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。
A series of special polyimides was synthesized to use them for aligning nematic liquid crystals accompanying a pretilt angle from a few degrees up to 30 degrees by using a rubbing technique. The chemically synthesized polyimide is comprised of two parts: one is an ordinary long-chain polymer and the other is an extra…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDimeric versus monomeric titanium(III) siloxide complexes. Syntheses and characterization of [(c-C6H11)7(Si7O12)TiIII]2 and [(c-C6H11)7(Si7O12)TiIII(C5H5N)]2Frank J. Feher, Shirley L. Gonzales, and Joseph W. ZillerCite this: Inorg. Chem. 1988, 27, 20, 3440–3442Publication Da…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntercomparisons of dielectric relaxation, dynamic light scattering, and viscoelastic properties of the local segmental motion in amorphous polymersK. L. Ngai, S. Mashimo, and G. FytasCite this: Macromolecules 1988, 21, 10, 3030–3038Publication Date (Print):October 1, 1988Pu…
In inner-shell photoionization of an atom followed by Auger decay, the Auger electron initially screens the ionic Coulomb field experienced by the photoelectron. A sudden change in screening occurs when the Auger electron overtakes the photoelectron, causing energy transfer from the latter to the former. According to…
A TEM investigation was conducted on the structure of a second phase precipitated between the grains of a polycrystalline TiO 2 ‐rich BaTiO 3 which was doped with 8 mol% Ca. This phase was identified as Ca‐stabilized Ba 2 Ti 5 O 12 with a 10‐layer orthorhombic structure and unit‐cell parameters a=0.990, b=1.131, and c…
The results of recent investigations of the effect of high pressures on grain boundary diffusion and grain boundary migration in Aluminium are compared. The activation volume for general grain boundaries migration was found to be less than 0.2 R <R- atomic volume). On the other hand the activation volume for di…
The photoacoustic spectrum P (λ) of the superionic conductors β-Ag 3 SI and α-Ag 3 SI has been measured in the range 270≦λ≦1800 nm at room temperature. A difference in the band gap is observed in each specimen; in the annealed β-phase and in the quenched α-phase. These data can be interpreted on the basis of a simple…
Ni-base alloys exhibit excellent corrosion resistance and are used extensively in corrosive applications, although environment-induced crack growth has occurred in several applications. Environment- induced crack growth in Ni-base alloys occurs in a number of environments, including water, acidic and basic solutions,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal and molecular structures of potassium aquatetrakis(nitrito)nitrosylplatinate(IV), a blue, mononuclear platinum complex with a bent nitrosyl group, and of potassium trichlorobis(nitrito)nitrosylplatinate(IV)E. S. Peterson, R. D. Larsen, and E. H. AbbottCite this: Inor…
A recently synthesized and characterized homologous series of liquid-crystal compounds (n4COOBC) is shown by high-resolution ac microcalorimetry experiments (on the n=3,6 homologs) to most likely exhibit smectic-A to smectic-B (hexatic) (Sm${B}_{H}$) phase transitions exclusively. This is in partial contrast to earlie…
The compressive stress for the shrinkage of a large pore during sintering has been analyzed by combining the effects of the pore size, the ratio of pore size to grain size, and the coordination number of the pore. Alumina has been selected to illustrate this model. The result shows that the compressive stress is a pos…
Grain boundaries in tungsten carbide crystals (hexagonal structure c/a = 0.976) show many coïncidence orientations. The most frequent orientation has a coïncidence index Σ = 2. H.R.E.M. images of such grain boundaries have been realized. These grain boundaries show a defect structure, only due to the mismatch of the a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStacked complexes of iridium and a novel form of charge compensationPaul G. Rasmussen, J. Bruce. Kolowich, and Juan Carlos. BayonCite this: J. Am. Chem. Soc. 1988, 110, 21, 7042–7049Publication Date (Print):October 1, 1988Publication History Published online1 May 2002Publish…
A practical method to correct X-ray powder diffraction patterns for the effects of preferred orientation in the case of monoclinic crystals is presented. The method is based on the use of symmetrized harmonics to describe the preferred orientation. To obtain a texture-free result the diffraction pattern must be measur…
Abstract Conversion distribution in particles of chlorinated poly(vinyl chloride) (CPVC) is conceptually described based on balance equations involving mass transfer and chemical reaction. In the physical sorption of chlorine in poly(vinyl chloride) (PVC) as measured by the constant volume cell method, equilibrium con…
Pseudo-hexagonally twinned orthorhombic crystals generally exhibit three domain variants related by mirror planes or (approximately) by 120° rotations. The reciprocal lattices of the three domains coincide partially. Those reciprocal-lattice points hkl with h + k = 2N coincide or are split depending upon the deviation…
Electrical conductivity due to halide ions has been measured for the glasses in the system 30SiO 2 · (70 − x )PbO · x PbX 2 (0 < x < 17.2 mol%; X = F, Cl). The conductivity increases with x by several orders of magnitude for both series of glasses. The contribution of principal factors to the conductivity has be…
The crystal structure of α-CrPO4, previously solved from high-resolution synchrotron powder X-ray data, has been refined by the Rietveld method. The peak shape variation is well fitted by a convolution of Gaussian and Lorentzian terms, which incorporate both instrumental and sample-broadening contributions. The struct…
Abstract The critical specimen thickness up to which the Cliff‐Lorimer method can be used without additional corrections was measured on some steels and nickel‐base alloys for soft x‐rays with line energies between 1 and 3 keV. The critical thickness values measured are 50 nm at 1 keV and 450 to 500 nm at 3 keV. These…
Abstract Through the exact number of contact points between the two components of a solids system, the reactivity of the solids is expressed in terms of the molar ratio, the particle size ratio and the nature of the reacting system. The theory is confirmed by existing experimental data, revealing that the contact poin…