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。
Polyurethanes based on diphenylmethane 4,4′-diisocyanate (MDI) were examined by electronic spectroscopy and by continuous and laser flash photolysis. Fluorescence and phosphorescence emissions were observed, and although the source of the fluorescence could not be identified, the phosphorescence appears to originate f…
The general rule that addition of a non-mesogenic solute causes a sharp decrease in the nematic-isotropic transition temperature (TN→ I) of a nematic solvent is not obeyed when the solute and solvent can enter into a donor-acceptor interaction. Addition of 4-aminobiphenyl to the nematic liquid crystal 4-cyano-4′-penty…
Abstract Data on the Raman spectra of natural α‐Glycine and 15 N‐substituted α‐Glycine are presented together with details of a computer calculation of the normal vibrations. Assignments are made and compared with previous assignments based on IR measurements.
Magnetic measurements and metallographic investigations are reported on Sm(Co,Cu)z alloys. The compositions lie between the rare-earth (RE) to transition-metal (TM) ratios of 1 : 5 and 2 : 17 with a content of copper of up to 35% of the TM fraction. The materials were analyzed both in the as-cast and heat-treatment co…
Summary Apjohnite, MnAl 2 (SO 4 ) 4 ·22H 2 O, is monoclinic, space group P2 1 /c, a 6·198 (2), b 24·347 (4), c 21·266 (4) Å, β 100·28 (3)° and Z = 4. The crystal structure was determined by means of direct methods applied to X-ray data collected with a single-crystal diffractometer. At the end of the refinement, perfo…
A capillary dilatometer has been automated by means of a capacitive transducer technique. The precision is 1 : 105 over a range in volume of 4% for a sample volume of 2 ml. Differential scanning dilatometry is achieved by comparing the sample dilatometer with a reference dilatometer. Some results for the density chang…
The effect of aging on the microstructures of Sm-Co-Cu alloys is reported. It is shown that small precipitates are present within the SmCo5-type phase in as-cast material. On aging below 650 °C these precipitates are exceptionally stable, but at 800 °C they coarsen rapidly. These results are rationalized in terms of a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTManganese Schiff base complexes. 7. Synthesis and circular dichroism of optically active tetradentate chelates of manganese(III) and of .mu.-oxo-.mu.-hydroxo-dimanganese(III,IV) dimersL. J. Boucher and C. G. CoeCite this: Inorg. Chem. 1976, 15, 6, 1334–1340Publication Date (…
Completing sour gas wells with materials that possess innate corrosion resistance may be more practical than to attempt chemical corrosion inhibition of steel alloys. A program of screening tests determined that alloy systems containing large amounts of nickel, cobalt, chromium, and molybdenum have exceptional corrosi…
The measurement of dielectric strengths is generally beset with numerous difficulties, and results depend to a large extent upon experimental conditions and sample geometry. The development of so-called cylindrical samples, in which spherical electrodes are almost completely embedded in the dielectric to be measured,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure and magnetic properties of copper citrate dihydrate, Cu2C6H4O7.cntdot.2H2ODonald. Mastropaolo, Dana A. Powers, Joseph A. Potenza, and Harvey J. SchugarCite this: Inorg. Chem. 1976, 15, 6, 1444–1449Publication Date (Print):June 1, 1976Publication History Pub…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe effect of crystal packing and defects on desolvation of hydrate crystals of caffeine and L-(-)-1,4-cyclohexadiene-1-alanineStephen R. Byrn and Chung-Tang LinCite this: J. Am. Chem. Soc. 1976, 98, 13, 4004–4005Publication Date (Print):June 1, 1976Publication History Publi…
The naturally occurring toxin L-2-amino-4-methoxy-trans-3-butenoic (AMB) acid irreversibly inhibits pyridoxal phosphate-linked aspartate aminotransferase. The inhibitor is a substrate for the enzyme, and as such is converted into a highly reactive intermediate which chemically reacts with an active site residue, thus…
The limiting low-frequency permittivity of ice VI at a pressure of about 9 kbar has been measured between 301 and 128 °K to seek evidence for an ordering transformation. In the experimental range, the quantity (ε0 −ε∞) T, where ε0−ε∞ is the orientation polarization, increased by a factor of 1.49, and follows a Curie–W…
An explanation of frictional electrification is suggested and experimentally proved. Because of the presence of structural imperfections, solid insulators are not electrically neutral. Under normal conditions the 'intrinsic' electric field of an insulator is compensated for by ions absorbed from air. Friction of one b…
Measurements of the spin-lattice relaxation rates in the group-III-V compounds, GaAs, GaSb, InAs, and InSb, are presented as a function of temperature from 4 to 300 K. These rates, except for GaSb, are separated into magnetic and quadrupolar parts. The quadrupolar rates are separated into relaxation by acoustic phonon…
The Brillouin spectra of the ferroelectric triglycine sulfate (TGS) and its isomorphous selenate (TGSe) crystals have been observed in three cases of orientations of the longitudinal or quasi-longitudinal phonon vector q ; (1) q // c -axis, (2) q // b -axis and (3) q deviates 5° from b -axis in the (100) plane. The te…
Abstract In the second part of this paper on the kinetics of crystallization of aluminum trihydroxide from caustic aluminate solutions, interest is specially focused on the analysis of crystal size distribution as a function of time, in an isothermal batch crystallizer. Breakdown and agglomeration are shown to affect…
In this paper methods and results of three-dimensional electron microscopy of individual molecules will be presented. Part I describes the general experimental and theoretical methods (microgoniometer, measuring scheme, two-dimensional and three-dimensional reconstruction, determination of the common origin of the pro…
The effect of changes in pH and the presence of ligands on the uptake of copper ions by an illite and a montmorillonite type clay has been investigated. The observed adsorption behaviour on montmorillonite can be interpreted in terms of an ion exchange model, i.e. all positively charged solution species compete for av…