Materials Literature
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We observe the build up of strong (~50%) spontaneous vector polarisation in emission from a GaN-based polariton laser excited by short optical pulses at room temperature. The Stokes vector of emitted light changes its orientation randomly from one excitation pulse to another, so that the time-integrated polarisation r…
We have examined the effect of a c(2x2) overlayer of CO on the surface phonons of the substrate, Cu(001), by applying the density functional perturbation theory with both the local (LDA) and the generalized-gradient (GGA) density approximations, through the Hedin-Lundqvist and the Perdew-Burke-Ernzerhof functionals, r…
In this study an extended low energy phase diagram for NaxCoO2 is experimentally established with emphasis on the high x range. It is based on systematic heat capacity studies on both polycrystalline and single crystalline samples and on uSR measurements. Main features are the existence of mass enhancement, spin fluct…
We observe a singularity in the temperature derivative drho/dT of resistivity at the Curie point of high-quality (Ga,Mn)As ferromagnetic semiconductors with Tc's ranging from approximately 80 to 185 K. The character of the anomaly is sharply distinct from the critical contribution to transport in conventional dense-mo…
Colloidal Mn (2+)-doped CdSe quantum dots showing long excitonic photoluminescence decay times of up to tau exc = 15 mus at temperatures over 100 K are described. These decay times exceed those of undoped CdSe quantum dots by approximately 10 (3) and are shown to arise from the creation of excitons by back energy tran…
Evidence of curvature effects on the interaction and binding of silver clusters on folded graphitic surfaces has been shown from both experiment and theory. Density Functional Theory (DFT) calculations within the local density and generalized gradient approximations have been performed for the structural relaxation of…
We present a new full-potential method to solve the one-body problem, for example, in the local density approximation. The method uses the augmented plane waves (APWs) and the generalized muffin-tin orbitals (MTOs) together as basis sets to represent the eigenfunctions. Since the MTOs can efficiently describe localize…
So far, research in the field of metamaterials has been carried out largely with arrays of flat, 2-dimensional structures. Here, we report a newly identified magnetic resonance in Split Cylinder Resonators (SCRs), a 3-dimensional version of the Split Ring Resonator (SRR), which were fabricated with the Proton Beam Wri…
Opening, in a controllable way, the energy gap in the electronic spectrum of graphene is necessary for many potential applications, including an efficient carbon-based transistor. We have shown that this can be achieved by chemical functionalization of bilayer graphene. Using various dopants, such as H, F, Cl, Br, OH,…
The precise atomic structure of activated carbon is unknown, despite its huge commercial importance in the purification of air and water.Diffraction methods have been extensively applied to the study of microporous carbons, but cannot provide an unequivocal identification of their structure.Here we show that the struc…
Genotoxicity of commercial colloidal and laboratory-synthesized silica nanoparticles was tested using the single cell gel electrophoresis or Comet assay. By using a carefully developed protocol and careful characterization of the nanoparticle dispersions, Comet assays were performed on 3T3-L1 fibroblasts with 3, 6, an…
Despite the great efforts that have been made toward obtaining Janus architectures, synthesizing sub-10 nanometer Janus nanoparticles (NPs) modified with different types of polymers remains a challenging task. In this Communication, "solid-state grafting-to" and "grafting-from" methods were combined to obtain Janus go…
We describe a "surface-protected etching" strategy that allows convenient conversion of sol-gel derived silica into porous structures. Poly(vinyl pyrrolidone) is used to protect the near surface layer, and NaOH is used to selectively etch the interior of the silica spheres. Etching initially yields porous structures a…
Abstract In this work the basic strategies for the preparation of Co 2 Mn 0.5 Fe 0.5 Si as an example for Heusler alloy thin films will be described. Texture and magnetic properties of these films will be discussed, especially with regard to different buffer layers and annealing temperatures. Finally, we will show the…
Abstract Diesel diffuses into neoprene matrices 10% faster than palm ethyl biodiesel at 20°C. In contrast, the palm biodiesel soaks highly plasticized PVC five times faster than diesel. Phthalate plasticizer leaks from the PVC matrix 14 times faster when biodiesel is the absorbed liquid, relative to petrodiesel. This…
In experiments on nonlinear-optical transmission of picosecond laser pulses at the wavelength of 1.064 μm three-order-of-magnitude enhancement of the photoinduced absorption in optically anisotropic mesoporous silicon films compared to crystalline silicon (c-Si) was found. The effect is not sensitive to the polarizati…
Serine hydroxymethyltransferase (SHMT) from Bacillus stearothermophilus (bsSHMT) is a pyridoxal 5'-phosphate-dependent enzyme that catalyses the conversion of L-serine and tetrahydrofolate to glycine and 5,10-methylene tetrahydrofolate. In addition, the enzyme catalyses the tetrahydrofolate-independent cleavage of 3-h…
In order to investigate the erosion extent and mode of cavitation in different states by the commercial code FLUENT and evaluate the reliability of the software, the collapse processes of a vapor bubble, which was near or on the wall under the conditions in the stationary water or the high speed water, were simulated…
Abstract Alumina-zirconia composite materials were produced with different acid ratios by the sol-gel method using aluminum isopropoxide and zirconium chloride. The composites were produced by changing acid/alkoxside ratio in alumina. The composite materials were calcinated at 600°C, 900°C and 1300°C. The effects of a…
Abstract The deposition of specific materials into ordered pores arranged in a regular lattice allows the fabrication of ordered fiber arrays. Porous silicon is an attractive candidate for use as a template because the porosity and pore size can be tuned. Polymer microfibers using macroporous silicon with various pore…