Engineering of gold surface work function by electrodeposition of spirobifluorene donor–acceptor bipolar systems

Charge separation in gold/spirobifluorene-based donor (triphenylamine)–acceptor (cyano) bipolar systems has been investigated by contact potential difference and surface photovoltage spectroscopy. Organic films were formed on gold electrode by electrochemical polymerization and by dipping in dye solution. The gold surface work function has been changed over more than 0.4 eV depending on the numbers of electrochemical deposition cycles. Photovoltage effects were analyzed in terms of internal photoemission from Au into organic film, and organic layer light absorption. The energetic differences between the Fermi-level of Au and HOMO levels of organic systems were obtained. The results showed that the electrodeposition is a versatile tool for electrode surface work function tuning.     

The analysis of rank ordered preference data based on Bradley-Terry Type ModelsDie Analyse von Präferenzdaten mit Hilfe von log-linearen Bradley-Terry Modellen

In this article we propose an approach to study the effect of consumer-specific information on (complete) rank ordered preference data by means of Bradley-Terry type models. The main idea is to transform the ranking data into paired comparison data, which can be modelled within the Generalised Linear Model framework by means of a log-linear model for a corresponding contingency table. Therefore, standard software can be used to estimate model parameters and a goodness-of-fit can be assessed in the usual way. This approach allows to simultaneously estimate object-specific parameters which, in the marketing context, can be interpreted as attractions of the analysed objects, as well as subject-object interaction parameters that represent the effects of consumer-specific variables on the attractions. The interaction parameters offer a statistically motivated approach for customer segmentation and market targeting. The outlined methodology is applied to preference judgements within a local daily newspaper market. It is shown that certain socio-economic characteristics of the consumers have significant influences on their preference structures.     

Datenbankunterstützung für den ingenieurwissenschaftlichen Entwurf

Zusammenfassung Datenbanksysteme zeichnen sich durch Charakteristika aus, die über den klassischen administrativ-betriebswirtschaftlichen Bereich hinaus zunehmend auch für Ingenieuranwendungen als vorteilhaft erkannt werden. Die Schwierigkeiten für einen sofortigen Einsatz in diesem Sektor liegen darin, daß existierende Systeme hinsichtlich Datenstrukturierung, Konsistenz, Mehrbenutzerbetrieb und Datensicherung keine den neuen Anforderungen entsprechenden Konzepte anbieten. Der Bericht nennt beispielhaft für den Bereich des Entwurfs technischer Objekte die wichtigsten Unterschiede zu traditionellen Anwendungen und stellt Lösungsvorschläge für die genannten Problemkreise vor.     

Reactively sputtered TiO2 layers on SnO2:F substrates: A Raman and surface photovoltage study

DC reactively sputtered TiO₂ layers on SnO₂:F substrates were investigated by Raman and surface photovoltage spectroscopy. The stoichiometry and layer thicknesses were investigated by elastic recoil detection analysis. The deposition temperature, the O₂/(O₂ + Ar) ratio and the deposition time were varied systematically. With increasing temperature, the layers become crystalline with the rutile modification dominating. Rutile phase preferentially forms on vertical facets of SnO₂ crystallites. Anatase phase starts to form during prolonged deposition and at lower O₂/(O₂ + Ar) ratios. The energy of the exponential absorption tails below the band gap, a measure of the defect density of the films, is determined by the deposition temperature and not by other parameters if the deposition temperature is relatively high, irrespective of the content of crystalline phases or the value of the band gap. Charge separation takes place at length scales significantly shorter than the layer thicknesses (diffusion length less than 6 nm). TiO₂ films sputtered at 380 °C show rectifying behaviour with a carbon contact.     

Über die Beschleunigung und Verzögerung von elektrischen Ladungsträgern im Vakuum bei explizit vorgegebenen elektrischen und kinetischen Randwerten

Übersicht Die Theorie der Ionenraketen basiert darauf, daß die elektrische Feldstärke und die Geschwindigkeit am Beginn der Beschleunigungsstrecke vernachlässigbar sind. Will man Ionen-Durchström-Triebwerke oder Ionen-Vielfachbeschleuniger konzipieren, so kann die elektrische Feldstärke und die Geschwindigkeit am Beginn der Umwandlungstrecke wesentlich von Null abweichen. Es wird deshalb hier eine Theorie der Ionenbeschleunigung entwickelt, bei der die elektrischen und kinetischen Randwerte innerhalb der physikalischen Grenzen frei wählbar sind und explizit vorgegeben werden können. Mit der gleichen Zielsetzung wird die Ionenverzögerung behandelt, welche die Grundlage für die Konzipierung von Ionenstrahl-Generatoren ist. Mit dieser Arbeit wird also ein Beitrag zur Theorie der elektrokinetischen Energiewandlungsprozesse geleistet.

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On the acceleration and deceleration of electric charge carriers in vacuum with explicitely given electrical and kinetic boundary values

Contents The theory of ion rocket engines is based upon the neglection of the electric field strength and the velocity at the beginning of the acceleration path. In the design of ion-flow accelerators or multi-stage ion accelerators the strength of the electric field and the velocity at the beginning of the transfer path may differ significantly from zero. A theory of the ion acceleration is therefore developed, where the electrical and kinetic boundary values can be chosen freely within the limits of physics and where these boundary values can be given explicitely. With the same intent the deceleration of ions is treated: the basic design of ion-jet power generators. This paper may therefore be a contribution to the theory of processes of electro-kinetic energy transfer.

     

Upgrading of Symbolic and Synthetic Knowledge Bases: Evidence from the Chinese Automotive and Construction Industries

This paper deals with the question of how upgrading of the symbolic and synthetic knowledge bases takes place and, by doing so, we contribute to the upgrading literature by linking upgrading with the concept of the differentiated knowledge bases. We discern a number of upgrading mechanisms, and based on empirical evidence from the construction industry and the automotive industry in China, we show that the main upgrading mechanisms for symbolic knowledge include “learning-by-interacting in project teams” and “monitoring”, while upgrading of synthetic knowledge takes place via “technology transfer” and “learning-by-doing and-using”. “Mobility” and “on-the-job training and learning in Transnational Corporations” are the main upgrading mechanisms contributing to the development of both knowledge bases.