Search results for "Crystal"

showing 10 items of 22886 documents

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…

defectMaterials sciencePhotoluminescenceExcitonGeneral Physics and Astronomy02 engineering and technology010402 general chemistryPhotochemistry01 natural sciencesIonlaw.inventionlawluminescenceSpontaneous emissionQuantum confinementPhysical and Theoretical ChemistryElectron paramagnetic resonanceSilicon nanocrystalsilicon021001 nanoscience & nanotechnologyphotoluminescence efficiencysilicon nanoparticles luminescence0104 chemical sciencesAmorphous solidlaser ablationQuantum efficiencynanoparticles0210 nano-technologyLuminescence
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Synthesis and characterization of ethylene-1-hexene copolymers prepared by using MgCl2(THF)2-supported Ziegler-Natta catalysts

2000

Ethylene was copolymerized with 1-hexene over vanadium (VOCl3 and VCl4) and titanium (TiCl4) catalysts supported on MgCl2(THF)2 and activated with Et2AlCl. So far these catalyst systems have not been known as initiators of ethylene-1-hexene copolymerization. The vanadium catalysts were more active than the titanium catalyst and, at identical comonomer concentrations in the feed, gave rise to a greater incorporation of 1-hexene into the copolymer. Even at relatively low fractions of 1-hexene, the MgCl2(THF)2-supported catalysts affected much the copolymer properties like density, melting point and crystallinity.

densityMaterials scienceEthylenePolymers and PlasticsbiologyGeneral Chemical Engineeringcopolymerization of ethylene with 1-hexeneVOCl3melting point and crystallinity of copolymarsNattabiology.organism_classificationCharacterization (materials science)Catalysis1-Hexenechemistry.chemical_compoundchemistryVCl4 and TiCl4 catalysts supported on MgCl2(THF0)2 and activated with Et2AlClPolymer chemistryMaterials ChemistryCopolymerOrganic chemistryPolimery
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Single π0 production off neutrons bound in deuteron with linearly polarized photons

2021

The quasifree γ→d→π0n(p) photon beam asymmetry, Σ, has been measured at photon energies, Eγ, from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49∘ to 148∘. In this kinematic region, polarization observables are sensitive to contributions from the Δ(1232) and N(1440) resonances. The extracted values of Σ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID and Bonn–Gatchina anal…

deuteronpolarizationN(1440)partial waveNuclear Theoryphoton: energyDelta(1232)beam: asymmetryMainz Linackinematicsisospin: symmetrycalorimeterelectron: beampi0: photoproductionNuclear Experimentphoton: beamCrystal Ball
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CCDC 1045982: Experimental Crystal Structure Determination

2015

Related Article: Michele Bedin, Alavi Karim, Marcus Reitti, Anna-Carin C. Carlsson, Filip Topić, Mario Cetina, Fangfang Pan, Vaclav Havel, Fatima Al-Ameri, Vladimir Sindelar, Kari Rissanen, Jürgen Gräfenstein, Máté Erdélyi|2015|Chemical Science|6|3746|doi:10.1039/C5SC01053E

di(pyridin-1-yl)iodonium hexafluorophosphateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1917460: Experimental Crystal Structure Determination

2020

Related Article: A. Carel N. Kwamen, Marcel Schlottmann, David Van Craen, Elisabeth Isaak, Julia Baums, Li Shen, Ali Massomi, Christoph Räuber, Benjamin P. Joseph, Gerhard Raabe, Christian Göb, Iris M. Oppel, Rakesh Puttreddy, Jas S. Ward, Kari Rissanen, Roland Fröhlich, Markus Albrecht|2020|Chem.-Eur.J.|26|1396|doi:10.1002/chem.201904639

di-lithium tris(246-trimethylphenylmethyl 23-dioxybenzoate)-titaniumSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 257790: Experimental Crystal Structure Determination

2005

Related Article: R.H.Laye, F.K.Larsen, J.Overgaard, C.A.Muryn, E.J.L.McInnes, E.Rentschler, V.Sanchez, S.J.Teat, H.U.Gudel, O.Waldmann, G.A.Timco, R.E.P.Winpenny|2005|Chem.Commun.||1125|doi:10.1039/b416770h

di-n-propylammonium hexadecakis(mu~2~-22-dimethylpropanoato)-octakis(mu~2~-fluoro)-hepta-iron(iii)-iron(ii)Space GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 992678: Experimental Crystal Structure Determination

2014

Related Article: Francisco R. Fortea-Pérez, Nadia Marino, Donatella Armentano, Giovanni De Munno, Miguel Julve, Salah-Eddine Stiriba|2014|CrystEngComm|16|6971|doi:10.1039/C4CE00669K

di-potassium bis(((26-dimethylphenyl)amino)(oxo)acetato)-palladium sesquihydrateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 2069070: Experimental Crystal Structure Determination

2021

Related Article: Borja Rodríguez-Barea, Júlia Mayans, Renato Rabelo, Adrián Sanchis-Perucho, Nicolás Moliner, José Martínez-Lillo, Miguel Julve, Francesc Lloret, Rafael Ruiz-García, Joan Cano|2021|Inorg.Chem.|60|12719|doi:10.1021/acs.inorgchem.1c01905

di-sodium [NN-bis(2-{bis[(carboxy)methyl]amino}ethyl)glycinato]-aqua-holmium octahydrateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1022517: Experimental Crystal Structure Determination

2015

Related Article: Khaleel I. Assaf, Merve S. Ural, Fangfang Pan, Tony Georgiev, Svetlana Simova, Kari Rissanen, Detlef Gabel, Werner M. Nau|2015|Angew.Chem.,Int.Ed.|54|6852|doi:10.1002/anie.201412485

di-sodium tris(gamma-cyclodextrin) dodecabromo-closo-dodecaborate unknown solvate pentatricontahydrateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1814349: Experimental Crystal Structure Determination

2018

Related Article: Raminder S. Mulla, Marikka S. Beecroft, Robert Pal, Juan A. Aguilar, Javier Pitarch‐Jarque, Enrique García‐España, Elena Lurie‐Luke, Gary J. Sharples, J. A. Gareth Williams|2018|Chem.-Eur.J.|24|7137|doi:10.1002/chem.201800026

di-t-butyl 22'-(ethane-12-diylbis(benzylimino))diacetateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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