Materials Literature
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The superexchange interactions in four three-center model systems A-L-B, for A and B being paramagnetic centers and L a diamagnetic bridging ligand, are analyzed by valence bond configuration interaction models in combination with fourth-order perturbation theory. We analyze the four distinct cases where a bridging li…
A novel cyclic octanuclear chromium(III) complex with hydroxo and acetato bridging ligands was isolated and its structure determined by X-ray crystallography. The complex [Cr8(OH)12(OAc)12] (1) (OAc- = CH3CO2-), as found in crystals of 1.34H2O, is obtained by refluxing an aqueous solution of the trinuclear "basic" chr…
Microbial degradation of thermally synthesized poly(aspartic acid) (PAA) was investigated. A PAA-P1 sample (Mn, 7500; Mw, 20,000; number of branched units/100 monomer units, 3.1) was completely degraded in natural river water within 15 days at 25 degrees C. A new PAA-degrading bacterium (strain KP-2: JCM10638) was iso…
The in-depth structural analysis of spherulites of artificial cellulose, formed by the enzymatic polymerization of cellobiosyl fluoride, is reported. Both positive- and negative-type spherulites were observed by polarization optical microscopy. Scanning electron microscopy revealed that the negative spherulites have a…
The mechanism of the selective catalytic reduction (SCR) of NO by C 3 H 6 on Cu−Al 2 O 3 catalysts, which consist of highly dispersed Cu 2+ ions in the surface aluminate phase, are investigated by in-situ FTIR spectroscopy. During NO + C 3 H 6 + O 2 reaction, the acetate is produced via the partial oxidation of C 3 H…
We study the surface dynamics of silica films grown by low pressure chemical vapor deposition. Atomic force microscopy measurements show that the surface reaches a scale invariant stationary state compatible with the Kardar-Parisi-Zhang (KPZ) equation in three dimensions. At intermediate times the surface undergoes an…
Weak localization leads to the same correction to both the conductivity and the electron-phonon coupling constant $λ$ (and $λ_{tr}$). Consequently the temperature dependence of the (thermal) electrical resistivity is decreasing as the conductivity is decreasing due to weak localization, which results in the decrease o…
Three malonato-bridged copper(II) complexes of the formulas [[Cu(H2O)3][Cu(C3H2O4)2(H2O)]]n (1), [[Cu(H2O)4]2[Cu(C3H2O4)2(H2O)]] [Cu(C3H2O4)2(H2O)2][[Cu(H2O)4][Cu(C3H2O4)2(H2O)2]] (2), and [Cu(H2O)4][Cu(C3H2O4)2(H2O)2] (3) (C3H2O4 = malonate dianion) have been prepared, and the structures of the two former have been s…
MCM-41/ZSM-5 composites were prepared using a dual templating method through a process of two-step crystallization. Mesoporous MCM-41 was first synthesized using the self-assembling of surfactant cetyltrimethylammonium bromide and subsequently the amorphous wall of MCM-41 was recrystallized with a structure-directing…
We report the synthesis of three sizes of thioglycerol-capped precipitated ZnS nanocrystallites with relatively narrow size distributions, having average sizes of 1.8, 2.5, and 3.5 nm, respectively. These crystallites were extracted as free-standing powders which remain stable under normal atmospheric conditions and c…
We apply an anisotropic version of the polymer reference interaction site model (PRISM) integral equation description of flexible polymers to analyze athermal liquid crystallinity. The polymers are characterized by a statistical segment length, σo, and by a physical hard-core thickness, d, that prevents the overlap of…
A systematic study of nonlinear optical (NLO) properties of inorganic transition metal (TM) thiometalates and metalates is reported. Polarizabilities (α) and second hyperpolarizabilities (γ) are calculated in solution within the polarizable continuum model. It is found that NLO properties of anionic inorganic complexe…
Thermal desorption spectroscopy, ultraviolet photoelectron spectroscopy, low energy electron diffraction (LEED), and the reactive scattering of a CO molecular beam have been applied to determine the relationship between the formation of the subsurface oxygen phase and the growth of oxides during oxidation of Ru(0001).…
The effect of substrate receptor group density on polymer adhesion was investigated. Model substrates with varying −NH 2 density on Al 2 O 3 were prepared by a self-assembly of mixed amine-terminated silanes and methyl-terminated silanes. The model polymer was synthesized through a high-pressure carboxylation of polyb…
The tricontinuous structure of ABC-type triblock copolymer in bulk at equilibrium was studied by both transmission electron microscopy (TEM) and small-angle x-ray scattering (SAXS). Sample is an anionically polymerized isoprene-styrene-2-vinylpyridine triblock copolymer whose volume fraction is 0.22–0.59–0.19 and tota…
Oxygen doping in metallic YBa_2Cu_3O_x induces quadrupolar "alpha-ortho'', and breathing "beta-ortho" deformations of the CuO_2 planes. Breathing beta-ortho deformations favour hybridizations of the pd sigma Cu3d_x^2-y^2 - O2p_x,y with the pd pi Cu3d_x,z, 3d_y,z-O2p_z bands relaxing the confinement of the carriers in…
A new procedure for the modification of gold nanospheres (2−7 nm diameter) with thiolated cyclodextrin receptors is described. The resulting monolayer-protected nanoparticles behave as multisite hosts in aqueous media, engaging in host−guest interactions with guest molecules in the solution.
Enzyme I mutants of the Salmonella typhimurium phosphoenolpyruvate:sugar phosphotransferase system (PTS), which show in vitro intragenic complementation, have been identified as Arg126Cys (strain SB1690 ptsI34), Gly356Ser (strain SB1681 ptsI16), and Arg375Cys (strain SB1476 ptsI17). The mutation Arg126Cys is in the N-…
In this publication the glass transition, melting behavior, cure behavior, and thermal stability of LaRC PETI-5 have been extensively studied utilizing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The material used here was subjected to different thermal history (cumulative cure and in…
Some major factors of the melt spinning of high-density polyethylene (HDPE) and a liquid paraffin (LP) blend, which affect the water permeability of HDPE hollow-fiber membrane obtained therefrom, were investigated. The water permeability of the membrane was found to increase as the membrane thickness decreases and as…