Results 131 to 140 of about 19,738 (285)

Seismic analysis and design of tunnels within fault ground: A review

open access: yesDeep Underground Science and Engineering, EarlyView.
The research methods of seismic response of tunnels within fault ground, including field investigations, analytical solutions, physical experiments, and numerical simulations, and seismic countermeasures are discussed. The present study examines the shortcomings and limitations of the current research and design, and puts forward proposals for future ...
Xingda Wang   +6 more
wiley   +1 more source

Elementary Steps of Energy Conversion in Strongly Correlated Systems: Beyond Single Quasiparticles and Rigid Bands

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
This article reviews the fundamental consequences of strong correlations on excitations and elementary steps of energy conversion leading to new opportunities to control energy conversion. Examples include friction at surfaces, thermal transport, and photovoltaic energy conversion.
Vasily Moshnyaga   +14 more
wiley   +1 more source

Phase‐Change‐Activated Slippery Organogel Composite for All‐in‐One Anti‐Corrosion, Antifouling, and Self‐Cleaning

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
A super‐slippery liquid‐infused composite organogel is engineered by localized interfacial grafting between hydrogel and oleogel networks, endowing the coating with a durable, multifunctional marine‐protective interface. Dynamic antifouling surfaces have emerged as a promising alternative, offering the potential for eco‐friendly and high‐performance ...
Mengsheng Xia   +6 more
wiley   +1 more source

Dibenzosuberene‐Winged Polycyclic Aromatic Hydrocarbons

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
The twisted acene 8, which features two dibenzosuberene “wings”, was prepared by the addition of a crowded aryne to a similarly “winged” cyclopentadienone. Compound 8 is chiral, and it has a high barrier to thermal racemization (ΔG‡rac = 36 kcal/mol), but it undergoes fast photochemical racemization even in ambient light.
Mingshu Xie   +3 more
wiley   +1 more source

The Influence of Different Rocks on Drillstring Stick-Slip Vibration

open access: yesScientific Journal of Technology
This paper establishes a torsional model of a two-degree-of-freedom drill string system composed of a rotary table and bottom-hole assembly, constructs a friction model between the drill bit and rocks, and considers the influence of five different rock types on the stick-slip vibration of the drill string system.
Changshuai Shi, Xin Du
openaire   +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

Optimizing sampling frequency of surface and downhole measurements for efficient stick-slip vibration detection

open access: yesPetroleum
Drilling vibrations significantly impact drilling operations with high costs due to early downhole equipment failure and loss of productive time. Stick-slip vibrations, a severe form of torsional vibrations, is known to be present up to 50% of total ...
Saket Srivastava   +2 more
doaj   +1 more source

NASA rotor system research aircraft flight-test data report: Helicopter and compound configuration [PDF]

open access: yes
The flight test activities of the Rotor System Research Aircraft (RSRA), NASA 740, from June 30, 1981 to August 5, 1982 are reported. Tests were conducted in both the helicopter and compound configurations.
Carter, R. D. G.   +5 more
core   +1 more source

Electronic jelly: Engineering the mechanics of hydrogels for flexible electronics

open access: yesFlexMat, EarlyView.
By unifying mechanical reinforcement strategies—double networks, structural ordering, and dynamic interactions—this review demonstrates how engineered hydrogels can transcend their fragility to achieve the strength, toughness, and reliability required for flexible electronics, including wearable sensors, energy devices, and soft robotic systems ...
Tianfu Zheng   +2 more
wiley   +1 more source

Multi‐material and dual‐stimulus coupled actuation micro‐gears for shape–rotation control in intelligent micro‐electro‐mechanical systems

open access: yesFlexMat, EarlyView.
A multi‐material and dual‐stimulus coupled actuation micro‐gear (MDCAMG) is developed via femtosecond‐laser 3D printing combined with magnetic nanoparticle absorption, enabling integrated environmental sensing and remote actuation at the microscale. The device incorporates a pH‐responsive hydrogel matrix for autonomous swelling/shrinking and a magnetic
Sida Peng, Shengzhi Sun, Jian Li, Yi Zhu
wiley   +1 more source

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