Stabilisation frontière indirecte du système de Timoshenko

In this Note, we study the indirect boundary stabilization of the Timoshenko system with only one dissipation law. Under the equal speed wave propagation condition, we establish the exponential stability of the system. On the contrary, we show that the decay rate is polynomial.     

Molecular ion yield enhancement induced by gold deposition in static secondary ion mass spectrometry

Static ToF-SIMS was used to evaluate the effect of gold condensation as a sample treatment prior to analysis. The experiments were carried out with a model molecular layer (Triacontane M = 422.4 Da), upon atomic (In⁺) and polyatomic (Bi₃⁺) projectile bombardment. The results indicate that the effect of molecular ion yield improvement using gold metallization exists only under atomic projectile impact. While the quasi-molecular ion (M+Au)⁺ signal can become two orders of magnitude larger than that of the deprotonated molecular ion from the pristine sample under In⁺ bombardment, it barely reaches the initial intensity of (M−H)⁺ when Bi₃⁺ projectiles are used. The differences observed for mono- and polyatomic primary ion bombardment might be explained by differences in near-surface energy deposition, which influences the sputtering and ionization processes.     

Approach to Synthesis of γ-Aminobutyric Acid (GABA) Analogues with Rigid Conformations - Convenient One Pot Synthesis of Functionalized Bisnaphthalenes

Silica gel supported cerium (IV) ammonium nitrate has been successfully employed to achieve functionalized C-C-linked bisnaphthalenes. The study demonstrates the utility of silica gel support for controlling over oxidation in cerium (IV) based oxidants and is of significance to prepare GABA analogues with restricted conformation required for studying GABAergic processes in neurochemical investigations.