Materials Literature
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Cyclic voltammetry (CV) has been performed on light‐emitting electrochemical cells (LECs) using poly(3‐octylthiophene) (P3OT) as the active luminescent polymer. Above the threshold voltage, current in an LEC consists of ionic and electronic components. A purely ionic (negative) component is clearly discernible in the…
Abstract Die mikroskopische Theorie von Bardeen, Cooper und Schrieffer lieferte ein grundsätzliches physikalisches Verständnis des Phänomens Supraleitung. Die Theorie stellt allerdings keinen direkten Stoffbezug her. Ausgehend von den speziellen Bindungsverhältnissen in Carbiden und Carbidhalogeniden der Seltenerdmeta…
Conducting crystalline polyazomethine polymers with high solubility and low melting points have been prepared and studied. The polymers were synthesized by the polycondensation of p-phenylene diamine and 2-nitro-p-phenylene diamine with terephthaldehyde and p-diacetylbenzene. Polymers with polar functional NO2 groups…
The non-isothermal crystallization behaviour of high purity β-phase and α-phase polypropylene (PP) and their calcium carbonate-filled composites was investigated by means of differential scanning calorimetry. High purity β-PP polymer was prepared by adding an effective β-nucleator consisting of equal amounts of pimeli…
Electrochemical growth of the polyazulene film and its electrochemical and spectroscopic properties were studied at platinum electrodes in acetonitrile by ac impedance and in situ spectroelectrochemical techniques. During polymer growth from the acetonitrile solution containing a millimolar concentration of azulene wi…
The temperature dependence of the vibrational wavenumbers, of the anharmonic and/or order–disorder origin of the damping and of the Raman intensities are briefly presented. On that basis, it is then shown that one can obtain information such as the height of the potential barrier, the orientational correlation time, t…
Surface and interface stresses, which are intrinsic thermodynamic quantities associated with all types of solid surfaces and interfaces, are reviewed. These stresses can significantly modify the thermodynamics of small scale solids as well as result in significant variations in the structure and physical behavior of m…
Using ab initio quantum-chemical and density functional methods we have determined novel structures of bare boron clusters. In addition to previously reported quasi-planar, convex and spherical cluster forms, boron nanotubules seem to be highly stable as well. These novel nanotubular structures are composed of hexagon…
We use a molecular dynamics simulation to investigate the properties and design space of molecular gears fashioned from carbon nanotubes with teeth added via a benzyne reaction known to occur with . Brenner's reactive hydrocarbon potential is used to model interatomic forces within each molecular gear. A Lennard - Jon…
Composite nanoclusters of gold and CdS with core/shell geometry have been synthesized using a chemical precipitation method in aqueous media. These nanoclusters are photoactive and exhibit transient bleaching in the 400−600 nm region when subjected to 355 nm laser pulse excitation. Capping of gold colloids with ultras…
The surface diffusion rate of bacterial cellulases from Cellulomonas fimi on cellulose was quantified using fluorescence recovery after photobleaching analysis. Studies were performed on an exo-beta-1-4-glycanase (Cex), an endo-beta-1-4-glucanase (CenA), and their respective isolated cellulose-binding domains (CBDs).…
Face-centred cubic metals deform by slip until the flow stress and dislocation density are very high, under certain conditions deformation may then proceed by twinning. The geometrical relation between the parent and twinned lattices has been studied in detail (1, 2). In the present work, the dislocation substructures…
Effects of the composition on the afterglow characteristics of phosphors have been evaluated using crystals grown by a floating zone technique for the first time. Phosphorescence spectrum due to ions peaking at λ = 520 nm does not vary with the compositions. Persistent times vary greatly with different compositions. D…
For describing the dislocation pattern formation, two different approaches are applied. In one of them the collective behavior of many individual dislocations is investigated by analytical or numerical methods, in the other one the dislocation system is described by continuous functions of the space coordinates. A met…
Despite many years of research, the detailed atomic structure of many important carbon materials remains poorly understood. In particular, the structure of those carbons which can not be transformed into graphite by high temperature heat treatment has never been clearly established. These non-graphitising carbons are…
High-resolution electron microscopy is used to study the structure of two typical non-graphitizing carbons before and after heat treatment at temperatures in the range 2100–2600°C. It is found that these heat treatments can result in the formation of closed carbon nanoparticles, which are apparently fullerene-like in…
Alcaligenes latus has been known to produce poly(3-hydroxybutyrate) (PHB) in a growth-associated manner even under nutrient-sufficient conditions. However, the PHB content obtained by fed-batch culture was always low, at ca. 50%, which makes the recovery process inefficient. In this study, the effect of applying nitro…
Several novel fluorinated fluoresceins (Oregon Green dyes) were prepared by the reaction of fluororesorcinols with phthalic anhydride and its derivatives. A novel regiospecific synthesis of fluororesorcinols was key to the successful synthesis of these new fluorophores. (Polyfluoro)nitrobenzenes were reacted with 2 eq…
Colloidal dispersions of bimetallic nanoparticles composed of gold and palladium were prepared by a sonochemical method, in which Au(III) and Pd(II) ions in an aqueous solution of sodium tetrachloroaurate(III)dihydrate and sodium tetrachloropalladate(II) were reduced by ultrasound irradiation in the presence of sodium…
Biosynthesis of N-acetylneuraminic acid (Neu5Ac), a prominent component of glycoconjugates, is initiated by the action of UDP-N-acetylglucosamine 2-epimerase (UDP-GlcNAc 2-epimerase, EC 5.1. 3.14) and N-acetylmannosamine kinase (ManNAc kinase, EC 2.7.1.60). We demonstrate for the first time that the two activities are…