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。
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagic-Angle 13C NMR Analysis of Motion in Solid Glassy PolymersJacob Schaefer, E. O. Stejskal, and R. BuchdahlCite this: Macromolecules 1977, 10, 2, 384–405Publication Date (Print):March 1, 1977Publication History Published online1 May 2002Published inissue 1 March 1977https…
En el presente trabajo, se investiga en micro-hormigones frescos preparados con esqueletos granulares compactos y agregados normales, la influencia de la finura de molido del cemento portland en la consistencia del cuerpo compuesto fresco, de distintas relaciones agua/cemento. La relación agua/cemento de la pasta cong…
En trabajos anteriores (1), (2), (3) y (4) se estudiaron por espectroscopia infrarroja las fases sintetizadas del clínker, el propio clínker, el cemento hidratado hasta una edad de 4 años y con distintas proporciones de yeso y CaCl2, hasta una edad de 28 días. En el presente trabajo, con el fin de poner de manifiesto,…
Se toma como base un interesante y reciente trabajo de A. VIRELLA (1) y se comentan y glosan, con el criterio personal del autor, algunos de los aspectos más importantes del mismo, relativos a las adiciones de los cementos que las contienen, y a la vista del nuevo Pliego RC-75 para los cementos en España.
No disponible
No disponible
El efecto que el dióxido de carbono produce sobre los compuestos anhidros e hidratados del cemento portland ha sido objeto de estudio por numerosos investigadores, debido a la influencia que ejerce en las propiedades de los conglomerados correspondientes. La reacción de carbonatación del cemento portland lleva consigo…
En un trabajo anterior (1) se analizaron las distintas características de los métodos electroquímicos empleados hasta la actualidad para la detección del ataque localizado en el caso de un acero de construcción sumergido en disolución saturada de hidróxido cálcico, así como el efecto despasivante e inhibidor que sobre…
Summary Measurements of equilibrium phosphate concentrations, adsorbed phosphate and isotopically exchangeable phosphate (E t ) were made on suspensions of acid soils at initial P concentrations ranging from 1–1000 μM and pH values between 4.2 and 6.8. At low P concentrations (1–100 μM), the affinity of the adsorption…
Tritium diffusion in aluminum and beryllium oxides was studied by recoiling tritium into specimens and measuring the time rate of tritium release during postirradiation heating. Results were consistent with classical diffusion solutions and gave single values for the diffusion activation energy over the temperature ra…
The uniaxial magnetic anisotropy Kuinduced by a magnetic anneal has been determined, after stress relief, for a series of alloys given by (FeyNi1-y)80B20. For all of these alloys Kudepends on anneal temperature as predicted by directional order theory. The concentration dependence of Kuin these alloys is also consiste…
The high strength potential of single‐phase mullite was investigated under compressive stress‐strain and creep testing conditions at 1400° and 1500°C. In single‐crystal experiments, no plastic deformation and, hence, no dislocation glide was observed. Polycrystalline mullite was deformed via the Nabarro‐Herring mechan…
Linear thermal expansion measurements have been carried out from 6 to 340 K on a high-purity silicon sample using a linear absolute capacitance dilatometer. The accuracy of the measurements varies from ±0.01×10−8 K−1 at the lowest temperatures to ±0.1×10−8 K−1 or 0.1%, whichever is greater, near room temperature, and…
Abstract This paper surveys the basic aspects of physical aging. It shows that aging i s a general and important phenomenon found in all organic and inorganic glasses and in some metals as well. Moreover, the behavior of all these materials is very similar. It further shows that aging cannot be ignored in the testing…
Abstract The free‐volume theory describing diffusion in polymer–solvent systems is reexamined. Calculation of the specific free volume for such systems is discussed, and equations are presented for the determination of the self‐diffusion coefficients of the polymer and the solvent. Conditions under which the mutual di…
Recent advances in the investigation of polyurethanes are surveyed. Considerable attention is paid to copolyurethanes based on multicomponent initial constituents, which may exhibit thermoplastic or thermoelastoplastic properties depending on the distribution of the components in the chain and the length of the glycol…
My high-resolution studies of the bound-exciton luminescence in Ga-doped Si reveal a triplet structure. Also, I report for the first time bound multiexciton complexes associated with Ga, which are similar to those previously reported for Si doped with P, Li, and and B. In the case of Ga, however, the $m=2$ bound-multi…
Abstract An extensive examination of the cathodoluminescent emissions from natural diamonds has been performed with due regard to their inhomogeneity, correlating cathodoluminescence properties point-by-point with the local crystal lattice texture and imperfection content as revealed by other topographic techniques (i…