First observation of 55, 56Zn

In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich zinc isotopes ^55,56Zn have been observed for the first time. The experiment was performed using a high-intensity ⁵⁸Ni beam at 74.5 MeV/nucleon impinging on a nickel target. The identification of ^55,56Zn opens the way to ⁵⁴Zn, a good candidate for two-proton radioactivity according to theoretical predictions. Received: 31 October 2000 / Accepted: 9 November 2000     

Design of SARS-CoV-2 Main Protease Inhibitors Using Artificial Intelligence and Molecular Dynamic Simulations

Drug design is a time-consuming and cumbersome process due to the vast search space of drug-like molecules and the difficulty of investigating atomic and electronic interactions. The present paper proposes a computational drug design workflow that combines artificial intelligence (AI) methods, i.e., an evolutionary algorithm and artificial neural network model, and molecular dynamics (MD) simulations to design and evaluate potential drug candidates. For the purpose of illustration, the proposed workflow was applied to design drug candidates against the main protease of severe acute respiratory syndrome coronavirus 2. From the ∼140,000 molecules designed using AI methods, MD analysis identified two molecules as potential drug candidates.     

Colloids for Catalysts: A Concept for the Preparation of Superior Catalysts of Industrial Relevance

Compared to conventional preparation methods for supported heterogeneous catalysts, the use of colloidal nanoparticles (NPs) allows for a precise control over size, size distribution, and distribution/location of the NPs on the support. However, common colloidal syntheses have restrictions that limit their applicability for industrial catalyst preparation. We present a simple, surfactant‐free, and scalable preparation method for colloidal NPs to overcome these restrictions. We demonstrate how precious‐metal NPs are prepared in alkaline methanol, how the particle size can be tuned, and how supported catalysts are obtained. The potential of these colloids in the preparation of improved catalysts is demonstrated by two examples from heterogeneous catalysis and electrocatalysis.     

Polar domains in lead titanate films under tensile strain

Thin films of PbTiO3, a classical ferroelectric, have been grown under tensile strain on single-crystal substrates of DyScO3. The films, of only 5 nm thickness, grow fully coherent with the substrate, as evidenced by synchrotron x-ray diffraction. A mapping of the reciprocal space reveals intensity modulations (satellites) due to regularly spaced polar domains in which the polarization appears rotated away from the substrate normal, characterizing a low-symmetry phase not observed in the bulk material. This could have important practical implications since these phases are known to be responsible for ultrahigh piezoelectric responses in complex systems.     

Nontrivial invariant measures and statistics for exclusion type processes

We consider three types of exclusion processes (collective random walks of countable configurations of particles with interactions of excluded volume type) with discrete time (two lattice and one in continuous space). Explicit representation for the corresponding nontrivial invariant measures and time-average velocities of the particles as a function of particle density in configuration (fundamental diagram) is obtained.     

Interval Methods for Real-Time Capable Robust Control of Solid Oxide Fuel Cell Systems

Reliable control strategies for complex dynamic systems have to account for stability and robustness despite the presence of both parameter uncertainty and measurement errors. In addition, such control strategies have to comply with performance specifications that can be described either by the minimization of suitable cost functions or by direct specifications of desired reference trajectories. To handle bounded uncertainty and errors in a reliable way, it is possible to include the use of interval analysis in real-time control environments. Previous work has shown that approaches based on the general methodology of sliding mode and predictive control are promising options in this context. This paper presents a comparison of the properties of interval extensions of both types of control procedures for the thermal subsystem of a high-temperature solid oxide fuel cell. Representative simulation results conclude this contribution.     

Convergence of Rothe's method for fully nonlinear parabolic equations

Convergence of Rothe's method for the fully nonlinear parabolic equation u_t+F(D²u, Du, u, x, t)=0 is considered under some continuity assumptions on F. We show that the Rothe solutions are Lipschitz in time, Hölder in space, and they solve the equation in the viscosity sense. As an immediate corollary we get Lipschitz behavior in time of the viscosity solutions of our equation.     

Design of a 3-MW 140-GHz gyrotron with a coaxial cavity

A design for a 3-MW 140-GHz gyrotron based on the use of a coaxial cavity is given. The cavity mode is TE_21,13, chosen so that the ohmic heating on both the inner and outer conductors would be low enough for CW operation. The mode selection process, nonlinear, multimode and time-dependent modeling of the beam wave interaction, and gun design are discussed in detail. An inverted magnetron injection gun (MIG) is used to accommodate the inner conductor. The radiation is coupled out via a quasi-optical mode converter, consisting of an irregular cylindrical waveguide section followed by a step-cut launching aperture and a single near-parabolic mirror. The design of these components is also described     

Improved cathode/electrolyte interface of SOFC

The electrochemical performance of porous La_0.6Sr_0.4Co_0.2Fe_0.8O_3 − δ (LSCF) cathodes is improved by inserting a dense LSCF layer. A 200 nm thin layer is deposited on the electrolyte substrate by pulsed laser deposition, prior to the screen printing process. This procedure enhances the adherence of the porous cathode layer to the electrolyte and allows a lower sintering temperature, which reduces grain growth during sintering. In air a decrease in polarization resistance with a factor of 3 is observed for electrodes sintered at 1100 °C. The apparent electrolyte resistance is also reduced with the dense PLD layer. A remarkable change in Po₂ dependence is observed for the Gerischer parameters that describe part of the electrode impedance, indicating a possible change in the oxygen transfer mechanism.