Materials Literature
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The type of bait determines the prey: in a pond with triethanolamine ligands and iron(III) ions, six- (1) or eight-membered (2) iron coronates can be captured, depending upon whether sodium or cesium ions are used as the bait. This finding is especially interesting in connection with a possible combinatiorial approach…
The equations of nematic liquid crystal hydrostatics are used to determine the driving forces that cause the breakup of catenoidal shaped liquid crystalline networks during the phase separation of isotropic and nematic phases. The catenoidal shaped liquid crystalline network is assumed to be an elastic network embedde…
The original theory of the fibrogram as developed by Hertel more than fifty years ago has served as the basis of all subsequent cotton length measurements. Hertel's mathematical derivation is based on the assumptions that the sampling probability of each fiber in forming a fiber beard is proportional to its length and…
Abstract A new superaustenitic stainless steel is described in terms of chemical composition. mechanical properties and corrosion resistance. Results obtained by using this highly alloyed stainless steel, EN 1.4652, in a number of hostile environments are reported. Applications include neutral and acid chloride contai…
The crystal structure of low temperature NaNiO 2 has been refined by Rietveld methods using powder X-ray diffraction and neutron scattering data. The starting model was based on parameters that had been obtained earlier by X-ray film methods. At room temperature NaNiO 2 is monoclinic, C 2/ m , a =0.53192(2), b =0.2845…
Using the p-type surface-conductive layer of diamond film, enhancement mode and depletion mode metal-semiconductor field effect transistors were fabricated on the same surface by changing the metals of the gate electrode. The threshold voltages of p-type metal semiconductor field effect transistors (MESFETs) can be co…
The formidable task of determining a mathematical form of the trap distribution in a solid has been solved for the case of an unusually broad thermoluminescence (TL) glow peak of a Brown microcline (feldspar, triclinic form of KAlSi3O8). An exponential distribution of traps gives the best fit to the experimental glow…
A simple and general stepwise procedure for the synthesis of linear monodisperse liquid crystalline (LC) polyethers with degrees of polymerization (DPs) up to 33 ( M n = 15 090) is presented. The particular examples used for this demonstration are based on the conformationally flexible mesogen 1-(4-hydroxy-4‘-biphenyl…
Polyfurfuryl alcohol (PFA) is pyrolyzed at 600 °C for different lengths of heat-treatment (HT) time (0–50 h) and at different pyrolytic temperatures (600–850 °C) for 4 h. Analysis by Raman spectroscopy shows that the crystallite size of PFA pyrolyzed at 600 °C decreases with increasing HT time. This suggestion is supp…
The theory of space-group representations is extended to aperiodic crystals by reformulating it as the theory of symmetry-required degeneracies of electronic levels that emerges from the Fourier-space approach to crystal symmetry. As an illustration it is shown that the nonvanishing of a simple linear combination of p…
Reports on investigations into the mechanism of sewing thread strength reduction. Results indicate that structural damage, namely, structural openness and pull‐out of fibre ends from the surface are the major cause of strength reduction and that the fibre strength reduction is found to be only marginal compared to the…
The subunit of the enzyme glutamate dehydrogenase comprises two domains separated by a cleft harboring the active site. One domain is responsible for dinucleotide binding and the other carries the majority of residues which bind the substrate. During the catalytic cycle a large movement between the two domains occurs,…
The geometries and proton and silylenium cation (H 3 Si + ) affinities as well as ring strain energies of several hydrogen-substituted cyclic siloxanes, cyclotrisiloxane (H 2 SiO) 3 ( 5a ), cyclotetrasiloxane (H 2 SiO) 4 ( 6a ), and 1,3-oxadisilacyclopentane ( 7a ), were calculated by ab initio quantum-mechanical meth…
A micromechanical approach is proposed in this work to predict the initial tensile response under uniaxial loading of a bonded two-dimensional fibrous network consisting of two kinds of fibers. The probabilities and statistical distributions of the hybrid bonding points and free fiber lengths between the bonding point…
Reversible machano- and thermochromic behavior are-features of the title bis(tricyclic) olefin. These characteristics are a consequence of the different proper ties of the interconvertible folded and twisted confomers. Despite the severe molecular deformation the conductive charge-transfer complexes and stable salts o…
TiO 2 thin films were grown onto SrTiO 3 substrates by a molecular beam epitaxy (MBE) method using an oxygen radical source. The structure of the thin films obtained was evaluated by X-ray reflection diffractometer (XRD) and reflection high energy electron diffraction (RHEED); TiO 2 thin films were determined to be of…
The appearance of wave front dislocations under interference among beams with simple wave fronts is considered. It is shown, that even two beams with the smooth wave fonts is possible the formation of dislocations screw type. The screw dislocations are formed in cross point of lines of equal amplitude of beams and min…
We describe a group-theoretical procedure that enables one to find necessary conditions for the appearance of spontaneous magnetization in domain walls. We illustrate the derivation of wall symmetries on example of Cr2O3 and present a brief summary of a systematic analysis of domain walls in antiferromagnetic non-ferr…
The nucleation rate ( I ) versus temperature type of curves for a Na 2 O2·CaO·3SiO 2 (NC 2 S 3 ) glass doped with 0.1 wt% platinum, 0.5 wt% Ag 2 O, and 2.0 wt% P 2 O 5 were determined using a previously developed differential thermal analysis (DTA) technique. In this DTA technique, a constant amount of glass sample wa…
Three bis(1,4,7-triazacyclonon-1-yl) ligands, 1,2-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene (L 1 ), 1,3-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene (L 2 ), and 1,4-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene (L 3 ), have been synthesized and their nickel(II) and copper(II) coordination chemistry investigated. Reacti…