Search results for "Splitting"
showing 10 items of 220 documents
A neural network clustering algorithm for the ATLAS silicon pixel detector
2014
A novel technique to identify and split clusters created by multiple charged particles in the ATLAS pixel detector using a set of artificial neural networks is presented. Such merged clusters are a common feature of tracks originating from highly energetic objects, such as jets. Neural networks are trained using Monte Carlo samples produced with a detailed detector simulation. This technique replaces the former clustering approach based on a connected component analysis and charge interpolation. The performance of the neural network splitting technique is quantified using data from proton-proton collisions at the LHC collected by the ATLAS detector in 2011 and from Monte Carlo simulations. …
A Heterobimetallic Anionic 3,6-Connected 2D Coordination Polymer Based on Nitranilate as Ligand
2016
In order to synthesize new coordination polymers with original architectures and interesting magnetic properties, we used the nitranilate ligand (C₆O₄(NO₂)₂2- = C₆N₂O₈2-), derived from the dianionic ligand dhbq2- (2,5-dihydroxy-1,4-benzoquinone = H₂C₆O₄2-). The use of this bis-bidentate bridging ligand led to [(DAMS)₂{FeNa(C₆N₂O₈)₃}·CH₃CN]n (1) (DAMS⁺ = C16H17N₂⁺ = 4-[4-(dimethylamino)-α-styryl]-1-methylpyridinium), a 2D heterometallic coordination polymer presenting an unprecedented structure for any anilato-based compound. This structural type is a 3,6-connected 2D coordination polymer derived from the well-known honeycomb hexagonal structure, where Fe(III) ions alternate with Na⁺ dimers …
Organometallic complexes with biological molecules. I. Diorganotin(IV)chloro protoporphyrin IX complexes: Solid-state and solution-phase characteriza…
1993
Protoporphyrin IX (H4PPIX) complexes of diorganotin(IV)chloro moieties with formula (R2SnCl)2H2PPIX (RMe, Bu and Ph) have been obtained and their solid-state and solution-phase configurations have been studied through spectroscopic investigations. Coordination of the side-chain carboxylates of H4PPIX to R2Sn(IV)Cl moieties, with bridging carboxylate (COO−) has been inferred by comparison of the free and coordinated H4PPIX IR spectra, while the occurrence of a five-coordinated tin(IV) atom in a cis-R2 trigonal bipyramidal structure has been deduced, for all of the synthesized complexes, by rationalization of the nuclear quadrupole splitting parameters, according to the point-charge model for…
On globally generated vector bundles on projective spaces II
2014
Extending a previous result of the authors, we classify globally generated vector bundles on projective spaces with first Chern class equal to three.
F-signature of pairs and the asymptotic behavior of Frobenius splittings
2012
We generalize $F$-signature to pairs $(R,D)$ where $D$ is a Cartier subalgebra on $R$ as defined by the first two authors. In particular, we show the existence and positivity of the $F$-signature for any strongly $F$-regular pair. In one application, we answer an open question of I. Aberbach and F. Enescu by showing that the $F$-splitting ratio of an arbitrary $F$-pure local ring is strictly positive. Furthermore, we derive effective methods for computing the $F$-signature and the $F$-splitting ratio in the spirit of the work of R. Fedder.
Qualitative analysis of matrix splitting methods
2001
Abstract Qualitative properties of matrix splitting methods for linear systems with tridiagonal and block tridiagonal Stieltjes-Toeplitz matrices are studied. Two particular splittings, the so-called symmetric tridiagonal splittings and the bidiagonal splittings, are considered, and conditions for qualitative properties like nonnegativity and shape preservation are shown for them. Special attention is paid to their close relation to the well-known splitting techniques like regular and weak regular splitting methods. Extensions to block tridiagonal matrices are given, and their relation to algebraic representations of domain decomposition methods is discussed. The paper is concluded with ill…
Complexes of organometallic compounds. XLVIII. Mössbauer and other studies on pyrazine derivatives of tin(IV) compounds. A relationship between isome…
1978
Abstract Adducts RSnCl 3 ·pyz (R = Me, Bu n , Oct n , Ph; pyz = pyrazine) have been synthesized and characterized in the solid state. It has been determined that RSnCl 3 ·pyz are polymeric compounds, where the ligand acts as bridging bis-monodentate and the tin atoms attain the coordination number six. This has been duduced from: i) temperature dependent Mossbauer spectroscopy; ii) the correlation between Mossbauer isomer shift, δ, and electrical charge on tin, Q Sn , concerning pyrazine adducts of RSnCl 3 and others; iii) an infrared study of the coordinated ligand in RSnCl 3 ·pyz. Other implications of the Mossbauer T dependent study ( e.g. , the decrease of the Debye temperature in RSnCl…
Mössbauer investigations of the hexachlorantimonate salt of the phenyliron 2,3,7,8,l2,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrinate, [Fe(oetp…
2002
Abstract The phenyliron derivative, [Fe(oetpp)C6H5)]SbCl6 (2) generated in dichloromethane by oxidation of the phenyliron(III) complex, Fe(III) (oetpp)C6H5 (1) of the 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrin with 1 equiv. of phenoxathiinylium hexachloroantimonate, [C12H8OS]SbCl6, was studied by Mossbauer spectroscopy. This compound exhibits an isomer shift δ of 0.13 mm s−1 and a quadrupole splitting ΔEQ of 3.23 mm s−1. The measured magnetic hyperfine pattern obtained in the temperature range 4.2–40 K in a field of 3.5 and 7 T, applied perpendicular to the γ-beam, has been consistently analyzed in the spin Hamiltonian approximation assuming an iron(IV) S=1 electronic con…
Quantitative evaluation of the preferential orientation ofpara-phenylene vinylene pentamers in polystyrene films by optically detected magnetic reson…
2007
The morphology of drop-casted and spin-coated films of blends ofpara-phenylene vinylenederived pentamers with polystyrene is investigated by means of X-band optically detected magnetic resonance (ODMR) of the triplet excited states. Adapting an electron spin resonance simulation program to ODMR, the orientation distribution function of the oligomers in the films could be quantified. After drop casting or spin coating the pentamers from a solution, the oligomers tend to lie with their backbones in the plane of the film. The parameters of film preparation and the type of pentamer strongly influence the orientation distribution function. Also, the study of preferentially oriented films allows …
Solving fractional Schroedinger-type spectral problems: Cauchy oscillator and Cauchy well
2014
This paper is a direct offspring of Ref. [J. Math. Phys. 54, 072103, (2013)] where basic tenets of the nonlocally induced random and quantum dynamics were analyzed. A number of mentions was maid with respect to various inconsistencies and faulty statements omnipresent in the literature devoted to so-called fractional quantum mechanics spectral problems. Presently, we give a decisive computer-assisted proof, for an exemplary finite and ultimately infinite Cauchy well problem, that spectral solutions proposed so far were plainly wrong. As a constructive input, we provide an explicit spectral solution of the finite Cauchy well. The infinite well emerges as a limiting case in a sequence of deep…