Search results for "Quantum"
showing 10 items of 9714 documents
Quantum Creativity and Cognition in Humans and Robots
2022
In this research, we present a categorical framework to connect research on creativity and cognition for humans and robots, in light of the quantum paradigm. These fields and their relationships suggest a wider vision: modeling human creativity/cognition through quantum computing, and creating robots that can help us learn more about the humans themselves. We represent the human–robot comparison through functors (function generalization). Fundamental elements to understand human creativity are motivation and feedback as aesthetic pleasure. Is it possible to model it? Can the quantum paradigm help us in such an endeavor? We envisage the concept of emergence and quantum computing as decisive…
Crystal structure and Hirshfeld surface analysis of (E)-1-[2,2-dichloro-1-(4-nitrophenyl)ethenyl]-2-(4-fluorophenyl)diazene
2019
The dihedral angle between the 4-fluorophenyl ring and the nitro-substituted benzene ring of the title compound is 63.29 (8)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds into chains parallel to the c axis. The crystal packing is further stabilized by C—Cl⋯π, C—F⋯π and N—O⋯π interactions
Crystal structure and Hirshfeld surface analysis of 2-[(1,3-benzoxazol-2-yl)sulfanyl]-N-(2-methoxyphenyl)acetamide
2019
Akkurt, Mehmet/0000-0003-2421-0929; Saylam, Merve/0000-0002-7602-4565
Crystal structure and Hirshfeld surface analysis of (E)-3-[(4-fluorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide
2019
TARAMAPUBMED TARAMASCOPUS TARAMAWOS In the cation of the title salt, C16H15FN3S+·Br−, the phenyl ring is disordered over two sets of sites with a refined occupancy ratio of 0.503 (4):0.497 (4). The mean plane of the thiazolidine ring makes dihedral angles of 13.51 (14), 48.6 (3) and 76.5 (3)° with the fluorophenyl ring and the major- and minor-disorder components of the phenyl ring, respectively. The central thiazolidine ring adopts an envelope conformation. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N—H...Br hydrogen bonds, which are further connected by weak C—H...Br hydrogen bonds into chains parallel to [110]. Hirshfeld surface an…
Geometrical and conformational preferences of the 9‐fluorenylmethoxycarbonyl‐amino moiety
2004
Structural parameters, originating from x-ray crystallographic data, have been compiled for 13 derivatives of amino acids, peptides and related compounds, which contain a total of 14 Fmoc-NH- moieties. For these moieties, molecular geometries and conformations--described by the omegao, theta1, theta2 and theta3' torsion angles--were analysed and compared with the corresponding parameters for the Z-NH- and Boc-NH-moieties (290 and 553, respectively). To gain a deeper insight into the conformational features of the Fmoc-NH- moiety, ab initio free molecule calculations were performed for fully relaxed minima. Also the potential energy surface as a function of the torsion angles (theta3', theta…
Substituent effects in nitro derivatives of carbazoles investigated by comparison of low-temperature crystallographic studies with density functional…
2014
The crystal structure of 9H-carbazole, C12H9N, (I), has been redetermined at low temperature for use as a reference structure in a comparative study with the structures of 1-nitro-9H-carbazole, C12H8N2O2, (II), and 9-nitrocarbazole, C12H8N2O2, (III). The molecule of (I) has crystallographically imposed mirror symmetry (Z′ = 0.5). All three solid-state structures are slightly nonplanar, the dihedral angles between the planes of the arene and pyrrole rings ranging from 0.40 (7)° in (III) to 1.82 (18)° in (II). Nevertheless, a density functional theory (DFT) study predicts completely planar conformations for the isolated molecules. To estimate the influence of nitro-group substitution on aroma…
Quantum effects, anomalies and renormalization in Electrodynamics, Cosmology and Black Holes
2023
La Teoria Quàntica de Camps en Espais Corbats ha demostrat ser una teoria semi-clàssica molt útil per a l'estudi de fenòmens físics que combinen gravetat i efectes quàntics. En particular, prediu que la dinàmica d'un camp gravitacional de fons pot excitar espontàniament partícules a partir del buit quàntic. El procés de producció de partícules té una importància especial en l'estudi de l'univers primerenc en cosmologia i és la base de la radiació de Hawking en la física dels forats negres. Físicament, aquest efecte quàntic és anàleg a l'efecte Schwinger ben conegut en l'electrodinàmica quàntica. L'objectiu d'aquesta Tesi és estudiar aquest fenomen general de producció de partícules, així co…
Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches
2018
Motivated by the recent galactic center gamma-ray excess identified in the Fermi-LAT data, we perform a detailed study of QCD fragmentation uncertainties in the modeling of the energy spectra of gamma-rays from Dark-Matter (DM) annihilation. When Dark-Matter particles annihilate to coloured final states, either directly or via decays such as $W^{(*)}\to q\bar{q}'$, photons are produced from a complex sequence of shower, hadronisation and hadron decays. In phenomenological studies, their energy spectra are typically computed using Monte Carlo event generators. These results have however intrinsic uncertainties due to the specific model used and the choice of model parameters, which are diffi…
Time-domain effective-one-body gravitational waveforms for coalescing compact binaries with nonprecessing spins, tides and self-spin effects
2018
We present TEOBResumS, a new effective-one-body (EOB) waveform model for nonprecessing (spin-aligned) and tidally interacting compact binaries.Spin-orbit and spin-spin effects are blended together by making use of the concept of centrifugal EOB radius. The point-mass sector through merger and ringdown is informed by numerical relativity (NR) simulations of binary black holes (BBH) computed with the SpEC and BAM codes. An improved, NR-based phenomenological description of the postmerger waveform is developed.The tidal sector of TEOBResumS describes the dynamics of neutron star binaries up to merger and incorporates a resummed attractive potential motivated by recent advances in the post-Newt…
Enhancing the luminescence efficiency of silicon-nanocrystals by interaction with H+ions
2018
The emission of silicon nanocrystals (Si-NCs), synthesized by pulsed laser ablation in water, was investigated on varying the pH of the solution. These samples emit μs decaying orange photoluminescence (PL) associated with radiative recombination of quantum-confined excitons. Time-resolved spectra reveal that both the PL intensity and the lifetime increase by a factor of ∼20 when the pH decreases from 10 to 1 thus indicating that the emission quantum efficiency increases by inhibiting nonradiative decay rates. Infrared (IR) absorption and electron paramagnetic resonance (EPR) experiments allow addressing the origin of defects on which the excitons nonradiatively recombine. The linear correl…