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41.
42.
The hydraulic behaviour of the karst aquifer in the Hubelj spring catchment area (SW Slovenia) was studied by using an indirect
research method based on natural tracers. The variations of natural tracers (in precipitation and in groundwater) during the
storm event made possible the separation of the Hubelj spring storm hydrograph by the three-component separation technique.
The results produced information on the aquifer recharge, storage and discharge processes, as well as on the mechanisms that
affected them. They verified the so-called epikarst hypothesis presuming that an important part of a karst aquifer recharge
reaches rapidly and intensively from the epikarst zone. It was demonstrated that epikarst water could occupy up to 50% of
the spring discharge during precipitation events. This phenomenon could have important consequences on protection and management
of the problems of karst aquifers, including engineering problems in karst areas. With this respect the results could give
way to new engineering ideas. 相似文献
43.
The analysis of the time and space distribution of specular (reflecting) points in bistatic altimetry between GPS and CHAMP
satellites or SAC-C (taken as examples) is extended from Wagner and Klokočník (2003 J. Geod 77: 128–138). We demonstrate a
significantly higher number and density of reflecting points in bistatic altimetry in comparison with traditional monostatic
altimetry. After an outline of our older accuracy assessment for the vertical position of the reflecting point, we add a new
independent derivation and compare both approaches. We account for orbit errors of both the transmitters (GPS) and receiver
(CHAMP) satellites, and the measurement (delay) error. We found that the accuracy of the vertical position of the reflecting
point decreases only slowly with increasing off-nadir angle and that the orbit errors must be accounted for if decimeter and
better accuracy is required. In this paper, we do not study errors such as state of the ocean, technical parameters of the
receiving system, and atmospheric corrections. 相似文献
44.
L. Vočadlo K. S. Knight G. D. Price I. G. Wood 《Physics and Chemistry of Minerals》2002,29(2):132-139
The thermal expansion and crystal structure of FeSi has been determined by neutron powder diffraction between 4 and 1173?K. No evidence was seen of any structural or magnetic transitions at low temperatures. The average volumetric thermal expansion coefficient above room temperature was found to be 4.85(5)?×?10?5?K?1. The cell volume was fitted over the complete temperature range using Grüneisen approximations to the zero pressure equation of state, with the internal energy calculated via a Debye model; a Grüneisen second-order approximation gave the following parameters: θD=445(11)?K, V 0=89.596(8)?Å3, K 0′=4.4(4) and γ′=2.33(3), where θD is the Debye temperature, V 0 is V at T=0?K, K 0′ is the first derivative with respect to pressure of the incompressibility and γ′ is a Grüneisen parameter. The thermodynamic Grüneisen parameter, γth, has been calculated from experimental data in the range 4–400?K. The crystal structure was found to be almost invariant with temperature. The thermal vibrations of the Fe atoms are almost isotropic at all temperatures; those of the Si atoms become more anisotropic as the temperature increases. 相似文献
45.
Smoothing the Marmousi Model 总被引:1,自引:0,他引:1
K. Žáček 《Pure and Applied Geophysics》2002,159(7-8):1507-1526
46.
A new method is presented for the computation of the gravitational attraction of topographic masses when their height information is given on a regular grid. It is shown that the representation of the terrain relief by means of a bilinear surface not only offers a serious alternative to the polyhedra modeling, but also approaches even more smoothly the continuous reality. Inserting a bilinear approximation into the known scheme of deriving closed analytical expressions for the potential and its first-order derivatives for an arbitrarily shaped polyhedron leads to a one-dimensional integration with – apparently – no analytical solution. However, due to the high degree of smoothness of the integrand function, the numerical computation of this integral is very efficient. Numerical tests using synthetic data and a densely sampled digital terrain model in the Bavarian Alps prove that the new method is comparable to or even faster than a terrain modeling using polyhedra. 相似文献
47.
