[en] Short communication

No abstract available

No abstract available

No abstract available

No abstract available

[en] A simple processing technology for oxide confined vertical-cavity surface-emitting lasers (VCSELs) fabrication is reported in this article. Results of the burn-in test up to the present-day show that the high temperature lifetime of the fabricated devices exceeded 70:00 h. The eye diagrams show that the devices can be modulated up to 10 Gbps

[en] Ceramic-Matrix Composites (CMCs) consist of a ceramic fiber architecture in a ceramic matrix, bonded together through a thin interphase. The present contribution is limited to non-oxide CMCs. Their constituents being oxidation-prone, they are protected by external coatings. We state here that CMCs display a hybrid feature, when at least one of their components is not homogeneous from a chemical or microstructural standpoint. Hybrid fiber architectures are used to tailor the mechanical or thermal CMC-properties whereas hybrid interphases, matrices and coatings to improve CMC resistance to aggressive environments.

[en] Electrostatic comb-drive actuators in electrolytes have many potential applications, the most popular of which is characterizing the mechanical properties of biological structures at small scales. Maximizing the utility of these devices for such applications requires a model capable of accurately predicting their behavior. The current state of the art model of these actuators assumes (i) that the native oxide is a pure dielectric, (ii) that the ion concentration of the bulk electrolyte is constant, and (iii) that the Stern layer can be neglected compared to the oxide layer. This model captures the general behavior of the electrostatic actuator in electrolytes, but has limited accuracy. We propose a hierarchy of models that addresses the suitability of these assumptions separately and in concert. We find that the model which removes assumptions (i) and (ii) is sufficient to accurately predict the displacement of a comb-drive actuator in electrolytes. (paper)

[en] The possibility is considered which opens for chemistry and material technology when semiquantitative theory of glass formation is used in chalcogenide systems. The use of this theory makes it possible to calculate the values of glass formation regions, to correct experimental errors in determining the boundaries of glass formation regions of known systems, to find the coordination of the series of the compounds in melted and glassy states; the theory allows for considering coordination effect, for instance, in telluride and other systems

[en] Recent work on the spectroscopy and structure of rare earth oxide molecules is reviewed. Various techniques used to examine specific aspects of the electronic structure and test the ligand field theoretical eigenvectors are discussed and illustrated with results obtained for specific molecules. 13 refs