Elektronengruppen,ihre Temperaturen und Dichten im diffusions- und rekombinationsbestimmten H2-Glimmlicht

Investigations of plasma parameters in the H₂-negative glow are made in the pressure range 0.06–0.6 Torr. With the help of a plane and a cylindrical grid probe, which both were heated, group character of the velocity distribution of electrons is found. The electron temperature of the slow group is almost 600 °K. The density of the slow group shows that there must be strong volume-recombination in H₂. — With increasing pressure we find that the group character vanishes.     

Commentary on "Mechanical properties of monodomain side-chain nematic elastomers" by P. Martinoty, P. Stein, H. Finkelmann, H. Pleiner and H.R. Brand

We discuss the background to static and dynamic soft elasticity. The evidence in the static case and the symmetry basis for soft and semi-soft elasticity is well understood. By contrast the dynamic analogy is less clear. Lack of clean time scale separation clouds the interpretation of director relaxation keeping up, or not, with imposed strains. However, the reduction in modulus between geometries obtaining at low frequencies and being lost at high frequencies confirms that director reaction indeed determines dynamical semi-softness.