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991.
Cappadocia is essentially covered by nine rhyolitic ignimbrite units, being the products of a multi-phase volcanism of Upper Miocene-Pliocene age. Around Ürgüp and the Kizilirmak River, these ignimbrites constitute a volcanic-sedimentary succession together with lacustrine sediments, called the Ürgüp formation. In the zeolite occurrences of Cappadocia that were found in the lacustrine parts of pyroclastics outcropping around the Tuzköy, Sarihidir, Karain, Çökek, Ibrahim Pasa and Karadag areas, clinoptilolite is the most common mineral and is associated with chabazite, erionite and phillipsite in some areas. A gain of alkaline-earths from the lake water, which is compensated by a loss of alkalis from the glass, took place during the formation of the different zeolite assemblages, which were probably controlled by the composition of the parent glasses. The distribution of erionite confirms its relation with mesothelioma cases in Tuzköy, Sarihidir and Karain villages that are located outside tourist areas. The high incidence of malignant mesothelioma in Karain may be explained by uncontrolled occupational exposure to erionite. The fairy chimneys, canyons and underground cities, which are situated in the unaltered or slightly altered parts of the Kavak, Zelve, Cemilköy, Gördeles and Kizilkaya ignimbrites do not constitute any health risk for the inhabitants or for visitors.  相似文献   
992.
Measurements of the Sun in the near-infrared He i 10830 Å absorption line were performed using the echelle spectrograph with a dispersion of 6.71 mÅ per pixel at the Vacuum Tower Telescope (German Solar Telescopes, Teide Observatory, Izaña, Tenerife, Spain) on May 26, 1993. These measurements were compared with full-disc soft X-ray images of the Sun (Japanese solar satellite Yohkoh), full-disc solar images in H (Big Bear Solar Observatory), full-disc solar images in the He i 10830 Å line (National Solar Observatory, Kitt Peak) and with full-disc microwave solar maps at 37 GHz (Metsähovi Radio Research Station). In the He 10830 Å line the Sun displays a limb darkening similar to that in the visible part of the spectrum. Active regions and H filaments show a strong absorption in the He 10830 Å line, whereas the absorption is weak in coronal holes.  相似文献   
993.
Lacustrine basins of Neogene age in Serbia were formed either in intramountain valleys-graben and half-graben structures or in the marginal part of the Pannonian sea during Oligocene or at the beginning of Miocene, lasted and ended at the end of Miocene or Pliocene. The formation of the numerous depressions of the Balkan Peninsula, due to tectonic activity, gave lake basins with alluvial, swamp and lacustrine facies. The cycle with these facies was repeated several times. The lakes are mostly meromictic, often permanently stratified (oil-shale). A high rate of sedimentation with thickness up to 2000 m is characteristic for many of these basins. In many lakes phytogenic sedimentation occurs, giving facies with coal and with oil-shales. In this paper only some basins with oil-shales will be discussed, e.g. Valjevo-Mionica, Jadar and Pranjani basin. The characteristics of Vranje and Aleksinac basin will be discussed only in general. The organic rich sequences (oil shales) are characterized by the thin lamination, preservations of fish remains and plant leaves and absence of bioturbation, which needed permanent stratification of water body and anoxic conditions. Paleoclimatic regimes at the time of deposition and diagenesis were warm, subtropic with the changes of humid and dry periods.  相似文献   
994.
The geopotential scale factor R o = GM/W o (the GM geocentric gravitational constant adopted) and/or geoidal potential Wo have been determined on the basis of the first year's (Oct 92 – Dec 93) ERS-1/TOPEX/POSEIDON altimeter data and of the POCM 4B sea surface topography model: R o °=(6 363 672.58°±0.05) m, W o °=(62 636 855.8°±0.05)m 2 s –2 . The 2°–°3 cm uncertainty in the altimeter calibration limits the actual accuracy of the solution. Monitoring dW o /dt has been projected.  相似文献   
995.
