Results 21 to 30 of about 112,664 (260)

High-sensitive acquisition method of GPS signal based on iridium assistance

open access: yesThe 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

The influence of frequency and amplitude modulation due to the sound source movement on radiated sound characteristics

open access: yesNihon Kikai Gakkai ronbunshu, 2021
The variation of the noise metrics of a group of sound sources due to its movement at a constant velocity along a straight track is discussed in the paper.
Yusuke MAKINO, Yasushi TAKANO
doaj   +1 more source

汶川地震的面波震级测定及其多普勒效应

open access: yesDizhen 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

Time-frequency doubly selective channel estimation based on compressed sensing

open access: yes上海师范大学学报. 自然科学版, 2017
In this paper,considering time-frequency doubly selective channel,we utilize the channel's time correlation that the channel coefficientscorresponding tothe neighboring instants have a strong correlation.And we present a linear approximation method,which
Tu Yuliang   +3 more
doaj   +1 more source

Christian Doppler and the Doppler effect

open access: yesEos, Transactions American Geophysical Union, 1984
A summary is given of Doppler's life and career. He was born 180 years ago on November 29, 1803, in Salzburg, Austria. He died on March 17, 1853 in Venice. The effect bearing his name was first announced in a presentation before the Royal Bohemian Society of the Sciences in Prague on May 25, 1842.
openaire   +1 more source

Difference in determination of surface wave magnitude of the M7.8 Kermadec Island earthquake on March 5,2021 in New Zealand

open access: yes地震科学进展, 2021
A magnitude M7.8 earthquake struck Kermadec Island,New Zealand on March 5,2021. In this study we determined surface wave magnitude using 692 stations from USGS global networks and 112 stations from China global earthquake monitoring system,then analyzed ...
Wenze Deng
doaj   +1 more source

Sudden anaerobization in Amphibacillus xylanus increases intracellular labile ferrous iron and inhibits cell growth

open access: yesFEBS Open Bio, EarlyView.
Abruptly changing from aerobic to anaerobic conditions (sudden anaerobization) induced growth inhibition and a significant increase in intracellular labile ferrous iron in the aerotolerant anaerobe Amphibacillus xylanus. We found that free flavins mediate efficient electron transfer from NADH to ferric iron under anaerobic conditions, suggesting that ...
Shinya Kimata   +13 more
wiley   +1 more source

Neurovascular Contacts in the Pathophysiology of Neuralgic Amyotrophy: An Observational Study

open access: yesAnnals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Neuralgic amyotrophy (NA) is a prevalent, monophasic, multifocal immune‐mediated neuropathy. A distinctive characteristic of the disease is the occurrence of nerve or fascicle constrictions and torsions (NA‐associated focal nerve lesions, NAFL). The pathophysiology underlying this phenomenon remains to be fully elucidated.
Johannes Fabian Holle   +4 more
wiley   +1 more source

Measurement of nonlinear and Doppler distortion in Distributed Mode Loudspeakers [PDF]

open access: yesInternational Journal of Electronics and Telecommunications
Distributed Mode Loudspeakers (DMLs), as other electroacoustic transducers with electrodynamic excitation, are susceptible to the occurrence of nonlinear distortion. The literature on nonlinear distortion in DMLs is scarce.
Karol Czesak, Piotr Kleczkowski
doaj   +1 more source

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