Results 71 to 80 of about 82,628 (256)

Extent and duration of marine anoxia during the Frasnian– Famennian (Late Devonian) mass extinction in Poland, Germany, Austria and France [PDF]

open access: yes, 2004
– The intensity and extent of anoxia during the two Kellwasser anoxic events has been investigated in a range of European localities using amultidisciplinary approach (pyrite framboid assay, gamma-ray spectrometry and sediment fabric analysis).
Bond, D.P.G., Racki, G., Wignall, P.B.
core   +1 more source

Consecutive D‐Band Center Regulation of Yolk‐Shell Co8FeS8‐FexCy for Enhanced Water Oxidation and Microwave Absorption

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Bifunctional Co8FeS8‐FeXCy for oxygen evolution and microwave absorption. Electronic modulation for balancing oxygen intermediates bending energy over oxygen evolution catalytic active sites is one of the most critical factors but still remains challenging.
Bin Wang   +7 more
wiley   +1 more source

Selenium and tellurium concentrations of Carboniferous British coals [PDF]

open access: yes, 2019
The authors wish to thank Kier Group, the British Coal Utilisation Research Association (BCURA) and Uniper (E.On) for kindly providing coal samples.
Armstrong, Joseph   +7 more
core   +1 more source

Machine Learning‐Driven Classification and Production Capacity Prediction of Tight Sandstone Reservoirs: A Case Study of the Taiyuan Formation, Ordos Basin

open access: yesEnergy Science &Engineering, EarlyView.
On the basis of core and log data, a Bayesian‐Optimized Random Forest model achieved 92.76% accuracy in classifying tight sandstone reservoirs. A gray relational analysis‐derived evaluation index shows > 80% consistency with actual gas zones. ABSTRACT Tight sandstone gas (TSG), an unconventional oil–gas resource, has heterogeneous reservoirs ...
Yin Yuan   +8 more
wiley   +1 more source

Arsenic-bearing phases in South Andean volcanic ashes: Implications for As mobility in aquatic environments [PDF]

open access: yes, 2015
Three samples of volcanic ashes collected after eruptions of the volcanos Hudson in 1991, Chaitén in 2008 and Puyehue in 2011 were analyzed in order to define the solid speciation of arsenic and the dynamics of its release to the aqueous phase.
Bia, Gonzalo Luis   +3 more
core   +1 more source

Origins of the Pangkaimen Au Deposit in the Northern Great Xing'an Range, China: Evidence From Geochronological, Geochemical, Fluid Inclusion, and H–O–S–Pb Isotope Data

open access: yesGeological Journal, EarlyView.
The Pangkaimen Au–Ag deposits belong to the epithermal Au deposits, which are of great significance for guiding the research and development of this type of gold deposit. Metallogenic model diagram of Pangkaimen Au–Ag deposit. ABSTRACT The gold (Au) metallogenic belt in the northern Great Xing'an Range is characterised by the wide occurrence of the ...
Sheng Lu   +8 more
wiley   +1 more source

Replacement of Ores Recorded by Textures and Chemical Compositions of Sphalerite: An Example From the Furutobe Kuroko Deposit, Akita, Japan

open access: yesGeological Journal, EarlyView.
Coupled dissolution‐reprecipitation of early formed Cd‐, Fe‐, Ag‐ and Sb‐poor sphalerite through interaction with high‐temperature and high‐sulphur fugacity Cu‐rich fluids, responsible for the formation of the yellow ores, resulted in the formation of Cd‐, Fe‐, Ag‐ and Sb‐rich, heavily chalcopyrite‐diseased sphalerite and enrichment of critical metals ...
Manuel Nopeia   +4 more
wiley   +1 more source

Interrelationship of hydrology, microbial colonisation and hydrometallurgy in a simulated chalcopyrite heap leach [PDF]

open access: yes, 2008
Includes bibliographical references (leaves 104-115).Chalcopyrite is the most abundant primary copper sulphide mineral found worldwide. As copper grades of ores available for extraction decrease, heap bioleaching is gaining interest as a potential ...
Spurr, Nicholas Robert Louis
core  

Molecular Palaeontology Prospects From Exceptionally Preserved Eocene Brackish‐Water Bivalve Batissa sitakaraensis (Venerida: Corbiculidae) From Hokkaido, Japan

open access: yesGeological Journal, EarlyView.
This study reports the exceptional preservation of the Eocene freshwater bivalve Batissa sitakaraensis from Hokkaido, Japan. Multimodal analyses reveal that both the aragonitic shell mineralogy and the delicate organic periostracum retain their original structural and chemical characteristics after millions of years.
Taro Yoshimura   +4 more
wiley   +1 more source

Influence of Ca2+ and Mg2+ on Pyrite Flotation at Different Slurry Temperatures

open access: yesKuangchan zonghe liyong
This is an article in the field of mineral processing engineering. Through single mineral flotation test, solution chemistry calculation, Zeta potential detection, XPS detection, the influence and regulation mechanism of Ca2+ and Mg2+ on the flotation of
Xin WANG   +4 more
doaj   +1 more source

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