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531.
The specific features of the generation and intensification of internal gravity wave structures in different atmospheric-ionospheric regions, caused by zonal local nonuniform winds (shear flows), are studied. The model of the medium has been explained and an initial closed system of equations has been obtained in order to study the linear and nonlinear dynamics of internal gravity waves (IGWs) when they interact with the geomagnetic field in a dissipative ionosphere (for the D, E, and F regions).  相似文献   
532.
Abstract. Internationalisation is used as a device with which to reexamine geographies of national development and geography in national development in New Zealand. The second half of the paper discusses national and internationalised forestry in New Zealand before considering some of the new possibilities confronting geographers as the New Zealand economy becomes increasingly internationalised.  相似文献   
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535.
This paper reports the results of an empirical usability experiment on the performance of the space-time cube in a GeoVisual analytics environment. It was developed to explore movement data based on the requirements of human geographers. The interactive environment consists of multiple coordinated views incorporating three graphical representations. For the experiment, two groups of the user, domain experts and non-domain experts, had to execute several map-use tasks to answers specific question. The data collected during the experiment were analysis resulting in a set of usability metrics related to the effectiveness, efficiency and user satisfaction of developed application. The comparison of both groups showed that domain experts were able to operate the visual analytical environment more effectively and efficiently due to their interest to explore their data. The user feedback derived from the analysis of both experiments was further processed for the improvement of the application.  相似文献   
536.
The isotopic composition of lutetium has been measured in a range of terrestrial and meteoritic materials using solid-source mass spectrometric techniques. The meteoritic and terrestrial isotopic abundances are identical within experimental errors. The absolute 175Lu/176Lu ratio as determined in this work is 37.36 ± 0.07 at the 95% confidence level. On the basis of this measurement the atomic weight of lutetium has been calculated to be 174.967 ± 0.002, which is in good agreement with the currently accepted figure of 174.97 ± 0.01.Using the stable isotope dilution technique the abundance of lutetium has been determined in 25 stone, 1 stony-iron and 8 iron meteorites, and in 12 standard rocks, with an accuracy of ±5% at the 95% confidence level. In general, there is good agreement between this work and other published data.The 176Lu-176Hf pair has been proposed as an s process nucleocosmochronometer, because of the long half-life of 176Lu and the unique fact that both are s process isobars. The isotopic and elemental abundances of lutetium as measured in this work have been used with published nuclear data to estimate the mean age of s process nucleosynthesis for this isobaric pair, using the Schramm-Wasserburg formalism. The mean age cannot be accurately determined at the present time because of the lack of 30 keV neutron capture cross-section data for s only process nuclides and an accurate measurement of the branching ratio of 175Lu + n. However, it is possible to place constraints on the nuclear parameters in this mass region using a reasonable s process chronology based on the decay of 176Lu.  相似文献   
537.
The determination of boundary points and their correlation are prerequisites for defining the PrecambrianCambrian boundary and the intercontinental correlation. A large number of good Precambrian-Cambrian boundary sections in South Asia not only possess the conditions for selection of a boundary stratotype, but also provide the basis for the long-distance correlation of those boundary sections.Through a detailed study of the latest data obtained from the typical sections in South China, the Lesser Himalaya Mountains and the Alborz Mountains. the locations of boundary points have been defined, and a correlation scheme is proposed, which contributes to the solution of the problem of worldwide correlation of boundary sections.  相似文献   
538.
Direct correlation have been observed between certain trace element and hydrocarbon anomalies in the near subsurface soils of Vindhyan basin, India. This relationship with hydrocarbon is very useful in hydrocarbon exploration. 52 soil samples from Vindhyan basin were collected from a depth of 2.5m. All the soil samples were analyzed for light hydrocarbon, isotope and trace element concentrations. The adsorbed light gaseous hydrocarbon analyses show the presence of methane (8–328 ppb), ethane (0–27 ppb) and propane (0–11 ppb) respectively and these values indicate the presence of hydrocarbon micro-seepage in the study area. The carbon isotopic values determined for methane and ethane for these soil samples are (?26.41 to ?47.70 ‰ PDB) and (?20.07 to ?35.30 ‰ PDB) respectively and they are thermogenic in nature. The trace element concentrations of nickel (33–220 ppm), vanadium (72–226 ppm), copper (20–131 ppm), chromium (94–205 ppm), zinc (66–561 ppm) and cobalt (9–39 ppm) have higher than the normal concentrations in soils. Trace element concentrations are used to plot with the data obtained from light gaseous hydrocarbon concentrations and carbon isotopic values of soil samples of the Vindhyan basin. Trace element anomalies have been observed around the hydrocarbon anomalies in the study area.  相似文献   
539.
On the basis of the complex of geological features, the eastern flank of the Salla-Pana-Kuolajarvi belt is a prospect structure for gold mineralization in the U-bearing albitites and related acid and mafic metasomatites. Visible tellurides and selenides, which are typical of gold deposits of the Fe-Co-Au-U group in the adjacent territory of Finland within the Salla-Pana-Kuolajarvi belt, were found in the Ozerny occurrence as a result of studies. Native gold is found in association with tellurides. Molybdenite from the occurrence has a high Re content up to 0.3%.  相似文献   
540.
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