Search results for "SPLIT"

showing 10 items of 362 documents

Area-efficient FPGA-based FFT processor

2003

A novel architecture for computing the fast Fourier transform on programmable devices is presented. Main results indicate that the use of one CORDIC operator to perform the multiplication by all the ‘twiddle factors’ sequentially leads to an area saving up to 35% with respect to other cores.

Cooley–Tukey FFT algorithmSplit-radix FFT algorithmComputer sciencebusiness.industryFast Fourier transformPrime-factor FFT algorithmMultiplicationElectrical and Electronic EngineeringCORDICField-programmable gate arraybusinessTwiddle factorComputer hardwareElectronics Letters
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Segregation of copper oxide on calcium copper titanate surface induced by Graphene Oxide for Water splitting applications

2020

Abstract Photoelectrochemical cells (PEC) are promising devices for hydrogen production via sunlight energy. One of the important challenges in this area is to design photoactive electrodes able to absorb visible light. A good photoelectrochemical behavior depends on the presence of surface active sites to photogenerate current at the lower possible potential for water splitting. Recent investigations in this field are focusing on perovskite materials such as CaCu3Ti4O12 (CCTO) as visible light active electrode due its outstanding structure in which CCTO encloses in its structure a visible light absorbance component (CuO). The presence CuO on the material surface is mainly responsible for t…

Copper oxideMaterials scienceOxideGeneral Physics and Astronomy02 engineering and technology010402 general chemistry7. Clean energy01 natural scienceslaw.inventionchemistry.chemical_compoundlawCalcium copper titanate[CHIM]Chemical SciencesComputingMilieux_MISCELLANEOUSPerovskite (structure)GrapheneSurfaces and InterfacesGeneral ChemistryPhotoelectrochemical cell021001 nanoscience & nanotechnologyCondensed Matter Physics0104 chemical sciencesSurfaces Coatings and FilmschemistryChemical engineeringWater splitting0210 nano-technologyVisible spectrum
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Mössbauer spectroscopic studies of clusters Mn2(CO)8[μ-Sn(hal)Mn(CO)5]2 (hal = Cl, Br) and related Mn and Re compounds

1977

Abstract In order to be acquainted with the nature of bonds at Sn involved in the title compounds, as well as to get information on the configuration of the strictly related derivatives I2Sn2Mn4(CO)18 and Cl2Sn2Re4(CO)18, the Mossbauer spectroscopic investigation reported in this paper has been carried out. The experimental parameters (isomer shifts, δ; nuclear quadrupole splittings, ΔE; for the bromide derivative only, the asymmetry parameter η and the sign of the nuclear quadrupole coupling constant e2qQ) have been discussed in connection with data concerning compounds with tin-transition metal bonds, mainly hal2Sn[Mn(CO)5]2 (hal = Cl, Br) and ClSn[Mn(CO)5]3. Rationalizations of ΔE and η …

Coupling constantChemistryQuadrupole splittingRelated derivativesInorganic ChemistryFormalism (philosophy of mathematics)chemistry.chemical_compoundCrystallographyBromideComputational chemistryQuadrupoleMössbauer spectroscopyMaterials ChemistryPhysical and Theoretical ChemistryMetallic bondingInorganica Chimica Acta
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Interpretation of Mössbauer Parameters of Iron Compounds

1978

The task of this section is to show that for the interpretation of Mossbauer parameters — in the present case of electron densities, field gradients and magnetic hyperfine fields — bonding effects can play an important role, and free-ion or crystal field approaches may be a poor approximation.

CrystalMaterials scienceField (physics)Condensed matter physicsAtomic orbitalMössbauer spectroscopyElectronQuadrupole splittingHyperfine structureElectric field gradient
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Homoleptic iron(II) complexes with the ionogenic ligand 6,6′-Bis(1H-tetrazol-5-yl)-2,2′-bipyridine: spin crossover behavior in a singular 2D spin cro…

