Results 81 to 90 of about 411,959 (304)

A New Statistical Approach to the Optical Spectral Variability in Blazars

Galaxies, 2016
We present a spectral variability study of a sample of about 25 bright blazars, based on optical spectroscopy. Observations cover the period from the end of 2008 to mid 2015, with an approximately monthly cadence.
Jose A. Acosta-Pulido, Noel Castro Segura, Maria Isabel Carnerero, Claudia M. Raiteri   +3 more
doaj   +1 more source

Direct Measurements of the Stellar Continua and Balmer/4000 Angstrom Breaks of Red z>2 Galaxies: Redshifts and Improved Constraints on Stellar Populations

, 2006
We use near-infrared (NIR) spectroscopy obtained with GNIRS on Gemini, NIRSPEC on KECK, and ISAAC on the VLT to study the rest-frame optical continua of three `Distant Red Galaxies' (having Js - Ks > 2.3) at z>2.
Danilo Marchesini, Eric Gawiser, Garth D. Illingworth, Gregory Rudnick, Hans‐Walter Rix, Ivo Labbe, Madau P., Marijn Franx, Mariska Kriek, Natascha M. Forster Schreiber, Paul van der Werf, Pieter G. van Dokkum, Ryan Quadri, Stijn Wuyts, Sune Toft   +14 more
core   +1 more source

Reduction of Oxide Inclusions During the High‐Frequency Welding of Steel via a Nonthermal Ar/H2 Plasma Jet

Advanced Engineering Materials, EarlyView.
High‐frequency (HF) welding of steel is limited by oxide inclusions that degrade weld quality. This study demonstrates, for the first time, the integration of a nonthermal Ar/H2 dielectric barrier discharge (DBD) plasma jet into HF welding. Local plasma treatment provides effective shielding and in‐situ oxide reduction, resulting in markedly fewer and ...
Viktor Udachin, Lienhard Wegewitz, René Gustus, Henning Wiche, Wolfgang Maus‐Friedrichs   +4 more
wiley   +1 more source

Type 2 Active Galactic Nuclei with Double-Peaked [OIII] Lines. II. Single AGNs with Complex Narrow-Line Region Kinematics are More Common than Binary AGNs [PDF]

, 2011
(Abridged) Approximately 1% of low redshift ...
Civano, Comerford, Comerford, Crenshaw, Crenshaw, Das, Fischer, Fu, Gerke, Greene, Hennawi, Hennawi, Hopkins, Jenny E. Greene, Kewley, Komossa, Liu, Liu, Liu, Michael A. Strauss, Myers, Peng, Persson, Rodriguez, Rosario, Rosario, Skrutskie, Smith, Tody, Veilleux, Wang, Whittle, Whittle, Xin Liu, York, Yue Shen, Zhou   +36 more
core   +2 more sources

Influence of an Argon/Silane Atmosphere on the Temperature of a Thermal Plasma

Advanced Engineering Materials, EarlyView.
The influence of a silane‐doped argon atmosphere on the chemical composition and temperature of a thermal nontransferring argon plasma is investigated using optical emission spectroscopy. As a result of the high amount of free electrons resulting from the stepwise ionization and dissociation of the silane molecule, even a silane addition of 0.01 vol ...
Lena Kreie, David Kramer, Thomas Scheithauer, Hans Jürgen Maier, Thomas Hassel   +4 more
wiley   +1 more source

Enhancing Strength and Electrical Conductivity in Al–Zr–Sc Conductor Alloys Through Sn and Sr Microalloying and Two‐Step Aging Treatment

Advanced Engineering Materials, EarlyView.
Trace additions of Sn and Sr combined with a two‐step aging treatment are shown to enhance the microstructure and performance of Al–Zr–Sc conductor alloys. Strength and electrical conductivity increase concurrently through accelerated precipitation of fine Al3(Sc, Zr) precipitates and improved dislocation resistance, offering a cost‐effective pathway ...
Quan Shao, Emad M. Elgallad, Alexandre Maltais, X.‐Grant Chen   +3 more
wiley   +1 more source

Electron-beam-sustained discharge revisited - light emission from combined electron beam and microwave excited argon at atmospheric pressure

, 2014
A novel kind of electron beam sustained discharge is presented in which a 12keV electron beam is combined with a 2.45GHz microwave power to excite argon gas at atmospheric pressure in a continuous mode of operation.
Dandl, T., Hagn, H., Neumeier, A., Ulrich, A., Wieser, J.   +4 more
core   +1 more source

Application of Raman and Photoluminescence Spectroscopy to MgO‐C Refractories

Advanced Engineering Materials, EarlyView.
Visible to near infrared luminescence of MgO is studied on MgO‐C bricks and nominally pure MgO powder, with focus on two similar sharp high‐intensity signals, at 699 and 871 nm, each surrounded by symmetrical sidebands. The nature of these sidebands is investigated by temperature‐dependent spectroscopic measurements, confirming phonon involvement by ...
Julia Richter, Felix Drechsler, Till M. J. Stadtmüller, Cameliu Himcinschi, Christos G. Aneziris, Jens Kortus   +5 more
wiley   +1 more source

Radioluminescence and photoluminescence of Th:CaF$_2$ crystals

, 2015
We study thorium-doped CaF$_2$ crystals as a possible platform for optical spectroscopy of the Th-229 nuclear isomer transition. We anticipate two major sources of background signal that might cover the nuclear spectroscopy signal: VUV-photoluminescence,
Schreitl, Matthias, Schumm, Thorsten, Stellmer, Simon   +2 more
core   +1 more source

Identification and tunable optical coherent control of transition-metal spins in silicon carbide [PDF]

, 2018
Color centers in wide-bandgap semiconductors are attractive systems for quantum technologies since they can combine long-coherent electronic spin and bright optical properties.
Bosma, Tom, Ellison, Alexandre, Gilardoni, Carmem M., Gällström, Andreas, Havenith, Remco W. A., Hendriks, Freddie, Ivanov, Ivan G., Lof, Gerrit J. J., Magnusson, Björn, Son, N. T., van der Wal, Caspar H., Zwier, Olger V.   +11 more
core   +5 more sources