Terpenoids. Part XXVIII. Total synthesis of enmein
The total synthesis of enmein (1) is reported. The diol acetal, ent-3β,20-epoxy-3-methoxy-17-norkaurane-6α,16α-diol (3) was used as the important relay compound.
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Mise en Évidence D'Un Composé BiBo3 et de Son Polymorphisme par Spectroscopie Vibrationnelle
Abstract Bismuth orthoborate BiBO 3 , a non‐existent compound after the Bi 2 O‐B 2 O 3 phase diagram, has been obtained by melting a mixture of H 3 BO 3 and Bi 2 O 3 corresponding to the BiBO 3 composition and subsequent cooling. Two different phases are obtained, depending on the cooling conditions. Infrared and Rama…
Electroinitiated Polymerization of Tetrahydrofuran
Electroinitiated polymerization of tetrahydrofuran (THF) was accomplished in 1 M LiClO 4 ‐ THF organic electrolyte solutions by anodic electrolysis on platinum electrodes in a three‐compartment cell. THF was found to polymerize to form a viscose gel at 25°C. The rate of polymerization was followed by measuring the ele…
Coupling strength in the theory of radiationless transitions: f → f and d → f relaxation of rare-earth ions in YAIO3 and Y3AI5O12
The dependences of the radiationless relaxation rate constant on the effective mediating phonon energy, the equilibrium displacement of the adiabatic surfaces, the energy gap, and the temperature are numerically examined in terms of a generalized theoretical rate expression derived from quantum statistical theory. Spe…
Thermophysical Properties of Matter-The TPRC Data Series. Volume 10. Thermal Diffusivity
Abstract : The TPRC Data Series published in 13 volumes plus a Master Index volume constitutes a permanent and valuable contribution to science and technology. This 17,000 page Data Series should form a necessary acquisition to all scientific and technological libraries and laboratories. These volumes contain an enorm…
Corrosion of Pure and Amalgamated Zinc in Concentrated Alkali Hydroxide Solutions
Corrosion of pure and amalgamated zinc in pure concentrated solutions was investigated using two methods: ( a ) galvanostatic measurements of the kinetics of hydrogen evolution with electrodic assessment of corrosion properties of the system, and ( b ) volumetric measurement of the hydrogen evolution reflecting direct…
Analysis of the Grain Size Dependence of the Yield Stress in Copper-Aluminum and Copper-Nickel Alloys
Grain size dependence of the yield stress in polycrystalline copper-aluminum and copper-nickel alloys is measured at 77, 194 and 293°K. It is found that the Hall-Petch relation is valid for these materials. The Petch slope ky is nearly independent of the temperature, but increases with increasing solute concentration.…
Magnetic and Magnetoelastic Properties of Highly Magnetostrictive Rare Earth-Iron Laves Phase Compounds
The rare earth‐Fe2 (RFe2) compounds possess huge magnetic anisotropies and magnetostrictions at room temperature. This, coupled with a relatively high Curie temperature and magnetic saturation, makes these alloys attractive for various applications, including magnetostrictive transducers and permanent magnets. A varie…
Spinodal Decomposition in Alnico 8 Magnet Alloy
An electron microscope study is made on isothermal decomposition in Alnico 8 alloy as annealed around 800°C for 10–90 min in a magnetic field. The results obtained are found to agree well in many essential aspects with Cahn’s theoretical predictions on spinodal decomposition in a ferromagnetic cubic alloy. In the case…
Preparation and Properties of Boron Arsenide Films
Boron arsenide films have been deposited on the basal plane of hexagonal silicon carbide and {111} oriented sodium fluoride and silicon substrates at 800°–850°C by the thermal decomposition of a diborane‐arsine mixture in a hydrogen atmosphere. Adherent films were deposited on silicon carbide substrates and were ident…
Testing to Determine the Effect of High-Pressure Hydrogen Environments on the Mechanical Properties of Metals
Equipment and procedures used in performing tension, fracture mechanics, fatigue, and creep tests on metal specimens in high-pressure hydrogen are described. Important test parameters, in particular, hydrogen purity and methods of achieving high purity are considered. The interpretation and use of data obtained from t…
Stereochemistry of low-spin cobalt porphyrins. IV. Molecular stereochemistry of (1-methylimidazole)-.alpha.,.beta.,.gamma.,.delta.-tetraphenylporphinatocobalt(II)
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereochemistry of low-spin cobalt porphyrins. IV. Molecular stereochemistry of (1-methylimidazole)-.alpha.,.beta.,.gamma.,.delta.-tetraphenylporphinatocobalt(II)W. Robert ScheidtCite this: J. Am. Chem. Soc. 1974, 96, 1, 90–94Publication Date (Print):January 1, 1974Publicati…
Metallurgy of boron-treated low-alloy steels
A review has been prepared of the metallurgical factors affecting the hardenability and mechanical properties of boron-treated low-alloy steels. Detailed experimental work has been carried out to clarify the following controversial aspects of these steels: (a) occurrence of boron in steels; (b) influence of boron cont…
Synthesis and Properties of ZnGeN[sub 2]
Abstract not Available.
THE EFFECT OF SURFACE CONDITIONS ON BOILING CHARACTERISTICS
Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Thesis. 1972. Ph.D.
Biochemical and Morphological Studies on Collagens of Horny Sponges. Ircinia Filaments Compared to Spongines
Three kinds of fibers with a widely different morphology were isolated from several species of horny sponges: (a) intercellular collagen fibrils (spongin A of Gross3); (b) spongin fibers (spongin B3); and (c) a distinct filament present only in Ircinia. In the last two fibers elementary fibrils can be distinguished un…
Desorption of soil phosphate by anion‐exchange resin
Kinetics of phosphate desorption from twenty soils by anion‐exchange resin were not satisfactorily explained by either film diffusion (or ion exchange mechanism) mechanism or particle diffusion mechanism. Eut the phosphate desorption process was adequately explained by a two‐constant rate equation. The two constants,…
Macronet isoporous gels through crosslinking of dissolved polystyrene
Abstract Macronet isoporous polystyrene gels, obtained by cross‐linking of linear polystyrene in solution with p ‐xylylenedichloride or 4, 4′‐bis‐chloromethylbiphenyl, differ from conventional styrene‐divinylbenzene (DVB) copolymers by high solvent‐uptake capacity, high inner surface area, and the ability to increase…
X-Ray investigations of the crystal structure and phase transitions of YMnO3
Lattice constants and atomic parameters of YMnO3 were investigated from room temperature up to 1010°C. Lattice constant c decreases slowly with temperature, contrary to earlier publication. With rising temperature small changes of the crystal structure were observed. The paraelectric phase is probably disordered and t…
X-ray photoelectron spectroscopic study of the reaction of evaporated metal films with chlorine gas
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTX-ray photoelectron spectroscopic study of the reaction of evaporated metal films with chlorine gasKosaku Kishi and Shigero IkedaCite this: J. Phys. Chem. 1974, 78, 2, 107–112Publication Date (Print):January 1, 1974Publication History Published online1 May 2002Published inis…