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。
Mineralogical properties of tobelite, a new ammonium-dominant dioctahedral mica, found in the Ohgidani pottery stone deposit at Tobe, Ehime Prefecture, Japan, are described.This mineral, accompanied by quartz, occurs as a hydrothermal alteration product of a biotite andesite dyke. Wet chemical analysis gives a structu…
The phase transitions in {N(CH 3 ) 4 } 2 XBr 4 (X: Zn, Co, Cu) were stuided by dielectric measurements. A phase transition which accompanied with a break on the dielectric constant vs temperature curve was found at 13.5°C and 13.8°C for {N(CH 3 ) 4 } 2 ZnBr 4 and {N(CH 3 ) 4 } 2 CoBr 4 , respectively. In {N(CH 3 ) 4 }…
Nous présentons une nouvelle et remarquable séquence mésomorphe dans un produit pur : le 4-nitrobenzoyloxybenzoate de 4-nonyloxyphényle à la pression atmosphérique : K(SC2)S ?SA1NreSAd reNreSAd NI. Cette séquence comporte deux phases nématiques rentrantes (phénomène jamais observé à ce jour) et une phase smectique SAd…
Decomposition of the Martensite in Two-Phase Titanium Alloys.- The Investigation of the Titanium Structure after Shock Wave Loading.- Embrittlement and Spontaneous Cracking of a Hardened (?+?) Titanium Alloy during Aging.- Transformation in Unstable Beta-Titanium Alloys.- Internal Friction Studies in Stable and Metast…
Electrical conductivity of α quartz is ionic, the current being carried by alkali ions (M+) moving in channels parallel to the c axis. A study was made of conductivity σ of one natural and three synthetic crystals in order to better understand these ionic defects. ac measurements were made over a wide range of frequen…
The diffusion of rod-like molecules is studied in the case of high density. It is argued that when one goes to densities higher than those permitting rotational freedom for the rods, the diffusion of one rod will depend critically upon the cooperation of the others. A calculation of this effect using mean-field theory…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsotactic polymerization of .alpha.-olefins: stereoregulation for different reactive chain endsA. Zambelli, M. C. Sacchi, P. Locatelli, and G. ZannoniCite this: Macromolecules 1982, 15, 1, 211–212Publication Date (Print):January 1, 1982Publication History Published online1 M…
Trente échantillons d'argiles kaoliniques provenant de Cornouailles anglaise et française, de Géorgie, des Charentes, ont été étudiés par analyses chimique, cristallographique, spectroscopique (I.R.), granulométrique, thermique différentielle et mesures des surfaces spécifiques. Le fer, sous forme d'oxydes ou hydroxyd…
In Escherichia coli, quinolinic acid, a precursor of NAD+, is synthesized from L-aspartate and dihydroxyacetone phosphate. This synthesis requires two enzymes, a FAD-containing "B protein" and an "A protein." The B protein has been purified 500-fold from E. coli cells. The enzyme behaves as an L-aspartate oxidase. In…
Hydrogen adsorption on high-surface-area alkaline-earth oxides has been studied by i.r. spectroscopy at 300 and 78 K. In the former case heterolytic dissociation of H2 molecules produces hydride and hydroxy groups which are partially reversible upon evacuation. Low-temperature hydrogen adsorption appears to be undisso…
This investigation has been aimed at a better understanding of epitaxy; particularly, but not exclusively, in monolayers. The description has been facilitated by the introduction of a configuration space γ, spanned by the parameters relevant to epitaxy, namely, lattice parameters, misorientation, bonding, etc. The rig…
Description This publication presents the latest developments in composites testing and design, including applications to the aircraft, automotive, and other industries. 31 papers comprise the contents and address subjects including test methods for mechanical and damage characterization; new types of composites, such…
Rietveld analyses of room-temperature neutron powder diffraction data for seven Nd2(CoxFe1−x)17 alloys (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) are reported. In the ternary systems we find that the c-type transition metal sites are preferentially occupied by Fe ions; concomitantly, the d and h sites have Co occupations lar…
X-ray diffuse scattering experiments on the superconducting salts (TMTSF)2X with X = PF6, AsF6 and ClO4 reveal no charge density wave instability, in contrast with the poorly conducting (TMTTF)2PF6 salt. New structural phase transitions coinciding with conductivity anomalies are found in (TMTSF)2NO3, (TMTSF)2ReO4, and…
A magnetic state is observed below ∼ 3.5 K in the organic superconductor (TMTSF)2ClO4 just above the superconducting transition (Tc ∼ 1 K). This state is obtained by fast cooling with a rate of ∼ 25 K/min. and evidenced by 77Se and 1H-NMR intensity and relaxation measurements. The onset temperature is nearly field-ind…
The alloy Ti-6Al-4V has been implanted with carbon and nitrogen ions. The microstructure produced by these implants is found to contain fine particles of TiC and TiN, respectively. Rotating beam fatigue tests show improved fatigue life for both implants, with the superior carbon implantation giving a 20% increase in e…
From the comparison of the physical properties of the (TMTTF)2X salts (mainly X = BF4, ClO4, PF6 and Br), the role of the counterion ordering is discussed and the intrinsic behaviour of the TMTTF chains is evidenced. Then, a parallel is drawn with the properties of the selenium analogs of these salts.
The technology of scanning electron microscopy (SEM) is described in brief. Its application to the study of cell and tissue structure is demonstrated and the evolution of the concept of "topographical histology" is discussed. Some current literature on the application of SEM is reviewed under the headings of experimen…
The absorptions of pure and codoped germanium silicate preforms made by modified chemical vapor deposition (MCVD) have been studied from 170 to 400 nm. Three bands with maxima at 185, 242, and 325 nm have been observed. The shortest wavelength band is attributed to GeO(2), while the other bands are assigned to GeO. Th…
Rigorous conditions for the metamagnetic transitions between the paramagnetic and ferromagnetic states and between the weak ferromagnetic and normal ferromagnetic states are derived. The expressions for the conditions and the critical field are derived in the simple model for an itinerant electron system and for a com…