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191.
Stanko Žuljić 《GeoJournal》1996,38(4):425-429
As of 1991, in the Republic of Croatia 16 percent of the total population was made up of national minorities. A large part of this figure consists of minrity nations who are the descendants of settlers from the era of Ottoman conquest during the sixteenth and seventeenth centuries, the Austrian colonization in the eighteenth and nineteenth centuries, and partially due to inter-republic migrations during the existence of the Yugoslav state.The most numerous national minority in 1991 were the Serbs (582,000, or 12.16% of the total population). The Serbian national minority is scattered throughout the Croatian state, so that in Croatia there is no integral Serbian ethnic territory. The other national minorities in Croatia are much smaller in number (Bosnian Muslims, 43,000; Slovenes, 22,000; Hungarians, 22,000; Italians, 21,000; Czechs, 13,000; Albanians, 12,000; etc.).The conflicts provoked by Greater Serbian politics and the wartime aggression against Croatia resulted in migrations, the consequence of which is the reduction in the number of the Serbian national minority in the Republic of Croatia. 相似文献
192.
GGOS-D: homogeneous reprocessing and rigorous combination of space geodetic observations 总被引:3,自引:3,他引:0
M. Rothacher D. Angermann T. Artz W. Bosch H. Drewes M. Gerstl R. Kelm D. K?nig R. K?nig B. Meisel H. M��ller A. Nothnagel N. Panafidina B. Richter S. Rudenko W. Schwegmann M. Seitz P. Steigenberger S. Tesmer V. Tesmer D. Thaller 《Journal of Geodesy》2011,85(10):679-705
In preparation of activities planned for the realization of the Global Geodetic Observing System (GGOS), a group of German scientists has carried out a study under the acronym GGOS-D which closely resembles the ideas behind the GGOS initiative. The objective of the GGOS-D project was the investigation of the methodological and information-technological realization of a global geodetic-geophysical observing system and especially the integration and combination of the space geodetic observations. In the course of this project, highly consistent time series of GPS, VLBI, and SLR results were generated based on common state-of-the-art standards for modeling and parameterization. These series were then combined to consistently and accurately compute a Terrestrial Reference Frame (TRF). This TRF was subsequently used as the basis to produce time series of station coordinates, Earth orientation, and troposphere parameters. In this publication, we present results of processing algorithms and strategies for the integration of the space-geodetic observations which had been developed in the project GGOS-D serving as a prototype or a small and limited version of the data handling and processing part of a global geodetic observing system. From a comparison of the GGOS-D terrestrial reference frame results and the ITRF2005, the accuracy of the datum parameters is about 5?C7?mm for the positions and 1.0?C1.5?mm/year for the rates. The residuals of the station positions are about 3?mm and between 0.5 and 1.0?mm/year for the station velocities. Applying the GGOS-D TRF, the offset of the polar motion time series from GPS and VLBI is reduced to 50 ??as (equivalent to 1.5?mm at the Earth??s surface). With respect to troposphere parameter time series, the offset of the estimates of total zenith delays from co-located VLBI and GPS observations for most stations in this study is smaller than 1.5?mm. The combined polar motion components show a significantly better WRMS agreement with the IERS 05C04 series (96.0/96.0???as) than VLBI (109.0/100.7???as) or GPS (98.0/99.5???as) alone. The time series of the estimated parameters have not yet been combined and exploited to the extent that would be possible. However, the results presented here demonstrate that the experiences made by the GGOS-D project are very valuable for similar developments on an international level as part of the GGOS development. 相似文献
193.
Andreas Richter Søren Rysgaard Reinhard Dietrich John Mortensen Dorthe Petersen 《Ocean Dynamics》2011,61(1):39-49
Based on pressure tide-gauge observations, sea-level records are derived for ten sites along the coast of West Greenland.
The ocean tidal signal is extracted by a harmonic tidal analysis. The accuracy of the determined tidal constants is discussed
in detail. The tides account for 85% of the observed sea-level standard deviation. The tide gauge records reveal significant
shallow-water tidal effects, in particular compound and overtide amplitudes reaching 5 cm. The propagation of the tidal waves
into the fjords depends strongly on local conditions and is in some cases accompanied by an amplification of the tidal amplitudes.
