Search results for "induced"

showing 10 items of 1287 documents

Multicollision-induced dissociation of multiply charged gold clusters, Aun2+, n = 7–35, and Aun3+, n = 19–35

2000

Abstract Multicollision-induced dissociation (MCID) has been applied to gold clusters, Au n 2+ (n = 7–35) and Au n 3+ (n = 19–35) stored in a Penning trap. By application of ion cyclotron resonance excitation and pulses of argon collision gas, fragmentation yields have been measured as a function of the clusters’ kinetic energy. The corresponding dissociation energies have been determined by use of the impulsive collision theory and the quantum Rice–Ramsperger–Kassel (RRK) model for the energy transfer to internal cluster modes and for delayed dissociation, respectively. As compared to earlier measurements of singly charged gold clusters the variation of the stability as a function of clust…

Collision-induced dissociationChemistryCondensed Matter PhysicsPenning trapDissociation (chemistry)Fragmentation (mass spectrometry)Physics::Atomic and Molecular ClustersCluster (physics)Physical and Theoretical ChemistryAtomic physicsValence electronInstrumentationSpectroscopyElectron ionizationIon cyclotron resonanceInternational Journal of Mass Spectrometry
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Studies in organic mass spectrometry. Part 17—Formation of phenol radical ions by rearrangement of the molecular ions of someN-arylthiophenecarboxami…

1995

It has been shown by exact mass measurements and collision-induced dissociation mass-analysed ion kinetic energy spectra that the structure of the m/z 124 ion observed in the mass spectra of N-(4-methoxyphenyl)thiophene-2-carboxamide, N-(4-methoxyphenyl)thiophene-3-carboxamide, N-(4-methoxyphenyl)-5-nitrothiophene-3-carboxamide and N-(4-methoxyphenyl)benzamide is identical with that of the molecular ion of 4-methoxyphenol. This ion becomes abundant in metastable energy window reactions. A probable mechanism for its formation is discussed.

Collision-induced dissociationChemistryPolyatomic ionMass spectrumAnalytical chemistryFast atom bombardmentMass spectrometryTandem mass spectrometryPhotochemistrySpectroscopyIon sourceIonJournal of Mass Spectrometry
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Unveiling anion-induced folding in tripodal imidazolium receptors by ion-mobility mass spectrometry.

2021

The anion-induced folding of tripodal imidazolium receptors has been investigated by NMR spectroscopy, electrospray ionization ion mobility mass spectrometry and DFT calculations. Such folding can be switched by anion release upon collision induced dissociation.

Collision-induced dissociationIon-mobility spectrometryChemistryElectrospray ionizationMetals and Alloyselectrospray ionizationion mobility spectrometersGeneral ChemistryNuclear magnetic resonance spectroscopyMass spectrometryPhotochemistryCatalysisSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsIonFolding (chemistry)Materials ChemistryCeramics and CompositesReceptormass spectrometrynuclear magnetic resonance spectroscopyChemical communications (Cambridge, England)
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Light Induced Excited Pair Spin State in an Iron(II) Binuclear Spin-Crossover Compound

1999

Colloid and Surface ChemistrySpin statesSpin crossoverChemistryExcited stateLight inducedGeneral ChemistryAtomic physicsBiochemistryCatalysisJournal of the American Chemical Society
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Correspondences Between 2-Brauer Characters of Solvable Groups

2010

Let G be a finite solvable group and let p be a prime. Let P ∈ Syl p (G) and N = N G (P). We prove that there exists a natural bijection between the 2-Brauer irreducible characters of p′-degree of G and those of N G (P).

CombinatoricsDiscrete mathematicsAlgebra and Number TheoryBrauer's theorem on induced charactersSolvable groupExistential quantificationBijectionPrime (order theory)MathematicsCommunications in Algebra
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On the Quadratic Type of Some Simple Self-Dual Modules over Fields of Characteristic Two

1997

Let G be a finite group and let K be an algebraically closed field of Ž characteristic 2. Let V be a non-trivial simple self-dual KG-module we . say that V is self-dual if it is isomorphic to its dual V * . It is a theorem of w x Fong 4, Lemma 1 that in this case there is a non-degenerate G-invariant alternating bilinear form, F, say, defined on V = V. We say that V is a KG-module of quadratic type if F is the polarization of a non-degenerate w x G-invariant quadratic form defined on V. In a previous paper 6 , the present authors described some methods to decide if such a module V is of w x quadratic type. One of the main results of 6 is the following. Suppose that Ž . G is a group with a s…

CombinatoricsDiscrete mathematicsFinite groupAlgebra and Number TheoryGroup of Lie typeInduced characterModuloBinary quadratic formQuadratic fieldBilinear formAlgebraically closed fieldMathematicsJournal of Algebra
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A partition of characters associated to nilpotent subgroups

1999

IfG is a finite solvable group andH is a maximal nilpotent subgroup ofG containingF(G), we show that there is a canonical basisP(G|H) of the space of class functions onG vanishing off anyG-conjugate ofH which consists of characters. ViaP(G|H) it is possible to partition the irreducible characters ofG into “blocks”. These behave like Brauerp-blocks and a Fong theory for them can be developed.

CombinatoricsDiscrete mathematicsNilpotentBrauer's theorem on induced charactersSolvable groupGeneral MathematicsPartition (number theory)Nilpotent groupMathematicsIsrael Journal of Mathematics
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Pattern Matching and Pattern Discovery Algorithms for Protein Topologies

2001

We describe algorithms for pattern-matching and pattern-learning in TOPS diagrams (formal descriptions of protein topologies). These problems can be reduced to checking for subgraph isomorphism and finding maximal common subgraphs in a restricted class of ordered graphs. We have developed a subgraph isomorphism algorithm for ordered graphs, which performs well on the given set of data. The maximal common subgraph problem then is solved by repeated subgraph extension and checking for isomorphisms. Despite its apparent inefficiency, this approach yields an algorithm with time complexity proportional to the number of graphs in the input set and is still practical on the given set of data. As a…

CombinatoricsDiscrete mathematicsSubgraph isomorphism problemMaximal independent setInduced subgraph isomorphism problemPattern matchingFast methodsNetwork topologyTime complexityAlgorithmMaximum common subgraph isomorphism problemMathematicsofComputing_DISCRETEMATHEMATICSMathematics
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The minimal number of characters over a normal p-subgroup

2007

Abstract If N is a normal p-subgroup of a finite group G and θ ∈ Irr ( N ) is a G-invariant irreducible character of N, then the number | Irr ( G | θ ) | of irreducible characters of G over θ is always greater than or equal to the number k p ′ ( G / N ) of conjugacy classes of G / N consisting of p ′ -elements. In this paper, we investigate when there is equality.

CombinatoricsFinite groupAlgebra and Number TheoryCharacter (mathematics)Brauer's theorem on induced charactersConjugacy classCharacter tableCharactersCounting charactersFinite groupsNormal p-subgroupsMathematicsJournal of Algebra
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p-Parts of Brauer character degrees

2014

Abstract Let G be a finite group and let p be an odd prime. Under certain conditions on the p-parts of the degrees of its irreducible p-Brauer characters, we prove the solvability of G. As a consequence, we answer a question proposed by B. Huppert in 1991: If G has exactly two distinct irreducible p-Brauer character degrees, then is G solvable? We also determine the structure of non-solvable groups with exactly two irreducible 2-Brauer character degrees.

CombinatoricsFinite groupAlgebra and Number TheoryCharacter (mathematics)Brauer's theorem on induced charactersSolvable groupStructure (category theory)Mathematics::Representation TheoryPrime (order theory)MathematicsJournal of Algebra
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