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。
The rapid formation (and erasure) of a dynamic phase grating is one condition required of materials for dynamic holography. The photochemical nematic–isotropic transition of the side-chain polymer liquid crystal (PLC) shown in the Figure, caused by the trans–cis photoisomerization of the azobenzene moiety, is reported…
Laminates containing a thin layer (5 to 200 µm thick) sandwiched between two thick layers (2 mm thick) were fabricated by sequential slip casting in order to study crack bifurcation. The thin layer was formed with a mixture of a pure ZrO 2 powder (MZ) and a Zr(Y)O 2 powder containing 3 mol% Y 2 O 3 (TZ). The thick lay…
Two nonmacrocyclic ligands with pyridine and carboxamide nitrogens as donors readily form bis complexes of the type [FeIIIL2]+ in which the Fe(III) centers exhibit preference for coordination to carboxamido nitrogens over pyridine nitrogens. These Fe(III) complexes with deprotonated carboxamido nitrogens are very stab…
Mean-square atomic displacements in lanthanum triiron cobalt dodecaantimonide, determined as a function of temperature using single-crystal neutron diffraction, show that the La atom exhibits an anomalously large displacement at room temperature, U(eq) = 0.0196 (9) Å(2), because it is too small to fill the atomic cage…
This paper presents a new method for determining the widths of the power and ground routes in integrated circuits so that the area required by the routes is minimized subject to the reliability constraints. The basic idea is to transform the resulting constrained nonlinear programming problem into a sequence of linear…
In small rings, strain energy is believed to be dominated by bond angles (Baeyer strain). However, it was found (Dill et al.) that, in bicyclobutane, bridgehead substitution effects on strain energy range from +10 to -30 kcal. Ab initio computations at the 6-31G and 6-31+G* levels have shown that the deformation cause…
High pressure Raman spectroscopic investigations have been carried out on Cs2SO4 up to a pressure of 164kbar. The behaviour of the internal modes of sulphate ions as a function of pressure are examined. In contrast to other disulphates, cesium sulphate does not exhibit any phase transition up to the highest pressures…
X-ray absorption fine structure (XAFS) spectroscopy using fluorescence mode detection has been successfully extended to quantitative examination of the local atomic environment of dilute analytes in a strongly scattering host matrices. This is applied to the characterization of thermally aged and neutron-irradiated Fe…
Refractories containing magnesium aluminate spinel (MgAl2O4) are materials for emerging technology in several applications like cement and steelmaking processes. In order to deep the understanding of these castables, this work presents the microstructural characteristics of an alumina-magnesia/self-forming spinel cast…
Abstract The ease with which plasticizer is combined with poly(vinyl chloride) resin is a measure of processing characteristics critical in the dry blending of suspension PVC and the gelation of plastisols. By using commercial grade plasticizers, this study developed predictive equations for the following processing p…
The effect of soil clay size phyllosilicates, particle size, and iron oxides on the activities of α‐ and β‐glucosidases, phosphomonoesterases, and urease were examined. The two clay fractions (0.2–2 and <0.2 μm) of selected soils had similar mineralogy and were illitic, kaolinitic, and smectitic in composition. In gen…
Eingebettet in einer schützenden äußeren [{Fe(pz3)}4]-Schale, die ihm Strukturstabilität verleiht, enthält der achtkernige Komplex [Fe8(μ4-O)4(μ-pz)12Cl4] einen cubanartigen Fe4O4-Kern (siehe Bild), der reversibel in vier aufeinanderfolgenden Ein-Elektronen-Übertragungen reduziert werden kann. Es wird gezeigt, daß Eis…
Iron enriched in the isotope 57Fe was dispersed in a nanocrystalline tungsten matrix by mechanical alloying. Mössbauer experiments were performed using as-milled, isochronally and isothermally annealed samples, both at room temperature and as a function of measurement temperature. The spectra were interpreted in terms…
The experimental results of an investigation of the surface morphology of the as-grown (100) faces of KDP single crystals grown on seeds from aqueous solutions containing different concentrations of Fe3+ and Cr3+ impurities are described and discussed. It was found that the behaviour of steps in terms of their mutual…
Abstract Blends of polystyrene and polyethylene (PS/PE), including belnds in which a styrene/ethylene‐butylene/styrene (SEBS) terpolymer was employed as a compatibilizer, were studied. Their rheology showed that the effect of the addition of SEBS to PS/PE blends was strongly affected by the blend composition and the s…
The reflective cholesteric texture mode between planar and homeotropic textures, which can achieve a high contrast ratio, needs to be coupled with an active matrix drive scheme such as a method using thin film transistors. In this article, the threshold voltage of the cholesteric–nematic phase transition, an important…
Banana-shaped compounds form several new smectogenic phases specific to this class. Several two-dimensional phases have been observed, and these can exhibit very complex and beautiful optical textures (see Figure). These phases are reviewed and their structures investigated by not only X-ray diffraction and nuclear ma…
A third crystalline modification of dodecaphenylporphyrin is described in which the pyrrole nitrogen atoms are hydrogen-bonded to two ethanol molecules. This is the first crystallographic proof for the accessibility of nitrogen atoms in saddle-distorted free base porphyrins for hydrogen bonding. No such coordination i…
Studies have been carried out to convert carpet waste into valued products. Two common processes, injection and compression molding, can be used to recycle carpet waste. Three types of carpet waste have been recycled: (1) edge trim from carpet manufacturing, (2) polypropylene shear lint from cutting tufted carpet loop…
Material evolution laws, such as those implicit in theories of plasticity and growth, are subjected to a systematic treatment. Using some concepts borrowed from the theory of inhomogeneities, the evolution of the material structure for materials of first and second order is expressed in terms of first-order differenti…