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 odd thermal conductivity behavior of transition metal carbides– K increasing with increasing T –has been interpreted as resulting from the strong scattering of electrons by carbon vacancies and polar optical phonons and from the strong scattering of phonons by vacancies and conduction electrons. These scattering p…
The release of the rare fission gases, krypton and xenon, from a high-temperature reactor pebble-bed core is predominantly determined by the heavy-metal contamination of the matrix material during manufacture. In the case of the Thorium High-Temperature Reactor prototype fuel, particles with failed coatings contribute…
The magnetization and susceptibility of flux-grown Fe${\mathrm{Nb}}_{2}$${\mathrm{O}}_{6}$ single crystals have been measured from 80 K down to 1.4 K. An antiferromagnetic ordering was observed at ${T}_{N}=5.5\ifmmode\pm\else\textpm\fi{}0.5$ K. The antiferromagnetic-paramagnetic phase transition induced by an external…
Electron paramagnetic resonance (EPR) in single crystals of gadolinium metal has been studied near its Curie temperature ${T}_{C} (\ensuremath{\simeq}293 \mathrm{K})$. The EPR linewidth $\ensuremath{\Delta}H$ and the resonance field ${H}_{r}$ are measured as a function of temperature between 280 and 330 K, for $\stack…
Abstract Titanium films, freshly evaporated and exposed to varying amounts of oxygen, are studied by ultraviolet and X‐ray photoelectron spectroscopy (UPS and ESCA), using HeI, HeII and AlKα1,2 radiation. The valence band results are compared with previous experimental results and with reported densities of states. Co…
Summary The crystal structure of killalaite has been approximately determined, using a crystal from the original locality. The ionic constitution is Ca 3+ x (H 1–2 x Si 2 O 7 ) (OH), with x ≈ 0·2 for the crystal studied. Crystal data are: monoclinic pseudo cell with a 6·807, b 15·459, c 6·811 Å, β 97·76°, space group…
Thermal annealing characteristics of the glow peaks from 200 to 650 degrees c in Al2O3 thermoluminescent (TL) phosphor have been studied. All the glow peaks show exponential decay and follow first-order kinetics. The trap depths and frequency factors for the glow peaks have been determined from their isothermal decay…
A new and improved gas distributor was developed for use in coating fuel particles for the high-temperature gas-cooled reactor. The coating gas enters the coating furnace through multiple thin regions of a porous plate. This more uniformly disperses the gas and leads to improved coating properties. High-quality carbon…
The silicon carbide (SiC) layer in Triso-coated high-temperature reactor fuel particles is occasionally attacked during irradiation by fission products generated within the kernel material. Investigations to define the cause of the SiC corrosion included ceramographic, microradiographic, and microanalytical studies on…
This paper describes the factors influencing the voltage or electric stress-failure time relation of cast and molded resins. It also discusses the reasons for similar failure times at equal stresses with surface and internal discharges, when the discharges are continuous, and presents data supporting those reasons. Th…
An investigation was made to examine the influence of Mn and S levels up to 0.65 and 0.02 wt%, respectively, on the magnetic properties and texture of non-oriented low carbon steels. The results indicate that at a particular sulfur level, the 15 kG core loss decreases linearly with Mn concentration at an estimated rat…
The chemical and thermal-mechanical stability of sputtered aluminum oxide films are examined. Sputtered alumina is quite soluble in bases and phosphate-containing solutions. Carbon dioxide was detected in the films by infrared spectroscopy and by mass spectroscopy during thermal gravimetric analysis; the presence of C…
This paper describes a study of the absorptance of thin films with the aim of elucidating the region of validity for a direct relationship between the absorptance and the absorption coefficient. The calculations are performed for an unsupported film, a film on a transparent or metallic substrate, and for the absorptan…
SUMMARYThe phragmosporous genera Magnaporthe and Telimenella are placed in the Physosporellaceae. Ceratosphaeria grisea is transferred to Magnaporthe and Telimenella phacidioidea is newly described. The differences between Hyponectria and Physalospora, both amerosporous genera of the family, are clarified. The species…
A Fresnel zone plate of variable size can be formed as a moiré pattern between a suitable pair of identical grids. The focusing power may be varied over a considerable range by relative translation of the grids if their line sbapejs are determined by a combination of cubic and linear functions. Elliptical and hyperbol…
The simulation of section topographs of distorted crystals may be performed with good accuracy; it is now possible to use it as a tool to determine the quantitative parameters of various defects. The simulation of traverse topographs is a more complicated problem: it needs a tremendous amount of computation time, but…
Abstract Primary textural features in dolostones and recrystallized limestones are difficult to see under the petrographic microscope. A simple light diffuser, placed directly under the petrographic thin section, helps delineate primary features in cases where textural "ghosts" occur as insoluble residues. Best result…
The coating of nuclear fuel particles with pyrolytic carbon derived from a hydrocarbon gas is a complex process, and, until recently, although adequate behavior in service has been demonstrated, the methods used to obtain a particular product have been largely empirical. A concerted effort was made to close the loop:…
Thalassiosira fluviatilis Hustedt and T. pseudonana Hasle et Heimdal have been found to be widespread in both large and small rivers, while a third taxon, apparently new, has been recorded several times. The appearance of the frustules by light and electron microscopy is commented upon and illustrated, and some of the…
Abstract Electron microscope image analysis of carbon blacks in specific rubber compounds has greatly expanded the range of useful applications for studies of this type. This dispersed carbon-gel procedure has improved the sampling and test precision at operating speeds that are now reasonably comparable to the simple…