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.     

Tandem Pd/C‐Catalyzed Reductive Coupling and Dehalogenation of Benzylic Halides

High‐yield reductive homocoupling of benzotrichloride and benzal chloride followed by consecutive reductive dechlorination to 1,2‐dichlorostilbene and stilbene is effected in the presence of sodium formate as the reducing agent and Pd/C catalysts.