Materials Literature
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Single crystals of ZnGeO 3 ilmenite have been synthesized at 180 kbar and 1500°C using a uniaxial split-sphere apparatus. The crystal structure of ZnGeO 3 ilmenite has been determined with 588 counter-measured intensities refined by the least-squares method to R = 0.020 and R w = 0.021. ZnGeO 3 ilmenite is trigonal wi…
A testing technique has been developed for measuring the tensile properties of ceramic matrix composite laminates at temperatures up to 1500°C in air. Using this technique, the tensile properties of unidirectional silicon carbide (SiC) fiber reinforced reaction bonded silicon nitride (SiC/RBSN) composite specimens wer…
Abstract The steric structures of helices and vesicles formed from bilayer membranes of ammonium amphiphiles were observed without metal coating by high-resolution scanning electron microscopy. These observations agreed with those made by transmission electron microscopy.
The ESR spectra of Cu(sal) 2 • 4H 20, Cu(sal)2(2-pycar)2 and Cu(sal)2(3-pycar)2 (sal = salicylate ion; pycar = pyridinemethanol) at 77 К were stud ied. The spin Hamiltonian parameters indicate that the unpaired electron is in the antibonding y/b]g molecular orbital. The ESR spectra of pentacoordinated Cu(II) complexe…
The crystal structure of babingtonite was determined from neutron diffraction data at 80K. The lattice constants are a=7.497(1), b=12.225(1), c=6.710(1) Å, α=86.18(1), β=93.90(1) and γ=112.27(1)° (at room temperature). The structure was refined assuming the space group symmetry of P-1. The cation distributions of Mn a…
The effect of frequency on eddy current loss was studied for nonoriented Si-Fe sheets of different grain sizes. In high-frequency regions, the eddy current loss accounts for a larger proportion of the core loss than in low-frequency regions; hence, the smaller the grain size, the smaller becomes the core loss. The edd…
This study was carried out to clarify the properties and antioxidation mechanisms of newly developed oxidation inhibitor consisting of refractory powder-SiO2-Si-SiC-synthetic mica-colloidal silica-surface active agent and caking bond. By applying this type of oxidation inhibitor to grain-oriented silicon steel, it was…
phosvitin from chicken eggs in water solution with an iron/protein molar ratio of 10/1 at pH 7.2. The main result is that the \niron atoms are bound to the protein in an octahedral environment and that the main binding sites are provided by the oxygen atoms \nof serine-bound phosphate groups at 1.93 (2) A from…
2,3-Dichloroquinoxaline when treated with the multi-sulphur dithiolate (1) gave the thione (2), which was coupled using neat triethyl phosphite to give the bisquinoxalinodithiin-fused tetrathiafulvalene, BQDT-TTF (3). Cross-coupling of thione (2) with 4,5-bis(methylthio)-1,3-dithiole-2-thione and 5,6-dihydro-1,3-dithi…
The effect of freezing treatment on the bending properties of wood was studied. The freezing was done for air-dried and water-saturated specimens, in the temperature range of -196 to -20℃. The results are summarized as follows: (1) Freezing had no influence on the modulus of elasticity and bending strength of air-drie…
As one of the difficult-to-machine materials, austempered bainitic spheroidal graphite cast iron (FCD 1000 A) have been machined so far only by grinding. In the present study, cutting of the FCD 1000 A was tried using CBN tools. Cutting performance of the tools was investigated through determining the optimum combinat…
A lead-based relaxor material for multilayer ceramic capacitors was ground by ball-milling with partially stabilized zirconia balls of 1, 3 and 15mm in diameter and the effects of ball size and particle size of powder on milling rate were studied. Particle size distribution and specific surface area of powders were ex…
Nanofibers are solid state linear nano materials characterized by high surface area to volume ratio. These materials attracted the attention of researchers due to enhanced micro and nanostructural characteristics. \nElectrospinning has been found as straight forward and viable technique to produce nanofibers. In t…
A double ion exchange method permits pillaring of the layered vanadium pentoxide xerogel with Al13 oxyhydroxide polymers and a single ion exchange permits pillaring it with Mo6 and Nb6 polynuclear cations.
α-Acetoxystyrene (ACOST) undergoes radical polymerization in contrast to α-methylstyrene. However, the polymerization is a slow equilibrium process with a ceiling temperature (Tc) of 47°C at 1mol/L. Poly(α-acetoxystyrene) (PACOST) possesses a tertiary benzylic carbon adjacent to an ester oxygen in its backbone and is…
Mechanical experiments on thin threads in discotic liquid crystal are described. Thread resonance under oscillating electric field excitation allows the measurement of the surface tension. Buckling instabilities are observed under mechanical compression and also under magnetic field. All these effects, dominated by su…
Enprofylline, a drug without adenosine antagonism and theophylline, a potent adenosine antagonist, were compared, double-blind, randomized, in acute asthma (n = 33). The drugs were given intravenously as loading over 10 min followed by maintenance infusion for 24 h. Mean final plasma levels were very high with enprofy…
Uniform oxidation is the most common type of corrosion of copper tubes in heat-exchanging refrigerating and air-conditioning units. Recently an unusual type of corrosion, “ant nest corrosion”, has been reported in such copper tubes at the final leakage test before shipment or a short time after installation. The corro…
Octaarylporphyrins were obtained in high yields by cyclization of 3, 4-darylpyrrole with formaldehyde and subsequant DDQ oxidation. The reaction intermediates identified as porphyrinogen and porphodimethene have been characterized spectroscopically.
La morphologie de particules de platine supportes sur l'alumine a t tudie avant et aprs la combustion catalytique du mthane en combinant des mesures de nanodiffraction et de microscopie lectronique par transmission. En fonction des conditions de prparation du catalyseur, la structure de l'alumine est, soit fortement d…