Materials Literature
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I t is flOW /)o ssible to unify th e descnj)tion of the J)lastic flow that occurs ill various circumstances; rangillg )i"om creep, through ordinaty tensile tests, to high-speed impact.T his is dOlle by using a sim/)le d)mamic statistical theOlY ill which the al'erage behavior of a large collection of dislocations is c…
Les relations théoriques établies dans la précédente publication sont comparées à diverses données expérimentales sur la loi de décroissance et sur l'intensité intégrée pour des monocristaux et des solutions aromatiques renfermant ou non de l'oxygène dissous. Dans tous les cas examinés, l'accord trouvé est excellent.…
Abstract Ferrous iron in the layers increased 2‐fold or more on deferration of coarser fractions of micaceous vermiculite naturally weathered from biotite (Colorado and Transvaal sources). The ferric iron content of the layers was decreased by the deferration treatment but the original content was restored by subseque…
Principles involved in analyzing a corrosion situation according to electrochemical methods are described. The basic formulas of reactions are given, together with an explanation of their implications and use. The commonly accepted theories of inhibition and passivation are discussed in electrochemical terms.
We studied the glass-formation range of tellurite systems containing TeO2. The experiments were made in the same way as in previous reports on the borate, silicate and germanate systems. The crucibles employed were made of Au-alloy containing 15% Pd. Except for TeO2, the Oxides used were of 16 kinds of a-group element…
Abstract Several series of ABA‐type “tapered” block polymers of styrene (monomer A) with isoprene or butadiene were prepared with the use of n ‐butyllithium or sec ‐butyllithium as initiators in benzene solution. The stress‐strain curves of the raw polymers are reported, showing that many of them behave at ambient tem…
Abstract The reflectivity of CdO has been measured up to 13 eV on single crystals and polycrystalline material. Moreover the absorption of thin films was studied. The frequency dependence of the optical constants evaluated by Kramers‐Kronig analysis is discussed with regard to the band structure calculated by Maschke…
Measurements of the e.s.r. and optical spectra of the potassium and sodium molybdenum bronzes have been made. It is concluded that the observed e.s.r. signals arise from Mo5+ donor levels situated < 1 eV below the conduction band of the host MoO3 matrix. A model for the electronic structures of these compounds is prop…
Abstract The decay kinetics of sinusoidal surface profiles on copper annealed in a hydrogen atmosphere were investigated in the temperature range 600 to 1030 °C in order to determine the temperature dependence of the surface self‐diffusion coefficient, D s . Below 910 °C the surface profiles were found to be faceted r…
The syntheses and chemical properties of several new trisdicyano-1,2-dithiolene complexes of transition metals are described. These complexes have anions of the type [MS6C6(CN)6]z where M = Mn, Fe, Mo, and W and z=–2 and M = Fe and Co where z=–3. An improved synthesis of the known [CrS6C6(CN)6]2– is reported. The beha…
La structure magnétique de la variété rhomboédrique de Cr2S 3 (a = 5,94 Å ; c = 16,7 Å ; groupe R3) comprend trois sous-réseaux magnétiques : 3a et 3b parallèles et 6c anti-parallèle. La variation thermique légèrement différente de l'aimantation des sous-réseaux donne lieu à un faible ferrimagnétisme croissant de zéro…
Simplification of Ramsey's equation applied to the 195Pt chemical shift in square-planar platinum(II) complexes leads to an equation in which the paramagnetic shift is proportional to a linear combination of the wavelengths of two transitions in the absorption spectra of the complexes. The factor of proportionality de…
, containing small quantities of dissolved iron, is the only oxide formed in the oxidation of iron‐chromium alloys in the range 22–68% Cr in oxygen at 800°–1200°C; it is also formed, at least initially, on alloys containing 14 and 18% Cr. The oxide growth is diffusion‐controlled, with an apparent activation energy of…
Abstract The theory of transfer of electronic excitation energy between impurity molecules is developed without employing perturbation theory. The role of the lattice vibrations in the transfer process of the electronic excitation energy is taken into account. It is shown that the transfer time of electronic dipole ex…
SummaryThe behaviour has been examined of second-phase constituents in super-purity aluminium during etching in caustic soda, chemical brightening and anodizing in oxalic acid. Specimens containing large second- phase constituents were prepared using a carefully selected casting technique. Surfaces of specimens were m…
Adsorbed hydrogen on platinum-silica gives infra-red bands at 2040 and 2120 cm–1, and on platinum alumina at 2040 and 2110 cm–1. The 2110–2120 band is much enhanced by treatment by oxygen, and adsorption-desorption behaviour together with deuterium shift establish the band as due to weakly adsorbed hydrogen. It is pro…
The mode of action of ATP citrate lyase [EC 4.1.3.8] was investigated using a single homogeneous preparation from rat liver. First, the enzyme was incubated with labelled citrate and after incubation the protein portion was isolated through a column of Sephadex G-50. It was found that an enzyme-citrate complex is form…
By obtaining a clearer understanding of the mechanism of damping operating in manganese-copper alloys it may be possible either to improve damping properties at elevated temperatures or to select alternative systems with better ancillary properties. Electron-microscope, X-ray, and neutron-diffraction techniques have b…
Abstract Some series of solid solutions with perovskite‐type structure are synthesized and investigated, viz. the binary systems Nd 1− x , Me x MnO 3 where MeCa 2+ , Sr 2+ , Ba 2+ , and the ternary systems (Bi 1− x La x ) 0.5 Ca 0.5 MnO 3 and Bi 0.5 (Ca 1− x Me x ) 0.5 MnO 3 where MeSr 2+ , Pb 2+ , Ba 2+ . Distortio…
Blue oxophlorins are relatively strong bases and accept one proton (on nitrogen) to form green monocations; addition of a second proton (to the oxo-group) occurs in strongly acidic media to afford the dications derived from the tautomeric hydroxyporphyrins. Oxophlorins also form metal complexes derived from the hydrox…