2015

Deprotonation of the ionogenic tetradentate ligand 6,6′-bis(1H-tetrazol-5-yl)-2,2′-bipyridine [H2bipy(ttr)2] in the presence of FeII in solution has afforded an anionic mononuclear complex and a neutral two-dimensional coordination polymer formulated as, respectively, NEt3H{Fe[bipy(ttr)2][Hbipy(ttr)2]}·3MeOH (1) and {Fe[bipy(ttr)2]}n (2). The anions [Hbipy(ttr)2]− and [bipy(ttr)2]2– embrace the FeII centers defining discrete molecular units 1 with the FeII ion lying in a distorted bisdisphenoid dodecahedron, a rare example of octacoordination in the coordination environment of this cation. The magnetic behavior of 1 shows that the FeII is high-spin, and its Mössbauer spectrum is characteriz…

DEVICESCoordination polymerStereochemistryPRESSURE010402 general chemistry01 natural sciences22'-BipyridineInorganic ChemistrySINGLE MOLECULESchemistry.chemical_compoundDeprotonationSpin crossoverSYSTEMS[CHIM.COOR]Chemical Sciences/Coordination chemistryPhysical and Theoretical ChemistryHomolepticSYNERGYCRYSTAL010405 organic chemistryLigandCOMPOUNDQuadrupole splittingSTATE3. Good health0104 chemical sciencesCrystallographychemistryOctahedronFISICA APLICADAMOSSBAUERPHASE-TRANSITIONS
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Slow Magnetic Relaxation in a Co (II)–Y (III) Single‐Ion Magnet with Positive Axial Zero‐Field Splitting

2013

This work was supported by the MINECO (Spain) (Project CTQ2011-24478), the Junta de Andalucía (FQM-195 and Project of excellence P08-FQM-03705), and the University of Granada. E.R. and E.Cr. thank MINECO grant No. CTQ2011-23862-C02-01 and Generalitat de Catalunya grant No. 2009SGR-1459, for financial support. We would like to thank Prof. Liviu Chibotaru for providing us the SINGLE_ANISO program and Dr. Andrew Ozarowski for the EPR simulation software. E.K.B. thanks the EPSRC and Leverhulme Trust for financial support. The NHMFL is funded by the NSF, DoE, and the state of Florida. J.C. acknowledges financial support by the Spanish Ministerio de Ciencia e Innovación through projects CTQ2010-1…

DYNAMICSModels Molecularpositive zero-field splittingINSchemistry.chemical_elementZero field splitting010402 general chemistry01 natural sciences7. Clean energyCatalysisO ligandsMOLECULE MAGNETNuclear magnetic resonancesingle ion magnetsYttriumMagnetic relaxationCompartmental ligandAnisotropyHYSTERESISComputingMilieux_MISCELLANEOUSANISOTROPY[PHYS]Physics [physics]IonsMolecular StructureCondensed matter physicsSingle ion010405 organic chemistryChemistryCobaltGeneral ChemistryYttriumNBARRIERcobaltCo(II)FAMILY0104 chemical sciencesyttriumHysteresisPositive axial ZFSDYSPROSIUM(III)TBMagnetic FieldsMagnetMagnetsSingle ion magnetCOMPLEXESCobaltBEHAVIOR
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Etude numérique d'équations aux dérivées partielles non linéaires et dispersives

2011

Numerical analysis becomes a powerful resource in the study of partial differential equations (PDEs), allowing to illustrate existing theorems and find conjectures. By using sophisticated methods, questions which seem inaccessible before, like rapid oscillations or blow-up of solutions can be addressed in an approached way. Rapid oscillations in solutions are observed in dispersive PDEs without dissipation where solutions of the corresponding PDEs without dispersion present shocks. To solve numerically these oscillations, the use of efficient methods without using artificial numerical dissipation is necessary, in particular in the study of PDEs in some dimensions, done in this work. As stud…

Davey-Stewartson systems[ MATH.MATH-GM ] Mathematics [math]/General Mathematics [math.GM]equations dispersivesdispersive shocksexponential time-differencing[MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM][MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph]spectral methodschocs dispersifsnumerical methodsdispersive equationsNo english keywordssplit stepschemas de decomposition d'operateursmethodes spectrales[MATH.MATH-MP] Mathematics [math]/Mathematical Physics [math-ph]Kadomtsev-Petviashvili equationintegrating factor methodparallel computing[ MATH.MATH-MP ] Mathematics [math]/Mathematical Physics [math-ph]Pas de mot clé en français[MATH.MATH-GM] Mathematics [math]/General Mathematics [math.GM]methodes numeriquesblow upequation de Kadomtsev-PetviashviliIntegrateurs exponentielssystemes de Davey-Stewartsoncalcul parallele
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Organotin(IV) complexes with tetraethyl ethylene- and propylene-diphosphonates

