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 fluorescence intensities and lifetimes of various no-phonon lines in ruby samples with 2.1 and 0.94% ${\mathrm{Cr}}^{3+}$ were studied from 13 to 700\ifmmode^\circ\else\textdegree\fi{}K. The temperature dependences of the intensities of numerous lines were used to determine the energy levels of two pair systems. T…
Measurements of the Jahn-Teller splittings of the $^{5}T_{2g}(^{5}D)\ensuremath{\rightarrow}^{5}E_{g}(^{5}D)$ optical transition of divalent iron in the near infrared are reported for Fe${\mathrm{F}}_{2}$, KFe${\mathrm{F}}_{3}$, KMg${\mathrm{F}}_{3}$:${\mathrm{Fe}}^{2+}$, FeSi${\mathrm{F}}_{6}$:6${\mathrm{H}}_{2}$O, F…
The optical absorption of substitutional ${\mathrm{Fe}}^{2+}$ impurities in natural single crystals of cubic ZnS has been measured in the far infrared (10 to 100 ${\mathrm{cm}}^{\ensuremath{-}1}$) at temperatures from 4 to 25\ifmmode^\circ\else\textdegree\fi{}K. Several absorption peaks are identified with electric- a…
Three-dimensional growth of large populations of cells in vitro has been observed in the interstices of a matrix consisting of collagen-coated cellu lose sponge. The growth of Walker tumor 256 in this composite matrix is com pared with that found in a matrix composed of either cellulose sponge alone or collagen sponge…
The electronic energy levels of ${\mathrm{U}}^{4+}$ in ZrSi${\mathrm{O}}_{4}$ have been obtained from the absorption spectra of oriented single crystals. This host was chosen because of the relatively high (${D}_{2d}$) symmetry of the ${\mathrm{Zr}}^{4+}$ site occupied by the ${\mathrm{U}}^{4+}$ ion. Spectra were obta…
A spin-$\frac{3}{2}$ ferromagnetic iron compound is reported. The ferromagnet is bis-($N,N$-diethyldithiocarbamato) ${\mathrm{iron}}^{\mathrm{III}}$ chloride, and has a Curie temperature of 2.5\ifmmode^\circ\else\textdegree\fi{}K. Extensive susceptibility, ESR, and M\"ossbauer data are presented which establish conclu…
The polarized emission and absorption spectra of single crystals of yttrium vanadate doped with ${\mathrm{Eu}}^{+3}$ were measured and analyzed. The spectra are consistent with the ${D}_{2d}$ site symmetry of the ${\mathrm{Eu}}^{+3}$ ion in this lattice, and no significant violation of the appropriate electric- and ma…
Abstract Es wird über die Syntheses hochmolekularer, thermoplastischer, glasklarer und vorwiegend amorpher Copolyharnstoffe mit periodisch wiederkehrender Harnstoffbindung in der Hauptvalenzkette berichtet. Unverzweigte aliphatische Diamine wurden mit steigenden Mengen von Diaminen cokondensiert, die Ätherbrücken oder…
Abstract Durch Reaktivierung der kurzlebigen Vanadiumkontakte mit Hexachlorcyclopentadien wird eine bessere Katalysatornutzung und damit eine größere Wirtschaftlichkeit bei der Herstellung von Äthylen/Propylen‐Copolymerisaten erzielt. Hexachlorcyclopentadien wirkt dadurch reaktivierend, daß es das bei der Umsetzung vo…
"Plastics as Corrosion-Resitant Materials." British Corrosion Journal, 2(2), p. 78
Sintered UO2 pellets irradiated at high temperature to a burnup of 2,700 MWD/T-UO2 were studied by replica electron microscopy. The as-irradiated pellet surfaces were covered by a thin layer easily soluble in dilute acid. This layer apparently was deposited as a sublimate during irradiation. The etched surfaces of the…
Technical Briefs A Lower Bound on Displacement Rates in Steady Creep A. C. Palmer A. C. Palmer Department of Mechanical Engineering, University of Liverpool, Liverpool, England Search for other works by this author on: This Site PubMed Google Scholar Author and Article Information A. C. Palmer Department of Mechanical…
A phenomenologic al constitutive equation has been developed to describe conventional stress-strain behaviors for several metallic and nonmetallic materials for strain rates up to 103 sec1. Ambient temperature behavior has been empirically related to strain rate in a com- mon manner for all materials investigated. The…
A simple and easy method for measuring the twist density in the yarn between the roller-nip and thread-guide of a ring spinning frame has been compared with the high speed photography technique and has been shown to be reliable. Measurements using the method have brought out the influence of such factors as doff-stage…
The modifications necessary to convert electron microscope specimen holders for use with field-ion microscope specimen tips are described. Microscopes having an immersion objective lens are most suitable, and a modified specimen holder constructed for one of these (Philips EM 200) was found to be particularly reliable…
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
The creep ductilities of irradiated Hastelloy N at 650°C have been determined at several neutron exposures. Elevated-temperature irradiation embrittlement greatly reduces the stress-rupture strength as measured in postirradiation uniaxial stress tests. The reduction in ductility to values as low as 0.4% is due to an i…
A liquid-helium object stage for the electron microscope has been used to observe directly magnetic domains in CrBr3, an ionic ferromagnet with a Curie point of 36°K. Some of the contrast effects observed are typical of the magnetic-domain wall observations made by Lorentz microscopy on materials such as Co which are…
A method is suggested to detect directly the deionization margin angle and to prevent the commutation failure of an inverter. The deionization margin angle is detected by anode- cathode voltage of a valve and ac phase voltage. The method to prevent the commutation failure, namely the one to hold the critical deionizat…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConductances of some uni-univalent electrolytes in adiponitrile at 25.degree.Paul G. Sears, Joseph A. Caruso, and Alexander I. PopovCite this: J. Phys. Chem. 1967, 71, 4, 905–909Publication Date (Print):March 1, 1967Publication History Published online1 May 2002Published ini…