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71.
The processes of formation and distribution of the resources of fresh groundwater and surface water in the territory of Crimea Peninsula are considered. Water availability in the natural–historic and administrative regions of the republic is characterized. The proportions between different categories of groundwater resources are shown with their role in water supply to Crimea taken into account. The presentday development of groundwater resources is analyzed and the possible increase in water consumption meeting geoecological requirements is substantiated. 相似文献
72.
Zusammenfassung Der Eisengehalt von Andalusiten und Disthenen aus Quarzknauern im Gebiet des Ötztaler—Stubaier Altkristallins wurde regional untersucht. Der Gehalt and Gesamteisen in primären Disthen liegt zwischen 0,17 und 0,22 Gew.% Fe2O3, während primäre Andalusite zwischen 0,26 und 1,93 Gew.% Fe2O3 schwanken. Dieser Unterschied in den Andalusiten wird auf ein wechselndes Angebot von Fe2O3 aus dem Nachbargestein der Knauern zurückgeführt.Ein Zusammenhang zwischen dem Eisengehalt der Andalusite und den verschiedenen Umwandlungsstadien Andalusit—Disthen konnte nicht nachgewiesen werden.
On the iron content of alumosilicates in quartz nodules
Summary A determination of the regional distribution of the ironcontent of andalusites and kyanites in quartz-segregations of the Oetztal—Stubai crystalline complex gave values of 0.17–0.22% for the total iron in primary kyanite and 0.26–1.93% in andalusite. This difference is probably due to a variation in the Fe2O3-content in the country rocks of the quartz veins. No relationship between the iron-content in andalusite and the different stages of transformation from andalusite to kyanite could be established.相似文献
73.
本文系统地研究了鄂尔多斯盆地南部延长组凝灰岩元素和同位素地球化学特征。结果表明:凝灰岩主量元素具有高K、高Al、Si中等至高、低Na的特征; REE总体特征为轻稀土富集、重稀土亏损,∑REE在4857~40212 μg/g 之间变化,Eu呈现出负异常,在034~082内变化,δCe范围在080~208之间; 微量元素中U含量在312~144 μg/g 之间,Ba、U、Th、Hf和Ce呈明显正异常,Nb、P、Ti和Rb呈现负异常。详细的分析表明:U的富集和一些微量元素如Ta、Dy、Lu等相关,Th与∑REE存在明显的正相关性,这些变化可能和盆地中铀矿的富集有关; 凝灰岩的硫同位素总体呈现深源特征。根据以上的研究对凝灰岩的形成原因及形成环境进行了探讨。鄂尔多斯盆地南部延长组凝灰岩来源于秦岭造山带火山作用,其中的铀元素富集是由于砂岩型铀矿中铀向凝灰岩迁移而被还原所致。本研究对盆地砂岩型铀矿的铀运移和富集机理认识具有一定指导意义。 相似文献
74.
We augment our scenario for the formation of astronomical objects from macroscopic superstrings by the assumption that the central matter keeps its identity in the fragmentation. From the condition that the angular momentum per mass squared of this matter should be less than the Kerr limit G/c, we obtain upper limits for the ratio of the mass of central black holes M(BH) to the mass M of the host object. This limit is M(BH)/M ≈ 0.001, and, expressed in observed quantities, approximately M(BH)/M ≈ σ2/(v · c) where σ is the r.m.s. velocity, v the rotational velocity and c the velocity of light. The valuesM(BH) agree with the observed behaviour both in order of magnitude and in the variation with velocity dispersion. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
75.
The Dynamical Attitude Model (DAM) is a simulation package developed to achieve a detailed understanding of the Gaia spacecraft attitude. It takes into account external physical effects and considers internal hardware components controlling the satellite. The main goal of the Gaia mission is to obtain extremely accurate astrometry, and this necessitates a good knowledge of Gaia’s behaviour as a spinning rigid body under the influence of various perturbations. This paper describes these perturbations and how they are modelled in DAM. 相似文献
76.
77.
The solar eclipse 1966 May 20 was observed at 3.2, 10, 15, 20, 54, 59 cm, 1.05, 1.34 and 2.7 m wavelength by the observatories of the Heinrich-Hertz-Institut. The meter-wavelength observations were superposed by a noise storm. The result shows a region of enhanced radiation from the plages near the central meridian at the short wavelengths. Consulting additionally the observations made at Kiel, NERA, and Ondejov in the region of about 1.2 m wavelength it is possible to localize the source of the noise storm. 相似文献
78.
This paper, based on a real world case study (Limmat aquifer, Switzerland), compares inverse groundwater flow models calibrated with specified numbers of monitoring head locations. These models are updated in real time with the ensemble Kalman filter (EnKF) and the prediction improvement is assessed in relation to the amount of monitoring locations used for calibration and updating. The prediction errors of the models calibrated in transient state are smaller if the amount of monitoring locations used for the calibration is larger. For highly dynamic groundwater flow systems a transient calibration is recommended as a model calibrated in steady state can lead to worse results than a noncalibrated model with a well-chosen uniform conductivity. The model predictions can be improved further with the assimilation of new measurement data from on-line sensors with the EnKF. Within all the studied models the reduction of 1-day hydraulic head prediction error (in terms of mean absolute error [MAE]) with EnKF lies between 31% (assimilation of head data from 5 locations) and 72% (assimilation of head data from 85 locations). The largest prediction improvements are expected for models that were calibrated with only a limited amount of historical information. It is worthwhile to update the model even with few monitoring locations as it seems that the error reduction with EnKF decreases exponentially with the amount of monitoring locations used. These results prove the feasibility of data assimilation with EnKF also for a real world case and show that improved predictions of groundwater levels can be obtained. 相似文献
79.
A. F. Morozov B. N. Khakhaev O. V. Petrov V. I. Gorbachev G. V. Tarkhanov L. D. Tsvetkov Yu. M. Erinchek A. M. Akhmedov V. A. Krupenik K. Yu. Sveshnikova 《Doklady Earth Sciences》2010,435(1):1483-1486
A thick (200 m) rock salt mass covering Late Archean granitoids was exposed for the first time in the Early Proterozoic volcanogenic-sedimentary
formations in the Onega trough of the east Baltic Shield by the Onega parametric well. The mineral composition of salts, their
geochemical features, and the isotopic composition of carbonate carbon and oxygen have been studied. After fluid inclusions
present in salts, their metamorphism temperature and isotopic composition of helium and argon were determined. The obtained
results give evidence of the fact that rock salts and magnesites associated with them were formed in an evaporate basin with
participation of deep crustal processes. The age of the underlying granitoids (2.716 ± 9 Ma) is determined using the Pb—Pb
method. 相似文献
80.