Search results for "ground"

showing 10 items of 2432 documents

Transition state theory thermal rate constants and RRKM-based branching ratios for the N((2)D) + CH(4) reaction based on multi-state and multi-refere…

2012

International audience; Multireference single and double configuration interaction (MRCI) calculations including Davidson (+Q) or Pople (+P) corrections have been conducted in this work for the reactants, products, and extrema of the doublet ground state potential energy surface involved in the N(2D) + CH4 reaction. Such highly correlated ab initio calculations are then compared with previous PMP4, CCSD(T), W1, and DFT/B3LYP studies. Large relative differences are observed in particular for the transition state in the entrance channel resolving the disagreement between previous ab initio calculations. We confirm the existence of a small but positive potential barrier (3.86 +/- 0.84 kJ mol-1…

N(D-2)ThermodynamicsUPPER-ATMOSPHERE010402 general chemistry01 natural sciencesATOMSMOLECULESTransition state theoryMETHANEReaction rate constantAb initio quantum chemistry methodsN(2(2)D)0103 physical sciencesDESCENTPOTENTIAL-ENERGY SURFACES[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]RRKM theorySIZE-EXTENSIVE MODIFICATION010304 chemical physicsElectronic correlationChemistryGeneral ChemistryConfiguration interaction0104 chemical sciencesComputational Mathematics[ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]Potential energy surfaceAtomic physicsGround stateJournal of computational chemistry
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Preliminary-Analysis of the Pentad of 13CH4 from Raman and Infrared-Spectra

1991

0022-2852

NU-4VIBRATIONAL POLYADSSPECTROSCOPYMETHANENU-2GROUND-STATE2-NU-4 BANDSINTERACTING UPPER STATESROTATIONAL ANALYSISTETRAHEDRAL MOLECULESLINE PARAMETERS
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Formation of linear Ni nanochains inside carbon nanotubes: Prediction from density functional theory

2013

Abstract First principles calculations have been performed to investigate the ground state properties of monoperiodic single-walled carbon nanotubes (CNTs) containing nanochain of aligned Ni atoms inside. Using the PBE exchange-correlation functional ( E xc ) within the framework of density functional theory (DFT) we predict the clusterization of Ni filaments in ( n ,0) CNTs for n ⩾  9 and for ( n , n ) CNTs for n ⩾  6. The variations in formation energies obtained for equilibrium defective nanostructures allow us to predict the most stable Ni@CNT compositions. Finally, the electronic charge redistribution has been calculated in order to explore intermolecular properties leading to stronger…

NanostructureMaterials scienceIntermolecular forceGeneral Physics and AstronomyCarbon nanotubeBond formationElementary chargelaw.inventionCondensed Matter::Materials SciencelawChemical physicsComputational chemistryRedistribution (chemistry)Density functional theoryPhysical and Theoretical ChemistryGround stateChemical Physics Letters
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Strongly Red-Emissive Molecular Ruby [Cr(bpmp)2]3+ Surpasses [Ru(bpy)3]2+

2021

Gaining chemical control over the thermodynamics and kinetics of photoexcited states is paramount to an efficient and sustainable utilization of photoactive transition metal complexes in a plethora of technologies. In contrast to energies of charge transfer states described by spatially separated orbitals, the energies of spin-flip states cannot straightforwardly be predicted as Pauli repulsion and the nephelauxetic effect play key roles. Guided by multireference quantum chemical calculations, we report a novel highly luminescent spin-flip emitter with a quantum chemically predicted blue-shifted luminescence. The spin-flip emission band of the chromium complex [Cr(bpmp)2]3+ (bpmp = 2,6-bis(…

Nephelauxetic effectPhotoluminescenceQuenching (fluorescence)ChemistryQuantum yieldGeneral ChemistryPhotochemistryBiochemistryCatalysisColloid and Surface ChemistryAtomic orbitalExcited stateLuminescenceGround stateJournal of the American Chemical Society
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A new proposed cloud computing based architecture for space ground data systems

2018

International audience; Many companies decided to move towards the cloud computing technology in order to manage, monitor and explore huge space data amount in the space ground data systems. The corresponding transition adaptation needs a study to classify each space related service in the appropriate cloud computing service model layer; SaaS, PaaS and IaaS. In this paper, we specify a representation of proposed cloud computing based ground data system architecture for earth observation missions. The proposed architecture takes into consideration the collaboration aspect between multiple space agencies. We evaluate the time, storage and processing performance when using the cloud computing …

Network architectureService (systems architecture)Earth observationComputer Networks and Communicationsbusiness.industryComputer scienceQuality of serviceSoftware as a serviceDistributed computingNetwork architectureQoS020206 networking & telecommunicationsCloud computing02 engineering and technologySpace mission0202 electrical engineering electronic engineering information engineeringSystems architectureCloud computingGround data systemData system[INFO]Computer Science [cs]020201 artificial intelligence & image processingbusinessInternational Journal of Communication Networks and Distributed Systems
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Graph Filtering with Quantization over Random Time-varying Graphs

2019

Distributed graph filters can be implemented over wireless sensor networks by means of cooperation and exchanges among nodes. However, in practice, the performance of such graph filters is deeply affected by the quantization errors that are accumulated when the messages are transmitted. The latter is paramount to overcome the limitations in terms of bandwidth and computation capabilities in sensor nodes. In addition to quantization errors, distributed graph filters are also affected by random packet losses due to interferences and background noise, leading to the degradation of the performance in terms of the filtering accuracy. In this work, we consider the problem of designing graph filte…

