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61.
K. A. Korotenko 《Oceanology》2007,47(3):313-324
A new high-resolution (<2 km) version of the DieCAST fourth-accuracy-order model for the ocean circulation is proposed for the study of the general circulation, mesoscale structures, and their variability in the Adriatic Sea. The model uses mean seasonal data on the temperature, salinity, buoyancy fluxes, and wind. The data of the COAMPS system with a 4-km resolution were used for the simulation of the sea response to the effects of various winds: Sirocco, Maestro, and two types of boras. The mean monthly runoffs from 38 rivers and mean daily runoffs from 12 main rivers throughout the year were given in the model. The conditions at the open boundary of the Strait of Otranto were given on the basis of the hierarchy of two coarser models for the Adriatic and Mediterranean seas. Due to the extremely weak dissipation and the high resolution (the mesh size is less than the baroclinic radius of deformation, 5–10 km), the model allows one to trace the development of a baroclinic instability along the Italian coast, to simulate mesoscale structures associated with the instability, and to estimate the scales of the structures. Mesoscale filaments, meanders, mushroom-like currents, fronts, and intrusions known from satellite observations were simulated and explained. The scenario of the anomalous upwelling near the Italian coast observed in the summer of 2003 was also simulated and analyzed. 相似文献
62.
Haploborolls and Ustifluvents with A-C horizonation characterize Holocene soil development in alluvium and colluvium of the Laddie Creek valley. Cumulic soils with overthickened A horizons, including those of Altithermal age, have formed along the valley walls under the influence of spring activity from the Amsden Formation (Mississippian-Pennsylvanian). Soil texture, mineralogy, and to some extent color, are inherited largely from sediment derived from the Amsden and Tensleep (Pennsylvanian) Formations. The valley was able to support human occupation during Altithermal time (ca. 7500-4000 B.P.) because of springs emanating from the valley walls. Past spring locations are identified from soil morphology and stratigraphy. Springs are still active along the valley, although they have shifted positions many times in the past. The association of spring soils with Altithermal-age occupation at the site (ca. 6600-5700 B.P.) does not coincide with the caliche concept of the Altithermal paleosol in Holocene alluvial valleys in Wyoming basins as identified by Leopold and Miller. Nevertheless, early man of Altithermal time probably sought higher elevations within mountains of the region where springs offered water and the environs provided food and shelter—thus enabling human groups to survive the drought, and possible high temperatures, which seemingly prevailed in the basins and plains. 相似文献
63.
G. Balmino 《Journal of Geodesy》1974,48(1):85-108
Résumé Un modèle de représentation du potential terrestre par 126 masses ponctuelles de profondeurs situées entre 1000 et 1500 km
a été construit à partir de la Standard Earth II du S.A.O. et utilisé avec succès pour la représentation du géo?de, des anomalies
de gravité, ainsi qu’en calcul d’orbites par correction différentielle utilisant des observations réelles de satellites artificiels.
Les propriétés de décroissance rapide de ces fonctions sont mises en évidence, et leur utilisation envisagée à l’analyse scientifique
de mesures altimétriques. 相似文献
64.
Digital Image Based Approach for Three-Dimensional Mechanical Analysis of Heterogeneous Rocks 总被引:2,自引:0,他引:2
Summary This paper presents a digital image based approach for three-dimensional (3-D) numerical simulation and failure analysis of
rocks by taking into account the actual 3-D heterogeneity. Digital image techniques are adopted to extract two-dimensional
(2-D) material heterogeneity from material surface images. The 2-D image mesostructures are further extrapolated to 3-D cuboid
mesostructures by assuming the material surface as a representation of the inner material heterogeneity within a very small
depth. The iterative milling and scanning system is set up to generate the 3-D rock mesostructures. A Hong Kong granite specimen
is used as an example to demonstrate the procedure of 3-D mesostructure establishment. The mechanical responses and failure
process under the conventional Brazilian tensile test condition are examined through numerical analyses. The stress distribution,
crack propagation process and failure model of heterogeneous material cases are simulated with a finite difference software.