1995

The series of organotin halide complexes with tetraethyl ethylene- and propylene-diphosphonates R n SnX 4-n .L [n=0, X=Cl; n=1, R=Me, X=Cl, Br; n=1, R=Ph, X=Cl; n=2 R=Me, Et, Bu, X=Cl, Br; n=2, R=Ph, X=Cl; L=(EtO) 2 P(O)CH 2 CHR'P(O)(OEt) 2 , R'=H, Me] were synthesized and characterized by means of NMR and Mossbauer spectroscopy. The crystal structure of the complex of diphenyltin dichloride with propylenediphosphonate was determined. The complex consists of polymer chains with bridging bidentate ligands and an octahedral tin environment containing two types of phosphoryl fragments. All of the R 2 SnX 2 adducts have trans-R 2 SnX 4 geometries of tin coordination octahedra according to the q…

DenticityCoordination sphereEthyleneChemistryStereochemistryGeneral ChemistryNuclear magnetic resonance spectroscopyQuadrupole splittingCrystal structureMedicinal chemistryAdductInorganic Chemistrychemistry.chemical_compoundMössbauer spectroscopyApplied Organometallic Chemistry
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Exchange Coupling Mediated by N–H···Cl Hydrogen Bonds: Experimental and Theoretical Study of the Frustrated Magnetic System in Bis(o-phenylenediamine…

2012

The title compound crystallizes in the monoclinic P2(1)/c space group with a = 11.2470(3) A, b = 5.9034(2) A, c = 12.0886(3) A, β = 115.143(1)°, and V = 726.58(4) A(3) and consists of discrete monomeric NiCl(2)(o-phenylendiamine)(2) molecules. Each o-phen ligand coordinates in a bidentate mode with the chloride ions occupying trans positions in the resulting tetragonally distorted octahedral coordination sphere. Two discrete sets of N-H···Cl hydrogen bonds link the octahedral molecules into a two-dimensional network, with type 1 interactions linking adjacent monomers along the c axis and type 2 interactions linking monomers along the diagonals in the bc plane. Analysis of the magnetic data …

DenticityCoordination sphereHydrogen bondStereochemistryZero field splittingInorganic ChemistryCrystallographychemistry.chemical_compoundOctahedronchemistryMoleculeAntiferromagnetismPhysical and Theoretical ChemistryNickel(II) chlorideInorganic Chemistry
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Characterization of complexes formed between [Me2Sn(IV)]2+ and carboxymethylcelluloses.

2006

Complexes formed between carboxymethylcellulose (CMC) and the [Me(2)Sn(IV)]2+ cation have been prepared in the solid state and characterized by FTIR and Mossbauer spectroscopy. The complexes contained CMC with varying molar weight and degree of carboxylation, and the complexes were isolated both from acidic and from neutral solutions at varying metal-to-ligand ratios. The characteristic vibration bands of the ligands were identified from their pH-dependent FTIR spectra. In the organotin(IV) complexes obtained at pH approximately 2, the -COO- moieties were found to be coordinated in a monodentate manner, and the band characteristic of the protonated (unbound) -COO- group(s) was also identifi…

DenticityMetal ions in aqueous solutionInorganic chemistryInfrared spectroscopyBiochemistryAnalytical ChemistrySpectroscopy MossbauerDeprotonationSpectroscopy Fourier Transform InfraredOrganotin CompoundsCarboxymethylcelluloseValence (chemistry)Sn(IV)Molecular StructureLigandChemistryOrganic ChemistryStructureTin CompoundsGeneral MedicineQuadrupole splittingInfrared spectraTrigonal bipyramidal molecular geometryCrystallographyCarboxymethylcellulose SodiumMössbauer spectraCarbohydrate research
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