Materials Literature
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Alkyl half-esters of oxalic acid photolysed with mercury(II) oxide–iodine reagent gave mainly dialkyl oxalates. 1-Apocamphyl hydrogen oxalate gave, in addition to the diester, 1-apocamphyl iodide. 9-Triptycyl hydrogen oxalate gave 9-triptycyl iodoformate, which was thermally decomposed to 9-iodotriptycene and with sil…
The theory of ring current transients at a ring-disc electrode has been tested for Fe(CN)4–6/Fe(CN)3–6 and Br2/Br– systems at three different rotation speeds. Good agreement between theory and experiment has been found.
Fischesserite, Ag₃AuSe₂ was found in carbonate veins at Predborice, Bohemia, Czechoslovakia, associated with naumannite, clausthalite, berzelianite, gold and other selenides. Isometric, isostructural with petzite ; space group O⁸-I4₁3₂ ; a₀ = 9.967 ± 0.003 Å ; Z = 8 ; dₓ = 9.05. The strongest X-ray lines are : 2.662 (…
Synopsis--The presetace of GAS BUBBLES iu cosmetic and pharmaceutical preparations is generally undesirable not only from the appearance vicwpoint, but also from physical, chem-ical, and biological stability considerations. The air bubbles in a product can affect emul-sion stability, promote oxidation, and, in some in…
The total vapor pressure, , over has been determined between 980° and 1169°K by using a sum manometric technique. The lower end of an evacuated, inverted, fused silica U‐tube was immersed in a large reservoir of melt inside a transparent furnace. The value of and the density of were obtained at each temperature by vis…
Collin Gaston, Laruelle Pierre. Structure de La6Cu2Si2S14. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 94, 2, 1971. pp. 175-176.
Using an iterative technique to obtain the exact solutions of the cubic Christoffel equation, the 21 elastic constants of copper sulphate pentahydrate have been determined at 25°C by the ultrasonic pulse echo method. The elastic constants, referred to the IRE recommended system of axes, are c 11 =5·65, c 12 =2·65, c 1…
The grain size dependence of yield stress and flow stress in the quenched and aged magnesium-3 wt% zinc alloy was studied by the tensile test and the electron and optical microscopic observations in the temperature range from room temperature to −195°C. The main results obtained are as follows:(1) This alloy does not…
<abstract language="eng">For the first time the Diatom flora of Bromeliaceae was investigated in the States of Rio de Janeiro and Guanabara. A total of 35 species was determined from 32 samples collected in Bromeliaceae of the genus Conistrum, Vriesia and Billbergia. Some ecological factors are also here considered.
Previous investigations have shown that matallic derivatives of bridgehead substituted adamantane compounds do not possess enough stability to be synthetically useful. Intial attempts to prepare such derivatives from 2-bromoadamantane at elevated tamperatures also failed, where-as treatment of this compund with methyl…
Under the axial tensile force in the fiber direction the distribution of crystal lattice strain in the b-axis direction of the cellulose (I) in the cell wall of tracheids were measured by the X-ray diffraction technique using (040) reflection of cellulose micelles.In this study the transit X-ray method was used and th…
The synthesis and characterisation of anhydro-2-arylamino-1,3,4-oxadiazolium hydroxides (II), a new class of meso-ionic compounds, is described.
Abstract The experimental study at 25°C of the system KClRbClCsClH 2 O has shown the existence of a new type of quaternary system with formation of mixed crystals. — The solubility diagram is characterized by the presence of one univariant line and one binary miscibility gap. Two types of solid solutions are presen…
Cubique, isotype de la tétraédrite, a = 10,88 ± 0,01 Å ; Z = 8, dx = 6,3. Les raies les plus intenses du diagramme de poudre sont : 3,140(10) ; 2,910 (7) ; 1,985 (7) ; 1,925 (9) ; 1,639 (8) Å. Les analyses chimiques (microsonde électronique) donnent : Cu 26,6 (26,6) ; Hg 15,3 (14,3) ; Sb 15,5 (19,1) ; As 3,2 (0,7) ; S…
A phase diagram of Al-Si system in the hypoeutectic region at 28kb has been composed. A girdle-type high pressure device was used to press and heat the specimens, and an electric resistance method to detect the phase transitions. The characteristic figures obtained are as follows;(1) The melting point of pure Al has b…
The ternary subsolidus phase equilibria has been determined for that portion of the system containing less than 50 m/o (mole per cent) . Limits of solid solution along the orthophosphate join were determined for , , and . The 3:3:2 compound had a rapid, reversible inversion at 1104°C and melted incongruently at . melt…
Summary. To study the site and mechanism of its ovulation-inhibiting effect, clomiphene citrate was implanted bilaterally into the hypothalamus and hypophysis of adult di-oestrous rats and of prepuberal females which were also treated with oestradiol benzoate. The results suggest that this effect is primarily due to t…
Unit-cell parameters have been measured for some alkali-metal hexanitrolanthanates. The electronic spectra of these complexes closely resemble that of NaNO2, as expected for very weak lanthanide–nitrite bonding, although the lowest triplet absorption is much more intense than in NaNO2. Ce(NO2)63– shows metal–ligand el…
The latest techniques in scanning electron microscopy have been applied to this study. In cholesterol gallstones, the fracture surface generally shows a crystalline plane radiating pattern, often showing dendritic growth, around the nucleus. On the surface or fracture plane of a cholesterol stone, parallelogram crysta…
The scattering of thermal energy atomic and molecular beams from macroscopically rough surfaces has been found to display scattered flux distributions that are typically skewed towards the incoming, beam i.e., backscattered. Such an observation is consistent with the results reported in the literature describing flow-…