The numerical results indicate that material heterogeneity plays an important role in determining the failure behavior of
rocks under external loading. 相似文献
65.
A Central-European nowcasting system which has been developed for use in mountainous terrain is tested in the Whistler/Vancouver area as part of the SNOW-V10 experiment. The integrated nowcasting through comprehensive analysis system provides hourly updated gridded forecasts of temperature, humidity, and wind, as well as precipitation forecasts which are updated every 15 min. It is based on numerical weather prediction (NWP) output and real-time surface weather station and radar data. Verification of temperature, relative humidity, and wind against surface stations shows that forecast errors are significantly reduced in the nowcasting range compared to those of the driving NWP model. The main contribution to the improvement comes from the implicit bias correction due to use of the latest observations. Relative humidity shows the longest lasting effect, with >50 % reduction of mean absolute error up to +4 h. For temperature and wind speed this percentage is reached after +2 and +3 h, respectively. Two cases of precipitation nowcasting are discussed and verified qualitatively. 相似文献
66.
67.
I. S. Lykova I. V. Pekov N. N. Kononkova A. K. Shpachenko 《Geology of Ore Deposits》2010,52(8):837-842
Jinshanjiangite (acicular crystals up to 2 mm in length) and bafertisite (lamellar crystals up to 3 × 4 mm in size) have been found in alkali granite pegmatite of the Gremyakha-Vyrmes Complex, Kola Peninsula. Albite, microcline, quartz, arfvedsonite, zircon, and apatite are associated minerals. The dimensions of a monoclinic unit cell of jinshanjiangite and bafertisite are: a = 10.72(2), b=13.80(2), c = 20.94(6) Å, β = 97.0(5)° and a = 10.654(6), b = 13.724(6), c = 10.863(8) Å, β = 94.47(8)°, respectively. The typical compositions (electron microprobe data) of jinshanjiangite and bafertisite are: (Na0.57Ca0.44)Σ1.01(Ba0.57K0.44)Σ1.01 (Fe3.53Mn0.30Mg0.04Zn0.01)Σ3.88(Ti1.97Nb0.06Zr0.01)Σ2.04(Si3.97Al0.03O14)O2.00(OH2.25F0.73O0.02)Σ3.00 and (Ba1.98Na0.04K0.03)Σ2.05(Fe3.43Mn0.37Mg0.03)Σ3.83(Ti2.02Nb0.03)Σ2.05 (Si3.92Al0.08O14)(O1.84OH0.16)Σ2.00(OH2.39F1.61)Σ3.00, respectively. The minerals studied are the Fe-richest members of the bafertisite structural family. 相似文献
68.
69.
Prof. Dr. H. G. Scharbert 《Mineralogy and Petrology》1971,16(4):252-267
Zusammenfassung Der Cyanit tritt immer nur in biotitfreien Granuliten auf; in den biotitreicheren kommt Sillimanit vor. Der Cyanit gehört einer frühen Kristallisationsphase im polymetamorphen Ablauf der Granulitgenese an und ist immer älter als der Sillimanit. Cyanit kann sich direkt in Sillimanit umwandeln, meistens jedoch wächst der Sillimanit unabhängig von Cyanit. Die Fe-Gehalte beider Aluminiumsilikate werden angegeben und die Granulitgenese kurz diskutiert.
Mit 8 Abbildungen
Herrn Prof. DDr.H. Wieseneder zum 65. Geburtstag gewidmet. 相似文献
Kyanite and sillimanite in moldanubian granulites
Summary Kyanite always occurs in granulites free from any biotite; in micaceous granulite kyanite is replaced by sillimanite. Kyanite belongs to an early phase of crystallization with in the polymetamorphic genesis of the granulite complexes, and is therefore older than sillimanite. Sillimanite may grow directly out of kyanite, in most cases, however, sillimanite appears to grow independently from kyanite. The iron-contents of both aluminium-silicates are indicated and the genesis of the granulites is shortly discussed.
Mit 8 Abbildungen
Herrn Prof. DDr.H. Wieseneder zum 65. Geburtstag gewidmet. 相似文献
70.