Network packetComputer scienceComputationQuantization (signal processing)020206 networking & telecommunications010103 numerical & computational mathematics02 engineering and technologyNetwork topology01 natural sciencesGraphBackground noise0202 electrical engineering electronic engineering information engineering0101 mathematicsWireless sensor networkAlgorithm2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)
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Neutrino interaction classification with a convolutional neural network in the DUNE far detector

2020

The Deep Underground Neutrino Experiment is a next-generation neutrino oscillation experiment that aims to measure CP-violation in the neutrino sector as part of a wider physics program. A deep learning approach based on a convolutional neural network has been developed to provide highly efficient and pure selections of electron neutrino and muon neutrino charged-current interactions. The electron neutrino (antineutrino) selection efficiency peaks at 90% (94%) and exceeds 85% (90%) for reconstructed neutrino energies between 2–5 GeV. The muon neutrino (antineutrino) event selection is found to have a maximum efficiency of 96% (97%) and exceeds 90% (95%) efficiency for reconstructed neutrino…

Neutrino Oscillations. Neutrino detectors.Physics - Instrumentation and DetectorsPhysics::Instrumentation and Detectorsfar detector01 natural sciencesPhysics Particles & FieldsHigh Energy Physics - Experimentcharged currentHigh Energy Physics - Experiment (hep-ex)[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Particle Physics ExperimentsMuon neutrinoneutrino/e: particle identificationNeutrino detectorsDetectors and Experimental Techniquesphysics.ins-detCharged currentneutrino: interactionInformáticaPhysicsTelecomunicacionesNeutrino oscillationsPhysicsNeutrino interactions neural network DUNE Deep Underground Neutrino ExperimentInstrumentation and Detectors (physics.ins-det)Experiment (hep-ex)Neutrino detectorPhysical SciencesCP violationNeutrinoParticle Physics - ExperimentParticle physicsdata analysis method530 Physicsneural networkAstrophysics::High Energy Astrophysical PhenomenaCONSERVATIONFOS: Physical sciencesAstronomy & AstrophysicsDeep Learningneutrino: deep underground detectorneutrino physics0103 physical sciencesNeutrino Oscillations. Neutrino detectorsObject DetectionNeutrinoCP: violationDeep Underground Neutrino ExperimentHigh Energy Physics[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]Neutrinos010306 general physicsNeutrino oscillationneutrino/mu: particle identificationIOUScience & TechnologyDUNENeutrino interactions010308 nuclear & particles physicshep-exHigh Energy Physics::PhenomenologyFísicaNeutrino InteractionDetector530 PhysiksensitivityefficiencyHigh Energy Physics::ExperimentElectron neutrino
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GEANT4 simulation of the neutron background of the C6D6 set-up for capture studies at n_TOF

2014

The neutron sensitivity of the C6D6 detector setup used at n_TOF facility for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n_TOF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has beeni mplemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with anatC sample, showing an excellent agreement above 1 keV. At lower energies, an additional compo…

Neutron captureNuclear and High Energy PhysicsPhysics - Instrumentation and DetectorsAstrophysics::High Energy Astrophysical PhenomenaGEANT4 simulations; Neutron time of flight; Neutron background; n_TOF; Neutron captureFOS: Physical sciencesNeutronN-TOF7. Clean energy01 natural sciencesPartícules (Física nuclear)Nuclear physicsCross section (physics)0103 physical sciencesNeutronNuclear Experiment (nucl-ex)010306 general physicsGEANT4 simulations;N-TOF;Neutron time of flight;Neutron capture;Neutron backgroundNuclear ExperimentInstrumentationphysics.ins-detNuclear ExperimentGEANT4Line (formation)Particles (Nuclear physics)PhysicsBonner sphere:Energies::Energia nuclear [Àrees temàtiques de la UPC]NeutronsGEANT4 simulation:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsDetectorFísicaNeutron sensitivityDetectorInstrumentation and Detectors (physics.ins-det)Neutron radiationNEUTRON TIME OF FLIGHTNeutron captureBackgroundDeuteriumN_TOFGEANT4 simulationsNeutron backgroundSimulation
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Disentangling decaying isomers and searching for signatures of collective excitations in β decay

2019

6 pags., 3 figs., 1 tab. -- 27th International Nuclear Physics Conference (INPC2019) 29 July - 2 August 2019, Glasgow, UK

Neutron-rich nucleiHistoryIsotope-separator-on-lineGround statePenning trapspektroskopiaBeta decay01 natural sciencesEducationNuclear physics0103 physical sciencesGamma-ray spectroscopy010306 general physicsNuclear ExperimentPhysicsPygmy dipole resonances010308 nuclear & particles physicsGamma rays[PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph]3. Good healthComputer Science ApplicationsQuasiparticleIsomeric stateFísica nuclearydinfysiikkaGamma ray spectrometersCollective excitations
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Implicit Wiener Filtering for Speech Enhancement In Non-Stationary Noise

2021

Speech quality is degraded in the presence of background noise, which reduces the quality of experience (QoE) of the end-user and therefore motivates the usage of speech enhancement algorithms. A large number of approaches have been proposed in this context. However most of them have focused on the case where the noise is stationary, an assumption that seldom holds in practice. For instance, in mobile telephony, noise sources with a marked non-stationary spectral signature include vehicles, machines, and other speakers to name a few. On the other hand, the usage of frequency-domain information in existing algorithms for speech enhancement in non-stationary noise environments can be made mor…

Noise powerComputer scienceSpeech recognitionWiener filterSpectral densityComputer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing)Context (language use)Background noiseSpeech enhancementNoisesymbols.namesakeComputer Science::SoundFrequency domainsymbols2021 11th International Conference on Information Science and Technology (ICIST)
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