Search results for "State."

showing 10 items of 8943 documents

Synthesis, characterization of diorganotin(IV) complexes of N-(2-hydroxyarylidene)aminoacetic acid and antitumour screening in vivo in ehrlich ascite…

2001

Some new diorganotin(IV) complexes have been prepared by reacting potassium N-(2-hydroxyarylidene)aminoacetate with R2SnCl2(R = Me,nBu,Ph). The complexes have been characterized by 1H,13C,119Sn NMR, IR and 119mSn Mössbauer spectroscopic techniques in combination with elemental analysis. In the solid state, the complexes possess penta- and hexa-coordinated tin centres. The hexa-coordinated tin complexes were found to dissociate in solution, giving rise to penta-coordinated species as revealed by 119Sn NMR spectroscopy. Antitumour screening in vivo of the complexes L4snPh2,L4SnPh2· Ph3SnCl and L4SntBU2·t Bu2SnCl2 (L4 = N-(2-hydroxyacetophenone)aminoacetate) is also reported. Copyright © 2001 …

AldiminesynthesisStereochemistryMossbauer spectroscopyInfrared spectroscopyAntitumour activityanimal cellantineoplastic activitydissociationChemical synthesisMedicinal chemistryEhrlich ascites tumor cellEhrlich ascites carcinomaInorganic Chemistryin vivo studychemistry.chemical_compoundAcetic acidOrganotinmalecomplex formationorganotin compoundcontrolled studyCarboxylateinfrared spectroscopyEhrlich ascites carcinoma cellmouseglycine derivativenuclear magnetic resonance spectroscopychemistry.chemical_classificationSchiff basenonhumananimal modelarticleGeneral ChemistryNuclear magnetic resonance spectroscopysolid stateNMRAmino acidchemistryreaction analysiSettore CHIM/03 - Chimica Generale E InorganicaIRSchiff baseschemical analysi
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Theozyme for antibody aldolases. Characterization of the transition-state analogueElectronic supplementary information (ESI) available: MP2/6-31G** e…

2003

A theozyme for antibody aldolases has been studied at the MP2/6-31G** computational level. Formation of two cooperative hydrogen-bonds between the acidic hydrogen atoms of the enamine and of a methanol molecule with the oxygen atom of the aldol acceptor markedly favors the C–C bond-formation associated with the aldol reaction. A comparative analysis of the geometry, the charge distribution and the shape of the molecular electrostatic potential of the transition structure (TS) with the covalent adduct, resulting from the reaction of methylamine and the β-diketone used as a hapten allows us to characterize the transition-state analogue (TSA) generated at immunization. This finding allows us t…

Aldol reactionCovalent bondStereochemistryTransition state analogChemistryOrganic ChemistryMoleculeTetrahedral molecular geometryPhysical and Theoretical ChemistryBiochemistryHaptenAcceptorAdductOrganic & Biomolecular Chemistry
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The diamond partial order for strong Rickart rings

2016

The diamond partial order has been first introduced for matrices, and then discussed also in the general context of *-regular rings. We extend this notion to Rickart rings, and state various properties of the diamond order living on the so-called strong Rickart rings. In particular, it is compared with the weak space preorder and the star order; also existence of certain meets and joins under diamond order is discussed.

Algebra and Number TheoryMathematics::Rings and Algebras010102 general mathematicsPreorderOrder (ring theory)JoinsDiamondContext (language use)010103 numerical & computational mathematicsState (functional analysis)engineering.materialStar (graph theory)Space (mathematics)01 natural sciencesCombinatoricsengineering0101 mathematicsMathematicsLinear and Multilinear Algebra
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Nonstochastic languages as projections of 2-tape quasideterministic languages

1998

A language L (n) of n-tuples of words which is recognized by a n-tape rational finite-probabilistic automaton with probability 1-e, for arbitrary e > 0, is called quasideterministic. It is proved in [Fr 81], that each rational stochastic language is a projection of a quasideterministic language L (n) of n-tuples of words. Had projections of quasideterministic languages on one tape always been rational stochastic languages, we would have a good characterization of the class of the rational stochastic languages. However we prove the opposite in this paper. A two-tape quasideterministic language exists, the projection of which on the first tape is a nonstochastic language.

AlgebraClass (set theory)TheoryofComputation_COMPUTATIONBYABSTRACTDEVICESFinite-state machineRegular languageProjection (mathematics)Deterministic automatonComputer scienceProbabilistic automatonCharacterization (mathematics)AlgorithmAutomaton
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Sui gruppi unitari finitari e sulla congettura di dieudonné

1996

In this paper we consider some questions concerning unitary spaces (V, h), even though (V, h) is not finitely generated.

