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51.
52.
This study presents an investigation of the orbital period variations of five Algol type binaries, UX Leo, RW Mon, EQ Ori, XZ UMa and AX Vul based on all available minima times. The OC diagrams of all systems exhibit a periodic variation superimposed on a downward parabolic segment. The mass loss due to magnetic braking effect in the cooler components is assumed to account for the parabolic variation with a downward shape, while it is suggested that the light-time effect (LITE) due to an unseen component around the eclipsing binaries explains the tilted sinusoidal changes in their OC diagrams. The orbital period decrease rates for the systems are estimated as approximately between about 0.7 and 2.5 s per century. It is clearly seen that mass loss effect is more dominant than the expected mass transfer for classical Algols in this study. The minimum mass of the probable third bodies around the eclipsing pairs was calculated to be ?0.5 M except for UX Leo, in which it was estimated to be approximately 0.9 M. In order to search for third lights in the light curves of five systems, the V-light curves of the systems were analyzed and their physical and photometric parameters were determined. For UX Leo, a significant third light contribution was determined. We found a very small third light that can be tested using multi-color light curves, for RW Mon, EQ Ori and XZ UMa, while a third light for AX Vul could not be exposed.  相似文献   
53.
The Çatallar Basin is one of the Miocene basins located in the southern part of the Bey Da?lar? Massif (SW Turkey). This basin has been reinvestigated and new stratigraphic and sedimentological data are now presented. The Çatallar Basin lies in paraconformity on the Bey Da?lar? carbonate platform of Late Cretaceous to Palaeogene age. It consists of an impersistent, shallow-marine carbonate base (Karabay?r formation, Late Oligocene to Early Burdigalian) followed by an onlapping detrital sequence including the Akçay and Ba?beleni formations (Langhian to Serravallian). The Akçay formation mainly contains turbidites in which several debris-flows and olistostromes are intercalated. The lowest debris flows derive from the local carbonate platforms of Cretaceous and Palaeogene age. Higher, the debris flows and olistostromes contain large carbonate blocks deriving from nearby sources (Bey Da?lar? platform carbonates), whereas the accompanying pebbles originate from the allochthonous ophiolitic units located farther to the north (Lycian Nappes) or to the east (Antalya Nappes). The origin of these ophiolitic detritus is a matter of debate. The new data obtained in this study favour a northern origin.  相似文献   
54.
55.
Eclogite and blueschist facies rocks occurring as a tectonic unit between the underlying Menderes Massif (MM) and the overlying Afyon Zone/Lycian Nappes and the Bornova Flysch Zone in western Anatolia represent the eastward continuation of the Cycladic Blueschist Unit (CBU) in Turkey. This high-P unit is attributed to the closure of the Pindos Ocean and consists of (a) a Triassic to Upper Cretaceous coherent series derived from passive continental margin sediments and (b) the tectonically overlying Upper Cretaceous Selçuk mélange with eclogite blocks embedded in a pelitic epidote-blueschist matrix. The coherent series has experienced epidote-blueschist facies metamorphism (490 ± 25°C/11.5 ± 1.5 kbar; 38 km depth). 40Ar/39Ar white mica and 206Pb/238U monazite dating of quartz metaconglomerate from coherent series yielded middle Eocene ages of 44 ± 0.3 and 40.1 ± 3.1 Ma for epidote-blueschist facies metamorphism, respectively. The epidote-blueschist facies metamorphism of the matrix of the Selçuk mélange culminates at 520 ± 15°C/13 ± 1.5 kbar, 43 km depth, and is dated at 57.5 ± 0.3–54.5 ± 0.1 Ma (40Ar/39Ar phengite). Eclogite facies metamorphism of the blocks (570 ± 30°C/18 ± 2 kbar, 60 km depth) is early Eocene and dated at 56.2 ± 1.5 Ma by 206Pb/238U zircon. Eclogites experienced a nearly isothermal retrogression (490 ± 40°C/~6 to 7 kbar) during their incorporation into the Selçuk mélange. The retrograde overprints of the coherent series (410 ± 15°C/7 ± 1.5 kbar from Dilek Peninsula and 485 ± 33°C/~6 to 7 kbar from Selçuk–Tire area) and the Selçuk mélange (510 ± 15°C/6 ± 1 kbar) are dated at 35.8 ± 0.5–34.3 ± 0.1 Ma by 40Ar/39Ar white mica and 31.6 ± 6.6 Ma by 206Pb/238U allanite dating methods, respectively. Regional geological constrains reveal that the contact between the MM and the CBU originally formed a lithosphere-scale transform fault zone. 40Ar/39Ar white mica age from the contact indicates that the CBU and the MM were tectonically juxtaposed under greenschist facies conditions during late Eocene, 35.1 ± 0.3 Ma.  相似文献   
56.
