurements at the Gorzów Wielkopolski gauge station (covering the whole catchment area) and at Poznań (middle and upper catchment area), and the Note? River is characterized by the gauge station at Nowe Drezdenko. The annual mean discharge of the Warta River for the period 1981–2010 was equal to the average value for the last 163 years (209 m3 s-1), and there was no significant change in comparison with the ratio of runoff in the summer and winter half-years. In the driest region of Poland, the climate has been described on the basis of precipitation and air temperature. The annual mean precipitation for 1981–2010 (544 mm) in the Warta River catchment area was the same as that for the period 1848–2010. The precipitation has been increasing in spring and winter, and decreasing in summer. There is a positive and very significant correlation (r = 0.705) between the annual discharge and annual precipitation totals. The annual mean air temperature has risen by 0.6°C between the periods 1848–1980 and 1981–2010.
Editor D. Koutsoyiannis

Citation Ilnicki, P., Farat, R., Górecki, K., and Lewandowski, P., 2014. Impact of climatic change on river discharge in the driest region of Poland. Hydrological Sciences Journal, 59 (6), 1117–1134. http://dx.doi.org/10.1080/02626667.2013.831979  相似文献   
27.
This study focuses on the assessment of relationships between flow and macrozoobenthos structure that was performed in a reconnected oxbow lake located in the S?upia River floodplain (northern Poland). The lake was created during river straightening at the beginning of 20th century by cutting off the right‐bank meander. The oxbow restoration was performed to enhance the ecological viability of this water body and restore riverine wetland. In July 2000 the oxbow was connected with the river channel through PVC pipes which enabled free water movement. Macrozoobenthos sampling, as well as chemical analyses of water and hydrological measurements, took place both before and after the oxbow reconnection. Before the oxbow reconnection, the dominant species was Asellus aquaticus, whereas after the reconnection the structure of benthic species changed significantly. During the first year it was replaced by bivalves and Chironomidae larvae and then A. aquaticus. After the reconnection, macrozoobenthos mean density was 5‐fold higher and the mean wet biomass was 77‐fold higher than before the reconnection. The number of taxa increased from 4 before the oxbow reconnection to 17 during the first year after the performed works and 20 in the next year. We stated that the revitalization process of the reconnected oxbow lake has long‐term consequences for the benthic communities. The most significant feature of the oxbow reconnection is the qualitative and quantitative recolonization by riverine macrozoobenthos species. The performed restoration significantly improved ecological status of the oxbow lake by the increase in biodiversity and water quality.  相似文献   
28.
The development of soft‐sediment deformation structures in clastic sediments is now reasonably well‐understood but their development in various deltaic subenvironments is not. A sedimentological analysis of a Pleistocene (ca 13·1 to 15 10Be ka) Gilbert‐type glaciolacustine delta with gravity‐induced slides and slumps in the Mosty‐Danowo tunnel valley (north‐western Poland) provides more insight, because the various soft‐sediment deformation structures in these deposits were considered in the context of their specific deltaic subenvironment. The sediments show three main groups of soft‐sediment deformation structures in layers between undeformed sediments. The first group consists of deformed cross‐bedding (inclined, overturned, recumbent, complex and sheath folds), large‐scale folds (recumbent and sheath folds) and pillows forming plastic deformations. The second group comprises pillar structures (isolated and stress), clastic dykes with sand volcanoes and clastic megadykes as examples of water‐escape structures. The third group consists of faults (normal and reverse) and extensional fissures (small fissures and neptunian dykes). Some of the deformations developed shortly after deposition of the deformed sediment, other structures developed later. This development must be ascribed to hydroplastic movement in a quasi‐solid state, and due to fluidization and liquefaction of the rapidly deposited, water‐saturated deltaic sediments. The various types of deformations were triggered by: (i) a high sedimentation rate; (ii) erosion (by wave action or meltwater currents); and (iii) ice‐sheet loading and seasonal changes in the ablation rate. Analysis of these triggers, in combination with the deformational mechanisms, have resulted – on the basis of the spatial distribution of the various types of soft‐sediment deformation structures in the delta under study – in a model for the development of soft‐sediment deformation structures in the topsets, foresets and bottomsets of deltas. This analysis not only increases the understanding of the deformation processes in both modern and ancient deltaic settings but also helps to distinguish between the various subenvironments in ancient deltaic deposits.  相似文献   
29.
The paper summarises the history of human settlement in the Sudetes from the Bronze Age. A more intensive stage was reached in the Middle Ages when settlers from the west established new villages deep in the mountain valleys. By the beginning of the 20th century the Sudetes were already overpopulated but after a near-complete ethnic replacement from a German to a Polish population in 1945–8, population continued to grow until the 1980s. However, the economic system was hardly sustainable by this time. There were many polluting industries in the region and massive transboundary pollution from adjacent areas of Czechoslovakia and Germany had a devastating effect on the forests. Moreover, subsidised state agriculture placed heavy pressure on vulnerable mountain grazings. Since 1989 there has been a process of deindustrialisation in the Sudetes and surrounding areas and, with the disappearance of the state farms and the reduction in subsidies, agriculture is now better adjusted to the natural potential and is complemented by a promising start with agrotourism. The population of the region is growing relatively slowly (0.8% per annum 1956–1999), with the rural areas now in decline. A sustainable future for the region is now a possibility, but while there is a consensus for continued environmental reconstruction, supported by alternative economies, this will have to be carefully managed in the years ahead when EU accession may bring heavier development pressures than those evident at the moment. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
30.
Despite substantial rural-urban migration, 38.1 percent of the population of Poland still live in the countryside and the total numbers are only 0.9mln fewer than in 1946. At present the rural population is increasing and the rate of natural increase (though falling) is higher than in the towns though the productive age group is smaller. However, these human resources are not being properly used and the results can be seen in terms of economic inefficiency, low living standards and a high level of state support. Loss of jobs in factories and state farms results in welfare payments by the state and considerable 'hidden unemployment' on small family farms where profitability is constrained by inefficient use of labour. Poverty among the rural population is evident through a collapse of house building and considerable domestic overcrowding. However, conditions vary considerably across the country and this must be reflected in the economic and social policies drawn up for the new administrative regions introduced in 1999. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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