Results 81 to 90 of about 7,336 (254)

Synthesis and Reactivity of 3‐Aminosydnones in Cycloaddition Reactions With Alkynes

open access: yesChemistry – A European Journal, EarlyView.
The synthesis, functionalization, and reactivity as dipoles of 3‐aminosydnones have been investigated. These neglected compounds undergo smooth cycloaddition reactions with strained alkynes, leading to 1‐aminopyrazoles. ABSTRACT We present in this article the synthesis, functionalization, and properties of 3‐aminosydnones, a forgotten class of ...
Apolline Dominic   +7 more
wiley   +1 more source

Shear behavior of bolt–grout interfaces under constant normal stiffness: Influence of grout strength and thickness

open access: yesDeep Underground Science and Engineering, EarlyView.
The effects of grout strength and thickness on the shear behavior of bolt–grout interfaces (BGI) under constant normal stiffness conditions are investigated. Shear strength, failure modes, and acoustic emission characteristics are examined. The findings reveal that grout strength exerts a significantly greater influence on BGI shear strength and ...
Sunhao Zhang   +5 more
wiley   +1 more source

Artificial Neural Networks for Earthquake Anomaly Detection

open access: yesJournal of Advanced Computational Intelligence and Intelligent Informatics, 2014
Earthquakes are natural disasters caused by an unexpected release of seismic energy from extreme levels of stress within the earth’s crust. Over the years, earthquake prediction has been a controversial research subject that has challenged even the smartest ofminds.
Aditya Sriram   +2 more
openaire   +1 more source

Experimental study on burning rate and flame geometry in construction tunnel fires under high geothermal conditions

open access: yesDeep Underground Science and Engineering, EarlyView.
Abstract As tunnel construction advances in lengths and depths, the construction of tunnels in high geothermal environments has become increasingly common, raising significant fire risks. In this study, a 1:20 scale model tunnel test platform was constructed to investigate the effects of a high geothermal environment on fire behavior in tunnels during ...
Xiaoxian Fei   +6 more
wiley   +1 more source

Permeability of granite from a shallow buried mountain pipe gallery tunnel under unloading confining pressure

open access: yesDeep Underground Science and Engineering, EarlyView.
Triaxial compression tests under unloading confining pressure conditions were conducted to systematically analyze the permeability behavior of granite retrieved from the different classification surrounding rocks. Abstract The rock mass within mountain tunnels undergoes complex changes in permeability, strength, and deformation during tunneling ...
Xiaoyan Zhang   +4 more
wiley   +1 more source

An assessment of stress and production rate of sucker rod heat pipes in oil well pumping system

open access: yesDeep Underground Science and Engineering, EarlyView.
The sucker rod pumping system is the preferred oil extraction technique. The concept about equipping the hollow vacuum space in solid sucker rods with heat pipe has been scrutinized in terms of stress and oil production evaluation. Abstract The implementation of the heat pipe concept in sucker rods for oil pumping systems negates the requirement for an
R. S. Anand   +5 more
wiley   +1 more source

Real‐time lithology identification while drilling based on drill cuttings image analysis with ensemble learning

open access: yesDeep Underground Science and Engineering, EarlyView.
A lithology identification while drilling method was developed, integrating an automated cuttings sampling system, a smart drilling rig, and an ensemble learning model. Underground trials achieved 97.42% accuracy in real‐time identification of cuttings lithology and composition, enhancing hazard management and supporting unmanned drilling technology in
Kun Li   +7 more
wiley   +1 more source

The damage and failure mechanism of prestatically loaded rock during medium‐strain rate cyclic impact loading

open access: yesDeep Underground Science and Engineering, EarlyView.
Based on experimental results and theoretical analysis, an established rock damage accumulation model that comprehensively considers the preapplied static load, impact peak value, impact frequency, and impact times. Abstract To study the rock damage mechanism under high static loading and superimposed medium strain rate cyclic impact loading, a series ...
Wei Wang   +6 more
wiley   +1 more source

Critical expansion points: Mechanical signs of surrounding rock instability

open access: yesDeep Underground Science and Engineering, EarlyView.
This study proposes the Rock Bearing‐Expansion Model (RockBEM) with critical expansion points (CEPs) to quantify post‐peak damage stages in deep‐buried rock masses via plane strain compression test (PSCT). CEP hysteresis&interval ratios reveal bearing performance dynamics and failure severity, advancing mechanistic insights into deep underground rock ...
Jiaqi Wen   +4 more
wiley   +1 more source

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