Materials Literature
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High‐temperature piezoceramics based on W 6+ ‐doped Bi 3 TiNbO 9 (BTNO) were prepared by solid‐state reaction sintering. A study of the donor doping effects on the structure, microstructure, and electrical properties was conducted. The Curie point ( T c ) decreased in the range of 860°–910°C with increasing amount of…
Nitrogen-enriched activated carbons were prepared from a Polish brown coal. Nitrogen was introduced from urea at 350 °C in an oxidizing atmosphere both to carbonizates obtained at 500−700 °C and to activated carbons prepared from them. The activation was performed at 800 °C with KOH in argon. It has been observed that…
The structure of glucose dehydrogenase from the extreme halophile Haloferax mediterranei has been solved at 1.6-A resolution under crystallization conditions which closely mimic the "in vivo" intracellular environment. The decoration of the enzyme's surface with acidic residues is only partially neutralized by bound p…
A photo- and thermoresponsive physical gel has been developed based on crosslinked supramolecular polymer networks. The gel shows reversible sol–gel phase transitions induced by heat or light irradiation. The photoinduced sol–gel phase transition shown in the figure results from the cis–trans photoisomerization of an…
The static and dynamic properties of liquid Si at high-pressure have been studied using the orbital free ab-initio molecular dynamics method. Four thermodynamic states at pressures 4, 8, 14 and 23 GPa are considered. The calculated static structure shows qualitative agreement with the available experimental data. We a…
The electronic and magnetic properties of Fe/GaAs(001) magnetic junctions are investigated using first-principles density-functional calculations. Abrupt and intermixed interfaces are considered, and the dependence of charge transfer, magnetization profiles, Schottky barrier heights, and spin polarization of densities…
The superconducting state of Ca-intercalated graphite CaC6 has been investigated by specific heat measurements. The characteristic anomaly at the superconducting transition (Tc = 11.4 K) indicates clearly the bulk nature of the superconductivity. The temperature and magnetic field dependence of the electronic specific…
Using scanning tunneling microscopy at low temperatures we investigated the adsorbate system Cu(111)-Cs for various cesium coverages. At low coverages we observe a hexagonally ordered Cs adsorption layer with a mutual adsorbate distance of 1.1 nm. This distance is discussed in terms of a commensurate adsorption supers…
Gone fishing: Unidirectionally oriented CaCO3 crystalline films have been prepared on chitin matrices in the presence of calcification-associated peptide (CAP-1), which was isolated from the exoskeleton of the red swamp crayfish. The interactions of CAP-1 with the matrix and the acidic nature of the peptide lead to a…
Cap in hand: The viscoelastic properties of low-molecular-mass organogelator–gold nanoparticle (LMOG–Au NP) composites can be modulated by the capping agent on the nanoparticle. The interactions between the LMOG and Au NP depend on the ability of ligands to interdigitate within the gel aggregates (see picture).
Butterfly hysteresis curves observed in dynamical magnetization measurements on systems of low-spin magnetic molecules such as ${\mathrm{V}}_{15}$ can be explained by the interplay of adiabatic Landau-Zener transitions and relaxation. We investigate the magnetization dynamics analytically in the basis of the adiabatic…
Sliding and rolling are two outstanding deformation modes in granular media. The first one induces frictional dissipation whereas the latter one involves deformation with negligible resistance. Using numerical simulations on two-dimensional shear cells, we investigate the effect of the grain rotation on the energy dis…
The properties of Mo_6S_6 nanowires were investigated with ab-initio calculations based on the density-functional theory. The molecules build weakly coupled one-dimensional chains, like Mo_6Se_6 and Mo_6S_(9-x)I_x, and the crystals are strongly uniaxial in their mechanical and electronic properties. The calculated mod…
We describe the design of polycyclic aromatic compounds with high performance that dissolve single-walled carbon nanotubes (SWNTs). Synthetic amphiphiles trimethyl-(2-oxo-2-phenylethyl)-ammonium bromide (1) and trimethyl-(2-naphthalen-2-yl-2-oxo-ethyl)-ammonium bromide (2) carrying a phenyl or a naphtyl moiety were no…
The photoluminescence dynamics of colloidal CdSe/ZnS/streptavidin quantum dots were studied using time-resolved single-molecule spectroscopy. Statistical tests of the photon-counting data suggested that the simple "on/off" discrete state model is inconsistent with experimental results. Instead, a continuous emission s…
The bactericidal effect of photocatalysis with TiO2 is well recognized, although its mode of action is still poorly characterized. It may involve oxidation, as illuminated TiO2 generates reactive oxygen species. Here we analyze the bactericidal effect of illuminated TiO2 in NaCl-KCl or sodium phosphate solutions. We f…
Intracellular uptake and degradation of polyelectrolyte capsules is reported in this work. Two types of intracellular degradable capsules are described: enzyme-sensitive and hydrolysis- sensitive capsules (see figure). The results may be a significant step towards the biomedical application of polyelectrolyte capsules.
A drop of water thrown on a super-hydrophobic solid will often bounce off. Here we discuss the conditions to be fulfilled on the surface design (which provides super-hydrophobicity) to observe such a behavior. This allows us to precise how a material can be made water-repellent. We show in particular how the reduction…
We present an experimental and theoretical study of the fluorescence rate of a single molecule as a function of its distance to a laser-irradiated gold nanoparticle. The local field enhancement leads to an increased excitation rate whereas nonradiative energy transfer to the particle leads to a decrease of the quantum…
The spectra of collective excitations of liquid and glassy tellurium have been studied by means of inelastic neutron scattering. Here we report on the dynamics of liquid Te as measured at two different temperatures, just above melting $({T}_{m}=723\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ and at $\ensuremath{\sim}1000\p…