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31.
Khamitov I. M. Bikmaev I. F. Burenin R. A. Glushkov M. V. Melnikov S. S. Lyapin A. R. 《Astronomy Letters》2020,46(1):1-11
Astronomy Letters - An example of simultaneous spectroscopic redshift measurements for a large number of galaxies in a cluster by multiobject spectroscopy with the medium- and low-resolution TFOSC... 相似文献
32.
Alameer Zakaria Elaziz Mohamed Abd Ewees Ahmed A. Ye Haiwang Jianhua Zhang 《Natural Resources Research》2019,28(4):1385-1401
Natural Resources Research - An accurate forecasting model for the price volatility of minerals plays a vital role in future investments and decisions for mining projects and related companies. In... 相似文献
33.
Glacial tills are highly compressible soils composed of loosely cemented sandy silt particles. Their role, for instance, as initial filler materials in geo-technical projects along temperate glacier regions warrant a systematic evaluation of their compressive characteristics. As such, we carry out a series of onedimensional compression tests on re-compacted glacial till samples obtained from Tianmo Gully, Tibet, with the aims of evaluating their compressive behavior under controlled initial stress conditions. The yield stress was determined from the void ratio versus consolidation pressure(e-log) planes. Its compression and swelling behaviors were observed during the primary and secondary compressions of the consolidation tests. From the compression curves, a correlation can be found between the consolidation stress and the void index. In addition, we find that the compression curves of glacial tills collapse into a single curve when normalized by the compression index. The experimental results in this study provide a basic understanding of the compression characteristics of the glacial tills in Tibet, China. 相似文献
34.
Geomagnetism and Aeronomy - The solar activity at different latitudes is analyzed based on daily observations at Kodaikanal, Mount Wilson, Sacramento Peak, and Meudon observatories in the CaIIK... 相似文献
35.
Dzhamalov R. G. Vlasov K. G. Myagkova K. G. Reshetnyak O. S. Safronova T. I. 《Water Resources》2019,46(1):S74-S84
Water Resources - The space–time variations in the Oka basin water chemistry have been considered. The specific features in the river water and groundwater pollution along the Oka channel and... 相似文献
36.
Geomagnetism and Aeronomy - We develop an approach to create a model of the solar extreme ultraviolet spectrum in the wavelength range responsible for dissociation of molecular oxygen... 相似文献
37.
GUDRÚN LARSEN Bryndís G. Róbertsdóttir Bergrún A. Óladóttir JÓN EIRÍKSSON 《第四纪科学杂志》2020,35(1-2):143-154
Hekla volcano is a major producer of large, widespread silicic tephras. About 3000 years ago, the dominant eruption mode shifted from infrequent large (>1 km3) to more frequent moderate (<1 km3) eruptions. In the following two millennia ≥20 explosive silicic-to-intermediate eruptions occurred, and six or more basaltic. Three categories can be identified with dacite/andesite to basaltic andesite in the oldest eruptions through basaltic andesite to basalt in the youngest eruptions. Ten tephra layers of the first category have distinct field characteristics: a pale lower unit and a dark upper unit (two coloured or TC-layers). Colour separation is sharp indicating a stratified magma chamber origin. The lower unit is dominantly andesitic (61–63% SiO2), while the upper unit is basaltic andesite (53–57% SiO2). Volumes of the eight largest TC-layers range from 0.2 to 0.7 km3 as freshly fallen. Radiocarbon and soil accumulation rate dates constrain the TC-layers to between 3000 and 2200 years ago. Two of these (~2890 and ~2920 b2k) are likely to occur overseas. Low SiO2 in the last erupted tephra of the TC-layers is comparable to that of historical Hekla lavas, implying a final effusive phase. The Hekla edifice may, consequently, be younger than 3000 years. 相似文献
38.
Matishov G. G. Ilyin V. G. Usyagina I. S. Valuyskaya D. A. Kirillova E. E. 《Doklady Earth Sciences》2020,494(1):730-734
Doklady Earth Sciences - This paper analyzes data on the concentration and dynamics of 137Cs and 90Sr in marine organisms on the Arctic shelf under modern conditions (2013–2018). It is shown... 相似文献
39.
Oceanology - Based on benthic foraminifera from three sediment cores, the deep-water circulation near the Hunter Channel (Southwest Atlantic) in the Late Pleistocene and Holocene has been... 相似文献
40.
Sauermilch Isabel Mateo Zenon Richard P. Boaga Jacopo 《Marine Geophysical Researches》2019,40(4):635-641
Marine Geophysical Research - Time–depth relationships (TDR) are required for correlating geological information from drill sites with seismic reflection profiles. Conventional... 相似文献