| 1. |
- Casaletti, Massimiliano, et al.
(författare)
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An overview of metasurfaces for thin antenna applications
- 2020
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Ingår i: Comptes rendus. Physique. - : Cellule MathDoc/CEDRAM. - 1631-0705 .- 1878-1535. ; 21:7-8, s. 659-676
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, metasurfaces have become a rapidly growing domain of research in several fields of engineering and applied physics due to their ability to manipulate both phase and amplitude of electromagnetic fields. These artificial 2D-materials, usually composed of metallic elements printed on dielectric substrates, have the advantages of being low profile, lightweight as well as easy to fabricate and integrate with standard circuit technologies. In this context, this paper reviews the latest progress in metasurface antenna design, where metasurfaces are used to miniaturize the profile, increase the bandwidth, and control the radiation pattern in the near- and far-field regions.
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| 2. |
- Gómez, Cesar Pay, et al.
(författare)
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Crystal chemistry and chemical order in ternary quasicrystals and approximants
- 2014
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Ingår i: Comptes rendus. Physique. - : Elsevier BV. - 1631-0705 .- 1878-1535. ; 15:1, s. 30-39
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Tidskriftsartikel (refereegranskat)abstract
- In this work we review our current understanding of structure, stability and formation of icosahedral quasicrystals and approximants. The work has special emphasis on Cd–Yb type phases, but several concepts are generalized to other families of icosahedral quasicrystals and approximants. The paper handles topics such as chemical order and site preference at the cluster level for ternary phases, valence electron concentration and its influence on formation and composition, fundamental building blocks and cluster linkages, and the similarities and differences between different families of icosahedral quasicrystals and approximants.
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| 3. |
- Magnani, Nicola, et al.
(författare)
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First-principles theory of multipolar order in actinide dioxides
- 2014
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Ingår i: Comptes rendus. Physique. - : Elsevier BV. - 1631-0705 .- 1878-1535. ; 15:7, s. 580-586
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Tidskriftsartikel (refereegranskat)abstract
- Magnetic phase transitions that involve multipolar degrees of freedom have been widely studied during the last couple of decades, challenging the common approximation which assumes that the physical properties of a magnetic material could be effectively described by purely dipolar degrees of freedom. Due to the complexity of the problem and to the large number of competing interactions involved, the simple (fcc) crystal structure of the actinide dioxides made them the ideal playground system for such theoretical and experimental studies. In the present paper, we summarize our recent attempts to provide an ab initio description of the ordered phases of UO2, NpO2, and AmO2 by means of stateof-the-art LDA U first-principles calculations. This systematic analysis of the electronic structures is here naturally connected to the local crystalline fields of the 5f states in the actinide dioxide series. Related to these we find that the mechanisms which lead to the experimentally observed insulating ground states work in distinctly different ways for each compound. (C) 2014 The Authors. Published by Elsevier Masson SAS on behalf of Academie des sciences.
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| 4. |
- Mahendran, Srinivasan, 1989, et al.
(författare)
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The core structure of screw dislocations with [001] Burgers vector in Mg 2 SiO 4 olivine
- 2021
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Ingår i: Comptes Rendus Physique. - 1878-1535 .- 1631-0705. ; 22:S3
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we report atomistic calculations of the core structure of screw dislocations with [001] Burgers vector in Mg SiO olivine. Computations based on the THB1 empirical potential set for olivine show that the stable core configurations of the screw dislocations correspond to a dissociation in {110} planes involving collinear partial dislocations. As a consequence, glide appears to be favorable in {110} planes at low temperature. This study also highlights the difference between dislocation glide mechanism in {110} versus (010) or (100) for which glide is expected to occur through a locking-unlocking mechanism.
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| 5. |
- Mahendran, Srinivasan, 1989, et al.
(författare)
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The core structure of screw dislocations with [001] Burgers vector inMg(2)SiO(4) olivine
- 2021
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Ingår i: Comptes Rendus Physique. - : Cellule MathDoc/CEDRAM. - 1878-1535 .- 1631-0705. ; 22, s. 7-18
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we report atomistic calculations of the core structure of screw dislocations with [001] Burgers vector in Mg2SiO4 olivine. Computations based on the THB1 empirical potential set for olivine show that the stable core configurations of the screw dislocations correspond to a dissociation in {110} planes involving collinear partial dislocations. As a consequence, glide appears to be favorable in {110} planes at low temperature. This study also highlights the difference between dislocation glide mechanism in {110} versus (010) or (100) for which glide is expected to occur through a locking-unlocking mechanism.
