Results 71 to 80 of about 922,402 (315)

Recovering Past Reflections: X-ray Fluorescence Imaging of Electrocleaned 19th Century Daguerreotypes

Heritage, 2019
The first commercially viable photographic image, the daguerreotype, captured images for a span of approximately 20 years (1839⁻1860). DeDterioration now disfigures many of these valuable images.
Madalena S. Kozachuk, Tsun-Kong Sham, Ronald R. Martin, Andrew J. Nelson, Ian Coulthard, Louisa Smieska, Arthur R. Woll   +6 more
doaj   +1 more source

Mechanochemical Synthesis and Characterization of Nanostructured ErB4 and NdB4 Rare‐Earth Tetraborides

Advanced Engineering Materials, Volume 27, Issue 6, March 2025.
ErB4 and NdB4 nanostructured powders are produced by mechanochemical synthesis. 5 h mechanical alloying and 4 M HCl acid leaching are used in the production. ErB4 and NdB4 powders exhibit maximum magnetization of 0.4726 emu g−1 accompanied with an antiferromagnetic‐to‐paramagnetic phase transition at about TN = 18 K and 0.132 emu g−1 with a maximum at ...
Burçak Boztemur, Faruk Kaya, Bora Derin, Mustafa Lütfi Öveçoğlu, Ju Li, Duygu Ağaoğulları   +5 more
wiley   +1 more source

Broad Balmer-line Absorption in SDSS J172341.10+555340.5 [PDF]

, 2010
I present the discovery of Balmer-line absorption from H alpha to H9 in iron low-ionizaton broad absorption line (FeLoBAL) quasar, SDSS~J172341.10+555340.5 by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) attached to the Subaru telescope.
arxiv   +1 more source

Photonic Technology for Precision Metrology

Applied Sciences, 2022
Precision metrology is important for understanding and monitoring various phenomena, especially in special and scientific applications. The subject of the article covers selected aspects of the study of high-resolution measurements of the absorption ...
Jacek Wojtas
doaj   +1 more source

Mechanisms of Increasing Weld Depth during Temporal Power Modulation in High‐Power Laser Beam Welding

Advanced Engineering Materials, EarlyView.
Temporal power modulation increases weld depth in high‐power laser beam welding of dissimilar round bars by nearly 20% compared to same average continuously welded welding power. The mechanism of action also applies to sheet welding and depends on the inertia of keyhole depth for the modulated laser beam power.
Jan Grajczak, David Reynders, Christian Nowroth, Jens Twiefel, Jörg Wallaschek, Sarah Nothdurft, Jörg Hermsdorf, Stefan Kaierle   +7 more
wiley   +1 more source

Quantum-enhanced weak absorption estimation with correlated photons [PDF]

PhysRevLett.134.133604 (2025)
Conventional absorption spectroscopy relies on coherent laser sources, and in turn suffers from the inherent limitation of shot noise, especially in estimating weak absorption. Here we propose a measurement strategy with correlated photons to determine the weak absorption by distinguishing the output with and without photons, dubbed as the on-off ...
arxiv   +1 more source

Non-linear spectroscopy of rubidium: An undergraduate experiment

, 2009
In this paper, we describe two complementary non-linear spectroscopy methods which both allow to achieve Doppler-free spectra of atomic gases. First, saturated absorption spectroscopy is used to investigate the structure of the $5{\rm S}_{1/2}\to 5{\rm P}
A Allafort, B Hingant, Bordé C, Cagnac B, Cahuzac P, Grynberg G, Grynberg G, Grynberg G, Grynberg G, J F Roch, Letokhov V S, M Pigeard, Schalow A L, V Jacques, Vasilenko L S   +14 more
core   +1 more source

Further Insight into the Manganese(II) 2,2′-Bipyridine-1,1′-dioxide Homoleptic Complex: Single-Crystal X-ray Structure Determination of the Perchlorate Salt and DFT Calculations

Crystals
The homoleptic cationic complex formed by reacting suitable manganese(II) salts with 2,2′-bipyridine-1,1′-dioxide (bipyO2) has been subjected to several studies in the past because of its peculiar absorption and electrochemical features.
Jesús Castro, Valentina Ferraro, Marco Bortoluzzi   +2 more
doaj   +1 more source

Influence of Cooling Rate on Primary Silicon Size in Hypereutectic Al–Si Alloy Fabricated by Laser Powder Bed Fusion

Advanced Engineering Materials, EarlyView.
Al–Si alloys are particularly in demand for automotive and electronic applications, thanks to their excellent wear and thermal properties. Nevertheless, when processed by conventional methods with low cooling rates, the coarse primary Si phases are responsible for increasing brittleness and inducing crack propagation.
Layla Shams Tisha, Daniel Knoop, Nils Ellendt, Anastasiya Toenjes   +3 more
wiley   +1 more source

Triplet absorption spectroscopy and electromagnetically induced transparency

, 2016
Coherence phenomena in four-level atomic system, cyclicly driven by three coherent fields, are investigated thoroughly at zero and weak magnetic fields. Each strongly interacting atomic state is converted to a triplet due to a dynamical Stark effect. Two
Ghafoor, F., Nazmitdinov, R. G.
core   +1 more source