The observed tidal signals are compared to the predictions of the global ocean tide model FES2004. At the outer coast, a good
agreement is found. Inside the fjords, however, the model performs worse and tide gauge observations may still be indispensable
when accurate tidal signals are required. 相似文献
194.
195.
A. Žgajnar Gotvajn M. Bistan T. Tišler A. J. Englande J. Zagorc-Končan 《International Journal of Environmental Science and Technology》2013,10(6):1141-1148
The aim of this research was to assess the efficiency of Fenton’s oxidation for degradation of endocrine disruptor bisphenol A (BPA) with emphasis on extent of accompanying adsorption. Adsorption on the waste sludge resulting from the Fenton’s oxidation could represent a significant impact on the final removal efficiency of BPA. Fenton’s oxidation was accomplished at two concentrations of BPA (0.228 and 22.8 mg L?1); both at the selected molar ratio of reagents Fe2+:H2O2 (1:10), as a function of reaction time. The kinetics of adsorption of BPA on waste sludge was determined for the same two concentrations of BPA at two concentrations of waste sludge (0.1 and 6.0 g L?1). In addition to changing concentrations of BPA and sludge, the adsorption process was also influenced by parameters such as temperature, pH and contact time. Adsorption isotherms were determined. Oxidation and adsorption were monitored by gas chromatography combined with mass spectrum. It has been confirmed that BPA is not completely oxidized in Fenton’s oxidation, because it is adsorbed to formed waste ferric sludge and thus necessary precautions for sludge deposition must be observed. 相似文献
196.
Emma S. Bullock Kim B. Knight Frank M. Richter Noriko T. Kita Takayuki Ushikubo Glenn J. MacPherson Andrew M. Davis Ruslan A. Mendybaev 《Meteoritics & planetary science》2013,48(8):1440-1458
Magnesium and silicon isotopic profiles across melilite grains in two type B1 and two type B2 calcium‐aluminum‐rich inclusions (CAIs) reveal differing but constant enrichments in heavy isotopes everywhere except ≤1000 μm from the CAI margins. There is no close correlation in the B1s or the B2s between isotopic composition and åkermanite content of the melilite, a measure of progressive igneous crystallization, yet such a correlation might be expected in a type B2: without a melilite mantle (as in B1s) to seal the interior off and prevent further evaporation, the melt would have maintained communication with the external gas. These observations indicate a model in which B1s and B2s solidified under differing conditions. The B2s solidified under lower hydrogen pressures ( ≤ 10?4 – 10?5 bars) than did B1s ( > 10?4 bars), so surface volatilization was slower in the B2s and internal chemical and isotopic equilibrium was maintained over the interval of melilite crystallization. The outermost zones of the CAIs (≤1000 μm from the edge) are not consistently enriched in heavy isotopes relative to the interiors, as might be expected from diffusion‐limited surface evaporation of the melt. In all cases, the magnesium in the CAI margins is lighter than in the interiors. In one case, silicon in the margin also is lighter, but locally in some CAIs, it is isotopically heavier near the surface. If melt evaporation played a role in the formation of these outer zones, a later event in many cases caused isotopic re‐equilibration with an external and isotopically near‐normal reservoir. 相似文献
197.
Jan Vilhelm Vladimír Rudajev Roman Živor Tomáš Lokajíček Zdeněk Pros 《Geophysical Prospecting》2010,58(6):1099-1110
The purpose of this paper is the comparison of P‐wave velocity and velocity anisotropy, measured at different scales under laboratory and field conditions. A shallow seismic refraction survey with shot/receiver spacing of up to 10 m was carried out on a flat outcrop of lhertzolite in the southern part of the Balmuccia massif. Oriented rock samples were also obtained from the locality. The particular advantage of the laboratory method used is the possibility of measuring velocity in any direction under controlled conditions. Laboratory tests were made on spherical peridotite samples, 50 mm in diameter, by ultrasonic velocity measurements in 132 directions (meridian and parallel networks) under confining stress ranging from atmospheric to 400 MPa. The mean P‐wave velocity of the field and laboratory data differed by between 20–30%. In addition, P‐wave velocity anisotropy of 25% was detected in the field data. Whereas the anisotropy in the laboratory samples in the same orientation as the field surveys was less than 2%. This observed scaling factor is related to the different sampling sizes and the difference in frequencies of applied elastic waves. With an ultrasonic wavelength of 10 mm, laboratory samples represent a continuum. The field velocities and velocity anisotropy reflect the presence of cracks, which the laboratory rock samples do not contain. Three sub‐vertical fracture sets with differing strikes were observed in the field outcrop. Estimates of fracture stiffness from the velocity anisotropy data are consistent with other published values. These results highlight the difficulty of using laboratory velocity estimates to interpret field data. 相似文献
198.
