Search results for "Stack"

showing 10 items of 392 documents

Multiple Decay Mechanisms and 2D-UV Spectroscopic Fingerprints of Singlet Excited Solvated Adenine-Uracil Monophosphate

2016

The decay channels of singlet excited adenine uracil monophosphate (ApU) in water are studied with CASPT2//CASSCF:MM potential energy calculations and simulation of the 2D-UV spectroscopic fingerprints with the aim of elucidating the role of the different electronic states of the stacked conformer in the excited state dynamics. The adenine 1La state can decay without a barrier to a conical intersection with the ground state. In contrast, the adenine 1Lb and uracil S(U) states have minima that are separated from the intersections by sizeable barriers. Depending on the backbone conformation, the CT state can undergo inter-base hydrogen transfer and decay to the ground state through a conical …

Models Molecularmolecular electronicsChemistry MultidisciplinaryMolecular electronicsphotophysic2-DIMENSIONAL ELECTRONIC SPECTROSCOPYSTATE DYNAMICSBASE-STACKINGPhotochemistry01 natural sciences[CHIM] Chemical SciencesNUCLEIC-ACIDSQuímica quànticaEspectrofotometriaConformational isomerismComputingMilieux_MISCELLANEOUSphotophysics010304 chemical physicsFull PaperHydrogen bondChemistryChemistry (all)Full PapersMolecular spectroscopy[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryChemistryFOURIER-TRANSFORM SPECTROSCOPYSpectrophotometryExcited statePhysical Sciences1ST-PRINCIPLES SIMULATION03 Chemical SciencesGround stateUridine MonophosphateQuantum chemistryEspectroscòpia molecularmolecular electronic010402 general chemistryMolecular physicsCatalysisUltraviolet visible spectroscopy0103 physical sciencesPhotophysics | Hot Paper[CHIM]Chemical SciencesSinglet stateUV/Vis spectroscopyULTRAFAST INTERNAL-CONVERSIONSpectroscopyLIGHT-HARVESTING COMPLEXab initio calculationScience & Technologyab initio calculationsOrganic ChemistryGeneral ChemistryDNAConical intersectionDNA FingerprintingAdenosine Monophosphate0104 chemical sciences[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistryAB-INITIO SIMULATIONSElectrònica molecularMOLECULAR-DYNAMICSSpectrophotometry Ultraviolet
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Enantioselective synthesis of fluorinated alpha-amino acids and derivatives in combination with ring-closing metathesis: intramolecular pi-stacking i…

2001

[reaction: see text]. Hydride reduction of C=N bonds stereocontrolled by intramolecular pi-stacking interactions of 1-naphthylsulfinyl and N-aryl groups, nonoxidative Pummerer rearrangement, and ring-closing metathesis are efficiently combined in a highly stereoselective entry to enantiomerically pure cyclic and acyclic fluorinated beta-amino alcohols and alpha-amino acid derivatives, respectively.

Molecular StructureChemistryHydrideStereochemistryPummerer rearrangementOrganic ChemistryStackingEnantioselective synthesisStereoisomerismFluorineMetathesisBiochemistryRing-closing metathesisIntramolecular forcePhysical and Theoretical ChemistryAmino AcidsAcyclic diene metathesisOrganic letters
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An ab initio study of the polytypism in InP

2016

AbstractThe existence of polytypism in semiconductor nanostructures gives rise to the appearance of stacking faults which many times can be treated as quantum wells. In some cases, despite of a careful growth, the polytypism can be hardly avoided. In this work, we perform an ab initio study of zincblende stacking faults in a wurtzite InP system, using the supercell approach and taking the limit of low density of narrow stacking faults regions. Our results confirm the type II band alignment between the phases, producing a reliable qualitative description of the band gap evolution along the growth axis. These results show an spacial asymmetry in the zincblende quantum wells, that is expected …

MultidisciplinaryValence (chemistry)Materials scienceCondensed matter physicsBand gapmedia_common.quotation_subjectStackingAb initioSemiconductor nanostructures02 engineering and technology021001 nanoscience & nanotechnology01 natural sciencesAsymmetryArticle0103 physical sciences010306 general physics0210 nano-technologyQuantum wellmedia_commonWurtzite crystal structureScientific Reports
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Size filtering effect in vertical stacks of In(Ga)As/GaAs self-assembled quantum rings

2006

3 páginas, 3 figuras.

NanostructurePhotoluminescenceMaterials sciencebusiness.industryBioengineeringRing (chemistry)SignalSelf assembledBiomaterialsLaser linewidthMechanics of MaterialsQuantum ringsVertical stackOptoelectronicsbusinessQuantumPhotoluminescenceMolecular beam epitaxy
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The positron distribution in a layered stack sample studied with the use of positron lifetime spectroscopy

2011

Abstract Computer simulation using GEANT4 codes indicates an enhancement of the fraction of implanted positrons stopped in the denser regions of a layered sample. However, positron lifetime measurements performed for layers of pure aluminum, silver and gold foils do not reveal this effect, indicating instead that backscattering plays an important role in determining the positron implantation profile in layered and/or heterogeneous samples.

