Materials Literature
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A current-controlled negative resistance has been found in thin single-crystal wafers of silicon-doped yttrium-iron garnet (Si-YIG). Switching properties have been examined, and relaxation oscillations in the range 0.5–1 MHz have been established in the negative resistance region. A conductive memory state having a be…
Abstract Mit Hilfe eines quasi-adiabatisch und kontinuierlich arbeitenden Hochtemperatur-Kalori-meters wurde die spezifische Wärme von Aluminium und Wolfram sowie die Schmelzwärme von Aluminium gemessen. Eine atomistische thermodynamische Analyse ermöglicht eine Aussage über den Beitrag der anharmonischen Gitterschwin…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRaman Scattering and Polarization Measurements of Isotactic PolypropyleneP. D. Vasko and J. L. KoenigCite this: Macromolecules 1970, 3, 5, 597–601Publication Date (Print):September 1, 1970Publication History Published online1 May 2002Published inissue 1 September 1970https:/…
Abstract Studies of the growth of single ozone cracks show that a critical severity of deformation is required for growth to occur. Above this deformation the rate of single crack growth is essentially independent of strain and for a number of rubbers at normal temperatures is proportional to the ozone concentration.…
Abstract SiH 3 K, SiH 3 Rb und SiH 3 Cs haben bei Raumtemperatur Kristallstrukturen vom NaCl‐Typ (Gitterkonstanten a = 7.23, 7.52 bzw. 7.86 Å). Hieraus resultiert für das Silyl‐Anion, SiH 3 − , ein effektiver Ionenradius von 2.2 6 Å. Die gegenüber CH 3 K (NiAs‐Typ) abweichenden Kristallstrukturen werden auf die mehr k…
Abstract By the use of thermal volatilization analysis (TVA), 292°C was chosen as a suitable temperature for a preliminary experimental survey of the thermal degradation of styrene–acrylonitrile copolymers. TVA also indicated that there is no fundamental change in reaction mechanism as the acrylonitrile content of the…
The most achromatic quarterwave plates appear to be rhomb-type devices. General relations are given for calculating the phase retardation of these devices and are used to determine the variation of the phase retardation with wavelength and with acceptance angle for different rhomb designs. Length-to-aperture ratio, be…
Magnetic properties of manganese compounds with C1 b -type crystal structure are studied. CuMnSb (lattice parameter a =6.09 5 Å) is antiferromagnetic with a Néel temperature of 55°K and an asymptotic Curie temperature of -160°K. The paramagnetic Bohr magneton number per Mn is 5.4 7 . PdMnSb ( a =6.24 6 Å) is ferromagn…
It is shown by transmission electron microscopy that a rather obvious distinction exists for the interfacial free energies of high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in f.c.c. metals and alloys. The characteristics of these differences are analysed, and a balance of interfacial fre…
A model has been developed to describe the kinetics of void growth in metals during irradiation which explicitly includes the presence of both migrating interstitials and vacancies. It is clear that void growth can occur only when an excess flux of vacancies arrives at the void surface and this can be achieved by taki…
The thermal effects of different types of void volumes within a fuel pin, such as porosity, central void, and the gas gap between fuel and clad are examined. A new general relation for the dependence of thermal conductivity on the closed porosity is deduced. For given gas contents and specific ranges of pore temperatu…
Arrays of gas bubbles of uniform size are generated in a liquid and subjected to sound at a frequency of 30 kHz. In a viscous mixture of glycerine and water, sonoluminescence is produced in the absence of cavitation noise or streamer activity. Under relatively low amplitude conditions the light occurs in flashes with…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic effect of metal oxides on thermal decomposition reactions. II. Catalytic effect of metal oxides on the thermal decomposition of potassium chlorate and potassium perchlorate as detected by thermal analysis methodsWinfried K. Rudloff and Eli S. FreemanCite this: J. P…
Small- and wide-angle X-ray investigation of drawing and annealing of polypropylene quenched films in wide ranges of draw ratio (λ = 1-20) and of temperature (20°-150°C) shows the discontinuity of the elementary act of transformation in the microneck of the original lamella of the microspherulitic into the microfibril…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSilyl-proton exchange reactionsJohann F. KlebeCite this: Acc. Chem. Res. 1970, 3, 9, 299–305Publication Date (Print):September 1, 1970Publication History Published online1 May 2002Published inissue 1 September 1970https://pubs.acs.org/doi/10.1021/ar50033a003https://doi.org/1…
Electronic transitions in B i–B iv have been studied with the beam-foil technique. Over 100 spectral lines were observed between 450 and 5000 Å. Only half of the lines could be assigned to earlier known boron transitions. Classifications are given for several of the new lines. Mean lives of 33 excited levels in B i–B…
Abstract The rubber phase volume (rubber + occluded polystyrene) can be widely varied in impact polystyrene by controlling the rate of agitation during polymerization. The tensile modulus and magnitude of the rubber phase mechanical loss transitions are related to the degree of polystyrene occlusion. It is shown that…
The lattice parameter of AlAs has been very accurately measured as a function of temperature between 15° and 840°C, and the coefficient of thermal expansion has been determined. The lattice parameter at 0°C is 5.6605±0.0005 Å and the coefficient of thermal expansion is (5.20±0.05) ×10−6/°C. A comparison is made to GaA…
Resistivity and magnetoresistance data obtained from 77 to 700 °K are presented. These data suggest an interpretation based on a strongly spin-polarized conduction band. A model is developed based on this interpretation which can consistently describe the present data and previously published data.
Abstract High‐density commercial polyethylenes have been crystallized under the combined orientation and pressure effects available in the Instron capillary rheometer. The samples so formed were found to have a high degree of crystal perfection and crystal orientation in combination with the unusual property of transm…