AlgebraPure mathematicsGeneral MathematicsFinitely-generated abelian groupAlgebra over a fieldUnitary stateMathematicsRendiconti del Circolo Matematico di Palermo
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Arithmetic Problems Formulation and Working Memory Load

1987

First, third, and fifth graders (French children in American-numbered grades) were asked to solve arithmetic problems in which an initial state was modified by two successive transformations. Three independent variables were manipulated systematically. First, the unknown state was either the final state (Sl) or the initial state (S2). Second, either the known state (01) or the transformations (02) appeared in the first place in the problem wording. Third, the question was either located at the end (Ql) or at the beginning (42) of the problem text. As anticipated, these modifications strongly affected the performances at every age: S1 appears clearly easier than S2; 0 1 leads to a better per…

AlgebraVariablesWorking memorymedia_common.quotation_subjectDevelopmental and Educational PsychologyExperimental and Cognitive PsychologyState (computer science)Mathematical problem solvingArithmeticGeneral PsychologyEducationmedia_commonMathematicsCognition and Instruction
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Interactions of Ultra-cold Alkaline-earth-like and Alkali Atoms with Light

2019

This paper presents the experimental results of photoionization and photoassociation experiments performed with both ultra-cold alkaline-earth-like and alkali atoms. Photoionization cross-section was studied for 88Sr at the blue magic 390 nm wavelength as well as for 87Rb at 254 nm. We also present preliminary results of photoassociation spectroscopy of the molecular line detected near the dissociation threshold of the excited Rb*Hg molecule at D1 Rb line (795 nm).

Alkaline earth metalMaterials scienceAnalytical chemistrychemistry.chemical_elementPhotoionization01 natural sciencesDissociation (chemistry)Rubidium010309 opticsWavelengthchemistryExcited state0103 physical sciencesMolecule010306 general physicsSpectroscopy2019 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum (EFTF/IFC)
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Static and Dynamic Properties of a n-C100H202 Melt from Molecular Dynamics Simulations

1997

We present in this work results from atomistic molecular dynamics simulations of a n-C100H202 melt. This work represents a first effort to simulate a fully equilibrated ensemble of chains of suffic...

Alkanechemistry.chemical_classificationSelf-diffusionWork (thermodynamics)Polymers and PlasticsOrganic ChemistryThermodynamicsPolyethyleneInorganic ChemistryMolecular dynamicschemistry.chemical_compoundMolten statechemistryMaterials ChemistryRadius of gyrationPhysical chemistryMacromolecules
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Crystalline-state reaction with allosteric effect in spin-crossover, interpenetrated networks with magnetic and optical bistability.

2003

A net change: A fully reversible ligand substitution involving coordination/ uncoordination of gaseous water and pyrimidine induces the repetitive allosteric transformation of three interpenetrated nets into a single three-dimensional net. The transformation does not affect the crystallinity of the sample but alters significantly the spin-crossover transition; the compound shows magnetic and chromatic bistability (see picture).

Allosteric effectSpin crossoverChemical physicsChemistryNanotechnologyGeneral ChemistryState (functional analysis)sense organsGeneral MedicineCatalysisOptical bistabilityAngewandte Chemie (International ed. in English)
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Comparative chemistry of 18-electron Mo(II) and 17-electron Mo(III) compounds containing only carbon-based ligands

1998

International audience; The chemical reactivity of various kinetically stable isomers of compound CpMo(η3-C3H5)(η4-C4H6), 1, and its oxidation product [1]+, as well as the bis-allyl Mo(III) complex CpMo(η3-C3H5)2, 2, and the bis-diene Mo(II) complex [CpMo(η4-C4H6)2]+, 3, is reviewed. The inertness toward isomerization processes of the allyl and butadiene ligands in the Mo(II) complexes has allowed a study of the relative reactivity toward both electrophilic and nucleophilic addition processes as a function of coordination mode. The dependence of various reaction pathways on the metal oxidation state has also been investigated. Of particular interest is the discovery that the electronically …

Allyl ligands010402 general chemistry01 natural sciencesMedicinal chemistryCatalysisInorganic ChemistryMetalButadiene polymerizationOxidation stateMaterials ChemistryOrganic chemistryMolecule[CHIM.COOR]Chemical Sciences/Coordination chemistryReactivity (chemistry)Physical and Theoretical ChemistryButadiene dimerizationMolybdenumNucleophilic addition010405 organic chemistryChemistry0104 chemical sciencesvisual_artElectrophilevisual_art.visual_art_mediumParamagnetic organometallicsReactivity of coordinated ligandsIsomerizationCoordination Chemistry Reviews
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