Search results for "angle"

showing 10 items of 1921 documents

2,2′-Bipyrimidine- and 2,3-bis(2-pyridyl)pyrazine-containing manganese(II) compounds: Structural and magnetic properties

2003

The preparation, crystal structures and magnetic properties of four different manganese(II) compounds of formula [Mn(bipym)Cl2]n·2nH2O (1), [Mn2(dpp)2(H2O)2Cl4]·2H2O (2), [Mn(dpp)(H2O)2]n(ClO4)2n·1.5nH2O (3) and [Mn(dpp)(dca)2]n (4) [bipym = 2,2′-bipyrimidine, dpp = 2,3-bis(2-pyridyl)pyrazine and dca = dicyanamide anion] are reported. Compounds 1 and 3 are uniform chains of six-coordinated manganese(II) ions bridged by bis(bidentate) bipym (1) and dpp (3) ligands with two chloride groups (1) and two water molecules (3) in cis position. The electroneutrality in 3 is achieved by uncoordinated perchlorate anions. The manganese atom in 1 and 3 exhibits a distorted octahedral environment mainly …

DenticityPyrazineInorganic chemistrychemistry.chemical_elementManganeseCrystal structureBite angleInorganic Chemistrychemistry.chemical_compoundCrystallographychemistryIntramolecular forceMoleculeDicyanamide
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Countercomplementarity and Strong Ferromagnetic Coupling in a Linear Mixed μ-Acetato, μ-Hydroxo Trinuclear Copper(II) Complex. Synthesis, Structure, …

2001

The structural and magnetic data of the trinuclear compound [Cu3(L)2(CH3COO)2(OH)2(dmf)2] (HL = N-(2-methylpyridyl)toluensulfonylamide) are reported. The compound crystallizes in the monoclinic system, space group P2(1)/n (no. 14), with a = 11.6482(6) A, b = 13.5772(6) A, c = 13.5306(7) A, alpha = 90 degrees, beta = 92.859(5) degrees, gamma = 90 degrees, and Z = 2. The three copper atoms form an exact linear arrangement. Neighboring coppers are connected by a hydroxo bridge and a bidentate syn-syn carboxylato group. The coordination spheres of the terminal copper atoms are square pyramidal with a dmf molecule as the apical ligand. The central copper has a regular square planar geometry. The…

Denticitychemistry.chemical_elementDihedral angleCopperSquare pyramidal molecular geometrylaw.inventionInorganic ChemistryCrystallographychemistrylawMoleculeMoietyPhysical and Theoretical ChemistryElectron paramagnetic resonanceMonoclinic crystal systemInorganic Chemistry
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Entanglement dynamics of two independent cavity-embedded quantum dots

2010

We investigate the dynamical behavior of entanglement in a system made by two solid-state emitters, as two quantum dots, embedded in two separated micro-cavities. In these solid-state systems, in addition to the coupling with the cavity mode, the emitter is coupled to a continuum of leaky modes providing additional losses and it is also subject to a phonon-induced pure dephasing mechanism. We model this physical configuration as a multipartite system composed by two independent parts each containing a qubit embedded in a single-mode cavity, exposed to cavity losses, spontaneous emission and pure dephasing. We study the time evolution of entanglement of this multipartite open system finally …

DephasingFOS: Physical sciencesQuantum entanglementOpen system (systems theory)Settore FIS/03 - Fisica Della MateriaOpen quantum systemsAtomic and Molecular PhysicsQuantum mechanicsMesoscale and Nanoscale Physics (cond-mat.mes-hall)Spontaneous emissionMathematical PhysicsPhysicsQuantum PhysicsCondensed Matter - Mesoscale and Nanoscale PhysicsTime evolutionCondensed Matter PhysicsAtomic and Molecular Physics and Optics; Mathematical Physics; Condensed Matter PhysicsAtomic and Molecular Physics and OpticsMultipartite68.65.Hb Quantum dots (patterned in quantum wells)Quantum dotQubitPhysics::Accelerator Physicsand OpticsQuantum Physics (quant-ph)68.65.Hb Quantum dots (patterned in quantum wells); Open quantum systems
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Audiovisual constructs of Paralympic Games : scalarity and camera angle

2014

This research will analyze the variables differentiating between the audiovisual television of the XIII edition of the Paralympic Games and the Games of the XXIX Olympiad, held in Beijing from the 7th of September to the 17th, 2008. This study will serve as a methodological basis for similar future research. By means of a qualitative and quantitative methodology, this study also focuses on determining if TV representations of Paralympic sportspersons favour their social integration or if, on the contrary, lead to higher stigmatization.