A. Smith I. A. Crawford R. A. Gowen A. J. Ball S. J. Barber P. Church A. J. Coates Y. Gao A. D. Griffiths A. Hagermann K. H. Joy A. Phipps W. T. Pike R. Scott S. Sheridan M. Sweeting D. Talboys V. Tong N. Wells J. Biele J. Chela-Flores B. Dabrowski J. Flannagan M. Grande J. Grygorczuk G. Kargl O. B. Khavroshkin G. Klingelhoefer M. Knapmeyer W. Marczewski S. McKenna-Lawlor L. Richter D. A. Rothery K. Seweryn S. Ulamec R. Wawrzaszek M. Wieczorek I. P. Wright M. Sims 《Experimental Astronomy》2009,23(3):711-740
While the surface missions to the Moon of the 1970s achieved a great deal, scientifically much was also left unresolved. The
recent plethora of lunar missions (flown or proposed) reflects a resurgence in interest in the Moon, not only in its own right,
but also as a record of the early solar system including the formation of the Earth. Results from recent orbiter missions
have shown evidence of ice or at least hydrogen within shadowed craters at the lunar poles. 相似文献
199.
N.J.T. Edberg A.I. Eriksson U. Auster S. Barabash A. Bößwetter C.M. Carr S.W.H. Cowley E. Cupido M. Fränz K.-H. Glassmeier R. Goldstein M. Lester R. Lundin R. Modolo H. Nilsson I. Richter M. Samara J.G. Trotignon 《Planetary and Space Science》2009,57(8-9):1085-1096
We present the first two-spacecraft near-simultaneous observations of the Martian bow shock (BS), magnetic pileup boundary (MPB) and photo-electron boundary (PEB) obtained by the plasma instruments onboard Rosetta and Mars Express during the Rosetta Mars flyby on February 25, 2007. Our observations are compared with shape models for the BS and MPB derived from previous statistical studies. The MPB is found at its expected position but the BS for this event is found significantly closer to the planet than expected for the rather slow and moderately dense solar wind. Cross-calibration of the density measurements on the two spacecraft gives a density profile through the magnetosheath, indicating an increasing solar wind flux during the Rosetta passage which is consistent with the multiple BS crossings at the Rosetta exit. 相似文献
200.
Planktonic foraminiferal Mg/Ca ratios and oxygen isotopic compositions of a spliced sediment record from Feni Drift, NE Atlantic Ocean (box core M200309 and piston core ENAM9606) trace late Holocene sea surface temperature (SST) and salinity changes over the past 2400 years. At this location, the variability of SST and oxygen isotopic composition of seawater (δ18Ow) reflects variable northward advection of warm and saline surface waters, which appears linked to climate variability over the adjacent European continent. Our records reveal a general long-term cooling trend. Superimposed on this overall trend, partly higher temperatures and salinities from 180 to 560 AD and 750 to 1160 AD may be ascribed to the Roman and Medieval Warm Periods, respectively. Subsequently, our record displays highly variable surface water conditions; the main Little Ice Age SST minimum is restricted to the 15th and 16th centuries AD. Pervasive multidecadal- to centennial-scale variability throughout the sedimentary proxy records can be partly attributed to solar forcing and/or variable heat extraction from the surface ocean caused by shifts in the prevailing state of the North Atlantic Oscillation (NAO). High salinities in the 17th and 18th centuries are considered to reflect tropical anomalies linked to a southward shift of the Intertropical Convergence Zone, propagating across the North Atlantic Ocean. 相似文献