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11.
Vladan čelebonović 《Earth, Moon, and Planets》1989,45(3):291-298
When subject to high pressure, H2 and 3He are expected to undergo phase transitions, and to become metallic at a sufficiently high pressure. Using a semiclassical theory of dense matter proposed by Savi and Kaanin, calculations of phase transition and metallisation pressure have been performed for these two materials. In hydrogen, metallisation occurs at p
M= (3.0 ± 0.2) Mbar, while for helium the corresponding value is p
M= (106 ± 1) Mbar. A phase transition occurs in helium at p
tr= (10.0 ± 0.4) Mbar. These values are close to the results obtainable by more rigorous methods. Possibilities of experimental verification of the calculations are briefly discussed. 相似文献
12.
Among the three principal regional units of Croatia, i.e. the elongated and spacious Adriatic littoral (with numerous islands), the relatively small and narrow mountainous belt (the Croatian transit doorway) and the Pannonian/peri-Pannonian region, the latter is the largest and accounts for 54 percent of the surface area and 66 percent of the population of Croatia (1991 census). It is part of the Pannonian (or Carpathian) basin, or the central Danube basin, so that Croatia is simply by its position a Danube country. Its Danube character is also highlighted by the fact that the Pannonian/peri-Pannonian region of Croatia through the Sava and Drava Rivers is directly linked to the navigable Danube, which is the historical and ethnic eastern boundary of Croatia. Croatia is an old historical Danube nation and country, although it has nominally appeared as a state after the break-up of Yugoslavia, and its international recognition as an independent state (1992). 相似文献
13.
Croatia is a country of tourism, and this is primarily due to its position by the warm Adriatic Sea, its varying and picturesque landscapes, its diverse and generally favorable climate for tourism, its rich Mediterranean and Central European cultural heritage and its proximity to the leading European consumer countries.In the international tourism market, Croatia presents itself with the slogan A Small Country for a Great Vacation, because its 4.8 million inhabitants and surface area of 56,538 km2 place Croatia in the ranks of the world's smaller countries. Its significance is increased by an additional 33,200 km2 of territorial waters, of which a large part is considered internal waters because of its location within the limits of a series of islands.The tourism offering of Croatia is very diverse, but its basis is formed by three differing and mutually complimentary regions, through their natural characteristics and cultural heritage: coastal, montane and Pannonian and peri-Pannonian Croatia. The total tourism offering of Croatia includes 900,000 beds, of which over one-fifth are in hotels or similar places, two-fifths are in private rooms and one-third in camps.The tradition of tourism in Croatia is over one hundred years old, and according to the number of foreign tourists it is ranked as the fifth country for tourism in southern Europe. 相似文献
14.
L. Lazić 《Meteorology and Atmospheric Physics》1993,52(3-4):101-111
Summary The University of Belgrade/National Meteorological Centre, Washington (UB/NMC) limited area Eta Model predicted the development, structure, associated precipitation and tracks of the Australian Monsoon Experiment (AMEX) (10 January through 15 February 1987) tropical cyclonesConnie, Irma, Damien andJason. The initial positions and intensities of the tropical cyclone vortices from the global European Centre for Medium-Range Weather Forecasts (ECMWF) analyses, which are used as initial data, do not quite agree with the observations. These disagreements produce additional erros in predicting the tropical cyclone tracks.To improve the initial position of the vortex, the flow is split into the small and the large scale motions, and during the first two hours of the integration, the small-scale part is forced in small steps towards its observed position. The adjustment is performaed with the reduced model dynamics (adjustment processes only) and no physics.With the adjustment during the first two hours of the integration, the model successfully adjusts to the new position of the initial vortex. After the completion of the adjustment stage, the model runs normally, i.e., without any modification. The tracks of the 48-h forecasts with the adjusted initial vortices are parallel to the tracks obtained in the control forecasts without the adjustment. However, e.g., the mean absolute error of the positions during 48-h forecast of the tropical cycloneConnie was reduced from 174 km in the control case to 129 km in the case with adjustment of the position.The latent heat, the thermal energy, the kinetic energy and the total energy of the extracted small scale vortices are calculated every three hours of the integration time. These small-scale energies obtained in the 48-h control forecast are compared to those of the rund with the initial vortex adjustment to monitor the spin up of the model.With 7 Figures 相似文献
15.
Gojko Djurašević 《Astrophysics and Space Science》1993,206(2):207-218
The paper is devoted to the actual problematics in the determination of orbital and physical parameters of active CB on the basis of the interpretation of photometric observations. One solves the problem in two stages: by obtaining a synthetic light curve in the case when the parameters of the corresponding CB model (Djuraevi, 1992a) are given a priori (direct problem) and by determining the parameters of the given model for which the best fit between the synthetic light curve and the observations is achieved (inverse problem) (Djuraevi, 1992b). In this paper, the above procedure is applied to a particular case of an interpretation of CB light curves AU Ser and RV Corvi. 相似文献
16.
Gojko Djurašević 《Astrophysics and Space Science》1993,206(1):129-144
The author considers the current problematics in the determination of the orbital and physical parameters for active close binaries (CB) of W Ser type based on the interpretation of photometric observations. In the particular case one analyses the light curves of CB RX Cas in the framework of the accretion-disc model explained in the second paper of this series (Djuraevi, 1992a). The change of the light curves with that of the system's physical-activity phase is analysed and the orbital and physical parameters of the system are determined for the maximum, minimum and the transition regime of the physical activity by applying the inverse-problem method described in the third paper of the series (Djuraevi, 1992b). In the paper a graphical illustration of the solutions obtained is also given. 相似文献
17.
A sample of 35 variable carbon stars has been considered. The stellar temperatures, radii, absolute luminosities, masses, and mass loss rates have been estimated. Then the spherical circumstellar dust shells around the analysed stars are discussed and the differences in the infrared properties between semi-regular, irregular, and long-period variables are indicated. 相似文献
18.
Summary Climatological studies show that the Altai-Sayan lee side is one of the major cyclogenesis areas in the Northern Hemisphere. In case of the Altai-Sayan lee cyclogenesis, the surface cyclone is generated when a primary cyclone is swept north of the mountains. In the mid-troposphere, a trough develops and finally turns into a cutoff low within 48 h. The main synoptic features are similar to those of Alpine cyclogenesis. Numerical simulations are performed to assess the effect of different representation of orography on the Altai-Sayan cyclogenesis. Two experiments are performed, a step-mountain (ETA) and an envelope orography (SGM) experiment. The ETA experiment produced the cyclogenesis in a way similar to that in the analysis both at the surface and at mid-troposphere. The SGM experiment failed in the simulation of the upper cutoff low. The difference in predicted pressure between the ETA and the SGM experiment shows a dipolar structure suggesting that the blocking effect of the mountains is essential in the development of the Altai-Sayan lee cyclogenesis.With 7 Figures 相似文献
19.
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
20.
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