A convenient preparation of aryltrifluoromethylketones

The reaction of aryllithium reagents prepared by halogen metal exchange or direct metallation with α,α,α-trifluoro-N,N-dimethylacetamide give the corresponding aryltrifluoromethylketones in good yield.     

On the dynamics of plastic circular plates

The paper is concerned with the dynamics of a thin circular plate made of a plastic-rigid material that obeys the yield condition ofTresca and the associated flow rule. The basic equations are established in the case of rotational symmetry, and their complete solution is given for a simply supported plate subjected to a uniformly distributed load which is brought on suddenly and, after a certain time interval, removed suddenly.

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Résumé Cet article étudie la dynamique d'une plaque circulaire infiniment mince fabriquée avec un matériau plastique qui obéit à la condition de plasticité deTresca et à la loi d'écoulement associée. Les équations fondamentales sont établies dans le cas où existe une symétrie de révolution. Leur solution complète est donnée pour une plaque reposant sur des appuis simples, soumise à une charge uniformément répartie qui est appliquée rapidement et demeure constante pendant un certain temps, après lequel elle est rapidement retirée.

     

Bonding properties in organolithium aggregates

Results are given of the application of the CNDO/2 method to bonding in alkyllithium aggregates. Calculations relative to monomers and dim ers of methyl-, ethyl-, and vinyllithium, plus methyllithium tetramer are described.     

Synthesis of 2-substituted isothiazolopyridin-3-ones

The synthesis of some 2-substituted derivatives 1–4 of all four isomeric isothiazolopyridin-3-ones is described. Several novel 1,2-dithiolopyridin-3-ones and 3-thiones were prepared as intermediates.     

Loss of continuum Lorentz invariance in gauge theories on a triangular lattice

On a triangular lattice, a weakly chiral lagrangian of interacting bosons and fermions is constructed to be naturally invariant under the triangular symmetry. The continuum limit of the resulting field theory is not Lorentz invariant. We explicitly show this for the propagator of the massive Schwinger model.