Materials Literature
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Electron-excited x-ray microanalysis performed in the variable pressure and environmental scanning electron microscopes is subject to additional artifacts beyond those encountered in the conventional scanning electron microscope. Gas scattering leads to direct contributions to the spectrum from the environmental gas,…
A highly efficient synthesis of 2-formyl-5,10,15,20-tetraarylporphyrins, 1 and 2, that can be carried out on multi-gram scales is reported. The key steps in the sequence involve use of copper(II) chelation to ensure very efficient electrophilic substitution, and the demetalation of the intermediate iminium salt that r…
The mechanism of intergranular-mode fracture in hydrogen-related failure of high-strength martensitic steels has been investigated. Pronounced degradation of tensile properties appeared with increasing manganese content in a slow-elongation-rate test under concurrent hydrogen charging. The fracture mode was intergranu…
Abstract When CO 2 is dissolved into a polymer, the viscosity of the polymer is drastically reduced. In this paper, the melt viscosities of low‐density polyethylene (LDPE)/supercritical CO 2 solutions were measured with a capillary rheometer equipped at a foaming extruder, where CO 2 was injected into a middle of its…
A new marine planktonic diatom, Pseudo-nitzschia galaxiae Lundholm & Moestrup sp. nov., isolated from Mexican and Australian waters, is described using light and transmission electron microscopy, including thin-sectioning. The diatom is very small and delicate and resembles species in the section Nitzschiella of Nitzs…
Our understanding of the genetics of species of the best-studied hyperthermophilic archaea, Pyrococcus spp., is presently limited by the lack of suitable genetic tools, such as a stable cloning vector and the ability to select individual transformants on plates. Here we describe the development of a reliable host-vect…
Abstract Filler flocculation was followed for silica filled compounds containing various alkoxy silanes and non-silane type polar additives. The methodology employed in this paper permitted a quantitative characterization of filler flocculation and polymer-filler interactions after heating the compound under condition…
Experimental evidence of the ferrimagnetic ground state of Sr2FeMoO6 probed by X-ray magnetic circular dichroism, M. Besse, V. Cros, A. Barthélémy, H. Jaffrès, J. Vogel, F. Petroff, A. Mirone, A. Tagliaferri, P. Bencok, P. Decorse, P. Berthet, Z. Szotek, W. M. Temmerman, S. S. Dhesi, N. B. Brookes, A. Rogalev, A. Fert
Oxidation–reduction equilibrium and coordination of transition metals ions (TM) in meta or more depolymerised phosphate glasses are reviewed. For small concentrations of metal ions, the basicity of the glass host plays an important role in determining the valency of the transition metal (TM) ion. If one considers the…
Intrinsic and extrinsic ultraviolet absorption and radiation-induced effects were investigated in different glass types, fluorides, phosphates and borosilicates. High-purity glass samples were prepared and their intrinsic absorption was measured in the vacuum ultraviolet region. The influence of doped iron and tin spe…
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Some 9,9'-spirobifluorene-bridged bipolar systems 1-3 containing 1,3,4-oxadiazole-conjugated oligoaryl and triarylamine moieties have been synthesized, in which 1 exhibits remarkable solvent-polarity dependent fluorescence properties due to a highly efficient photoinduced electron transfer reaction.
Piezoelectric materials are capable of actuation and sensing and have found uses in applications including ultrasonic transducers, hydrophones, micropositioning devices, accelerometers, and structural actuators. A composite configuration for structural actuation having significant advantages over conventional piezoele…
The model of structure and structural transformation of the mesostructured carbon material CMK-1 was established by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) investigations. The investigations showed that the enantiomeric carbon subframeworks formed within the pores of the MCM-48 mesopo…
Applying a one-dimensional formulation, the authors give a short overview on thermoelectric effects. Starting from the first principles of thermoelectricity, differential equations governing the coupling of thermal and electric transports have been analytically and numerically solved by the software tool Mathematica.…
The three-dimensional structures of brain pyridoxal kinase and its complex with the nucleotide ATP have been elucidated in the dimeric form at 2.1 and 2.6 A, respectively. Results have shown that pyridoxal kinase, as an enzyme obeying random sequential kinetics in catalysis, does not possess a lid shape structure comm…
The electrical resistivity of thin films of Ta and TaN has been examined as a function of film thickness and other processing parameters. The films were deposited by magnetron sputtering of Ta cathodes with Ar, or mixtures of Ar and N2 for the case of TaN. Ta films deposited on silicon dioxide or Cu surfaces were alwa…
This paper discusses the effectiveness and mechanism of inhibition of a number of novel corrosion inhibitors for mild steel, based on cerium (III) and substituted carboxylates. The organic component was chosen to be benign, and known to have some inhibitive action in its own right. The compounds discussed in this work…
In-situ deformation studies in a transmission electron microscope equipped with an environmental cell have shown that solute hydrogen increases the velocity of dislocations, decreases the stacking-fault energy, and increases the stability of edge character dislocations. Theoretical modelling has established that the h…
Thin ZnO and ZnO:Al films have been prepared by reactive dc magnetron sputtering, using both metallic and ceramic targets. The influence of oxygen flow and total pressure on film stress, structure, texture, and surface roughness has been examined. The properties of the films strongly depend on the deposition condition…