Monolithic ZnTe-based pillar microcavities containing CdTe quantum dots

Micropillars of different diameters have been prepared by focused ion beam milling out of a planar ZnTe-based cavity. The monolithic epitaxial structure, deposited on a GaAs substrate, contains CdTe quantum dots embedded in a ZnTe λ-cavity delimited by two distributed Bragg reflectors (DBRs). The high refractive index material of the DBR structure is ZnTe, while for the low index material a short-period triple MgTe/ZnTe/MgSe superlattice is used. The CdTe quantum dots are formed by a novel Zn-induced formation process and are investigated by scanning transmission electron microscopy. Micro-photoluminescence measurements show discrete optical modes for the pillars, in good agreement with calculations based on a vectorial transfer matrix method. The measured quality factor reaches a value of 3100.     

Large‐scale Synthesis of Urchin‐like Mesoporous TiO2 Hollow Spheres by Targeted Etching and Their Photoelectrochemical Properties

A versatile targeted etching strategy is developed for the large‐scale synthesis of urchin‐like mesoporous TiO₂ hollow spheres (UMTHS) with tunable particle size. Its key feature is the use of a low‐temperature hydrothermal reaction of surface‐fluorinated, amorphous, hydrous TiO₂ solid spheres (AHTSS) under the protection of a polyvinylpyrrolidone (PVP) coating. With the confinement of PVP and water penetration, the highly porous AHTSS are selectively etched and hollowed by fluoride without destroying their spherical morphology. Meanwhile TiO₂ hydrates are gradually crystallized and their growth is preferentially along anatase (101) planes, reconstructing an urchin‐like shell consisting of numerous radially arranged single‐crystal anatase nanothorns. Complex hollow structures, such as core–shell and yolk–shell structures, can also be easily synthesized via additional protection of the interior by pre‐filling AHTSS with polyethylene glycol (PEG). The hollowing transformation is elucidated by the synergetic effect of etching, PVP coating, low hydrothermal reaction temperature, and the unique microstructure of AHTSS. The synthesized UMTHS with a large surface area of up to 128.6 m² g^‐1 show excellent light‐harvesting properties and present superior performances in photocatalytic removal of gaseous nitric oxide (NO) and photoelectrochemical solar energy conversion as photoanodes for dye‐sensitized mesoscopic solar cells.     

Strategie mit vielen Problemen

Zusammenfassung  Die von der Bundesregierung 2005 beschlossene eCard-Strategie ist ein ambitioniertes Projekt. Auf der technischen Ebene geht es darum, die Sicherheitsfunktionen aller künftigen Bürger-Chipkarten interoperabel zu machen. Der elektronische Personalausweis (ePA), die elektronische Gesundheitskarte (eGK), Signaturkarten für die elektronische Steuererkl?rung (ELSTER) und der elektronische Einkommensnachweis (ELENA) sollen einer einheitlichen Architektur gehorchen. Damit will der Bund sicherstellen, dass elektronische Dienstleistungen auch mittel- und langfristig kostengünstig bleiben: Dank economy of scales und der Freiheit von Lizenz- und Patentforderungen sollen Karten und Kartenanwendungen billiger ausgegeben werden k?nnen, als es bei einer „reinen“ Marktl?sung m?glich w?re. Zum Autor: Detlef Borchers ist freier IT-Fachjournalist und einer breiteren ?ffentlichkeit durch zahlreiche Beitr?ge für Fachmagazine und die Tagespresse (u. a. Neue Zürcher Zeitung) bekannt.     

Bestimmung niedriger Borgehalte in feuerfesten Stoffen und Stahlwerksschlacken

Anpassen des für die Stahlanalyse entwickelten photometrischen Curcuminverfahrens an die Belange der Oxidanalyse. Vergleich mit dem für die Untersuchung von Magnesitprodukten vorgeschlagenen Carminsäureverfahren sowie mit drei weiteren photometrischen Verfahren.     

A knowledge-based system for information management in an automated and integrated manufacturing system

In recent years there has been considerable interest in flexible automation of manufacturing processes in an effort to improve the productivity of manufacturing industry. Central to an integrated, flexible and intelligent manufacturing system is the information management function. The sharing of data is the basis of flexible and intelligent decision-making, the means of integrating the system components, the mode of synchronizing their processes and the method of maintaining the consistency of their states.

It appears that the data management and manipulation function in manufacturing systems is increasingly becoming a bottleneck for further performance improvement of manufacturing systems. New information management systems need to be developed that meet the needs of modern manufacturing systems in terms of efficiency, flexibility, reliability and intelligence. A new model for an integrated manufacturing information system is presented. A double structure of two parallel but independent system is proposed for manufacturing control and manufacturing information management. The objective is to improve service efficiency. representational adequacy, consistency of information and reliability in the information system.