Results 101 to 110 of about 121,274 (339)
Doppler effect and frequency-shift in optics
, 2004 A critical review of frequency-shift phenomena a la Doppler effect is presented. The importance of Fermi's theory of 1932 is pointed out, and it is argued that there exists a gap in our understanding of this phenomena at a fundamental level. Alternative mechanism in terms of photon number oscillations is suggested for polarization changing experiments.
openaire +2 more sources
The delta Doppler technique for LDV measurements at long distances [PDF]
A technique for measuring velocity, referred to as a Delta Doppler technique, was presented. This technique determines scattering source velocities by measuring the difference in Doppler shifts of two different frequencies.
Cliff, W. C.
core +1 more source
Advanced Science, EarlyView.This study uncovers two overlooked bottlenecks in cryogenic laser cooling of solids: symmetry‐driven fluorescence trapping and water vapor condensation. We demonstrate that breaking sample symmetry enhances fluorescence escape, while condensation dominates parasitic heating below 135 K.
Biao Zhong +5 more
wiley +1 more source
Analysis of Doppler frequency shift response mechanism based on OFDM system
MATEC Web of Conferences, 2018 OFDM system is widely used in mobile communication because of its high spectral efficiency and strong anti-multipath capability. However, in high dynamic scenarios, the Doppler shift between the transmitter and the receiver destroys the orthogonality ...
Li Ke +3 more
doaj +1 more source
Disturbances of Doppler Frequency Shift of Ionospheric Signal and of Telluric Current Caused by Atmospheric Waves from Explosive Eruption of Hunga Tonga Volcano on January 15, 2022 [PDF]
, 2023 Н. М. Салихов +6 more
openalex +1 more source
Advanced Science, EarlyView.This carrier‐free, esterase‐responsive nanoaggregate integrates a mitochondria‐targeting photosensitizer with a non‐nucleotide STING agonist to achieve localized photoactivation and immune reprogramming. ICyM2 remodels tumor stroma, induces potent immunogenic cell death, and triggers intratumoral STING activation, collectively revitalizing the ...
Yixuan Zhang +18 more
wiley +1 more source
Joint estimation of target time delay and Doppler frequency in passive radar system
Tongxin xuebao, 2015 A novel method of joint estimation of time delay and Doppler shift in passive radar system based on short-time fractional Fourier transform (STFRFT) was proposed.Firstly,the mathematical expression of the STFRFT time-frequency resolution was studied for ...
ANGPeng W +3 more
doaj +2 more sources
Extended Kalman Filtering of Satellite Doppler Tracking Data and IT¡¯S Application to Orbit Determination Problems [PDF]
Journal of Astronomy and Space Sciences, 1995 Using a directional antenna, the Doppler effect of satellites can be detected and the orbital elements can be obtained by the Extended Kalman Filter with the observed frequency shift data. We obtained the orbital elements of NOAA-11 by the application of
Dong-Kyu Kim, Kyu-Hong Choi
doaj
Advanced Science, EarlyView.Disrupted neurovascular coupling contributes to ovarian dysfunction in polycystic ovary syndrome. Using near‑infrared II long‑wavelength imaging, this study visualizes how electroacupuncture dynamically regulates ovarian blood vessels in vivo. Immediate and cumulative stimulation elicit distinct vascular responses via a Netrin‐1 dependent mechanism ...
Yicong Wang +15 more
wiley +1 more source
Advanced Science, EarlyView.This review outlines association between vasculitis and malignancies and provides practical value for clinicians in distinguishing primary vasculitis from malignancy‐associated forms and optimizing patient surveillance, improving recognition of tumor‐associated vasculitis to reduce the risk of misdiagnosis, supporting more accurate clinical decision ...
Xiaofei Shi +8 more
wiley +1 more source