Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The thermal resistivity $w$ contributed to Ge at low temperatures by electrically active impurities has been investigated by measurements on a series of single crystals ($n$-type) between 1.3 and 150\ifmmode^\circ\else\textdegree\fi{}K. By comparing compensated [(Sb+Ga)-doped] with noncompensated (Sb- or As-doped) sam…
The lattice thermal conductivity for monatomic crystals is discussed for high temperatures, above and around the Debye temperature. While this problem cannot be treated in a suitable way by conventional methods for calculating transport coefficients, it represents an excellent example of the use of correlation-functio…
The exponential absorption edge of GaAs may be interpreted as reflecting the presence of tails of states extending both intrinsic bands into the energy gap. The distribution of these tail states seems exponential, varying with energy as $\mathrm{exp}(\frac{E}{{E}_{0}})$ where ${E}_{0}$ increases with doping. ${E}_{0}$…
Abstract Nachdem es feststand, daß es drei Typen kondensierter anorganischer Phosphate — Metaphosphate, Polyphosphate und vernetzte Phosphate — gibt, wurde versucht, ihre Bildungswege und gegenseitigen Beziehungen aufzuklären und ihre bemerkenswerten Eigenschaften verständlich zu machen. — Meta‐ und Polyphosphate mit…
Molecular fragmentation of organic liquids was produced by cavitation due to ultrasound waves, even in the absence of water. The sonolysis of acetonitrile under argon yielded N(2), CH(4), and H(2); but under oxygen the products were N(2), CO, CO(2), and H(2)O. Pure nonaqueous carbon tetrachloride also underwent sonoly…
The distribution of fission fragments recoiled from a thick layer of uranium oxide into aluminum was measured with the application of an anodizing technique to strip layers from aluminum. Details of the procedure are described. The distribution thus determined gave the recoil ranges of the fission fragments: They were…
The coefticient K (Huberty) has been introduced to obtain a characterization of the irregularity of yarns, which depends only on the structure of the distribution of the fiber endpoints along the axis of the yarn and not on the length L and cross section Q of the fibers, and also not on the expected number of fiher en…
Some ferroelectric materials exhibit a transition from stable to unstable partial switching at a critical pulsewidth t*. Schemes are proposed for utilizing this t* effect for coincident and successive addressing of a matrix memory, for a nondestructive readout from a matrix and for the simplification of a ferroelectri…
Thick target x-ray photoelectric yield formulas are derived assuming a simple range for photoelectrons in the target. The predictions are compared with available experimental results for Cu Kα x rays impinging on Al, Cr, and Sn targets at an angle of 70°. Agreement is within a factor of 2 for Al and within 10% for Cr…
The dissolution kinetics of iron filamentary single crystals in dilute acidic environments were shown to obey the topographical theorems proposed by Frank to describe etch-rate anisotropy. Successive dissolution profiles of iron whiskers were observed in situ. by using time-lapse motion picture photomicroscopy. Reluct…
This paper gives an analytical investigation of the hydromagnetic theory for squeeze films between two conducting surfaces. It is shown that increase in load capacity, pressure, and time of approach are possible by increasing either the strength of the magnetic field, or conductivities of the surfaces, or both.
Methyl 6-deoxy-6-nitro-D-glucopyranoside and methyl 6-deoxy-6-nitro-L-idopyranoside under mild alkaline conditions undergo fission of the pyranoside ring followed by loss of the aglycon and cyclization of the resulting nitro sugars to a mixture of scyllo and myo-1 deoxynitroinositols. A mechanism for the alkaline glyc…
The energy required to form one hole-electron pair in gallium phosphide has been measured to be 7.8±0.8 eV/pair. The experimental method consisted of determining the charge produced and collected when α particles of known energy bombarded a surface barrier which had been formed by evaporating a thin layer of gold onto…
The electrical conductivity of both single‐crystal and sintered near‐stoichiometric rutile was investigated over the range 600° to 1400°C and the oxygen pressure range 0.005 to 1.0 atm. Above 1200°C, the conductivity of single‐crystal and sintered rutile obeys the relation σ∼ P o 2 −1/4 . This can be explained on the…
Abstract Basal spacing data for neutral amine complexes with montmorillonite and vermiculite are explained on the basis of two layers of fully extended amine molecules inclined at about 65° to (001) with the NH 2 groups closely associated with pairs of silicate oxygen atoms. The molecular orientation is shown to be fa…
A unified treatment of phonon bottleneck theory is given, using a thermodynamic method which includes both the direct and Orbach processes. The key parameter is the phonon relaxation time, which is calculated in a variety of cases, including several in which it is determined by magnetic impurities. The theory is exten…
Measurements have been made of the heat-transfer rate to the stagnation point of catalytic spheres and cylinders placed in the slow flow of dissociated oxygen produced in a glow-discharge tube. The use of a rapid-response thin-film heat-transfer gauge permitted operation in a transient mode; that is, a step function o…
Collapse of a spherical bubble in a compressible liquid, including the effects of surface tension, viscosity, and an adiabatic compression of gas within the bubble is investigated by numerical solutions of the hydrodynamic equations. A limiting value of shear viscosity causes the bubble collapse to slow down markedly,…
Stress‐strain curves for five types of polycrystalline MgO are presented as a function of temperature. All types were nominally dense and pure but differed in grain size, composition, and porosity. Above 1200°C deformation occurred by grain boundary shearing accompanied in some cases by slip; below 800°C, specimens fr…
A freshwater diatom flora has been shown to exist on sand grains. The species have been determined from samples of four bodies of water. This epipsammic flora is composed of minute diatoms, many of which require electron microscope study before their identification can be made certain. The chemistry of the water undou…