Results 121 to 130 of about 129,213 (353)

An examination of gas compressor stability and rotating stall [PDF]

open access: yes
The principal sources of vibration related reliability problems in high pressure centrifugal gas compressors are the re-excitation of the first critical speed or Resonant Subsynchronous Vibration (RSSV), and the forced vibration due to rotating stall in ...
Fozi, Aziz A.
core   +1 more source

Transition From Lattice Oxygen to Radical‐Mediated Oxidation in Ammonium‐Intercalated Birnessite Catalysts for Selective Valorization of Biomass to Produce Formic Acid

open access: yesAdvanced Functional Materials, EarlyView.
The catalytic valorization of biomass represents an essential approach for achieving sustainable chemical production, with formic acid (FA) being recognized as a valuable platform chemical for hydrogen storage and environmentally friendly synthetic applications.
Yiqi Geng   +6 more
wiley   +1 more source

A Programmable Semiconductor Containing Active Molecular Photoswitches Located in the Crystal's Volume Phase

open access: yesAdvanced Functional Materials, EarlyView.
A novel approach for the design of functional semiconductors is presented, which utilizes the excellent optoelectronic properties of layered hybrid perovskites and the possibility to introduce a molecular photoswitch as the organic spacer. This concept is successfully demonstrated on a coumarin‐based system with the possibility to change the bandgap ...
Oliver Treske   +4 more
wiley   +1 more source

同步带传动纵向振动的分析

open access: yesJixie chuandong, 2002
The axial vibration models and the equation of motion of the transmission timing-belt are established in this paper. According to the equation, the natural frequency and the forced vibration when pulley is eccentric are obtained.
杨玉萍, 钱永明, 沈世德
doaj  

Applications of Jacobi’s Elliptic Functions in Forced Vibration in Nonlinear Rotor Dynamics [PDF]

open access: green, 2021
Gulama-Garip Alisher Ibrayev   +2 more
openalex   +1 more source

Suppression of Photo‐Mediated Traps in Integrated Organic Photovoltaic–Photodetector Devices via N‐Type Self‐Assembly‐Driven Interfacial Engineering

open access: yesAdvanced Functional Materials, EarlyView.
Conventional unstable electron transport layers (ETLs) limit self‐powered organic sensors. This work resolves this by developing a n‐type self‐assembled monolayer (SAM), “3‐PAPh”. This SAM forms a chemically stable and structurally ordered interface that fundamentally suppresses defect formation.
Ohhyun Kwon   +11 more
wiley   +1 more source

Digital Actuation Control of Soft Robotic Origami With Self‐Folding Liquid Crystal Elastomer Hinges

open access: yesAdvanced Functional Materials, EarlyView.
Self‐folding soft‐rigid hybrid robotic origami is enabled by liquid crystal elastomer actuators with embedded Joule heating and closed‐loop digital control. Digitally addressable hinges provide reversible and programmable transitions between distinct folded states while maintaining actuation performance at high cycle counts (over 1500).
David C. Bershadsky   +3 more
wiley   +1 more source

Scalable Thermal Engineering via Femtosecond Laser‐Direct‐Written Phononic Nanostructures

open access: yesAdvanced Functional Materials, EarlyView.
This study demonstrates that femtosecond laser‐induced periodic surface structures (fs‐LIPSS) can function as phononic metasurfaces, reducing thermal conductivity below the plain thin‐film limit. Phonon Monte Carlo analysis reveals that the periodic structures restrict phonon mean free paths.
Hiroki Hamma   +4 more
wiley   +1 more source

Planning, creating and documenting a NASTRAN finite element model of a modern helicopter [PDF]

open access: yes, 1985
Mathematical models based on the finite element method of structural analysis as embodied in the NASTRAN computer code are widely used by the helicopter industry to calculate static internal loads and vibration of airframe structure.
Gabal, R.   +3 more
core   +1 more source

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