Search results for "Homogeneous"

The minimal free resolution of fat almost complete intersections in ℙ1 x ℙ1

2017

AbstractA current research theme is to compare symbolic powers of an ideal I with the regular powers of I. In this paper, we focus on the case where I = IX is an ideal deûning an almost complete intersection (ACI) set of points X in ℙ1 × ℙ1. In particular, we describe a minimal free bigraded resolution of a non-arithmetically Cohen-Macaulay (also non-homogeneous) set 𝒵 of fat points whose support is an ACI, generalizing an earlier result of Cooper et al. for homogeneous sets of triple points. We call 𝒵 a fat ACI.We also show that its symbolic and ordinary powers are equal, i.e, .

1,2,3-Triazole in Heterocyclic Compounds, Endowed with Biological Activity, through 1,3-Dipolar Cycloadditions

2014

1,3-Dipolar cycloaddition reactions can be considered a powerful synthetic tool in the building of heterocyclic rings, with applications in different fields. In this review we focus on the synthesis of biologically active compounds possessing the 1,2,3-triazole core through 1,3-dipolar cycloaddition reactions. The 1,2,3-triazole skeleton can be present as a single disubstituted ring, as a linker between two molecules, or embedded in a polyheterocycle. The cycloaddition reactions are usually catalysed by copper or ruthenium. Domino reactions can be achieved through dipolarophile anion formation, generally followed by cyclisation. The variety of attainable heterocyclic structures gives an ill…

Olefin metathesis reactions with fluorinated substrates, catalysts, and solvents.

2014

Catalytic Oxidation of Alkanes and Alkenes by H 2 O 2 with a μ‐Oxido Diiron(III) Complex as Catalyst/Catalyst Precursor

2015

A new mu-oxo diiron(III) complex of the lithium salt of the pyridine-based unsymmetrical ligand 3-[(3-{[bis(pyridin-2-ylmethyl)amino]methyl}-2-hydroxy-5-methylbenzyl)(pyridin2-ylmethyl)amino] propanoate (LiDPCPMPP), [Fe-2(mu-O)(LiDPCPMPP)(2)](ClO4)(2), has been synthesized and characterized. The ability of the complex to catalyze oxidation of several alkanes and alkenes has been investigated by using CH3COOH/H2O2 (1:1) as an oxidative system. Moderate activity in cyclohexane oxidation (TOF = 33 h(-1)) and good activity in cyclohexene oxidation (TOF = 72 h(-1)) were detected. Partial retention of configuration (RC = 53%) in cis- and trans-1,2-dimethylcyclohexane oxidation, moderate 3 degrees…

Obcy czy inni? Czesi w Zelowie

2018

We wstępnej części artykułu zostaną zaprezentowane kategorie OBCY, INNY oraz SWÓJ w różnych konfiguracjach (opozycja komplementarna, triada), obecnych w dyskursie tożsamościowym. Następnie przedstawione zostaną determinanty tożsamości: konfesja i język grupy mieszkańców Zelowa – potomków czeskich emigrantów religijnych. W końcowej części artykułu podkreśla się, że obraz potomków czeskich emigrantów jest zmienny w czasie: początkowo była to grupa homogeniczna pod względem wyznaniowym, etnicznym i językowym, a obecnie jest grupą zasymilowaną językowo i kulturowo.

Dagger closure and solid closure in graded dimension two

2013

We introduce a graded version of dagger closure and prove that it coincides with solid closure for homogeneous ideals in two-dimensional N \mathbb {N} -graded domains of finite type over a field.

ELECTRE III to dynamically support the decision maker about the periodic replacements configurations for a multi-component system

2013

The problem tackled by the present paper concerns the selection of the elements of a repairable and stochastically deteriorating multi-component system to replace (replacements configuration) during each scheduled and periodical system stop within a finite optimization cycle, by ensuring the simultaneous minimization of both the expected total maintenance cost and the system unavailability. To solve the considered problem, a combined approach between multi-objective optimization problem (MOOP) and multi-criteria decision making (MCDM) resolution techniques is proposed. In particular, the @e constraint method is used to single out the optimal Pareto frontier whereas the ELECTRE III multi-cri…

Effective pseudopotential for energy density functionals with higher-order derivatives

2011

We derive a zero-range pseudopotential that includes all possible terms up to sixth order in derivatives. Within the Hartree-Fock approximation, it gives the average energy that corresponds to a quasi-local nuclear Energy Density Functional (EDF) built of derivatives of the one-body density matrix up to sixth order. The direct reference of the EDF to the pseudopotential acts as a constraint that divides the number of independent coupling constants of the EDF by two. This allows, e.g., for expressing the isovector part of the functional in terms of the isoscalar part, or vice versa. We also derive the analogous set of constraints for the coupling constants of the EDF that is restricted by sp…

Phase diagram of the quarter-filled extended Hubbard model on a two-leg ladder

2000

We investigate the ground-state phase diagram of the quarter-filled Hubbard ladder with nearest-neighbor Coulomb repulsion V using the Density Matrix Renormalization Group technique. The ground-state is homogeneous at small V, a ``checkerboard'' charge--ordered insulator at large V and not too small on-site Coulomb repulsion U, and is phase-separated for moderate or large V and small U. The zero-temperature transition between the homogeneous and the charge-ordered phase is found to be second order. In both the homogeneous and the charge-ordered phases the existence of a spin gap mainly depends on the ratio of interchain to intrachain hopping. In the second part of the paper, we construct an…

Bone regeneration using particulate grafts : an update

2010

Objective: A review is made of the publications on bone regeneration using particulate grafts, with an evaluation of the success of implants placed in such regenerated areas. Material and Method: A Medline search using different key words was made of the articles published between 1999-2009 involving at least two patients subjected to grafting with autologous, homologous or xenogenic bone, non-bony substitutes, or a combination of these grafts for the placement of dental implants. Studies involving block grafting were excluded. A total of 11 studies were evaluated. Results: These grafts are indicated in cases of small or peri-implant bone defects such as dehiscences and fenestrations, with …