Deportes para discapacitados físicos.Paralympics (13. 2008. Pekín China)computer.software_genreOlympics (29. 2008. Pekín China)Televisión y deportes.Social integrationCamera angleBeijingTelevisionbroadcasting of sports - Content analysis.OlympiadSports for people with disabilities.Juegos Paralímpicos (13. 2008. Pekín China)Juegos Olímpicos (29. 2008. Pekín China)Televisión - Programas deportivos - Producción.Mass media and sports.Narrativa audiovisual.Televisionbroadcasting of sports - Production.Medios de comunicación social y deportes.MultimediaQuantitative methodologyGeneral MedicineGeographyAudio-visual materials - Fiction.computerTelevisión - Programas deportivos - Análisis de contenido.Television and sports.
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Combined proton NMR wideline and NMR relaxometry to study SOM-water interactions of cation-treated soils

2013

Abstract Focusing on the idea that multivalent cations affect SOM matrix and surface, we treated peat and soil samples by solutions of NaCl, CaCl2 or AlCl3. Water binding was characterized with low field 1H-NMR-relaxometry (20 MHz) and 1H wideline NMR spectroscopy (400 MHz) and compared to contact angles. From 1H wideline, we distinguished mobile water and water involved in water molecule bridges (WaMB). Large part of cation bridges (CaB) between SOM functional groups are associated with WaMB. Unexpectedly, 1H NMRrelaxometry relaxation rates suggest that cross-linking in the Al-containing peat is not stronger than that by Ca. The relation between percentage of mobile water and WaMB water in…

Dewey Decimal Classification::500 | Naturwissenschaften::550 | GeowissenschaftenDewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften BiologieDewey Decimal Classification::600 | Technik::630 | Landwirtschaft VeterinärmedizinAnalytical chemistrySoil organic matter (SOM); Low field 1H NMR relaxometry; 1H wideline NMR spectroscopy; Contact angle; Cation bridges; Water molecule bridges.TA Engineering (General). Civil engineering (General)soil organic matter (som)Low field H-1 NMR relaxometrystateContact angleNuclear magnetic resonancewater molecule bridgesddc:550ddc:630natural organic-mattercontact angleWater Science and TechnologyFluid Flow and Transfer Processeschemistry.chemical_classificationhumic substancesWater molecule bridges.Nuclear magnetic resonance spectroscopycation bridgesCation bridgemultiexponential decay datanuclear-magnetic-resonanceH-1 wideline NMR spectroscopyProton NMRWater bindingTC1-978Relaxometryuniform-penalty inversionlow field 1h nmr relaxometrySettore AGR/13 - Chimica AgrariaContext (language use)1h wideline nmr spectroscopyforest soilsCation bridgesddc:570sandy soilOrganic mattercontact-angleContact angleSoil organic matter (SOM)repellencyMechanical EngineeringHydraulic engineeringchemistrySoil waterWater molecule bridgesJournal of Hydrology and Hydromechanics
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Meningioma of the cerebellopontine angle mimicking benign paroxysmal positional vertigo.

2009

Not available

Diagnosis DifferentialMalemeningioma Benign paroxysmal positional vertigoMeningeal NeoplasmsVertigoContrast MediaHumansGadoliniumCerebellopontine AngleMiddle AgedMeningiomaMagnetic Resonance ImagingJournal of otolaryngology - headneck surgery = Le Journal d'oto-rhino-laryngologie et de chirurgie cervico-faciale
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Agreement among 3 optical imaging methods for the assessment of optic disc topography.