Water samples were collected from the Truckee River-Pyramid Lake system, the Walker River-Walker Lake system, and the Carson River, all located in eastern California and western Nevada, U.S.A., at three different times (i.e., summer 1991, spring 1992, and autumn 1992) over a two year period. The concentrations of As, Na, Cl, PO4, and pH were measured in these river samples and the associated terminal lakes. Arsenic values ranged from below 13 nmol/kg near Truckee, California to 160 nmol/kg at Nixon, Nevada in the Truckee River, from 40 nmol/kg in the headwaters of both West and East Walker Rivers to 270 nmol/kg below Weber Reservoir on the main branch of the Walker River, and from <27 nmol/kg to 234 nmol/kg for the lower Carson River system. Arsenic concentrations in Steamboat Creek (0.91 mol/kg–1.80 mol/kg) in the Truckee River catchment are above the U.S. EPA drinking water maximum contaminant level of 0.67 mol/kg, as are the As concentrations in both Pyramid Lake (1.33 mol/kg–1.57 mol/kg ) and Walker Lake (13.7 mol/kg–18.7 mol/kg). Sources of As for all three rivers include weathering of As-rich rocks and/or regolith and input of high-As geothermal spring waters, both processes primarily, although not exclusively, adding As to the headwater regions of these rivers. Steamboat Hot Springs (29 mol/kg As 54.5 mol/kg), for example, is identified as a source of As to the Truckee River via Steamboat Creek. The high As concentrations in Pyramid and Walker Lakes are likely due to (1) desorption of arsenate from aquatic particulate matter in these high pH waters (9.0 pH 9.5), (2) limited biologic uptake of arsenate, and (3) evaporative concentration of the lake waters. Evaluation of molar PO4}/As ratios of river waters and geothermal spring waters (e.g., Steamboat Hot Springs), indicates that phosphate is substantially enriched in Steamboat Creek as well as the mid to lower reaches of the Walker and Carson Rivers. These regions of each river are dominated by agricultural interests and, additionally, in the case of Steamboat Creek, residential areas and golf courses. Our data strongly imply that phosphate-rich agricultural return flow has likely added P to these streams and, consequently, increased their respective P:As ratios.  相似文献   
996.
The intense urbanization of the Mediterranean coast as a result of the development of residential-tourist activities since the 1960s, especially from the mid-1990s to 2008, has generated new urban environments associated with extensive urban typologies. These include gardens linked to houses with outdoor spaces that are shared between all of the residents of the residential developments. The aim of this study is to determine the main characteristics of these new urban green spaces and their effect on domestic water consumption in Alicante (Spain). To do this, we analysed the characteristics that define these types of gardens (surface area, density, plant species and irrigation system) and determined their water needs using the Water Use Classifications of Landscape Species method. The main conclusions are that the increase in paved areas is one of the strategies to reduce water consumption in spaces where turf grass is the most common plant species. This is due to increased water prices and lack of water resources.  相似文献   
997.
Nine beryl samples from Western Carpathians, Slovakia, were investigated by infrared and Raman spectroscopy and differential thermal analysis. Two types of water H2O I and H2O II were detected. Infrared spectroscopy proved the presence of water type I and II in the presence of alkali cations with several bands: (1) symmetric stretching vibration—ν1; (2) antisymmetric stretching mode—ν3; (3) bending vibration—ν2. The presence of singly and doubly coordinated type II water (IIs and IId) was confirmed by single-crystal IR spectroscopy. From Raman spectra a band at 3606 cm?1 was assigned to ν1 of water type I and the range of 3597–3600 cm?1 to water type II. The presence of doubly coordinating water indicates a relatively highly hydrated environment with the presence of alkali ions including Na as the dominant cation coordinated by H2O II. CO2 bands were detected only by single-crystal IR spectroscopy. Thermal analysis proved total water loss in the range of 1.4–2.0 wt% and three main dehydration events. Based on the study of bond-topological arrangements two molecules of H2O IId are each bound with two H···O1 bonds and one Na–OW bond with an angular distortion, and by releasing one H2O molecule more stable H2O IIs is produced. The H2O I molecule is bound only by two equivalent hydrogen bonds. The H2O IIs molecule with a Na–OW bond strength of 0.28 vu and two H···O1 bonds of 0.14 vu without any forced angular distortion is the most stable of all.  相似文献   
998.
This study presents a method of two‐dimensional scanning electron microscope image analysis that directly quantifies microporosity abundance in clay‐rich, fine‐grained sediments. The method is novel in that it is specifically designed to circumvent the challenge to porosity quantification posed by mineral surface charging and topographical artifacts created during Ar‐ion cross‐section polishing. It utilizes the finding that differences in circularity values can be used to distinguish micropores from blemishes in a thresholded image. This method is powerful because it is fast and provides a direct microporosity estimation technique to augment or replace experimental data. The pore size range to which the method is applicable is clear and can be selected depending on the application of the analysis. When used appropriately, the method can be implemented on microporous sediments and sedimentary rock in general. The method is developed using marine muds of Pliocene and Miocene ages from the Nankai margin (burial depths from approximately 200 to 1100 m). The close match between imaging‐derived microporosity and bulk N2 microporosity measurements shows that porosity in these young and relatively shallowly buried sediments is dominated by pores of sizes that can be imaged by scanning electron microscopy. In Kumano, forearc basin sediments of the Nankai Trough, results of this method show a significant increase in microporosity with burial depth, probably due to microporosity preservation during compaction and possibly early volcanic ash diagenesis.  相似文献   
999.
1000.
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