Materials Literature
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The electronic situation of boron atom frameworks in boron-rich solids is not easy to understand. Attempts to describe such compounds according to known bonding theories such as the Lipscomb or Zintl−Klemm approaches, are not completely unambiguous. To gain further insight and to create a solid experimental basis for…
This review covers most of the authors' work on ring-opening polymerization and copolymerization of heterocyclic monomers during the time of their cooperation since 1985. The mechanistic aspects of anionic ring opening polymerization of cyclic carbonates with a variety of functional groups are described first. By sequ…
We have studied the crystallization of poly(ε-caprolactone) (PCL) with in situ optical rheometry and ex situ optical microscopy as a function of applied stress. The evolution of the birefringence and dichroism was monitored in parallel with the viscosity following a temperature jump from the melt to a final crystalliz…
Pulsed glow discharge plasma from a 1 Pa gas mixture of acetylene (C2H2) and hexafluoroethane (C2F6) was used to produce fluorinated diamond-like carbon (F-DLC) films on glass and polymethyl-methacrylate (PMMA) substrate. The composition of the F-DLC coatings was measured by using Rutherford backscattering spectroscop…
This study investigated the development of chromate-free corrosion protection systems for Alclad 2024-T3 (UNS A92024) aluminum alloy ([2A]) based on the concept of system approach interface engineering (SAIE) by chemical and plasma techniques. Anode magnetron enhanced direct current (DC) cathodic plasmas were used to…
A series of methyl-terminated oligooxyethylene ( CH 3 ( OCH 2 CH 2 ) n O , n = 8.8)-substituted phthalocyanines with peripheral substitution at four β positions, at four α positions and at the eight α positions was synthesized and structurally characterized. These compounds are isotropic liquids above 10 °C. Non-linea…
Microcalorimetric techniques have been employed to investigate the adsorption of water on chemically modified, high surface area carbons. A matrix of treatments and carbons were selected to test some hypotheses. Heats of adsorption of water indicate that adsorption is a strong function of surface chemistry. Three mech…
X-ray scattering measurements on ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ $(x=0.35,0.40,0.50)$ have revealed the existence of diffuse scattering above the charge and orbital ordering transition temperature ${(T}_{\mathrm{CO}}).$ The diffuse scattering has local intensity maxima at incommen…
The use of the Diels–Alder reaction of unsubstituted tetraazaporphine as dienophile with some dienes of the anthracene series for the synthesis of novel substituted tetraazachlorins, tetraazabacteriochlorins and tetraazaisobacteriochlorins is reported. The condensation of tetraazaporphine with anthracene, 9,10-dimethy…
The Influence of minor elements, such as Be. Zr, Fe and Mn. on grain size and grain-refining effect of Mg-9%Al alloy was investigated by use of high-purity Mg-9%Al alloy (high-purity alloy). This high-purity alloy was prepared from distilled pure magnesium and 99.99% commercial aluminum. Given amounts of Be. Zr, Fe an…
The $2.8\ensuremath{-}\ensuremath{\mu}\mathrm{m}$ emission of ${\mathrm{Er}}^{3+}$-doped low silica content calcium aluminate glasses sensitized by ${\mathrm{Yb}}^{3+}$ is investigated using conventional spectroscopy. The experimental data are quantitatively analyzed in terms of the energy transfer among the ${\mathrm…
This paper reports on the application of a phase shifting interferometry technique for the concurrent measurement of the thermal expansion coefficient αf and the elastic modulus Ef /1 - Vf of Ta2O5 thin film. The Ta2O5 films were prepared by ion beam sputter deposition. The stresses in the thin films were measured wit…
We propose a model of the oxygen-deficiency-related defect in silica glass on the basis of the ab initio molecular-orbital calculations. This model can be regarded as an oxygen vacancy derived from the edge-sharing structural unit and will be inherent in glassy silica. Our calculations demonstrate that this defect can…
Abstract A method is proposed to measure the absolute concentration of paramagnetic Fe 3+ ions in kaolinite from various geochemical environments using powder X-band electron paramagnetic resonance (EPR) data. An Fe 3+ -doped corundum sample is used as a concentration standard. The Fe 3+ signal is calibrated by calcul…
It is likely that feathers evolved from a conical shaped tubercle rather than a plate-like structure. Although the morphology of the presumably most primitive feather is unknown, minimal conditions for its production include the cellular capacity to synthesize feather proteins (=ϕ-keratin) which provides the molecular…
MurA, an essential enzyme for the synthesis of the bacterial cell wall, follows an induced-fit mechanism. Upon substrate binding, the active site forms in the interdomain cleft, involving movements of the two domains of the protein and a reorientation of the loop Pro112-Pro121. We compare two structures of un-liganded…
The strong segregation theory (SST) of block-copolymers/polymer brushes is extended by incorporating a new leading correction to the asymptotic (χ N → ∞ ) limit. In particular we found an additional feature of the brush structure: a proximal layer of thickness μ where the molecular potential is essentially non-parabol…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTRedox-Induced "Zipper" Action in the Solid State. Unprecedented Single-Crystal to Single-Crystal to Single-Crystal Cascade Conversions in Cs3Bi7Se12. Framework Evolution from 2D to 2D' to 3DLykourgos Iordanidis and Mercouri G. KanatzidisView Author Information Departme…
In order to clarify the influence of precipitated hydride on the fracture behavior of Zircaloy cladding tubes, the stress-strain distribution of the cladding was estimated by finite element method (FEM) analysis. The mechanical properties of α-phase of zirconium and zirconium hydride required for the analysis were exa…
Individual carbon nanotubes (CNTs) have been located and investigated using scanning confocal Raman microscopy. In particular, the geometry of thin bundles and individual single-walled CNTs was able to be examined by combining Raman with scanning force microscopy. Spatially resolved Raman spectroscopy could thus be pe…