Search results for "CONSTANT"

A new tetranuclear defective dicubane azide-bridged cobalt(II) complex

2013

Abstract The new tetranuclear cobalt(II) complex with formula [Co4(N3)8(4,5-diazafluoren-9-one)4] (1) is reported. Complex 1 is a cobalt(II) defective dicubane azide-bridged compound showing only azido bridging ligands in the μ1,1– and μ1,1,1– coordination modes. The magnetic properties of 1 are reported. Magnetic susceptibility measurements indicate ferromagnetic coupling. The magnetic data have been fitted to 2 K by considering two different superexchange coupling constants. The out-of-phase signal χM″ displays frequency-dependence below approximately 9 K.

A DFT study of the vicinal 3J(119Sn,13C) and 3J(119Sn,1H) coupling constants in trimethyl- and chlorodimethyl-stannyl propanoates.

2013

Abstract We have tested the performance of DFT protocols, both at the Scalar relativistic ZORA and non-relativistic level of theory, for the calculation of the 3 J( 119 Sn, 13 C) and 3 J( 119 Sn, 1 H) vicinal couplings for a series of flexible organotin(IV) derivatives with formula XMe2SnCHRCHR′COOMe (X = Me, Cl; R, R′ = Me, Ph). A satisfactory agreement between experimental and calculated vicinal couplings has been obtained by taking into account the conformational behaviour of the compounds investigated. The protocols used, mainly the relativistic one, were found to give a correct picture of the populations and a sufficiently high overall performance in calculating the vicinal couplings, …

A quantitative test of the mode-coupling theory of the ideal glass transition for a binary Lennard-Jones system

1996

Using a molecular dynamics computer simulation we determine the temperature dependence of the partial structure factors for a binary Lennard-Jones system. These structure factors are used as input data to solve numerically the wave-vector dependent mode-coupling equations in the long time limit. Using the so determined solutions, we compare the predictions of mode-coupling theory (MCT) with the results of a previously done molecular dynamics computer simulation [Phys. Rev. E 51, 4626 (1995), ibid. 52, 4134 (1995)]. From this comparison we conclude that MCT gives a fair estimate of the critical coupling constant, a good estimate of the exponent parameter, predicts the wave-vector dependence …

Photo- and Electroproduction of Eta Mesons on Nucleons and Nuclei

1995

Eta photo- and electroproduction off the nucleon is investigated in an approach that contains Born terms, vector meson and nucleon resonance contributions. In a comparison with the new Mainz data we find a large sensitivity on the elementary ηN N coupling. Our analysis results in a pseudoscalar ηN N coupling with a coupling constant of g ηN N 2 /4π=0.4. Furthermore, we also study coincidence cross sections for eta electroproduction and present calculations for structure functions and kinematical conditions that are most sensitive to the S 11(1535) and the D 13(1520) resonances. Finally, we show results on the inclusive eta photoproduction off complex nuclei with a very good agreement with r…

Unexpected high robustness of electrochemical cross-coupling for a broad range of current density

2017

Solvent effect enables electrosynthesis of organic compounds with strong variation of electric current at constant efficacy.

Force probe simulations using a hybrid scheme with virtual sites.

2017

Hybrid simulations, in which a part of the system is treated with atomistic resolution and the remainder is represented on a coarse-grained level, allow for fast sampling while using the accuracy of atomistic force fields. We apply a hybrid scheme to study the mechanical unfolding and refolding of a molecular complex using force probe molecular dynamics (FPMD) simulations. The degrees of freedom of the solvent molecules are treated in a coarse-grained manner while atomistic resolution is retained for the solute. The coupling between the solvent and the solute is provided using virtual sites. We test two different common coarse-graining procedures, the iterative Boltzmann inversion method an…

La declaracion del Credo, ordenado por los Apóstoles para informarnos en las verdades ciertas y seguras de la santa fe católica.

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Adaptive Planning in-Service Inspections of Fatigued Structures in Damage Tolerance Situations via Observations of Crack Growth Process

2017

From an engineering standpoint the fatigue life of a fatigued structure consists of two periods: (i) crack initiation period, which starts with the first load cycle and ends when a technically detectable crack is presented, and (ii) crack propagation period, which starts with a technically detectable crack and ends when the remaining cross section can no longer withstand the loads applied and fails statically. The main aim of this paper is to present more accurate innovative stochastic fatigue model for adaptive planning inspections of fatigued structures in damage tolerance situations via observations of crack growth process during a crack propagation period. A new crack growth equation is…

First-principles calculations of the atomic and electronic structure of SrZrO3 and PbZrO3 (001) and (011) surfaces.

2010

We present the results of calculations of surface relaxations, rumplings, energetics, optical band gaps, and charge distribution for the SrZrO(3) and PbZrO(3) (001) and (011) surfaces using the ab initio code CRYSTAL and a hybrid description of exchange and correlation. We consider both SrO(PbO) and ZrO(2) terminations of the (001) surface and Sr(Pb), ZrO, and O terminations of the polar SrZrO(3) and PbZrO(3) (011) surfaces. On the (001) surfaces, we find that all upper and third layer atoms relax inward, while outward relaxations of all atoms in the second layer are found with the sole exception of the SrO-terminated SrZrO(3) (001) surface second layer O atom. Between all (001) and (011) s…

Detailed study of defects in thin fullerite films

2012

The structural investigations of fullerite films were performed using high-resolution electron microscopy, electron diffraction and electron energy loss spectroscopy and X-ray photoelectron spectroscopy. In particular defects such as dislocations, stacking faults and twins were studied in details. It was shown that fullerite films could be characterized by a face-centered cubic (f.c.c.) structure with lattice parameter a = 1.416 nm. They are distinguished for their rich polytypic structure that is caused by breaking of alteration of closely packed planes of (111) type. The quantitative method based on information theory using the “run-length encoding” algorithm was suggested to evaluate the…