Results 51 to 60 of about 11,011,498 (241)
Open Geosciences, 2019 Aiming at the problem of the sudden increase of the working resistance of the support in the transition section of the mixed workface, this paper adopts the physical simulation to study the fracture and movement characteristics of the overburden strata ...
Tai Yang, Guo Shuai, Fang Kun
doaj +1 more source
Applied Economic Perspectives and Policy, EarlyView.ABSTRACT We conducted two framed field economic experiments with citrus farmers in Florida, United States and soybean farmers in Argentina to investigate their willingness to coordinate pest and weed management efforts. Despite the contrast between these two agricultural contexts, we find striking behavioral commonalities.
Ariel Singerman, Sergio H. Lence
wiley +1 more source
Energies, 2021 China recently implemented a “Green Mine” policy focused on promoting the filling method, aiming to mitigate the environmental impacts of underground mining; nevertheless, quantitative inventories have rarely been provided to support or negate such ...
Yang Liu +5 more
doaj +1 more source
Technique of top coal caving with vibration [PDF]
, 2009 How to understand the top coal caving process and increase the top coal recovery ratio is one of the urgent problems to be resolved for the longwall top coal caving technology.
Xie, Yao-she, Zhao, Yang-sheng
core +1 more source
Unsteady flow model of caving materials at the caving window.
, 2023 Point P on the top is the vertex of the spheroid geometry in Fig 6. Section A-A is the boundary between the main roof and caved immediate roof; Section B-B is the coal-roof mass boundary before caving operation; Section C-C is the coal-roof mass boundary
Chunhua Zhang (148898) +3 more
core +1 more source
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
Beating the Standard Quantum Limit With Single‐Photon‐Added Coherent States
Advanced Physics Research, EarlyView.The standard quantum limit (SQL) defines how quantum fluctuations of light constrain measurement precision. Here, we show that injecting a single‐photon‐added coherent state and a weak coherent state in the input ports of a Mach–Zehnder interferometer reduces phase uncertainty below the SQL.
Pankaj K. Jha +4 more
wiley +1 more source
Open pit or block caving? A numerical ranking method for selection [PDF]
, 2014 Mining in the 21st century is facing many challenges, among which are low-grade and high tonnage orebodies. One great (r)evolution in mining occurred in the early 20th century when Daniel Jackling proposed the concept of economies of scale for large ...
Suorineni, Asi, Rashidi Nejad, F
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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
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