Previously published results of a study of electron bombardment conductivity in diamond have been revised by the use of an improved alternating field method of internal space-charge neutralization. In addition lower limits are set for the mobilities of electrons and positive holes at room temperature. Measurements hav…

Electronic and Structural Properties of OxidesHigh-pressure geophysics and materialsDiamond and Carbon-based Materials Research

Element 97

S.G. Thompson、A. Ghiorso、G.T. Seaborg1950-03-15Physical Review

NGLE graphite crystals are known to be good conductors along the graphite planes and very poor ones across (ratio of resistivities 104 or higher. '} Coulson' and Wallace' have shown that a graphite crystal along the planes is a semiconductor with zero activation energy, the only difference with a metal consisting in a…

Graphite, nuclear technology, radiation studiesOccupational and environmental lung diseasesNuclear and radioactivity studies

The Effect of Electronic Paramagnetism on Nuclear Magnetic Resonance Frequencies in Metals

C. H. Townes、Conyers Herring、W. D. Knight1950-03-15Physical Review

Observations on the shifts of nuclear resonances in metals (Id {sup 7}, Na {sup 23}, Ou {sup 63}, Be {sup 9}, Fe {sup 207}, A1 {sup 27} and Oa {sup 69}) due to free electron paramagnetism; comparison with theoretical values.

Crystallography and Radiation PhenomenaElectromagnetic Effects on MaterialsSolid-state spectroscopy and crystallography

The crystal structure of hollandite, the related manganese oxide minerals, and α-MnO2

Ann Marie Byström、Ann Marie Byström1950-03-02Acta Crystallographica

Hollandite cryptomelane, coronadite and alpha-MnO 2 form an isostructural series of the general formula A 2-y B 8-z X 16 , A being large ions such as Ba 2+ , Pb 2+ , and K + , B small and medium-sized ions such as Mn 4+ , Fe 3+ , Mn 2+ , and X in the cases investigated O 2- and OH - ions. The unit cell, which contains…

Nuclear materials and radiation effectsRadioactive element chemistry and processingChemical Synthesis and Characterization

Dependence of Elastic Properties of Vulcanized Rubber on the Degree of Cross-Linking

Paul J. Flory、Norman Rabjohn、Marcia C. Shaffer1950-03-01Rubber Chemistry and Technology

Abstract The results reported above demonstrate a progressive increase in the force of retraction τ at fixed elongation with increase in the fraction p of the structural units which are cross-linked from ρ=0.10×10 −2 to 3.0×10 −2 . Over this range, τ at 100 per cent elongation increases about thirteenfold. Swelling me…

Polymer Nanocomposites and PropertiesForce Microscopy Techniques and Applications

A Microcalorimeter Suitable for Study of Easily Absorbed Nuclear Radiations

C.V. Cannon、G.H. Jenks1950-03-01Review of Scientific Instruments

A microcalorimeter suitable for measuring the energy of easily absorbed nuclear radiations is described. The calorimeter is an isothermal type operating at the temperature of liquid nitrogen and using the rate of vaporization of nitrogen under constant pressure as a measure of the heat input. The calorimeter is fairly…

Graphite, nuclear technology, radiation studiesthermodynamics and calorimetric analyses