The preparation of the preliminary seismic hazard maps of the territory of Slovenia has been based on an expansion of the basic approach laid out by Cornell in 1968. Three seismic source models were prepared. Two of them are based mainly on the earthquake catalogue using the Poissonian probability model. A map of seismic energy release and a map of earthquake epicenter density are used to delineate seismic sources in these models. The geometry of the third model which is based on a rough estimate of seismotectonic setting is taken from the probabilistic seismic hazard analysis of a nuclear power plant in Slovenia. Published ground motion attenuation models based on strong motion records of recent strong earthquakes in Italy are used. Test maps for variable and uniform b-values are presented. The computer program, Seisrisk III, developed by the U.S. Geological Survey is used. 相似文献
48.
Nikola Stražičić 《GeoJournal》1996,38(4):445-453
Croatia, through its geographic position, is a Mediterranean/Adriatic and Central European/Danube state. As an Adriatic coastal state, it has a long maritime tradition, which is apparent in its well-developed shipping (2.4 million GT), the high-quality ship-building industry (among the top six in the world) and through its numerous sea ports, of which many were established in ancient times. The leading national port is Rijeka, which is at the same time an important transit port for Austria, Hungary, Slovakia and the Czech Republic.The exceptionally indented Croatian Adriatic coast with its attractive archipelagos and favorable climatic and oceanographic conditions in the coastal sea offers very advantageous conditions for comprehensive tourist utilization. This is particularly true of nautical tourism, which is complimented by a larger number of constructed and well-equipped yachting ports/marinas on the coast and islands. 相似文献
49.
The Carpatho-Balkanides and adjacent area: a sector of the Tethyan Eurasian metallogenic belt 总被引:3,自引:1,他引:3
S. Janković 《Mineralium Deposita》1997,32(5):426-433
The Tethyan Eurasian metallogenic belt (TEMB) was formed during Mesozoic and post-Mesozoic times in the area of the former
Tethyan ocean on the southern margin of Eurasia, with the Afro-Arabian and Indian plates to the south. It extends from western
Mediterranean via the Alps and southeastern Europe through the Lesser Caucasus, the Hindu Kush, and the Tibet Plateau to Burma
and SW Indonesia, linking with the West Pacific metallogenic belt. The Carpatho-Balkan region is one of the sectors of the
TEMB, characterized by some specific features. The emplacement of ore deposits is related to a definite time interval, and
to specific tectonic settings such as:
1. Late Permian-Triassic intracontinental rifting along the northern margin of Gondwanaland and/or fragments already separated.
This setting involves volcanogenic and volcano-sedimentary deposits (iron, lead/zinc, manganese, antimony, mercury, barite),
skarn deposits associated with volcano-plutonic complexes of bimodal magmatism, and low temperature carbonate-hosted lead/zinc
deposits.
2. Jurassic intraoceanic rifting – ophiolite complexes: This setting hosts major magmatic (particularly podiform chrome deposits)
and volcano-sedimentary deposits, mainly of the Cyprus type.
3. Subduction-related setting involves porphyry copper deposits, lesser skarn deposits (iron, locally Pb-Zn), massive sulphide
Cu (e.g. Bor) accompanied locally by Pb-Zn of replacement type, epithermal gold deposits, associated with calc-alkaline igneous
complexes of the Early Tertiary-Late Cretaceous, and the Neogene gold/silver and base metals deposits.
4. Post-collision continent-continent setting includes deposits of Pb-Zn, Sb, As, Au-Cu associated with volcano-plutonic complexes
of calc-alkaline affinity.
Several major Alpine metallogenic units are developed in the Carpatho-Balkanides and adjacent area, each characterized by
specific development, mineral associations, and types of ore deposits.
Received: 3 June 1996 / Accepted: 10 January 1997 相似文献
50.
The western part of the Bohemian Massif is characterized by repeated occurrences of intraplate earthquake swarms. To study surface deformations of this anomalous region, a network covering about 2000 square kilometres for repeated geodetic measurements was established in 1993 - 1994. The positions of the individual points of the network were carefully picked with respect to local tectonic structure and earthquake foci distribution. GPS and precise levelling measurements were performed 1-2 times a year. The GPS data were processed by Bernese GPS software.
No tendency to any displacement - either horizontal or vertical - of geological blocks was derived from the geodetic data for the period 1993 - 96. Only displacements of less than 5 mm/year in average could occur in the whole region in that period; larger displacements would have been revealed by our measurements. 相似文献