Materials Literature
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The structure of cytochrome b562 from Escherichia coli has been determined at 2.5 A resolution by x-ray diffraction methods. Protein phases were computed by the single isomorphous replacement method with anomalous scattering measurements from the native and uranyl acetate-substituted crystals. The electron density was…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemical behavior of tetrathiafulvalene-tetracyanoquinodimethane electrodes in aqueous mediaCalvin D. Jaeger and Allen J. BardCite this: J. Am. Chem. Soc. 1979, 101, 7, 1690–1699Publication Date (Print):March 1, 1979Publication History Published online1 May 2002Publis…
The cancer chemotherapeutic cis-dichlorodiammineplatinum (cis-DDP) was administered to 8 patients (1-hr intravenous infusion) at a dose of 70 mg/m2. Plasma and urine concentrations of platinum were determined by flameless atomic absorption spectrometry. Measured plasma platinum concentrations revealed a biphasic clear…
A review is given of the theory of scattering of conduction electrons from surface defects and its effect on electrical conductivity and high-frequency properties of the metal. We derive and investigate in detail the boundary condition for the electron distribution function, and analyze the properties of the surface s…
Abstract Extrusion shrinkage is caused by molecular relaxation of polymer after exit from the die. The rate of molecular relaxation is extremely rapid and under the present experimental conditions, 80% of limiting extrusion shrinkage, L ∞ , is reached in less than 10 sec. The dependence of extrusion shrinkage L , on t…
To obtain an understanding of pitting corrosion in geothermal brines, an evaluation was made of failures in a surface pipeline and wellhead casing exposed to hypersaline brine in the Salton Sea Geothermal Field. Uniform corrosion, pitting corrosion, and various forms of highly localized, selective attacks were observe…
Measurements are reported for the temperature dependence of the single crystal elastic constants C11 and C44 of US in its para- and ferromagnetic regions. A softening of C11 sets in from approximately 20 K above Tc to exhibit a minimum at Tc. The shear constant C44 undergoes a softening over the entire paramagnetic re…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExcited-state spectroscopy of hexacyanocobaltate(III)L. Viaene, J. D'Olieslager, A. Ceulemans, and L. G. VanquickenborneCite this: J. Am. Chem. Soc. 1979, 101, 6, 1405–1409Publication Date (Print):March 1, 1979Publication History Published online1 May 2002Published inissue 1…
An alloy containing about 2 at% Mn and 98 at% Bi should solidify at 230°C to give a eutectic consisting of about 3 vol % ferromagnetic MnBi in a matrix of diamagnetic Bi. Directional solidification of this alloy produces a structure of elongated parallel MnBi rods with diameters from 0.1 to 1.5 μm, decreasing with inc…
Abstract High-temperature X-ray diffraction analysis has revealed that Ca2Fe2O5 remains in the original brownmillerite-like form up to ca. 1100 °C, whereas Sr2Fe2O5 changes in crystal structure from brownmillerite to anion-deficient perovskite, without a change in oxygen content, above 700 °C.
Abstract 1. Conventional silica-reinforced NBR vulcanizates are characterized by stiffness at low elongation and low modulus at high elongations. These properties are associated with reticulate structure formation of silica particles, which occurs rapidly when compounds are heated to curing temperatures. 2. An NBR ter…
The anodic oxidation of nickel in solution has been studied employing potentiostatic and galvanostatic techniques. It has been found that although a large amount of charge is consumed during anodic oxidation, only about 5% of this charge is involved in film growth. The thickness of the passive film on nickel in is bet…
Approximate probabilities of electron excitation (shakeup/shakeoff) from various atomic states during nuclear $\mathrm{ns}$ electron capture have been calculated in the sudden approximation, using Hartree-Fock wave functions. Total excitation probabilities are much lower than during inner-shell ionization by photons o…
Cine films of eight species of diatoms were analysed with the aid of computers and the technique is described in detail. Programs were written for graphical presentation of the data obtained from the film to illustrate velocity and acceleration characteristics of movement. Movement is characterized by rapidly fluctuat…
The magnetocaloric effect in polycrystalline Dy was measured between 84 and 280 K in measuring fields from 1 to 7 T. These adiabatic temperature changes reflect structural changes in Dy with applied field and temperature, and include the first magnetocaloric data for a helical antiferromagnet. These measurements were…
The response of an ideally soft magnetic cylinder is calculated by approximating magnetostatic interactions while taking into account the exchange energy of curling patterns with point singularities. Detailed calculations of the magnetic surface charge distribution of paramagnetic materials are used as a guide in para…
The spin wave spectra of three Heusler alloys (X2MnZ) measured by Ishikawa et al have been analysed by means of a model containing the three magnetic interactions which we believe are present in these materials: Coulomb exchange between localized dl and itinerant di electrons, s-dl exchange, and superexchange via the…
Abstract The process of polyethylene terephthalate (PET) formation in the presence of dicarboxylic acids has been studied. Certain amounts of terephthalic acid (TPA) have two‐ to threefold accelerating efficiency in the polycondensation process. To elucidate the causes of the acceleration the main reactions leading to…
Corrosion products initially formed in a wet H2S environment with varying oxygen concentrations were consistently found to be FeS (Mackinawite). After exposure to the atmosphere, these products oxidized to FeO(OH) (Lepidocrocite) and elemental sulfur. Upon further exposure, the FeO(OH) transformed to Fe3O4 (magnetite)…
Abstract The mechanical degradation of pulp cellulose fiber was studied at ambient temperature and at 77°K. ESR findings reveal that mechanical degradation occurs via free‐radical routes. Three types of mechanoradicals contributing singlet, doublet, and triplet ESR signals are identified. The singlet signals are deriv…