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| 6. |
- Sathyamoorthy, Sankar Raman, 1984, et al.
(författare)
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Detecting itinerant single microwave photons
- 2016
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Ingår i: Comptes Rendus Physique. - : Elsevier BV. - 1878-1535 .- 1631-0705. ; 17:7, s. 756-765
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Single-photon detectors are fundamental tools of investigation in quantum optics and play a central role in measurement theory and quantum informatics. Photodetectors based on different technologies exist at optical frequencies and much effort is currently being spent on pushing their efficiencies to meet the demands coming from the quantum computing and quantum communication proposals. In the microwave regime, however, a single-photon detector has remained elusive, although several theoretical proposals have been put forth. In this article, we review these recent proposals, especially focusing on non-destructive detectors of propagating microwave photons. These detection schemes using superconducting artificial atoms can reach detection efficiencies of 90% with the existing technologies and are ripe for experimental investigations. (C) 2016 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
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| 7. |
- Shekhter, Robert I., 1947, et al.
(författare)
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Mechano-electronic and electro-mechanical energy transfer in mesoscopic superconducting weak links
- 2012
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Ingår i: Comptes Rendus Physique. - : Elsevier BV. - 1878-1535 .- 1631-0705. ; 13:5, s. 426-439
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Forskningsöversikt (refereegranskat)abstract
- In this review we discuss how the nano-electro-mechanical properties of a superconducting weak link, formed by a suspended nanowire bridging two superconductors, can strongly affect mesoscopic effects in both the electronic and the mechanical subsystem. In particular we will discuss how quantum coherence and electron–electron (Coulomb) correlations may result in the possibility to resonantly redistribute energy between the electronic and mechanical degrees of freedom, allowing controllable switching between pumping and cooling of the nano-mechanical vibrations of the suspended nanowire. The two regimes of a given current and a given voltage supplied to the nano-electro-mechanical weak link is considered, resulting respectively in the possibility of ground-state cooling or resonant generation of nano-mechanical vibrations for realistic experimental parameters.
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| 8. |
- Tasse, C., et al.
(författare)
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LOFAR calibration and wide-field imaging
- 2012
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Ingår i: Comptes Rendus Physique. - : Elsevier BV. - 1878-1535 .- 1631-0705. ; 13:1, s. 28-32
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- LOFAR is a revolutionary instrument, operating at low frequencies (nu less than or similar to 240 MHz). It will drive major breakthroughs in the area of observational cosmology, but its use requires the development of challenging techniques and algorithms. Since its field of view and sensitivity are increased by orders of magnitude as compared to the older generation of instruments, new technical problems have to be addressed. The LOFAR survey team is in charge of commissioning the first LOFAR data produced in the imager mode as part of building the imaging pipeline. We are developing algorithms to tackle the problems associated with calibration (ionosphere, beam, etc.) and wide-field imaging for the achievement of the deep extragalactic surveys. New types of problems arise in that context, and notions such as algorithmic complexity and parallelism become fundamental.
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| 9. |
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| 10. |
- An, Jiabin, et al.
(författare)
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Inactivation of the CYLD Deubiquitinase by HPV E6 Mediates Hypoxia-Induced NF-kappa B Activation
- 2008
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Ingår i: Cancer Cell. - : Elsevier BV. - 1878-3686 .- 1535-6108. ; 14:5, s. 394-407
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Tidskriftsartikel (refereegranskat)abstract
- The biochemical mechanisms that underlie hypoxia-induced NF-kappa B activity have remained largely undefined. Here, we find that prolonged hypoxia-induced NF-kappa B activation is restricted to cancer cell lines infected with high-risk human papillomavirus (HPV) serotypes. The HPV-encoded E6 protein is necessary and sufficient for prolonged hypoxia-induced NF-kappa B activation in these systems. The molecular target of E6 in the NF-kappa B pathway is the CYLD lysine 63 (K63) deubiquitinase, a negative regulator of the NF-kappa B pathway. Specifically, hypoxia stimulates E6-mediated ubiquitination and proteasomal degradation of CYLD. Given the established role of NF-kappa B in human carcinogenesis, these findings provide a potential molecular/viral link between hypoxia and the adverse clinical outcomes observed in HPV-associated malignancies.
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