Simultaneous Raman spectroscopic and differential double-layer capacitance measurements of pyridine adsorbed on roughened silver electrodes

It is shown that differential double-layer capacitance data can be obtained simultaneously with the recording of the Raman spectra of adsorbates at a roughened silver microelectrode. The use of such data to provide information about the structure of the silver electrode/aqueous KCl (0.1 M)/pyridine (0.1 M) interface is demonstrated.     

The behavior of microdisk and microring electrodes. Mass transport to the disk in the unsteady state : The ac response

We describe the time dependent response of a finite disk electrode under conditions of constant applied flux (chronopotentiometry). The exact solution is recovered by solving the differential equations in the circular cylindrical coordinate system with the use of suitable discontinuous integrals. In addition, we present the result for the case of linear sweep amperometry, which will generally be more useful for controlled current experiments with microelectrodes.     

Untersuchung der γ-Strahlung bei Einfang thermischer Neutronen in Sm149 mit der Summen-Koinzidenzmethode

Two-step cascades of neutron captureγ-rays of Sm¹⁴⁹ (n, γ) Sm¹⁵⁰ have been studied by means of the sum-coincidence method. 11 two-step transitions from the capturing state to the 0,33 and 0.77 MeV states were found. Most of them agree with the decay scheme ofGroshev et al., some are new. The relative intensities of the cascades were determined. No two-step transition from the capturing state to the ground state could be observed. Fig. 3 shows the main result.     

An integral test for a critical multitype spatially homogeneous branching particle process and a related reaction-diffusion system

An integral test (Theorem 5) is established for the dichotomy concerning local extinction and survival (even persistence) at late times for critical multitype spatially homogeneous branching particle systems in continuous time. Our conditions on the branching mechanism are close to the ones known from “classical” processes without motion component. This generalizes and complements results of López-Mimbela and Wakolbinger [LMW96] and others. Our approach is based on some genealogical tree analysis combined with the study of the long-term behavior of L ¹-norms of solutions of related systems of reaction-“diffusion” equations, which is perhaps also of some independent interest. Received: 13 August 1997 / Revised version: 12 May 1998 / Published online: 14 February 2000