The aim of this study was to investigate long-term seasonal trends and decadal change patterns of monthly mean water vapor pressure (WVP) observation series at 16 meteorological stations scattered point-wisely over the Southeastern Anatolian Project (GAP) area in Turkey, where large-scale soil and water development projects have been put into practice since the 1970s. The record length of WVP observation series of each station varied between 31- and 41-years between 1962 and 2002. The monthly mean WVP observation series of each station was rearranged on seasonal basis. Sequential Mann–Kendall trend test, Sen’s slope estimator, and Spearman’s rank–order correlation tests were employed for detection of likely trends, and Kruskall–Wallis test was used to detect decadal variations in WVP series of each observation station. A possible area of representation for each meteorological station was determined by using the Thiessen polygons technique in a geographical information systems media. It was found that 15 seasonal WVP series have a positive trend covering 97% of the GAP area in the summer season; although one WVP series has a negative trend direction. However, in the spring season, 33% of the area had a positive trend, and a negative trend did not appear in any stations. WVP records in the winter season showed an increasing trend over 19% of the GAP area, whereas a decreasing trend prevailed in 9% of the area. The study results led us to conclude that the substantial increase of WVP observations in summer season could be attributed to both the shift from rain-fed agriculture to irrigated agriculture being made increasingly spacious year by year and building large water reservoirs in the GAP located in a semi-arid region. The results also indirectly suggested that the historical trends in the WVP parameters might be related to global climate change phenomenon.  相似文献   
57.
Paleomagnetic results obtained from Upper Cretaceous sandstones in Northeastern Anatolia demonstrate that the entire area from Erzincan to Kars has been remagnetised. The remagnetisation was acquired before the Middle Eocene collision between the Eastern Pontides and the Arabian Platform because Middle Eocene sandstones carry primary natural remanent magnetisations. The post-folding in situ mean direction of the Upper Cretaceous sandstones is compared with mean directions of younger, Middle Eocene to present rock formations. As a result, a two-stage antagonistic rotation mechanism is proposed. First, the collision between the Pontides and the Taurides between Late Cretaceous and Middle Eocene was associated by clockwise rotation of  ~ 26°. In the second stage between Middle Eocene and Middle Miocene and beyond, counterclockwise rotations up to ~ 52° of the Pontide and Anatolide blocks and clockwise rotations of the Van Block were characterised by regional shortening and westward escape.  相似文献   
58.
An on‐line solid phase extraction method for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry has been described. The procedure is based on the retention of Cu(II) ions at pH 6.0 on a minicolumn packed with Amberlite XAD‐1180 resin impregnated with chrome azurol S. After preconcentration, Cu(II) ions adsorbed on the impregnated resin were eluted by 1 mol L?1 HNO3 solution. Several parameters, such as pH, type of eluent, flow rates of sample and eluent solutions, amount of resin were evaluated. At optimized conditions, for 3.5 min of preconcentration time, the system achieved a detection limit of 1.0 µg L?1, and a relative standard deviation of 1.2% at 0.2 µg mL?1 copper. An enrichment factor of 56‐fold was obtained with respect to the copper determination. The proposed method was successfully validated by the analysis of standard reference material (TMDA 54.4 lake water) and recovery studies. The method was applied to the preconcentration of Cu(II) in natural water samples.  相似文献   
59.
Abstract

An attempt was made to compensate for the lack of long hydrological time series and the lack of information on maximum streamflow in the Alzette River basin (Luxembourg) via the regionalization of stormflow coefficients. Streamflow data recorded since 1995 with a very dense streamgauge network allowed the determination of maximum stormflow coefficients in 18 sub-basins of the Alzette. The stormflow coefficients were then regionalized via stepwise multiple regression analysis for 83 different sub-basins of the Alzette. Combined with 10-year daily rainfall heights (statistical estimation), this regionalization allowed the spatial variability of storm runoff in the Alzette basin to be mapped, thus providing a view of hazard and risk-producing areas, as well as of risk-exposed areas. In a basin with little historical hydrological information this technique can help identify areas where storm runoff reducing measures should be applied from the outset.  相似文献   
60.
In order to simulate earthquake ground motions for the Instanbul (Turkey) region, acceleration time series from western Turkey are modeled by transforming the series into a stationary one which can be described by an autoregressive moving-average (ARMA) process. The ARMA and other parameters used in the stationary transformation are related to physical parameters (e.g. magnitude, distance to epicenter, depth to hypocenter and duration) via a regression analysis. To create simulations for a given set of physical parameters, the modelling procedure is reversed.  相似文献   
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