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581.
We report an experimental study of ultra-high-frequency chaotic dynamics generated in a delay-dynamical electronic device. It consists of a transistor-based nonlinearity, commercially-available amplifiers, and a transmission-line for feedback. The feedback is band-limited, allowing tuning of the characteristic time-scales of both the periodic and high-dimensional chaotic oscillations that can be generated with the device. As an example, periodic oscillations ranging from 48 to 913 MHz are demonstrated. We develop a model and use it to compare the experimentally observed Hopf bifurcation of the steady-state to existing theory [Illing and Gauthier, Physica D 210, 180 (2005)]. We find good quantitative agreement of the predicted and the measured bifurcation threshold, bifurcation type and oscillation frequency. Numerical integration of the model yields quasiperiodic and high dimensional chaotic solutions (Lyapunov dimension approximately 13), which match qualitatively the observed device dynamics. 相似文献
582.
583.
Gediminas Galinis Gauthier Torricelli Atea Akraiam Klaus von Haeften 《Journal of nanoparticle research》2012,14(8):1-6
Experimental studies have been performed on unisize tungsten clusters constructed on a graphite surface by means of the scanning tunneling microscopy. It was found that the geometry of the clusters changes instantaneously from a monatomic-layer tungsten disk to a diatomic-layer structure between the cluster size of 10 and 11. We concluded that this transition is driven by a change in the dominant interaction from the attractive electrostatic interaction between the cluster and the surface to intracluster cohesive metallic interaction. 相似文献
584.
585.
Jacques-Louis Lions (1928-2001) was an exceptional mathematician, whose lasting influence is still deeply felt all over the world.He was a universally recognized and admired expert in partial differential equations, to the study of which he has made outstanding contributio 相似文献
586.
Xiaoxuan Yang Shreya Mukherjee Thomas O'Carroll Prof. Yang Hou Prof. Meenesh R. Singh Prof. Joseph A. Gauthier Prof. Gang Wu 《Angewandte Chemie (International ed. in English)》2023,62(10):e202215938
Unrestrained anthropogenic activities have severely disrupted the global natural nitrogen cycle, causing numerous energy and environmental issues. Electrocatalytic nitrogen transformation is a feasible and promising strategy for achieving a sustainable nitrogen economy. Synergistically combining multiple nitrogen reactions can realize efficient renewable energy storage and conversion, restore the global nitrogen balance, and remediate environmental crises. Here, we provide a unique aspect to discuss the intriguing nitrogen electrochemistry by linking three essential nitrogen-containing compounds (i.e., N2, NH3, and NO3−) and integrating four essential electrochemical reactions, i.e., the nitrogen reduction reaction (N2RR), nitrogen oxidation reaction (N2OR), nitrate reduction reaction (NO3RR), and ammonia oxidation reaction (NH3OR). This minireview also summarizes the acquired knowledge of rational catalyst design and underlying reaction mechanisms for these interlinked nitrogen reactions. We further underscore the associated clean energy technologies and a sustainable nitrogen-based economy. 相似文献
587.
A.M.C. Dawes D.J. Gauthier S. Schumacher N.H. Kwong R. Binder A.L. Smirl 《Laser \u0026amp; Photonics Reviews》2010,4(2):221-243
We review recent theoretical and experimental efforts toward developing an all‐optical switch based on transverse optical patterns. Transverse optical patterns are formed when counterpropagating laser beams interact with a nonlinear medium. A perturbation, in the form of a weak switch beam injected into the nonlinear medium, controls the orientation of the generated patterns. Each state of the pattern orientation is associated with a state of the switch. That is, information is stored in the orientation state. A realization of this switch using a warm rubidium vapor shows that it can be actuated by as few as 600 ± 40 photons with a response time of 5 µs. Models of nonlinear optical interactions in semiconductor quantum wells and microresonators suggest these systems are also suitable for use as fast all‐optical switches using this same conceptual design, albeit at higher switching powers. 相似文献