Results 251 to 260 of about 94,387 (307)

Acceleration of Diels-Alder reactions by mechanical distortion

Science, 2023
Challenges in quantifying how force affects bond formation have hindered the widespread adoption of mechanochemistry. We used parallel tip-based methods to determine reaction rates, activation energies, and activation volumes of force-accelerated [4+2] Diels-Alder cycloadditions between surface-immobilized anthracene and four dienophiles that differ in
Yerzhan S. Zholdassov, Li Yuan, Sergio Romero Garcia, Ryan W. Kwok, Alejandro Boscoboinik, Daniel J. Valles, Mateusz Marianski, Ashlie Martini, Robert W. Carpick, Adam B. Braunschweig   +9 more
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Mechanical aspects of chest wall distortion

Journal of Applied Physiology, 1985
During passive inflation of the respiratory system, the rib cage (RC) expands because the pressure applied to it [approximately equal to abdominal pressure (Pab)] increases. Similar Pab-tidal volume (VT) relationships between passive and spontaneous inspirations would occur only if 1) Pab acts on RC equally in the two situations (no distortion) or 2 ...
Mortola JP, SAETTA, MARINA, Fox G, Smith B, Weeks S.   +4 more
openaire   +3 more sources

Mechanical distortions in advanced photomasks

SPIE Proceedings, 1998
Finite element (FE) models have been developed to determine mechanical distortions produced by photomask - blank fabrication. The fabrication process involves the deposition of stressed thin films and the removal of parts of those films, the latter of which is referred to as pattern transfer.
Andrew R. Mikkelson, Roxann L. Engelstad, Edward G. Lovell   +2 more
openaire   +1 more source

Mechanisms for phase distortion in a traveling wave tube

Physical Review E, 2004
We present a view of the physics of phase distortion in a traveling wave tube (TWT) based on unique insights afforded by the MUSE models of a TWT [IEEE Trans. Plasma Sci. 30, 1063 (2002)]]. The conclusion, supported by analytic theory and simulations, is that prior to gain compression phase distortion is due to harmonic frequencies in the electron beam
John G, Wöhlbier, John H, Booske
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Hierarchical watermarking technique of distortion control mechanism

Proceedings of the 2nd international conference on Ubiquitous information management and communication, 2008
This paper proposed an effective information hiding scheme. The proposed scheme calculates the confidential information from a medium and embeds the information into the medium to generate the stego medium for medium integrity protection. When necessary, the verifier can extract the embedded information from the stego medium to authenticate whether the
Tzu-Chuen Lu, Li-Ling Hsu
openaire   +1 more source

Influence of mechanical distortion on the solubility of fluorapatite

Minerals Engineering, 2007
The effect of grinding on the solubility of fluorapatite from the Burenkhaan deposit, Mongolia, has been studied. Mechanical activation distorts the crystalline structure and reduces the particle size, but did not result in the observation of any new crystalline phases.
A. Minjigmaa, J. Temuujin, D. Khasbaatar, G. Oyun-Erdene, J. Amgalan, K.J.D. MacKenzie   +5 more
openaire   +1 more source

CueR activates transcription through a DNA distortion mechanism

Nature Chemical Biology, 2020
The MerR-family transcription factors (TFs) are a large group of bacterial proteins responding to cellular metal ions and multiple antibiotics by binding within central RNA polymerase-binding regions of a promoter. While most TFs alter transcription through protein-protein interactions, MerR TFs are capable of reshaping promoter DNA.
Chengli Fang, Steven J. Philips, Xiaoxian Wu, Kui Chen, Jing Shi, Liqiang Shen, Juncao Xu, Yu Feng, Thomas V. O’Halloran, Yu Zhang   +9 more
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Distortion-Free Logrolling Mechanism

2013
In a large population, the first mover advantage causes only a vanishingly small distortion to the unanimity bargaining outcome. However, if the bargainers form parties through which bargaining takes place—as is the case in representative democracies—the first mover distortion remains significant.
openaire   +1 more source

Analysis of the Distortion Mechanism in Delta–Sigma Beamforming

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2016
Dynamic receive beamforming on a Delta-Sigma modulator's low-resolution output bit-stream suffers from a severely increased noise floor, rendering the promising method infeasible. This paper addresses the mechanism behind the increased noise floor. By using multirate theory and bifrequency analysis, we show that the increased noise floor is caused by ...
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