Materials Literature
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Results are presented for a study on the influence of molecular and polymeric carboxylate-containing additives on the nucleation of CaCO 3 in solutions similar in ion composition and pH to those used in wood pulping operations. Investigated additives included aminocarboxylic acids, ethylenediaminetetraacetic acid and…
Leitend verbunden: Eine zentrale Tetrathiafulvalen(TTF)-Einheit vermittelt im abgebildeten Dichinon-Tetrathiafulvalen effektiv die elektronische Kopplung zwischen den Chinonfunktionen in der Peripherie. Es erfolgt schrittweise Einelektronenreduktion; die Potentialdifferenz zwischen den Reduktionsschritten zeigt, dass…
Dihydroxyacetone (Dha) kinases are homologous proteins that use different phosphoryl donors, a multiphosphoryl protein of the phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system in bacteria, ATP in animals, plants, and some bacteria. The Dha kinase of Escherichia coli consists of three subunits, DhaK…
The dihedral angle between the two porphyrins in meso–meso-linked ZnII diporphyrin can be modulated effectively by adding 1,7-diaminoheptane, which coordinates at the both ZnII centers (see picture). This mechanical torsion gives rise to a decrease in the energy of the S1 state in the meso–meso-linked ZnII-diporphyrin…
Gold-Nanopartikel mit enger Größenverteilung wurden durch oberflächeninitiierte lebende Radikalpolymerisation mit wohldefinierten Polymerbürsten beschichtet. Die Goldteilchen bilden hochgeordnete zweidimensionale Strukturen (siehe Bild), und die Abstände zwischen den einzelnen Teilchen können gut kontrolliert werden.
Blattgold: In neuartigen gemischtvalenten AuI/AuIII-Perowskitstrukturen werden Schichten aus [AuI2]−- und [AuI4]−-Einheiten durch I3−-Ionen und geeignete organische Dikationen zu dreidimensionalen Architekturen verbunden. Die experimentell bestimmten optischen Bandlücken dieser organisch-anorganischen Hybridhalbleiter…
Powder Kurtz-Perry measurements were performed for the title crystals. The efficiencies of second harmonic generation were determined (0.34, 0.84, 0.80, 0.97 and 1.01) relative to potassium hydrogen phosphate. The l -lysine moiety was characterized by wavenumbers and relative intensities of the infrared and Raman band…
A new fully automated powder diffraction furnace that operates from 20 to 1600°C under controlled atmosphere or vacuum is reported. The diffraction furnace provides a large heated volume and stable sample positioning, thus minimizing systematic errors in the powder diffraction patterns and temperature control. The the…
Polymer-directed enzyme prodrug therapy (PDEPT) is a novel two-step antitumor approach that uses a combination of a polymeric prodrug and polymer-enzyme conjugate to generate a cytotoxic drug rapidly and selectively at the tumor site. Previously we have shown that N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-bou…
The nature of the magnetic transition of the Na-rich thermoelectric ${\mathrm{Na}}_{0.75}{\mathrm{CoO}}_{2}$ at 22 K was studied by positive muon-spin-rotation and relaxation $({\ensuremath{\mu}}^{+}\mathrm{SR})$ spectroscopy, using a polycrystalline sample in the temperature range between 300 and 2.5 K. Zero-field $\…
It is generally accepted that the doping of chiral materials with achiral molecules diminishes the chirality of the system. Here we report the opposite phenomenon. It was found that the structural chirality of smectic phases made of rodlike molecules, Sm-C(*) or Sm-C(*)(A) phases, measured as the reverse length of the…
A family of well-defined highly ordered mesoporous silica materials (designated as HOM) was synthesized by using a high concentration of nonionic amphiphile of Brij 56 surfactant (C 18 EO 10 ) as a structure-directing species. Monolithic nanostructures with regular arrays and extended periodicity were produced under a…
Tungsten hexaaryloxide complexes of formula W(OAr) 6 (Ar = C 6 H 5, 1; C 6 H 4 F-4, 2; C 6 H 3 F 2 -3,4, 3 ) have been synthesized by the reaction of W(O)Cl 4 and ArOH in 22 − 28% yield. The complexes were characterized by 1 H, 13 C, 19 F, and 183 W NMR ( 1, δ = −474.8; 2, δ = −416.3; 3, δ = −446.3), melting point ( 1…
Assuming the Mulliken electronegativity density functional theory (DFT) formulation as the primary structural information on atomic systems, we propose a new atomic radii quantitative definition and scale. The radii scale based on DFT first principles is further used to evaluate the atomic diamagnetic susceptibility,…
Synthetic biodegradable poly(butylene adipate-co-butylene terephthalate), P(BA-co-BT), with 56 mol % butylene adipate, BA, was characterized by solid-state NMR spectroscopy, thermal analysis, X-ray diffraction, computer modeling, and polarization microscopy. The NMR study showed the presence of BA and butylene terepht…
Novel ground-state spin structures in undoped and lightly doped manganites are investigated based on the orbital-degenerate double-exchange model, via mean-field and numerical techniques. In undoped manganites, a new antiferromagnetic (AFM) state, called the E-type phase, is found adjacent in parameter space to the A-…
Radical bridge design: The diquinone-tetrathiafulvalene (TTF) species shown exhibits effective electron coupling between the quinone centers which is mediated by the TTF bridge. Stepwise one-electron reduction of the molecule occurs, and the observed potential difference between reduction events is an indication that…
Intracellular poly[D-(-)-3-hydroxybutyrate] (PHB) depolymerases degrade PHB granules to oligomers and monomers of 3-hydroxybutyric acid. Recently an intracellular PHB depolymerase gene (phaZ1) from Ralstonia eutropha was identified. We now report identification of candidate PHB depolymerase genes from R. eutropha, nam…
Turning over a new leaf: Leaves of Equisetum Arvense can be successfully treated to yield zeolite-type structures which, after calcination, are transformed into a micro-/mesoporous material which keeps all of the morphological features of the vegetal template (see SEM image). Faithful zeolitization of the plant struct…
Using density-functional theory in the local-density approximation and spin-fluctuation theory, the Curie temperatures of the zinc-blende half-metallic ferromagnets VAs, CrAs, MnAs and the Heusler compound NiMnSb have been estimated, the lower bounds obtained being ab initio. The orders of magnitude are the same as th…