Materials Literature
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Ein Muster aus magnetischen Mn12-Clustern entsteht, wenn eine Dispersion solcher Cluster in einer Polymermatrix auf eine strukturierte Vorlage (z. B. eine DVD) gegossen wird. Die Erhöhungen auf der Polymeroberfläche verschwinden bei der Einwirkung von Lösungsmitteldampf, und die Cluster konzentrieren sich an deren urs…
We perform a first-principles calculation within the local density approximation $(\mathrm{LDA})+\mathrm{U}$ approximation for the delafossite $\mathrm{Y}\mathrm{Cu}{\mathrm{O}}_{2.5}$, which up to now was considered as a sawtooth lattice. The magnetic interactions are mapped onto a Heisenberg model whose exchange int…
Abstract Summary: Optically active poly[( R )‐ or ( S )‐1,4‐bis(2‐(3′,4′‐ethylenedioxy)thienyl)‐2‐benzoic acid 1‐methylheptyl ester] was prepared by an electrochemical technique and characterized by circular dichroism measurements. It was found that the optical activity and optical rotation of the film could be contro…
Well-aligned core–shell Ga2O3/TiO2 nanowires of high quality are synthesized using a two-stage metal-organic chemical vapor deposition technique. Annealing of the nanowires at high temperatures results in either the formation of Ga2O3–TiO2 ‘nanobarcodes’ (in which the wires have alternating segments of Ga2O3 and TiO2)…
The synthesis and characterization of a family of alternative precursors for the production of CdE nanoparticles (E = S, Se, and Te) is reported. The reaction of Cd(NR2)2 where NR2 = N(SiMe3)2 with n HOR led to the isolation of the following: n = 1 [Cd(mu-OCH2CMe3)(NR2)(py)]2 (1, py = pyridine), Cd[(mu-OC6H3(Me)(2)-2,…
The nonequilibrium relaxational properties of a three-dimensional Coulomb glass model are investigated by kinetic Monte Carlo simulations. Our results suggest a transition from stationary to nonstationary dynamics at the equilibrium glass transition temperature of the system. Below the transition the dynamic correlati…
A combined photoconductivity and luminescence quenching study, both temperature and spectrally resolved, has revealed the role played by electron delocalization in luminescence quenching of ${\mathrm{Ce}}^{3+}$ impurities in the wide band-gap inorganic insulator ${\mathrm{GdAlO}}_{3}$. The anticorrelation found betwee…
An octupolar crystal is produced from octupolar molecules of 1,3,5-tricyano-2,4,6-tris(p-diethylaminostyryl)benzene and its structure is elucidated experimentally using the combined polarization analysis of two-photon fluorescence and second-harmonic generation (SHG). The optimal crystalline packing of the molecules i…
Superparamagnetic particles offer a new way to probe the kinetics of adhesive processes. Two different scenarios of physical adhesion are studied. The thermal activation of van der Waals adhesion is well described by an Arrhenius model. In contrast, it is necessary to go beyond the Arrhenius description to understand…
The stability of the gyroid phase of diblock copolymers has been studied using combined oscillatory shear and small-angle neutron scattering (SANS) techniques. It is shown that the gyroid phase of polystyrene−polyisoprene (PS−PI) is unstable when exposed to combined large-amplitude and high-frequency shear deformation…
The gene phaPAh, encoding the protein phasin that is associated with poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) granule of Aeromonas hydrophila 4AK4, was cloned and characterized. Recombinant strains harboring additional copies of the phasin gene (phaPAh) and the polyhydroxyalkanoate (PHA) synthase gene (p…
A recent high pressure experiment on ${\mathrm{L}\mathrm{a}\mathrm{A}\mathrm{l}\mathrm{O}}_{3}$ has revealed that the compound is an exception for the ``general rule'' of displacive phase transition associated with zone-boundary phonons. In the present study, the experimental result is successfully confirmed by first…
Focused ion beam (FIB) lithography can be used to selectively close nanochannels in an ordered array on an anodic-alumina film, producing templates with the nanochannels arranged in custom-designed geometries (see Figure). Nanochannel closing can be monitored by in-situ FIB imaging. Nanodevices such as photonic-crysta…
The synthesis of a zinc porphyrin linked conjugated homopolymer is presented. The synthetic strategy employed a directional polymerization of 1-iodo-2,5-dioctyl-4‘-ethynyltolane in the presence of [10,20-bis(3,5-bis- tert -butylphenyl]-5,15-diethynylporphinato]zinc(II) ( 12 ) or [10,20-bis(3,5-bis- tert -butylphenyl]-…
Fixing of the anisotropic orientation of DAST nanocrystals , trans ‐4‐[4‐(dimethylamino)]stilbazolium p ‐toluenesulfonate, a well‐known organic second‐order nonlinear optical material, is described. The DAST nanocrystals were oriented in an acrylate monomer by an applied magnetic field and then immobilized by UV‐curin…
The way in which reagents are mixed can have a large influence on the product distribution of chemical reactions and the size distribution of particles of the solid product. To model effects of mixing on various scales on the course of chemical reactions and precipitation processes, a nonequilibrium multiple-time-scal…
Optically active polybithiophene is successfully prepared by electrochemical polymerization in a chiral nematic liquid crystal field. Polarizing and phase-contrast optical micrographs of the polymer reveal a well-resolved spiral morphology similar to the optical texture of the chiral nematic phase. Circular dichroism…
Various (linear, triarms, ABA or ABCBA type) amphiphilic multiblock copolymers containing acetal-protected sugars have been prepared by the coupling of an end-functionalized ROMP copolymer with poly(ethylene glycol) (PEG). The synthesis involves three key steps: (i) termination of the block ROMP copolymer prepared by…
The linear optical properties of semiconducting carbon nanotubes are dominated by quasi-one-dimensional excitons formed by single electron-hole pairs. Hence, the nonlinear response at high pump levels most likely leads to the formation of exciton complexes involving several electron-hole pairs. Such complexes would th…
Phosphoglycerate dehydrogenases exist in at least three different structural motifs. The first D-3-phosphoglycerate dehydrogenase structure to be determined was from Escherichia coli and is a tetramer composed of identical subunits that contain three discernable structural domains. The crystal structure of D-3-phospho…