Results 91 to 100 of about 7,991 (237)

Dental development in the tropical gar (Atractosteus tropicus) and the evolution of vertebrate dentitions

open access: yesDevelopmental Dynamics, EarlyView.
Abstract Background Dentitions have diversified enormously during vertebrate evolution, involving reductions, modifications, or allocations to prey seizing and processing regions. A combination of ancient and novel features related to dental and oropharyngeal apparatuses is found in extant lineages of non‐teleost fishes, such as the gars.
Anna Pospisilova   +4 more
wiley   +1 more source

New‐Generation Integrated Devices: Multiple‐Energy Utilization and Integration Systems Based on Perovskite Photovoltaics

open access: yesEcoEnergy, EarlyView.
This review highlights emerging integrated energy systems based on perovskite photovoltaics, including PSC–thermoelectric, photovoltaic–electrochemical, self‐charging, and building‐integrated architectures. By coupling multiple energy conversion and storage pathways, these multifunctional platforms enable enhanced solar utilization, improved stability,
Yihuai Huang   +10 more
wiley   +1 more source

Study on fracture law and energy evolution characteristics of inclined thick-hard roof

open access: yesMeikuang Anquan
Fracture of the inclined thick-hard roof structure is the direct cause of dynamic disasters such as rock burst. To clarify the fracture law and energy evolution characteristics of the inclined thick-hard roof, taking the 1303 working face with inclined ...
Jinliang ZHANG   +7 more
doaj   +1 more source

Weak‐Story Mitigation and Drift Redistribution in Moment‐Resisting Frames Using Stepping Rocking Walls

open access: yesEarthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT This study investigates the seismic response of moment‐resisting frames retrofitted with a stepping rocking wall, with emphasis on weak‐story mitigation and residual drift reduction under both ordinary and pulse‐like ground motions. Nonlinear response‐history analyses are conducted on 9‐story and 20‐story SAC Los Angeles frames.
Mehrdad Aghagholizadeh
wiley   +1 more source

Strong mine pressure appearing mechanism and control at deep buried working face with large mining height

open access: yesMeitan kexue jishu
During the mining of the adjacent working face, the strong mine pressure caused by the hard thick roof has obvious zoning characteristics due to the mining of the previous deeply buried large mining height working face.
Zhaoyuan LEI   +4 more
doaj   +1 more source

Study of Reasonable Hanging Roof Length on Hard Roof

open access: yes, 2011
The thesis, from the character of hard roof on longwall working face, moving character and control request, by establishing mechanical model and theoretic deduced method, achieves supporting strength of the breaker props and pressure interval control ...
Kai, WANG
core   +1 more source

Research on Optimal Width of Coal Pillars in Both Sides of Abandoned Mining Areas and Tunnel Control Technology

open access: yesEnergy Science &Engineering, EarlyView.
This study primarily investigates the optimal width for coal pillar retention in both sides of the worked‐out face section. Taking the 42201 haulage roadway of the 42201 working face at Shengxin Coal Mine as the primary research target, it analyses the optimum width for coal pillar retention through theoretical calculations, numerical simulations, and ...
Shuaifeng Yin   +4 more
wiley   +1 more source

Stability Evaluation and Parametric Optimization of Coal‐Concrete Composite Bearing Systems Under Mine‐Water‐Induced Deterioration: Experiments and FEINN Analysis

open access: yesEnergy Science &Engineering, EarlyView.
Mine‐water immersion tests reveal pronounced coal weakening (vs. minor concrete degradation), identifying coal pillars as the stability‐limiting component in composite dams. A coupled FEINN framework quantifies extreme‐pressure stability and ranks multi‐parameter designs via a normalized multi‐indicator scheme, enabling optimized dam configuration for ...
He Wen   +6 more
wiley   +1 more source

Characteristics and mechanism of strong dynamic load mine pressure in large mining height full-mechanized caving face with multiple thick and hard roof

open access: yesMeitan xuebao
In view of the problems of strong mine pressure such as rapid shrinkage of hydraulic support column and easy support crushing in working face under the fully mechanized caving face with large mining height in multi-layer thick and hard roof of extra ...
Zhen ZHANG   +6 more
doaj   +1 more source

Simulation Study on Energy Release and Weakening Effects of Pre-Fracturing in Hydraulic Fracturing of Thick Hard Roof

open access: yesApplied Sciences
In this study, the thick, hard roof group of the 20103 working face in the Dahaize Coal Mine is used as the research object. UDEC discrete element simulations were conducted to examine fracture-induced energy release characteristics under unweakened conditions and single-layer hydraulic fracturing at different burial depths.
Xiaolong Shi   +5 more
openaire   +1 more source

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