Results 61 to 70 of about 33,183,762 (290)
Meitan xuebaoThe fully mechanized top-coal caving support is a critical device that serves both as a support mechanism and an active means for top-coal caving in fully mechanized top-coal caving mining operations.
Qingliang ZENG +5 more
doaj +1 more source
Import Wheat Tenders and the Effects of the Russian Invasion
Agribusiness, EarlyView.ABSTRACT Risk and volatility for many commodities escalated sharply following the Russian invasion of Ukraine, creating numerous uncertainties for trading firms and importers. The purpose of this study is to analyze the bidding behavior in Egyptian wheat import tenders in the pre‐ and post‐invasion periods.
William W. Wilson +2 more
wiley +1 more source
Optimization of Caving Technology in an Extrathick Seam with Longwall Top Coal Caving Mining
Advances in Materials Science and Engineering, 2021 The optimization of top coal caving technology is an efficient method to improve the recovery ratio in longwall top coal caving (LTCC). In extrathick coal seams, the conventional single-opening sequential caving technology (SOSCT) shows the following ...
Liu Yang, Lianghui Li, Weijie Wei
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Behaviors of overlying strata in extra-thick coal seams using top-coal caving method
, 2016 Accidents such as support failure and excessive deformation of roadways due to drastic changes in strata behaviors are frequently reported when mining the extra-thick coal seams Nos.
Bin Yu
semanticscholar +1 more source
digitAR - Digital Journal of Archaeology, Architecture and Arts, 2018 This paper presents the results of the geophysical survey to mapping a section of the "Lapa do sono" cave, situated in Serra da Arrábida (Sesimbra), which is known to have had funerary occupation in the old Neolithic Age. Nowadays this cave finds itself widely obstructed by sediments, whose extension we intent know.
Caldeira, Bento +5 more
openaire +2 more sources
Frontiers in Earth Science, 2022 With the ending of deep-concave open-pit phosphorite extractions and gradual exhausting of shallow mineral resources, stoping of phosphorite seams has entered or will enter into underground mining.
Xiaoshuang Li +5 more
doaj +1 more source
The Anatomical Record, EarlyView.Abstract The Pleistocene is a key period for understanding the evolutionary history and palaeobiogeography of the European rabbit (Oryctolagus cuniculus). The species was first documented in southeastern Iberia at the beginning of the Middle Pleistocene and appears to have rapidly spread throughout Southwestern Europe, where it was found in numerous ...
Maxime Pelletier
wiley +1 more source
MATEC Web of Conferences, 2015 According to the characteristics of the 1-2 coal seam of Shangwan coal mine 4th panel, this research analyzed the feasibility of sublevel caving hydraulic support in the fully-mechanized mining face through estimation method and numerical simulation ...
Liu Yingjie, Wang Xiaomou
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The Anatomical Record, EarlyView.Abstract Neandertals are known to possess very distinctive traits in their bony labyrinth morphology, such as an inferiorly positioned posterior canal and a very low number of turns in the cochlea. Hence, the inner ear has been often used to assess the Neandertal status of fragmentary fossils.
Alessandro Urciuoli +6 more
wiley +1 more source
Method of tail beam posture prediction of top coal caving hydraulic support based on LSTM
Meitan kexue jishuFully mechanized caving is the main mining method for extra-thick coal seams in my country. The control accuracy of the caving actuator depends largely on the data feedback of the tail beam posture.
Yupeng YAO, Jinglin ZHANG, Wu XIONG
doaj +1 more source