Results 51 to 60 of about 16,712,159 (288)

Artificial optical emissions at HAARP for pump frequencies near the third and second electron gyro-harmonic [PDF]

, 2005
International audienceHigh-power high-frequency radio waves beamed into the ionosphere cause plasma turbulence, which can accelerate electrons. These electrons collide with the F-layer neutral oxygen causing artificial optical emissions identical to ...
F. T. Djuth, T. Pedersen, A. Senior, Hughes, J., Gerken, E., E. Gerken, Marshall, R., Pedersen, T., Senior, A., McCarrick, M., R. Marshall, Djuth, F. T., Kosch, M. J., M. J. Kosch, D. Sentman, J. Hughes, M. McCarrick, Sentman, D.   +17 more
core   +2 more sources

Rapidly Solidified High‐Strength Invar 36 Prepared by Planar‐Flow Melt Spinning

Advanced Engineering Materials, EarlyView.
The Invar 36 alloy was rapidly solidified using the planar‐flow melt‐spinning technique. Ribbon samples with thicknesses ranging from 20 to 160 mm were produced. As the grain size of the ribbon decreased to sub‐micron levels, the hardness increased by more than 2 times.
Bekir Akgül, Mehmet Kul
wiley   +1 more source

Temporal evolution of pump beam self-focusing at the High-Frequency Active Auroral Research Program [PDF]

, 2007
On 4 February 2005 the High-Frequency Active Auroral Research Program (HAARP) facility was operated at 2.85 MHz to produce artificial optical emissions in the ionosphere while passing through the second electron gyroharmonic.
Gerken-Kendall, E., Pedersen, T., Kosch, Mike J., Mishin, E., Watkins, B., Starks, M., Oyama, S., Sentman, D.   +7 more
core   +4 more sources

Vibrational state effect on frequency modulation of harmonic emission from H2+

四川大学学报. 自然科学版, 2019
High-order harmonic generation from H2+ with different vibrational states has been theoretically investigated. The results show that the red-shifts of the harmonics can be found in the lower vibrational states. As the vibrational state increases, the red-
LIU Hang, LI Yi, JING Xiao-Dan, FENG Li-Qiang   +3 more
doaj  

High-Frequency Modeling of Three-Phase Transformers Considering Inter-Phase and Capacitive Coupling Based on Enhanced Magnetic Circuit

IEEE Access
The high-frequency harmonics in the power grid have significantly increased, necessitating the construction of equivalent circuit models for large power transformers under the influence of high-frequency harmonics.
Yingying Wang, Jindi Pang, Xiongyang Cai, Lili Hou   +3 more
doaj   +1 more source

Time-frequency representations of high order harmonics [PDF]

, 2001
We calculate time-frequency representations (TFRs) of high-order short pulse harmonics generated in the interaction between neon atoms and an intense laser field, including macroscopic effects of propagation and phase matching in the non-linear medium ...
Gaarde, Mette B.
core   +1 more source

Materials‐Driven Additive Manufacturing for Electrical Machines: Qualification‐Oriented Design Beyond Geometric Freedom

Advanced Engineering Materials, EarlyView.
This perspective reframes additive manufacturing for electrical machines as a qualification‐limited materials and architecture design problem. It links process–structure–property–performance relationships to magnetic, conducting, dielectric, and thermal property windows, highlighting where AM can enable segmented magnetic circuits, permanent magnet ...
Dénes Fodor, Loránd Szabó
wiley   +1 more source

Chemical State Detection and Charge Transfer in Complex Oxide Heterostructures via In Situ Auger Electron Spectroscopy

Advanced Functional Materials, EarlyView.
In situ Auger Electron Spectroscopy resolves oxidation states with high fidelity during the pulsed laser deposition of multivalent perovskite manganate and vanadate heterostructures. The chemical‐state signature is carried by the valence‐electron population of the transition‐metal cation, read out through the relative intensities of Auger fine ...
Harish Kumarasubramanian, Jayakanth Ravichandran   +1 more
wiley   +1 more source

Coexistence of Bloch and Parametric Mechanisms of High-Frequency Gain in Doped Superlattices

Nanomaterials, 2023
The detailed theoretical study of high-frequency signal gain, when a probe microwave signal is comparable to the AC pump electric field in a semiconductor superlattice, is presented.
Vladislovas Čižas, Natalia Alexeeva, Kirill N. Alekseev, Gintaras Valušis   +3 more
doaj   +1 more source

Optical Signature of Moiré Superlattices Formed by Twisted SrTiO3 Membranes

Advanced Functional Materials, EarlyView.
We discover optical signatures from bonded interfaces in twisted SrTiO3 moiré superlattices, including low‐frequency Raman vibrational modes and strong second‐harmonic generation, consistent with strong interlayer coupling inferred from cross‐sectional electron microscopy and ab initio calculations. ABSTRACT Moiré superlattices formed at the interfaces
T. A. M. Ragib Shahriar, Fumikazu Murakami, Xing He, Konnor Koons, Xinyan Li, Bumseop Kim, Shihan Qin, Varun Harbola, Jochen Mannhart, Yimo Han, Ruijuan Xu, Shengxi Huang, Andrew M. Rappe, Hanyu Zhu   +13 more
wiley   +1 more source