Materials Literature
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The helical structure of the chiral nematic phases induced by chiral dopants in nematic solvents provides a macroscopic information of the molecular chirality of the dopant. Chiral dopant molecules considered in this paper are challenging systems because their twisting ability has a relatively strong dependence on the…
Changement de phase induit par broyage m�canique dans l'hydrure de magn�sium. La synth�se de l'hydrure de magn�sium par broyage r�actif m�ne � la formation d'une phase orthorhombique m�tastable (?-MgH2) en plus de la phase quadratique ?-MgH2. Les structures des phases ?-MgD2 et ?-MgD2 du MgD2 nanocristallin broy� ont…
Nuclear quadrupole resonance and SQUID-magnetometric studies on magnetic properties of bismuth(III) oxy compounds comprising neither d- nor f-elements are surveyed and systematised. The magnetic properties, not conventionally expected in the Main Group element substances, were found to exist in most of the compounds d…
We report time-dependent density functional theory calculations of the vertical excitation energies for the singlet states of three-coordinate 5H-dibenzoborole (DBB) derivatives and four-coordinate 5-fluoro-5H-dibenzoborole ion (FDBB) derivatives. These molecules show remarkable hypsochromic (blue) shifts in their flu…
Phosphate ${\mathrm{PbCu}}_{2}({\mathrm{PO}}_{4}{)}_{2}$ was found in the $\mathrm{Pb}\text{\ensuremath{-}}\mathrm{Cu}\text{\ensuremath{-}}\mathrm{P}\text{\ensuremath{-}}\mathrm{O}$ system. Its structure parameters were refined by the Rietveld method using synchrotron x-ray diffraction data [space group Pccn (No. 56);…
Spin wave equations describing the nonequilibrium precessional state of a ferromagnetic system are given. The equations reveal a new type of spin wave instability (SWI) towards growing domains of uniform magnetization. In the developed stages of SWI a nonstationary picture of domain chaos is revealed by numerical simu…
The NMR pulse sequence RAI (recoupling of anisotropy information) has been improved to obtain powder patterns at high MAS spinning speeds. The 2D iso-aniso experiment displays the static chemical shift spectra on the indirect dimension and the MAS spectra on the direct dimension; hence overlapping chemical shift tenso…
Characterization of magnetic cores is an indispensable task in order to securely accomplish the requirements of a power electronic design and prevent failures. The hysteresis cycle of the material is one of the more complex features to characterize due to the well-known nonlinear and memory effects; moreover, there is…
A technique for measuring the difference between the splay and bend flexoelectric coefficients in a nematic liquid crystal is demonstrated. The method uses the flexoelectric-optic effect, but instead of a uniform lying helix structure, a TN cell geometry with an in-plane electric field is used. This has the advantage…
Isothermal desorption of o-terphenyl thin-film bilayers was used to measure self-diffusion coefficients of supercooled o-terphenyl near the glass transition temperature (Tg=243 K). Diffusion coefficients from 10(-15.5) to 10(-12) cm2 s(-1) were obtained between 246 and 265 K. Protio and deuterio o-terphenyl were seque…
Single-walled carbon nanotubes (SWNTs) were well-functionalized for a study of their defect-derived luminescence properties. The soluble nanotube sample was homogeneously dispersed in poly(vinyl alcohol) (PVA) films via solution-phase mixing and then wet-casting. The PVA films embedded with the functionalized SWNTs we…
Polymer-supported heterogeneous catalysts in a form of complexes of 8-hydroxy- quinoline with cobalt acetate were synthesized. Conjugated polymers - polyaniline (PANI), poly-o-toluidine (POT), poly-o-anisidine (POA) - were used as supports. Oxidation reactions of aliphatic and aromatic hydrocarbons were carried out in…
This paper presents an innovative method for an efficient characterization of relevant characteristics of nonlinear overvoltage protection elements in low-voltage applications. Standard measuring equipment was modified to enable an efficient and repeatable experimental procedure in order to investigate characteristics…
The functional assignment of enzymes that catalyze unknown chemical transformations is a difficult problem. The protein Pa5106 from Pseudomonas aeruginosa has been identified as a member of the amidohydrolase superfamily by a comprehensive amino acid sequence comparison with structurally authenticated members of this…
Abstract By means of time resolved spectroscopy we compare two samples of ZnO nanorods with respect to their suitability as stimulated emitters. In the case of narrow nanorods their wave guiding quality causes a suppression of exciton–exciton scattering whereas no laser emission is detectable. Unlike their narrow coun…
10.1021/ma0520601
A new Suzuki-based strategy for the synthesis of 4,4'-diaryl (or heteroaryl)-substituted 2,2'-bipyrroles (10), precursors of 2,7,12,17-tetraaryl (or heteroaryl)-substituted porphycenes, is described. Bromination of the previously described diethyl 4H,5H-thieno[3,2-b:4,5-b']dipyrrole-3,6-dicarboxylate afforded dibromo…
Abstract Polymerization Compounding (PC) offers the possibility to design composite materials by controlling the architecture of a grafted polymer on the surface of solid substrates to be incorporated in a polymer matrix. The approach consists in involving the surface of a reinforcement in a polymerization process of…
We have fabricated a neodymium-doped phosphate glass fiber with a silica cladding and used it to form a fiber laser. Phosphate and silicate glasses have considerably different glass transition temperatures and softening points making it hard to draw a fiber from these two glasses. A bulk phosphate glass of composition…
Abstract Poly(methyl methacrylate) (PMMA)/copper hydroxy methacrylate (CHM) composites were prepared via solution blending and bulk polymerization. Addition of 3% by weight of the CHM additive using solution blending resulted in a significant increment (∼45°C) in thermogravimetric analysis (TGA) T 50 , the temperature…