Nuclear and High Energy PhysicsPositronMaterials sciencechemistryStack (abstract data type)AluminiumPositron Lifetime SpectroscopyPhysics::Accelerator Physicschemistry.chemical_elementAtomic physicsInstrumentationSample (graphics)Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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SEE on Different Layers of Stacked-SRAMs

2015

International audience; This paper presents heavy-ion and proton radiation test results of a 90 nm COTS SRAM with stacked structure. Radiation tests were made using high penetration heavy-ion cocktails at the HIF (Belgium) and at RADEF (Finland) as well as low energy protons at RADEF. The heavy-ion SEU cross-section showed an unusual profile with a peak at the lowest LET (heavy-ion with the highest penetration range). The discrepancy is due to the fact that the SRAM is constituted of two vertically stacked dice. The impact of proton testing on the response of both stacked dice is presented. The results are discussed and the SEU cross-sections of the upper and lower layers are compared. The …

Nuclear and High Energy PhysicsSEE rateMaterials scienceProtonDiceRadiationLow energyProton radiation90 nmElectronic engineering90 nmStatic random-access memoryElectrical and Electronic Engineeringradiation testingstacked dice[PHYS]Physics [physics]single event upset (SEU)ta213ta114business.industrymultiple cell upset (MCU)SRAM[SPI.TRON]Engineering Sciences [physics]/ElectronicsRadiation testingNuclear Energy and EngineeringOptoelectronicsbusinessstatic and dynamic mode testingIEEE Transactions on Nuclear Science
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Mikrotik virtuālās laboratorijas ReSeLa vidē

2016

Strauji attīstoties virtualizācijas un mākoņskaitļošanas tehnoloģijām, tās tiek izmantotas ar vien plašākiem mērķiem. Virtualizācijas izmantošana virtuālo sistēmu veidošanā ir tikai viens no tās daudziem pielietojumiem. Darba mērķis ir, datortīklu apguves mācību procesā izmantojamu, virtuālo laboratoriju izveide uz ReSeLa platformas. Darba gaitā ir iepazīta MikroTik izveidotā maršrutētāju operētājsistēma un apgūta laboratoriju veidošanai izmantotā OpenStack sistēma. Darba laikā tika izveidotas strādājošas laboratorijas ar speciāli tām izveidotu testēšanas sistēmu, to pārbaudei un vērtēšanai.

OpenStackDatorzinātneReSeLaMikroTikvirtuālā laboratorija
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OpenStack Swift uzstādīšana un lietošana

2018

Kvalifikācijas darbs “OpenStack Swift uzstādīšana un lietošana” veltīts tam, lai izpētītu Swift glabātuvi. Savā darbā autors iepazīstina lasītāju ar OpenStack sistēmu, īpašu uzmanību pievēršot Swift komponentam. Dotā darba mērķis ir iepazīt OpenStack Swift, ieviest to testa vidē un parādīt kā tas lietojams. Darba gaitā autors parāda, kā uzstādīt Swift uz virtuālās mašīnas testēšanas vidē, tāpat kā izmantot objektu glabātuvi un pārvaldīt to caur komandas rindu bez grafiskās saskarnes.

OpenStackDatorzinātneSAIOSwiftObjektu glabātuve
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OpenStack augstas pieejamības risinājumi

2016

Šis bakalaura darbs ir pētījums par OpenStack IaaS mākoņpakalpojumu platformu. Tā mērķis ir sniegt ieskatu augstas pieejamības pamatprincipos un OpenStack mākoņpakalpojumu platformas piedāvātajos augstas pieejamības nodrošināšanas risinājumos. Bakalaura darba gaitā ir veikta augsti pieejamas OpenStack trīs mezglu sistēmas uzstādīšana, izmantojot Galera Cluster datubāzu klasteri un HAProxy slodzes līdzsvarotāju. Tika pārbaudīta OpenStack augsta pieejamība, testējot OpenStack Glance komponentes funkcionalitāti tās servisu darbības pārrāvuma laikā. Bakalaura darba rezultātā ir izzināti OpenStack sistēmas piedāvātie augstas pieejamības risinājumi un praktiski pārbaudīta to darbība testa vidē.

OpenStackDatorzinātneaugsta pieejamībaHAProxyGalera Cluster
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Izmaksu sistēmas integrācija Openstack mākoņu sistēmā

2015

Izmaksu sistēma ir programma priekš OpenStack atvērta pirmkoda mākoņu sistēmai, kas ir uzrakstīta ar Python programmēšanās valodas palīdzību. Programmas izstrādes nolūks ir paplašināt OpenStack platformu ar precīzu izmaksu radītājiem. Sistēma ir domāta tikai OpenStack lietotājiem. Izmaksu programma dod iespēju lietotājam zināt, cik viņām būtu jāmaksā par patērētiem resursiem konkrētajos periodos, ja OpenStack būtu par maksu. Rezultātā tika iegūta programma, kas dabū virtuālu mašīnu strādāšanas laiku no OpenStack datu bāzes, aprēķina strādāšanas maksu katrām projektam un katrām lietotājam, kas ir izveidoti testēta OpenStack'ā.

OpenStackDatorzinātneizmaksasresursisistēmas lietotājs
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