Results 71 to 80 of about 295,573 (332)

Characterization of the permeability evolution of hard and soft rocks under hydro‐mechanical coupling conditions

Deep Underground Science and Engineering, EarlyView.
The permeability variation of rocks during complete stress–strain processes was investigated. A mathematical model describing the influence of rock damage on permeability was constructed. The permeability–stress relationship between soft rock and hard rock was proposed.
Zhen Huang, Jian Yu, Yun Wu, Cong Gong, Xiaozhao Li, Kui Zhao, Dickson Moyo   +6 more
wiley   +1 more source

Sedimentary facies controlled biogeochemical process of biotic extinction and turnover across the Cambrian SPICE event

Communications Earth & Environment
The Steptoean positive carbon isotope excursion (SPICE) event, one of the largest carbon cycle perturbations in the Cambrian, coincides with shallow-shelf-fauna extinction and plankton revolution (critical transition of plankton).
Haozhe Wang, Haizu Zhang, Yiman Zhang, Bin Cheng, Qian Deng, Donghui Wang, Guanyu Zhao, Zewen Liao   +7 more
doaj   +1 more source

Tracing nitrate sources with dual isotopes and long term monitoring of nitrogen species in the Yellow River, China

Scientific Reports, 2017
A heavy load of nitrogenous compounds reflects nutrient loss and influences water quality in large rivers. Nitrogenous concentrations and dual isotopes of nitrate were measured to ascertain the spatial and temporal distributions of nitrate transformation
Fu-Jun Yue, Si-Liang Li, Cong-Qiang Liu, Zhi-Qi Zhao, Hu Ding   +4 more
doaj   +1 more source

Rock magnetic and geochemical evidence for authigenic magnetite formation via iron reduction in coal-bearing sediments offshore Shimokita Peninsula, Japan (IODP Site C0020) [PDF]

, 2017
Sediments recovered at Integrated Ocean Drilling Program (IODP) Site C0020, in a fore‐arc basin offshore Shimokita Peninsula, Japan, include numerous coal beds (0.3–7 m thick) that are associated with a transition from a terrestrial to marine ...
Clyde, William C., Johnson, Joel E., Maxbauer, Daniel P., Phillips, Stephen C., Riedinger, Natascha, Setera, Jacob B., Severmann, Silke   +6 more
core   +1 more source

Strain‐based modeling and analysis for rock blasting and geomechanics applications

Deep Underground Science and Engineering, EarlyView.
This paper introduces a novel strain‐based modeling approach for blasting and geomechanical applications, using measurable variables like particle velocity, strain, and displacement. By bypassing complex constitutive relations, strain‐based models capture critical blasting trends and full‐blast design parameters with minimal calibration.
Ruilin Yang
wiley   +1 more source

Ultrafast core-to-core luminescence in BaF2 - LaF3 single crystals

Scientific Reports
This study investigates the mechanisms underlying the ultrafast cross-luminescence observed in BaF2 crystals doped with LaF3. We identified an ultrafast luminescent component with a decay time of approximately 150 ps, which emerges under excitation ...
Roman Shendrik, Evgeny Radzhabov, Alexandra Myasnikova, Viktorija Pankratova, Anatolijs Šarakovskis, Alexander Nepomnyashchikh, Alexander Bogdanov, Veronika Gavrilenko, Ekaterina Kaneva, Dmitry Sofich, Tatiana Garmysheva, Vladimir Pankratov   +11 more
doaj   +1 more source

Effects of joint geometric configurations on cyclic shear behavior of intermittent joints under constant normal stiffness conditions

Deep Underground Science and Engineering, EarlyView.
The present manuscript explored the effects of joint configurations on the cyclic shear behavior of intermittent joints for the first time. The cyclic shear response, shear strength degradation, dilation characteristics evolution, frictional property, fractal dimension, and dissipative energy were further analyzed during shear cycles, which is crucial ...
Bin Wang, Yujing Jiang, Qiangyong Zhang, Hongbin Chen   +3 more
wiley   +1 more source

Petrological and Geochemical Constraints on the Origin of Early Cretaceous Volcanic Rocks in the Central‐East Asia: Implications for Crustal Growth and Evolution

Geochemistry, Geophysics, Geosystems, 2018
New petrological and geochemical data for Early Cretaceous volcanic rocks in the North China Craton (NCC) combined with published data of cotemporaneous volcanic rocks in the NCC and eastern Central Asian Orogenic Belt (ECAOB) are used to understand ...
Sheng‐Ping Qian, Zhong‐Yuan Ren, Le Zhang, Lei Zhang, Ya‐Dong Wu, Sheng‐Wang Mei, Xiao‐Bo Xu, Qing‐Chen Luo   +7 more
doaj   +1 more source

Probability prediction of true‐triaxial compressive strength of intact rocks based on the improved PSO‐RVM model

Deep Underground Science and Engineering, EarlyView.
In this work, we propose an improved particle swarm optimization (PSO) algorithm and develop an improved PSO‐relevance vector machine (RVM) model as a substitute for traditional true‐triaxial testing. The model's high prediction accuracy was validated through comparisons with two other machine learning methods and five three‐dimensional Hoek–Brown type
Qi Zhang, Maohui Wang, Ning Wang, Yixin Shen, Xuzhen He   +4 more
wiley   +1 more source

National Soils Database [PDF]

, 2007
End of project reportThe objectives of the National Soils Database project were fourfold. The first was to generate a national database of soil geochemistry to complete the work that commenced with a survey of the South East of Ireland carried out in ...
Carrigg, Cora, Carton, Owen T., Fay, Deirdre, Grennan, Eamonn J., Kramers, Gaelene, McGrath, David, O'Flaherty, Vincent, Zhang, Chaosheng   +7 more
core