Results 21 to 30 of about 5,894 (171)

Review of millimeter‐wave and terahertz near‐field synthetic aperture radar imaging technology

InfoScience, EarlyView.
Abstract This paper comprehensively reviews the development of millimeter‐wave (MMW) and terahertz (THz) near‐field imaging technologies, with an emphasis on the state of synthetic aperture radar (SAR)‐based imaging technologies. Near‐field imaging technologies are categorized into passive and active imaging modes, among which active imaging is favored
Qi Yang, Hongqiang Wang, Xu Chen, Xin Peng   +3 more
wiley   +1 more source

Using baseline-dependent window functions for data compression and field-of-interest shaping in radio interferometry

, 2016
In radio interferometry, observed visibilities are intrinsically sampled at some interval in time and frequency. Modern interferometers are capable of producing data at very high time and frequency resolution; practical limits on storage and computation ...
Atemkeng, M. T., Foster, G., Jonas, J., Smirnov, O. M., Tasse, C.   +4 more
core   +2 more sources

The mobile Sousy-Doppler radar: Technical design and first results [PDF]

, 1983
A mobile VHF Doppler system was developed. The electronic part is installed in a 20 ft container and tested using a special log periodic aerial to illuminate the 300 m dish.
Czechowsky, P., Ruster, R., Schmidt, G.
core   +2 more sources

Next Generation 7 Tesla Arterial Spin Labeling With Rotated Spiral Acquisition Enables Mesoscale Resolution in 3D Brain Perfusion and Functional MRI

Magnetic Resonance in Medicine, Volume 95, Issue 5, Page 2702-2717, May 2026.
ABSTRACT Purpose To achieve high resolution (≤ 1 mm isotropic) whole‐brain perfusion imaging at 7 T with next generation ASL pulse sequence, reconstruction algorithm, and MRI hardware. Methods We capitalized on three major innovations: (1) FLASH‐based pseudo‐Continuous ASL (pCASL) sequence with rotated golden‐angle stack‐of‐spirals (rGA‐SoS) sampling; (
Chenyang Zhao, Fanhua Guo, Zidong Yang, Xingfeng Shao, Samantha J. Ma, Alexander J. S. Beckett, An T. Vu, David A. Feinberg, Danny J. J. Wang   +8 more
wiley   +1 more source

Improved orbit utilisation by interferometric sidelobe suppression

Electronics Letters, 1980
Auxiliary defocused feeds with weak excitation can be used to cancel or reduce specific near-angle sidelobes of double reflector antennas. Existing earth terminals may be upgraded in this way to provide improved isolation between interfering satellites when the tight station-keeping tolerances agreed at WARC-79 come into force.
van Ommeren, M.J.S., Herben, M.H.A.J., Arnbak, J.   +2 more
openaire   +2 more sources

Numerical Investigation of a Dual‐Mode Shape Memory Alloy Stent Enabling Secondary Expansion via Focused Ultrasound: A Potential Strategy for Correcting In‐Stent Restenosis

Advanced Engineering Materials, Volume 28, Issue 6, 18 March 2026.
This study demonstrates a novel noninvasive strategy to treat in‐stent restenosis using focused ultrasound. A shape memory alloy stent initially expands at body temperature. If restenosis occurs, targeted ultrasound heating thermally actuates the stent, enabling a secondary expansion to reopen the blocked vessel, offering a potential alternative to ...
Stephen Asare, Lucinda Duncan, Josiah Owusu‐Danquah, Brian L. Davis   +3 more
wiley   +1 more source

Polymer‐Derived Nickel‐Iron Silicide‐Based Bimetallic Catalysts: Synthesis, Characterization, and Enhanced Catalytic Properties Toward the Oxygen Evolution Reaction

ChemElectroChem, Volume 13, Issue 6, 17 March 2026.
The growing demand for green energy highlights the need for efficient hydrogen production through water splitting. Designing bimetallic electrocatalysts is crucial for this goal. Transition metal silicides are promising due to their abundance and high electrical conductivity.
Yaohao Zhang, Zhaoju Yu, Wei Li, Chuanmu Tian, Marcus Einert, Jan P. Hofmann, Marcel Risch, Ralf Riedel   +7 more
wiley   +1 more source

Optical data storage using orthogonal wavelength multiplexed volume holograms [PDF]

, 1992
We propose a volume holographic data storage scheme that employs counterpropagating reference and image beams and wavelength multiplexing for page differentation. This method is compared with that based on angular multiplexing. A reduction in holographic
Leyva, Victor, Rakuljic, George A., Yariv, Amnon   +2 more
core  

First Coincident Radar and Optical Observations of a Meteor Radio Afterglow

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract It has been hypothesized that Meteor Radio Afterglows (MRAs) occur due to resonant transition radiation (RTR) where suprathermal electrons emit as they pass through electron density inhomogeneities in a turbulent plasma. Meteor trails are thought to produce suprathermal electrons through anion oxidation, which can be identified through meteor ...
K. S. Obenberger, J. L. Chau, J. Vierinen, D. Vida, L. E. Cordonnier, Z. Balint, M. Clahsen, E. Dao, J. Dowell, J. M. Holmes, R. F. Kelly, D. Kastinen, N. Pfeffer, K. Robinson, G. B. Taylor, J. M. Urco   +15 more
wiley   +1 more source

Near‐Bed Flow Turbulence Beneath Ice Cover Under Varying Hydrological Conditions: A 9‐Year Field Measurement‐Based Analysis From a Meander Bend

Water Resources Research, Volume 62, Issue 3, March 2026.
Abstract Climate change alters hydrological and ice conditions, but how these changes affect turbulence beneath ice cover has been poorly studied. This study presents a multi‐year observational analysis of near‐bed turbulence under ice cover in a subarctic meandering river reach.
Karoliina Lintunen, Essi Vilhonen, Tuure Takala, Linnea Blåfield, Elina Kasvi, Eliisa Lotsari, Petteri Alho   +6 more
wiley   +1 more source