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。
Abstract The complex piezoelectric constant ( d = d ′ − id ″), elastic constant ( c = c ′ + ic ″), and dielectric constant (ε = ε′ − i ε″) were measured at a frequency of 10 Hz over the temperature range from −150 to 50°C and for a range of hydration up to 0.26 g/g for decalcified bone and up to 0.084 g/g for bone. Fo…
The exchange coupling between rare-earth ($R$) and transition-metal ($T$) moments in ${R}_{x}{T}_{y}$ compounds is not so large as to hold the $R$ and $T$ moments rigidly parallel (for light rare-earth elements) or antiparallel (for heavy rare-earth elements); ionic magnetocrystalline anisotropy energy can be comparab…
The aging of simulated nuclear waste glass by contact with a controlled-temperature, humid atmosphere results in the formation of a double hydration layer penetrating into the glass and in the formation of minerals on the glass surface. The hydration process described here provides insight into the aging kinetics of n…
Abstract Protoporphyrin IX and its various ester derivatives have been previously shown to undergo self‐sensitized photooxygenation to yield hydroxyaldehydes (photoprotoporphyrin) and mono‐ and diformyl deuteroporphyrin derivatives. In the present study the photoreactions of these products in the presence of oxygen ha…
Neutron inelastic scattering measurements have been carried out on two single crystals of the thermally quenched gamma phase (FCC) alloy Fe 1-x Pd x with x=0.28 and 0.37. The x=0.28 sample (crystal 2) exhibits a face centred cubic to face centred tetragonal (FCC-FCT) transition at T m approximately 265K. The x=0.37 sa…
When rhombohedral BN, which has a layer structure with a three‐layered stacking sequence, was shock‐compressed at 40, 60, and 100 GPa, it was converted to cubic BN. Hexagonal BN was converted to wurtzite‐type BN under the same conditions. These results indicate that the transformation proceeds by a diffusionless mecha…
Abstract The transfer of plasticizer from compression‐molded sheets of plasticized poly(vinyl chloride) into ethanol–water mixtures was studied over the temperature range of 30–55°C. A simultaneous diffusion occurred for ethanol and water into polymer and for dioctylphthalate plasticizer from polymer into liquid. The…
We present a simple theory of rod/plate liquid-crystal mixtures in which the angle-dependent pair interactions are assumed to be of second-rank form. Calculations are reported for varying relative anisotropies of the “rods” and “plates”. Temperature vs. mole-fraction phase diagrams show successive isotropic (I) → unia…
Abstract Carbon fibres, surface treated by an industrial process, were analysed by x‐ray photoelectron spectroscopy (XPS). The results allow the surface chemistry to be compared with that achieved by controlled laboratory methods. It is found that industrial treatment has less control over individual fibre surface tre…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTungsten-183 NMR of heteropoly and isopolytungstates. Explanations of chemical shifts and band assignments and theoretical considerationsRafael Acerete, Charles F. Hammer, and Louis C. W. BakerCite this: J. Am. Chem. Soc. 1982, 104, 20, 5384–5390Publication Date (Print):Octo…
Beginning with a 19BaF 2 −27ZnF 2 −27YbF 3 −27ThF 4 (mol%) base glass, compositional modifications were made to improve optical properties and glass‐forming ability. Replacement of YbF 3 by LuF 3 removed a strong near‐ir electronic absorption band, and small additions of LiF and NaF improved glass quality. The multico…
Tetragonal and rhombohedral phases always coexist in Pb(Zr x Til 1−x )0 3 near the morphotropic phase boundary compositions (0.52≤x≤0.55) when prepared by solid‐solid reaction among the constituent oxides. A special technique was developed to obtain perovskite ceramics exhibiting no co‐existence in the boundary compos…
Abstract The crystallization and melting behavior of the system N ‐methylmorpholine‐ N ‐oxide (MMNO)–H 2 O–cellulose has been studied by differential scanning calorimetry, optical and electron microscopy, and x‐ray scattering. The phase diagram of the MMNO–H 2 O solvent system is reported up to a water content of 28%…
Article Polymorphie, Leitfähigkeit und Kristallstrukturen von Oxo-phthalocyaninato-titan(IV) was published on October 1, 1982 in the journal Zeitschrift für Kristallographie - Crystalline Materials (volume 159, issue 1-4).
Abstract Exchange reactions in molten bisphenol‐A polycarbonate–poly(butylene terephthalate) mixtures are investigated by means of model reactions. Transesterification can result either from direct ester‐ester interchange or via alcoholysis or acidolysis. Among the various reactions investigated, only the PBTP alcohol…
Abstract The rheological properties of a thermotropic polyester were determined in the nematic and isotropic states. In the isotropic state, the viscosity is almost constant and the polymer is only slightly elastic. The nematic phase has a lower viscosity than the isotropic, except at low frequencies or shear rates, w…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoordination intercalation reactions of the layered compounds vanadyl phosphate (VOPO4) and vanadyl arsenate (VOAsO4) with pyridineJack W. Johnson, Allan J. Jacobson, John F. Brody, and Suzanne M. RichCite this: Inorg. Chem. 1982, 21, 10, 3820–3825Publication Date (Print):Oc…
Abstract The structure of the four‐component copolyester resulting from the exchange reaction between molten bisphenol‐A polycarbonate and poly(butylene terephthalate) is analyzed as a function of the reaction time by infrared and nuclear magnetic resonance spectroscopy. By applying a statistical method developed earl…
Anisotropy Induced during Compression Molding o f RubberMany physical tests of elastomeric vulcanizates are carried out using specimens cut from flat sheets that were prepared by compression molding.Generally, an excess quantity of rubber is placed into the mold to assure that the mold cavity will be completely filled…
X-ray absorption spectroscopy has been used to study the dimeric iron center in azidomethemerythrin from Phascolopsis gouldii. Absorption edge data confirm that the two iron atoms are present as Fe(III) and suggest a hexa-coordination site for each of the iron atoms. The extended x-ray absorption fine structure (EXAFS…