Materials Literature
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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…
Abstract Poly(2‐alkyl‐2‐oxazoline)s having an acrylate group at both chain ends were synthesized by terminating living bifunctional poly(2‐methyl‐2‐oxazoline) or poly(2‐ethyl‐2‐oxazoline) with acrylic acid. These macromonomers have been polymerized to the corresponding polyoxazoline networks. Thermal as well as UV‐ini…
Iron tellurite glasses in the system Fe2O3–Sb–TeO2 have been prepared by the melt-quenching technique. The glass forming region for the above system has been determined. A comparative study of the direct current electrical conductivity, σ, of the 15Fe2O3–5Sb–80TeO2 (mol%) glass together with 15Fe2O3–5Sb2O3–80TeO2 and…
Single crystals of (VO) 2 (SeO 3 ) 3 have been prepared from SeO 2 and V 2 O 5 . The crystal structure has been determined by single-crystal X-ray diffraction. Crystal data: (VO) 2 (SeO 3 ) 3, M r = 514.75; monoclinic, space group P 2 1 / a (No. 14); cell parameters a = 9.151(1) Å, b = 6.353(1) Å, c = 14.992(1)Å, β =…
The structure of the tetragonal NaBi(MoO4)2 crystal was determined. The space group is I4=S42 with cell dimensions a=5.267, c=11.565 Å and Z=2. The molybdenum atoms occupy two different sites of 4 symmetry. The Na+ and Bi3+ cations are situated on two positions with different occupancy factors and are short-range orde…