Search results for "force"
showing 10 items of 3423 documents
Mixed MHD convection and Tritium transport in fusion-relevant configurations
2005
Mixed MHD flow and Tritium transport were computed for a slender poloidal duct, representative of a DEMO HCLL blanket element. 2-D flow and temperature fields were computed in the duct's cross section under the assumption of parallel, fully developed flow, while Tritium concentration C was found by solving a fully 3-D problem with simplifying assumptions at the duct's ends. The spatial distribution of C depended on the intensity and direction of the forced flow. Significant peak factors were obtained if the net flow rate was so low that re-circulation occurred; C maxima were attained near the walls for upward flow, in the core region for downward flow.
Versatility and dynamics of the copper(I) coordination sphere in sterically hindering tris(pyrazolyl)methane-incorporating macrobicycles
2009
Two arene-capped macrobicycles (1 and 2) incorporating the tris(pyrazolyl)methane (Tpm) chelate have been prepared from a benzylthiol-functionalized Tpm precursor (3). Reaction of either macrobicycle with Cu(CH3CN)4+ leads to tetrahedral or trigonal-planar, fluxional complexes incorporating the Cu(CH3CN)+ subunit ([Cu(1)(CH3CN)]+ and [Cu(2)(CH3CN)]+). The acetonitrile ancillary ligand does not fit inside the macrobicycle cavity and can be removed by heating under vacuum, which produces the [Cu(1)]+ and [Cu(2)]+ species probably involving intramolecular thioether coordination. The [Cu(1)(CH3CN)]+ complex was shown to convert slowly in wet acetone into a helical coordination polymer, which is…
Vibrational properties of 1D- and 3D polynuclear spin crossover Fe(II) urea-triazoles polymer chains and quantification of intrachain cooperativity
2020
Abstract The vibrational dynamics of the iron centres in 1D and 3D spin crossover Fe(II) 4-alkyl-urea triazole chains have been investigated by synchrotron based nuclear inelastic scattering. For the 1D system, the partial density of phonon states has been modelled with density functional theory methods. Furthermore, spin dependent iron ligand distances and vibrational modes were obtained. The previously introduced intramolecular cooperativity parameter H coop (Rackwitz et al, Phys. Chem. Chem. Phys. 2013, 15, 15450) has been determined to −31 kJ mol−1 for [Fe(n-Prtrzu)3(tosylate)2] and to +27 kJ mol−1 for [Fe(n-Prtrzu)3(BF4)2]. The change of sign in H coop is in line with the incomplete an…
The first silver(I) nitrate π-complexes with unsaturated organosilicons: Synthesis and structural characterization of [Ag(DADPS)xNO3] (DADPS=diallyld…
2011
Abstract Tetraethylene glycol dimethyl ether (tetraglyme) was used for the first time to induce the activation of silver nitrate resulting in the step-by-step formation of complexes with diallyldiphenylsilane (DADPS). Two crystal compounds of this series were examined by FTIR spectroscopy and X-ray diffraction. The analysis of the obtained data showed that the Ag (C C) η 2 -interaction is involved in the synergistic effect of intra and intermolecular forces. In particular the interlayer π–π stacking interactions promoted by asymmetric weak Ag C(phenyl) bond have a significant influence on the thermal behavior and stability of the synthesized products. It was also found that a decrease of si…
L'incidence de l'épidémie de coronavirus sur les contrats d'affaires : de la force majeure à l'imprévision
2020
International audience
Surface-directed spinodal decomposition in a thin-film geometry: A computer simulation
1994
The phase separation kinetics of a two-dimensional binary mixture at critical composition confined between (one-dimensional) straight walls which preferentially attract one component of the mixture is studied for a wide range of distancesD between the walls. Following earlier related work on semiinfinite systems, two choices of surface forces at the walls are considered, one corresponding to an incompletely wet state of the walls, the other to a completely wet state (forD→∞). The nonlinear Cahn-Hilliard-type equation, supplemented with appropriate boundary conditions which account for the presence of surfaces, is replaced by a discrete equivalent and integrated numerically. Starting from a …
Theoretical absorption spectrum of the Ar–CO van der Waals complex
2003
The three-dimensional intermolecular electric dipole moment surface of Ar–CO is calculated at the coupled cluster singles and doubles level of theory with the aug-cc-pVTZ basis set extended with a 3s3p2d1f1g set of midbond functions. Using the rovibrational energies and wave functions of our recent study [J. Chem. Phys. 117, 6562 (2002)], temperature-dependent spectral intensities are evaluated and compared to available experimental data. Based on the theoretical spectrum, alternative assignments of the experimentally observed lines in the fundamental band of CO around 2160 and 2166 cm−1 are suggested. Thomas.Bondo@uv.es
ChemInform Abstract: Molybdenum Pentachloride Mediated Synthesis of Spirocyclic Compounds by Intramolecular Oxidative Coupling.
2016
Oxidative treatment of 4-methoxy substituted 2-aryl cinnamates leads to an dealkylative C—C coupling and gives access to spirocyclic compounds.
ChemInform Abstract: Versatile Oxidative Approach to Carbazoles and Related Compounds Using MoCl5.
2014
Oxidative intramolecular coupling of tertiary amines with at least two electron-rich arenes gives carbazoles in good to excellent yields.