Materials Literature
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The ferroelectric domain structures of tetragonal lead zirconate titanate (PZT) ceramics were evaluated by investigating the poling field ( E ) dependence of the planar coupling factor ( k p ) and the relative intensity of X-ray diffraction (002) peak, I 002 . Fifteen typical domain configurations were proposed. Furth…
A purely organic mixed‐valence high‐spin species in which the existence of an electron transfer process has been clearly established by NIR spectroscopy is reported. Since magnetic coupling and electron transfer are by no means independent of each other the opportunity to study the first organic material to exhibit bo…
Abstract Inherent flaw sizes were determined from fatigue lifetimes, and from the crack length dependence of the strain energy to break, for four cis -1,4-polyisoprenes compounded to have the same crosslink density and low strain hysteresis. Both techniques indicated that the flaws intrinsic to guayule rubber (GR), an…
Carbon nanotubes prepared by de arc discharge of graphite electrodes in He and CH4 gas took markedly different morphology. Thick nanotubes embellished with many carbon nanoparticles were obtained by evaporation under high CH4 gas pressure and high arc current. Thin and long carbon nanotubes were obtained under a CH4 g…
Abstract Coal combustion by‐product (CCBP; a wallboard‐quality gypsum), limestone, and cellulose had been found to influence the dissolution of North Carolina phosphate rock (NCPR) in an acid Lily loam soil (fine‐loamy, siliceous, mesic Typic Hapludult). Laboratory and incubation experiments were carried out in this s…
Small Al 2 O 3 additions (∼ 4 vol%) made to Y‐TZP using an infiltration technique increased the fracture toughness and strength by ∼15% and the amount of transgranular fracture. Ionic conductivity measurements showed decreased grain‐boundary conductivity, confirming a change in the grain‐boundary composition. The pred…
Abstract Poly(β-malic acid) was prepared by lipase-catalyzed ring-opening polymerization of benzyl β-malolactonate with subsequent debenzylation. Benzyl β-malolactonate was readily polymerized by porcine pancreatic lipase or Novozyme 435 lipase at 60 °C to yield poly(benzyl β-malate) having a molecular weight of great…
The photoionization cross sections for ${\mathrm{Ar}}^{+}$ through ${\mathrm{Ar}}^{4+}$, produced by the Auger decay of a 2p hole in argon, have been measured between 242 eV and 253 eV by the use of synchrotron radiation. The high resolution of the monochromator has allowed a detailed study of the postcollision intera…
Analytical procedures are developed for a composite system consisting of shape memory alloy fibers within an elastic matrix subject to uniform temperature fluctuations. Micromechanics for the calculation of the equivalent properties of the composite are presented by extending the multi-cell model to incorporate shape…
The two possible causes of depth inhomogeneities of the microstructure of porous silicon are changes in the HF concentration with depth and a varying chemical etching rate of the porous silicon layer. During anodization chemical etching will become important for microporous silicon — e.g. p-porous silicon — due to the…
A number of new chiral binaphthol (BN) derivatives with different substituents R,R′ in the 6,6′-positions in open (BN-diethylethers) and bridged forms (BN-acetals) have been synthesized. The syntheses of the chiral 6,6′-disubstituted-2,2′-diethoxy-1,1′-binaphthyls (R,R′ = -CH'CHCHO, -CH'CH-(p-BrPh), -CH'CH-(p-CHOPh))…
Abstract Several macromonomers were prepared by cationic ring‐opening polymerization of 2‐nonyl‐ and 2‐phenyl‐2‐oxazoline using different techniques of functionalization. Introduction of the unsaturated functional group directly via a suitable termination agent proved to be superior to the use of a phenol‐functionaliz…
Shaping zeolites into useful forms is very important for technical applications in areas such as catalysis, separation, and sensing. Normally it is difficult to form zeolites into appropriate shapes without mixing them with binders. Here, a method is presented for transforming preformed layered silicates into silicali…
Abstract The mineralogy, crystallochemistry and microfabric of clay minerals from acidic soils were studied using transmission electron microscopy (TEM) and analytical electron microscopy (AEM). Soil profiles, developed on saprolites, sampled in the main crystalline massifs of France represent different pedological en…
Electroactive organic molecular gels based on the title compound (see Figure) are reported along with their sol‐gel behavior and ionic conductivities, and their application as electrochromic materials is discussed. Furthermore the correlation between molecular structure and gel formation is examined in order to provid…
The dynamics of proton and deuteron glasses has been studied via the NMR spin-lattice relaxation (${T}_{1}$) of $^{87}\mathrm{Rb}$ and O-D\ifmmode\cdot\else\textperiodcentered\fi{}\ifmmode\cdot\else\textperiodcentered\fi{}\ifmmode\cdot\else\textperiodcentered\fi{}O deuterons down to $T=1.6$ K in ${\mathrm{Rb}}_{0.50}$…
Spectral and decay properties of the photoluminescence (PL) emission in the range 3.5-5.0 eV are investigated in various types of silica ($a$-Si${\mathrm{O}}_{2}$), as grown and after $\ensuremath{\gamma}$ irradiation. We report experimental results on the ultraviolet (5.0 eV) absorption, on the emission and excitatio…
The fluid-solid equilibrium of a system made of charged hard spheres with positive and negative ions of the same size is considered. At high temperatures freezing occurs in a substitutionally disordered close packed structure, the face centered cubic solid (fcc). At low temperatures freezing occurs in the ordered cesi…
The luminescence intensity of trivalent lanthanides, especially terbium(III) and europium(III), is shown to be enhanced by coordination with the ligand 2,6-pyridinedicarboxylic acid (DPA). Further enhancement can be obtained by forming a columinescent complex aggregate with ions such as gadolinium(III), terbium(III),…
Abstract Modern solid state nuclear magnetic resonance (NMR) techniques afford powerful experimental strategies for elucidating detailed structural information in noncrystalline materials. While previous research emphasis has been on the identification and quantification of local environments (short‐range‐order), prim…