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Harmonic

About: Harmonic is a research topic. Over the lifetime, 44833 publications have been published within this topic receiving 495922 citations. The topic is also known as: overtone & partial.


Papers
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Journal ArticleDOI
TL;DR: In this article, the phase of high-order harmonic generation from transiently aligned molecules was measured using extreme ultraviolet interferometry and the dispersion relation of the returning electron wave packet as a function of harmonic order was analyzed.
Abstract: We use extreme-ultraviolet interferometry to measure the phase of high-order harmonic generation from transiently aligned ${\mathrm{CO}}_{2}$ molecules. We unambiguously observe a reversal in phase of the high-order harmonic emission for higher harmonic orders with a sufficient degree of alignment. This results from molecular-scale quantum interferences between the molecular electronic wave function and the recolliding electron as it recombines with the molecule, and is consistent with a two-center model. Furthermore, using the combined harmonic intensity and phase information, we extract accurate information on the dispersion relation of the returning electron wave packet as a function of harmonic order. This analysis shows evidence of the effect of the molecular potential on the recolliding electron wave.

114 citations

Patent
07 May 2001
TL;DR: In this paper, a method for reducing the noise in a measured telemetry signal is described, which includes tracking a characteristic of at least one harmonic of a noise component in the measured signal band.
Abstract: A method is disclosed for reducing noise in a measured telemetry signal The method includes tracking a characteristic of at least one harmonic of a noise component in the measured telemetry signal band The at least one harmonic has a frequency outside a telemetry signal band The characteristic of the noise component is determined for at least one other harmonic thereof The at least one other harmonic has a frequency inside the telemetry signal band A noise reference is generated from the characteristic of the in band harmonic, and the noise reference is combined with the measured telemetry signal to generate a noise-canceled telemetry signal

113 citations

Journal ArticleDOI
29 Jun 1992
TL;DR: In this paper, the advantages of using multiple modules of the current-source, sinusoidal pulsewidth-modulation (SPWM), three-phase, six-valve converters as the power conditioner for a superconducting magnetic energy storage system were discussed.
Abstract: The authors point out the advantages of using multiple modules of the current-source, sinusoidal pulse-width-modulation (SPWM), three-phase, six-valve converters as the power conditioner for a superconducting magnetic energy storage system. A high degree of controllability is obtained by using dynamic SPWM trilogic as the operating strategy. Very low switching losses are assured by using two carrier triangles per modulating cycle. By parallel connection of coverter modules and by phase shifting the triangle carriers, the following are the gains: increasing the current capacity to the level required by the superconducting magnet, reducing conduction losses, meeting harmonic standards, without the need for an expensive filter, by harmonic cancellation, and achieving a high frequency bandwidth. >

113 citations

Journal ArticleDOI
TL;DR: In this paper, the propagation of harmonic plane waves in media described by the two-temperature theory of thermoelasticity (2TT) is investigated, and exact dispersion relation solutions are determined and several characterizations of the wave field are examined.

113 citations

Journal ArticleDOI
TL;DR: This paper describes the merits of a recently developed form of a three-phase permanent-magnet (PM) brushless AC machine in which the concentrated coils of each stator phase are wound either on adjacent teeth or on alternate teeth, which offers a number of significant advantages over conventional PM brushless machines.
Abstract: This paper describes the merits of a recently developed form of a three-phase permanent-magnet (PM) brushless AC machine in which the concentrated coils of each stator phase are wound either on adjacent teeth or on alternate teeth. Such a machine is often referred to as modular and offers a number of significant advantages over conventional PM brushless machines. For example, it results in a smaller number of slots for a given number of poles, which is a distinct manufacturing advantage, and yields a fractional number of slots per pole, which is conducive to low cogging torque. It also enables a significant increase in the achievable machine inductance to facilitate constant power operation over a wide speed range by flux weakening. However, the torque in modular machines is developed by the interaction of a high-order stator space harmonic MMF with the PMs, since the fundamental stator MMF has fewer poles than the PM rotor. Hence, significant eddy currents may be induced in the rotor by the fundamental and low-order space harmonic MMFs. The eddy-current loss can, however, be reduced by segmenting the magnets. Given that modular machines combine the high specific power and efficiency of conventional PM brushless machines with a high machine inductance, to enable a wide speed range, constant power operation, their potential for low manufacturing cost, and the fact that they have inherently low cogging torque, they are eminently suitable for in-wheel traction applications.

113 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,223
20222,724
20211,878
20202,330
20192,612
20182,495