Results 121 to 130 of about 57,270 (311)

Generating Helical Polymorphic Beams Using Dielectric Metasurfaces

Laser &Photonics Reviews, EarlyView.
Helix‐shaped polymorphic beams are optical fields whose intensity maxima spiral around the propagation axis, enabling particle manipulation through attractive or repulsive forces. Traditionally requiring expensive spatial light modulators, metasurfaces now provide a compact, cost‐effective alternative. This work demonstrates general helical polymorphic
Maryam Setareh, Yang Xu, Jose A. Rodrigo, Kenneth B. Crozier   +3 more
wiley   +1 more source

A new broad K/Ka-band receiver (18.0–32.3 GHz) for the Yebes Observatory’s 40 meter radio telescope★

Astronomy & Astrophysics
Since 2010, the 40 m radio telescope of the Yebes Observatory has been devoted to very long baseline interferometry (VLBI) and single-dish observations. Up until 2019, it covered frequency bands between 2 GHz and 90 GHz in discontinuous and narrow radio ...
López-Pérez J. A., Tercero F., Gallego-Puyol J. D., Albo-Castaño C., Amils-Samalot R., Bautista-Durán M., Barbas L., Beltrán F., Díez-González M., García-Carreño P., García-Merino A., García-Pérez O., Gómez-Molina G., González-García J., López-Fernández I., Malo-Gómez I., Martínez-Parra A., Patino-Esteban M., Tercero B., Marcelino N., Esplugues G., Gallardo Cava I., García-Miró C., Gómez-Garrido M., Santander-García M., Tarrío P., Vidal-García A., de Vicente P., Cernicharo J.   +28 more
doaj   +1 more source

Spectroscopic Studies of Early-type Stars with the Kourovka 1.2-m Telescope

Open Astronomy, 2016
We briey describe the characteristics of the 1.2-m telescope of Kourovka Observatory of the Ural Federal University, equipped with a fiber-optic echelle spectrometer, and report the results of spectroscopic studies of several early-type stars (CC Cas ...
Gorda S. Yu., Sobolev A. M., Bisyarina A. P., Zakharova P. E., Kuznetsov E. D.   +4 more
doaj   +1 more source

The research productivity of small telescopes and space telescopes [PDF]

, 2003
We present statistics on the research productivity of astro- nomical telescopes. These were compiled by finding papers in which new data were presented, noting which telescopes were used, and then counting the number of papers, number of pages, and other
Ringwald, Frederick, Lovell, Rebecca L, Torres, Yolanda V., Kays, Sarah Abbey, Culver, John   +4 more
core  

An Adaptive Metasurface for Adjustable Magnetic Resonance Imaging Enhancement at 3 T and 7 T: A Feasibility Study

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose Ultra‐high field (≥ 7 T) and 3 T MRI suffer from B1+ inhomogeneity and signal loss. Conventional metasurfaces that mitigate B1+ inhomogeneity and improve image SNR are “fixed” in nature and designed for a single Larmor frequency. This study demonstrates the feasibility of an adaptive metasurface utilizing voltage‐controlled capacitors ...
Paul S. Jacobs, Pradnya Narvekar, Neil E. Wilson, Gabor Mizsei, Wyger Brink, John A. Detre, Mark A. Elliott, Ravinder Reddy   +7 more
wiley   +1 more source

High-energy neutrino telescopes

, 1999
A review of the potential of Neutrino Telescopes to contribute to Astrophysics and Elementary Particle Physics is presented. The status of the neutrino telescopes presently under construction is reviewed.
Resvanis, LK
core   +1 more source

Lightning electromagnetic emission location using arrival time differencing (LEELA): An introduction to the Met Office's next generation Very Low Frequency lightning location system

Quarterly Journal of the Royal Meteorological Society, EarlyView.
This paper describes the Met Office's new lightning location system LEELA. A brief overview of the upgraded hardware and geolocation algorithms is given. LEELA has improved lightning detection capabilities, especially at night. When comparing LEELA to the previous ATDnet system against ground truths LEELA has 100% storm detection efficiency within 5 km
Graeme Marlton, Mike Protts, Stephen Prust, Edmund Keith Stone, Debbie O'Sullivan, Sue Twelves, Francesco Devoto, Claire Witham   +7 more
wiley   +1 more source

Satellite-borne γ-ray astrophysics from coherent interactions in oriented crystals

Astronomy & Astrophysics
High-density and high-Z crystals are key elements of most space-borne γ-ray telescopes operating at gigaelectronvolt energies (such as Fermi-LAT). The lattice structure is usually neglected in the development of a crystalline detector, although its ...
Monti-Guarnieri P., Paternò G., Sytov A., Cavazzuti E., Costamante L., Cutini S., Duranti M., Fedeli P., Gaitskell R. J., Guidi V., Haurylavets V., Koushiappas S. M., Longo F., Mangiacavalli S., Mazzolari A., Prest M., Romagnoni M., Selmi A., Soldani M., Tikhomirov V., Vagelli V., Vallazza E., Bandiera L.   +22 more
doaj   +1 more source

8. Space telescopes

, 2016
The last seven decades have seen telescopes launched into space, vastly enhancing the crispness of the images they produce and expanding the range of observable wavelengths to include UV, X- and gamma-ray wavelengths.
Geoff Cottrell
core   +1 more source

Investigation of the laser fluence and wavelength dependence in surface‐assisted laser desorption/ionization mass spectrometry using gold nanoparticles

Rapid Communications in Mass Spectrometry, EarlyView.
Rationale Surface‐assisted laser desorption/ionization (SALDI) mass spectrometry (MS) builds on the use of nanostructured surfaces (e.g., coatings of colloidal nanoparticles) to promote analyte desorption and ionization. The SALDI process is believed to occur mainly through thermal processes, resulting from heating of the nanosubstrate upon absorption ...
Wendy H. Müller, Alexander Potthoff, Klaus Dreisewerd, Jens Soltwisch   +3 more
wiley   +1 more source