2005

Purpose To assess the agreement of disc topography measurements between the Heidelberg Retina Tomograph (HRT II), Retinal Thickness Analyzer (RTA), and Optical Coherence Tomograph (StratusOCT). Design Observational cross-sectional study. Participants Forty-two randomly chosen eyes of 42 subjects. Methods Each subject underwent HRT II, RTA, and StratusOCT examination. Two experienced examiners drew the contour lines for the HRT II and RTA. Bland and Altman plots were used to evaluate agreement for each topographic parameter among the instruments. The Spearman coefficient of rank correlation was evaluated for each topographic parameter. Main Outcome Measures Agreement in the measurement of op…

Diagnostic ImagingMaleRetinal Ganglion Cellsmedicine.medical_specialtygenetic structuresOptic DiskGlaucomaSpearman's rank correlation coefficientRetinal thickness analyzerOptical imagingNerve FibersOphthalmologyLinear regressionOptic Nerve DiseasesMedicineHumansIntraocular PressureRank correlationAgedRetrospective Studiesbusiness.industryReproducibility of ResultsMiddle Agedmedicine.diseaseeye diseasesOphthalmologymedicine.anatomical_structureCross-Sectional StudiesFemalesense organsTomographybusinessGlaucoma Open-AngleOptic discOphthalmology
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Synthesis of 8-aminomorphans with high KOR affinity

2021

2-Azabicyclo[3.3.1]nonanes (morphans) with a (3,4-dichlorophenyl)acetyl group at 2-position and a pyrrolidino moiety at 8-position were designed as conformationally restricted analogs of piperidine-based KOR agonists. The synthesis started with 4-oxopiperidine-2-carboxylic acid comprising 13 reaction steps. At first the ketone 10 was transformed into diester 7 bearing a propionate side chain. Dieckmann condensation of diester 7 to afford bicyclic enolester 14 and subsequent Krapcho deethoxycarbonylation represent the key steps of the synthesis. The enantiomeric pyrrolidines (1S,5R,8R)-5a and (1R,5S,8S)-5a were separated by chiral HPLC. The eutomer (1S,5R,8R)-5a showed high KOR affinity (K-i…

Diastereoselective reductive aminationEnantiomeric excessStructure-affinity relationshipsPharmacologyPyrrolidinesReceptors Opioid kappaNOESY spectrumOrganic ChemistryMolecular ConformationStereoisomerismGeneral MedicineKOR agonistsEndo-configurationStructure-Activity RelationshipKOR pharmacophoreConformational restrictionChiral HPLCDihedral angleDrug DiscoveryCis/trans-configurationMorphan2-azabicyclo[3.3.1]nonaneEuropean Journal of Medicinal Chemistry
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5,12-Diselena-3,4,13,14-tetraazatricyclo[9.3.0.02,6]tetradeca-3,13-diene

2020

The title compound, C8H8N4Se2, crystallizes in a non-symmetrical conformation with a dihedral angle between the heterocycles of 45.0 (3)° and a nearly strain-free tetramethylene tether. The crystal studied was non-merohedrally twinned with a fractional contribution of 0.342 (3) for the minor twin component.

Dienebiology010405 organic chemistryChemistryComponent (thermodynamics)Crystal structureDihedral angle010402 general chemistrybiology.organism_classification01 natural sciences0104 chemical sciencesCrystalCrystallographychemistry.chemical_compoundTetraDeca-IUCrData
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[2,5-Bis(dipropylamino)-4-(hydroxymethyl)phenyl]methanol

2021

The centrosymmetric title compound, C22H36N2O2, was prepared in five steps from diethyl succinate. The dipropylamino groups are almost orthogonal to the central phenylenedimethanol ring [dihedral angle = 87.62 (9)°]. In the crystal, the molecules are connected by O—H...N hydrogen bonds, forming (101) layers separated by the propyl chains.

Diethyl succinatecrystal structurehydrogen bondCrystallographyChemistryHydrogen bondalcoholAlcoholCrystal structureDihedral angleRing (chemistry)Medicinal chemistryCrystalchemistry.chemical_compoundQD901-999phenylenediamineMethanolIUCrData
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