Universal scaling in transient creep

We present experimental evidence that pressure solution creep does not establish a steady-state interface microstructure as previously thought. Conversely, pressure solution controlled strain and the characteristic length scale of interface microstructures grow as the cubic root of time. Transient creep with the same scaling is known in metallurgy (Andrade creep). The apparent universal scaling of pressure solution transient creep is explained using an analogy with spinodal dewetting.     

Descente de Shintani et Restriction des Scalaires

An interpretation is given of the Shintani descent from thepoints of a connected algebraic group over a finite field toits group of points over a subfield in terms of a Shintani descentbetween two different rational structures over the same finitefield, using restriction of scalars. From this a generalizationis deduced of a result of Gyoja's on the Shintani descent ofDeligne–Lusztig characters of a finite group of Lie type.     

Phenyl-6 phospha-5 phenanthrene

The title compound has been prepared by a three-step method including a ring enlargement of benzyl-5 dibenzophosphole by reaction with benzoyl chloride.     

Vibrational study of layered ZnPS3 compounds intercalated with [Co(η5 -C5H5)2+] and [Cr(η6 -C6H6)2+] CATIONS

Infrared and Raman spectra (10–3100 cm^?1) of the layered ZnPSs compound and of intercalates with [Co(η⁵ ? C₅H₅)₂⁺] and [Cr(η⁶ ? C₆H₆)₂⁺] cations in the polycrystalline state have been recorded 300–10 K temperature range. A complete assignment of the spectra is proposed in terms of PSs group motions, Zn²⁺ ion translations and [Co(η⁵ ? C₅H₅)₂⁺] or [Cr(η⁶ ? C₆H₆)₂⁺] internal vibrations. New low frequency for the [Co(η⁵-C₅H₅)₂⁺] intercalate at low temperature are assigned to librational and torsional modes of C₅H₅ rings. Moreover, the preresonance Raman spectra of this intercalate show a selective enhancement for the metal-ligand vibrations when the charge transfer band of the cobalticenium is approached. One concludes that guest molecules are intercalated under their cationic form, are weakly interacting with the host lattice and seem to be dynamically disordered at room temperature.     

Numerical modelling of viscous non-Newtonian effects in lubricating systems

Modern lubricants often exhibit shear-thinning due to the presence of high molecular weight polymers as additives. Therefore the influence of such non-Newtonian effects on the performances of lubricating systems must be predicted. The corresponding fluid film flow is governed by a non-linear partial differential equation, which generalizes the classical Reynolds equation. Having prescribed adequate boundary conditions, this equation is solved by a finite element method with optimal control. The problem of the square slider bearing lubricated by the Rabinowitsch fluid is solved in order to test the accuracy of the numerical scheme. The pressure and velocity fields are given and compared with the corresponding ones obtained for the Newtonian fluid.     

Reaction du cyclopentadienylthallium avec les liaisons P-Cl : Preparation et proprietes des cyclopentadienylphosphines

The reaction of cyclopentadienylthallium with chlorophosphines yields cyclopentadienyl phosphines 1, 4, 6 and 8. Some of their derivatives (oxides, sulfides and methyl iodides) have been prepared. Their NMR shows that phosphorus is mainly bonded to the first position of the cyclopentadiene nucleus. Starting with diphenyl (1,3-cyclopentadienyl) phosphine sulfide 2 we have also studied the Diels-Alder reactivity, the bromination and the metalation of the cyclopentadienyl group. This last reaction allows the synthesis of some new phosphorus substituted fulvenes 16, 17 and 18. We have also prepared the new cyclopentadienylid 19 from the dimeric methyliodide 11.