Results 31 to 40 of about 345,531 (342)
Relativistic Doppler effect in quantum communication [PDF]
, 2002 When an electromagnetic signal propagates in vacuo, a polarization detector cannot be rigorously perpendicular to the wave vector because of diffraction effects. The vacuum behaves as a noisy channel, even if the detectors are perfect.
Alsing P. M. +7 more
core +2 more sources
Guidelines for ultrasound examination in ophthalmology. Part III: Color Doppler ultrasonography
Journal of Ultrasonography, 2019 The aim of this article was to present the possibilities of use and application of color-coded Doppler ultrasonography in the diagnosis of various diseases of the eyeball and orbit which result from vascular disorders. Color-coded Doppler ultrasonography
Monika Modrzejewska
doaj +1 more source
Doppler-Induced Dynamics of Fields in Fabry-Perot Cavities with Suspended Mirrors [PDF]
, 2001 The Doppler effect in Fabry-Perot cavities with suspended mirrors is analyzed. Intrinsically small, the Doppler shift accumulates in the cavity and becomes comparable to or greater than the line-width of the cavity if its finesse is high or its length is
Abramovici +6 more
core +3 more sources
High-sensitive acquisition method of GPS signal based on iridium assistance
The Journal of Engineering, 2019 Global positioning system (GPS) signal is severely attenuated in indoor, urban, and forest environments. To capture weak GPS signal, long-time coherent integration and non-coherent integration are used to increase signal to noise ratio (SNR).
Hao Zihuan, Zhang Lei
doaj +1 more source
Open Physics, 2021 In a microscopic model of the photoelectric effect, it becomes clear that the conservation of energy is exclusively determined by Doppler shift processes, i.e., the whole energy of the photon vanishes by means of Doppler redshifts.
Schultheiss Christoph
doaj +1 more source
Rotational Doppler effect in left-handed materials
, 2008 We explain the rotational Doppler effect associated with light beams carrying with orbital angular momentum in left-handed materials (LHMs). We demonstrate that the rotational Doppler effect in LHMs is unreversed, which is significantly different from ...
Dianyuan Fan +7 more
core +1 more source
Tomographic Simulations of Accretion Disks in Cataclysmic Variables - Flickering and Wind [PDF]
, 2006 Both continuum and emission line flickering are phenomena directly associated with the mass accretion process. In this work we simulate accretion disk Doppler maps including the effects of winds and flickering flares.
A.P. Linnell +5 more
core +3 more sources
Dizhen xuebao, 2018 本文介绍了全球主要地震机构对2008年5月12日汶川地震参数的速报和修订情况，分析了美国地质调查局国家地震信息中心测定的面波震级。通过对比198个全球地震台站测定的面波震级和面波周期，得出如下结论：测定面波震级偏大的台站主要分布在震中的东北方向，测定面波震级偏小的台站主要分布在震中的西南和东南方向，面波周期偏小的台站主要分布在震中东北方向。由于此次地震破裂方向是以北东向单侧破裂为主，且地震多普勒效应导致震中东北方向振动加强，因此该方向上的面波震级偏大，地震烈度衰减慢；而震中西南方向的振动减弱 ...
Ruifeng Liu, Liye Zou, Liwen Zhang
doaj +1 more source
A New Approach for Testing Fetal Heart Rate Monitors
Sensors, 2020 In this paper, a new approach for the periodical testing and the functionality evaluation of a fetal heart rate monitor device based on ultrasound principle is proposed.
Daniele Bibbo +10 more
doaj +1 more source
Reverse Doppler Effect of Sound
, 2009 We report observation of reverse Doppler effect in a double negative acoustic metamaterial. The metamaterial exhibited negative phase velocity and positive group velocity.
C. Caloz +6 more
core +1 more source