Materials Literature
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The crystal structures of chitosan acid salts were studied by X-ray diffraction measurements on a fiber diagram and a new procedure to obtain an anhydrous polymorph of chitosan was found. The salts prepared by immersing a chitosan into a mixture of acid solution and isopropanol were classified into two types (Types I…
The atomic structure of Pb(Zr, Ti)O3 solid solutions near the morphotropic phase boundary (MPB) was examined using time-of-flight neutron diffraction. In addition to the conventional crystallographic refinement the atomic pair distribution function (PDF) analysis was used. Crystallographic analysis suggests that the a…
Abs tract-4,5-Diiodo-, 4,5-dibromo-, and 4,5-dichloro-4' ,5' -ethylenedioxytetrathiafulvalenes (EDO-TTFI 2 , EDO-TTFBr 2 , and EDO-TTFCl 2 ) were synthesized in moderate to good yields by the two routes.The first route contains the reaction of EDO-TTF with LDA, followed by quenching with halogenated reagents, and the…
A novel metal-free phthalocyanine 3 fused in peripheral position with four diazatetrathiabicyclomacrocycles has been prepared by bicyclotetramerization of cryptand 1 and its isoindolinediimine derevative 2; the new compounds were characterized by elemental analyses, IR, 1H and 13C NMR, UV–VIS and MS spectroscopy.
The phenomenon of protonation of phthalocyanines (Pc) and its effect upon their photophysical properties has seen considerable neglect in the literature. The work reported here clearly shows that tetrasulfonated zinc Pc, a known photodynamic therapy (PDT) agent, is strongly susceptible to protonation at the azomethine…
Preface 1. Introduction 1.1 Modern VLSI 1.2 The Driving Forces for Continued Integration Growth 1.3 Moore's Law 1.4 Types of Materials References 2. The Crystalline Nature of Materials 2.1 The Various States of Matter 2.2 Space Lattices 2.3 Crystalline Directions 2.4 X-Ray Diffraction References Problems 3. The Wave M…
The in vitro degradation of microspheres of polymers of lactic and glycolic acids were investigated by monitoring the mass loss from the device, the molecular weight of the polymer and the morphological changes of the particles with time. Two different sequences of morphological changes were found to be operative, dep…
A methodology allowing one to include iron losses in voltage fed time stepping finite elements simulations is presented in this paper. Hysteresis, eddy currents and anomalous losses models are introduced in the 2D field formulation based on the magnetic vector potential. The influence of the losses on the behavior of…
The first achiral bent core banana-shaped mesogen consisting of a thermally and hydrolytically stable salicylaldimine (2-hydroxybenzylideneamine) mesogenic segment has been synthesized and evaluated for its liquid crystalline behavior. This novel compound exhibits a single switchable mesophase over 60 °C temperature r…
Thin films of polycarbosilane were deposited on Si and SiO 2 substrates. Instead of conventional oven annealing (high temperatures, inert atmosphere), laser pyrolysis was used to achieve the polymer‐to‐ceramic conversion. In some conditions, especially when laser radiation absorption was enhanced by depositing a carbo…
Monomeric iridium(II) porphyrin complexes of tetrakis(2,4,6-trialkylphenyl)porphyrin ligands that are generated by photolysis of the Ir–Me derivatives are found to have the dxy2 dz22 dxz,yz3 ground electron configuration which differs from the dxy2 dxz,yz4 dz21 configuration observed for the Co(II) and Rh(II) analogs;…
In order to clarify the mechanism of remarkable creep strength of the 9Cr–2W–0.2V–Ta steels, high-Cr heat-resistant steels with Mo replaced by W and Nb by Ta for reducing induced radioactivity, the microstructural evolution during creep tests has been studied and compared with that in conventional 9Cr–1Mo–0.2V–Nb stee…
The experimentally postulated mechanism for the interconversion between (S)-vinylglycolate and (R)-vinylglycolate catalyzed by mandelate racemase enzyme consists of a two-step quite symmetric process through a dianionic enolic intermediate that is formed after the abstraction of the alpha-proton of vinylglycolate by a…
Ultrafine strontium barium niobate ((Sr x Ba 1− x )Nb 2 O 6 , SBN) powders were prepared using sol–gel and hydrolysis aging processes. Their structural properties were examined via X‐ray diffractometry and Raman spectroscopy. Our results indicated that the SBN powders crystallize to a pure tetragonal phase at annealin…
D,L-3-Methylglycolide (MG) was successfully polymerized with bimetallic (Al/Zn) μ-oxo alkoxide as an initiator in toluene at 90 °C. The effect of the initiator concentration and monomer conversion on the molecular weight was studied. It is shown that the polymerization of MG follows a living process. A kinetic study i…
Electroless Deposition of Thin-Film Cobalt-Tungsten-Phosphorus Layers Using Tungsten Phosphoric Acid ( H 3 [ P ( W 3 O 10 ) 4 ] ) for ULSI and MEMS Applications , Shacham-Diamand, Yosi, Sverdlov, Y., Petrov, N.
Nanocrystalline MgH2/MexOy composite powders were produced by high energy ball milling (MexOy=Sc2O3, TiO2, V2O5, Cr2O3, Mn2O3, Fe3O4, CuO, Al2O3, SiO2). The hydrogen absorption and desorption kinetics were determined in view of a technical application. The addition of selected oxides lead to an enormous catalytic acce…
A set of natural and heat-treated cordierite crystals has been analyzed using single-crystal X-ray diffraction, EMPA, SIMS, and 57Fe Mössbauer-spectroscopy. Structure determination of natural cordierite shows that the average size of the tetrahedrally coordinated T 1 1 cation increases systematically by about 0.01 Å a…
Amphiphilic dendritic–linear–dendritic triblock copolymers based on hydrophilic linear poly(ethylene oxide) (PEO) and hydrophobic dendritic carbosilane were synthesized with a divergent approach at the allyl end groups of diallyl-terminated PEO. Their micellar characteristics in an aqueous phase were investigated with…
A previously reported theoretical treatment for self-assembly macrocyclisations occurring under thermodynamic control has been tested experimentally. The fundamental quantities on which the treatment is based are the effective molarity (EM) of the self-assembling cyclic n-mer and the equilibrium constant for the inter…