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91.
This paper addresses the geochemical features of the noble metal disseminated sulfide and Timagnetite mineralization in the rocks of the Kalar group of autonomous gabbro-anorthosite massifs. The investigations suggest that this mineralization was formed in two stages. The first stage is related to the gabbroanorthosites proper and may be promising for low-sulfide PGE mineralization as well as PGE-bearing Ti-magnetite mineralization, while the second stage is linked to the ultrabasic intrusions associated with copper-nickel or chromite mineralization accompanying by PGE. The horizons of low-sulfide mineralization in the gabbro-anorthosites and copper-nickel mineralization in the dunite-pyroxenites are characterized by the Pd predominance over Pt, while the Cr-bearing and Ti-magnetite ores show the Pt predominance over Pd. 相似文献
92.
We have estimated the upper and lower limits of sunspot activity, in terms of active day fraction during the Maunder minimum
(1645–1710), using raw information on individual daily observations (Hoyt and Schatten, 1998). Establishing the relation between
the sunspot activity and active day fraction after 1850, we evaluate the upper limit of annual group sunspot number during
the deep Maunder minimum (1645–1700) which does not exceed 4. The earlier finding of a dominant 22-year periodicity during
the Maunder minimum is verified and shown to be robust. Also we confirm that the start of the Maunder minimum was very abrupt. 相似文献
93.
94.
95.
J. I. Rostovceva A. N. Stafeev T. V. Sukhanova I. V. Latysheva V. L. Kosorukov 《Moscow University Geology Bulletin》2016,71(4):281-289
Based on the spore-pollen data, the mineral composition of clay rocks, analyzed structures and facies, and a general paleogeographic analysis, the sedimentation conditions and landscapes of islands located during the Late Bajocian in the region of the present-day the Crimean Mountains have been reconstructed. It is shown that the sublatitudinally elongated insular land zone had a width of 30 km, the heights of the islands were no more than 1 km, with steep mudflow-affected northern slopes and with an extensive river system on the southern slopes. 相似文献
96.
Doklady Earth Sciences - This paper discusses sources of significant errors that occur in the course of determination of the primary environmental standard for natural waters: the maximum... 相似文献
97.
Properly designed precast concrete cladding could potentially provide lateral stiffness, ductility, and energy dissipation for an overall building structure, especially during earthquakes. This paper describes a set of advanced connections that take advantage of the interaction between facade panels and structure (mainly due to horizontal interstorey drift) to dissipate energy, thereby reducing the response of the main structure. The results of an experimental program to characterize the hysteretic behaviour of advanced connections are presented. Design equations for the advanced connections are then calibrated against the test results, and the corresponding design charts are presented. It is anticipated that this research will lead to innovative ways of viewing the entire cladding system of a building. 相似文献
98.
Astronomy Letters - Techniques for solving the problem of constructing a Stäckel model by generalizing the potential from the equatorial plane to the entire space are considered. The initial... 相似文献
99.
Ivanova J. N. Vyhristenko R. I. Vikentyev I. V. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(12):1537-1545
Izvestiya, Atmospheric and Oceanic Physics - The central part of the Malouralsky volcanic–plutonic belt, which includes the Manyukuyu–Vorchatinsky ore cluster, is analyzed using... 相似文献
100.
Five gabarbands (dams), components of integrated soil and water conservation systems, were investigated in the arid region of Sindh Kohistan. The dams are associated with two prehistoric Kot Dijian settlements, Phang and Kohtrash (3200–2800 B. C.). The dams were constructed with relatively permeable materials. Three of the dams, South, East, and North, close off water gaps and a strike valley, respectively, to form a detention basin. The West Dam, located on Phang Nai, upstream of the detention basin removed the coarser sediment fraction from the flows. Spring Dam, located in a water gap to the north of the detention basin, acted as a low-head weir to distribute flow from a perennial spring onto the floodplain of Baran Nai, where double-cropping was probably practiced. Faulting eliminated the spring, which had probably supported the Kohtrash site, and led to construction of the detection basin for the purposes of subsurface storage of detained flows. Association of both modern and prehistoric sites with springs suggests that there has not been appreciable climate change in Sindh Kohistan in the last 5000 years. © 1993 John Wiley & Sons, Inc. 相似文献