Correlation of charge transport with structural order in highly ordered melt‐crystallized poly(3‐hexylthiophene) thin films

A series of well‐defined poly(3‐hexylthiophene)s (P3HT) of different molecular weight (MW) and high regioregularity was investigated for charge transport properties in as‐cast and melt‐crystallized films. The semicrystalline structure of the P3HT was characterized by X‐ray scattering and Atomic force microscopy. Crystallization by cooling from the melt led to a substantial increase in crystallinity and a stronger alignment of the crystals in comparison to as‐cast films. The increase in crystallinity went along with an increase in hole mobility of up to an order of magnitude as measured by the space charge limited current method. Additionally, the hole mobility depended on the long period of P3HT lamellae and consequently on the MW. In compliance with the long period, the charge carrier mobility first increased with the MW before decreasing again at the onset of chain folding. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 943–951     

Generalizations of common ILF models

In Germany (and various other countries) a specific ILF model, which was proposed by Riebesell in 1936, is frequently used for exposure rating in liability insurance and reinsurance. This model is based on the assumption that the doubled limits surcharge (DLS) – i.e. the percentage surcharge on the premium for doubling policy limits – does not depend on the policy limit. The drawback of this method is its lack of flexibility with respect to the corresponding severity distribution. In this paper we analyze the following generalizations of this concept which offer more flexibility regarding the severity: stepwise reduction of the DLS, continuously decreasing DLSs and construction of an ILF formula based on the DLS at a certain policy limit and the tail of a severity distribution.     

On the correlation of pseudorandom numbers generated by inversive methods

We introduce two new types of inversive generators for pseudorandom numbers. These new methods offer several advantages over the conventional inversive generator. For instance, we establish good correlation properties of our generators that cannot be obtained for the conventional inversive generator with current methods. A new bound on character sums for finite fields is the essential technical tool for this work. Authors’ addresses: Harald Niederreiter, Department of Mathematics, National University of Singapore, 2 Science Drive 2, Singapore 117543, Republic of Singapore; Jo?l Rivat, Institut de Mathématiques de Luminy, Université de la Méditerranée, CNRS-UMR 6206, 163 avenue de Luminy, Case 907, 13288 Marseille Cedex 9, France     

Aglairubine: Structure Revision of a Chemotaxonomically Interesting Bisamide in Aglaia (Meliaceae)

 The bisamide aglairubine was isolated from different Aglaia species. The original structure was revised on the basis of FDMS and 2D-NMR data. Since all isolates were obtained from species belonging to the section Amoora of the genus Aglaia, aglairubine might serve as a taxonomic marker.