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。
On a fritte β-SiC a plus de 95% de la densite theorique entre 1850 et 1950°C avec addition de Al 2 O 3 et Y 2 O 3 . On a realise la densification en utilisant une phase liquide formee entre Al 2 O 3 , Y 2 O 3 et SiO 2 a environ 1760°C. Le liquide presente une bonne mouillabilite vis-a-vis de SiC. La ceramique obtenue…
Highly oriented multilayered films of polyaniline are fabricated by intercalative polymerization of aniline in fluorohectorite, a synthetic mica-type silicate. The insulating hybrid becomes electrically conductive when exposed to HCl vapors with an in-plane conductivity of 0.05 S cm−1. The conductivity of the multilay…
Synthetic barite crystals, prepared under conditions chosen to mimic those encountered in off-shore oil fields, have a simple rhombic plate-like morphology in which large (001) faces are bound by smaller (210) sides. The addition of certain stereochemically related diphosphonates produces a characteristic morphologica…
Techniques were developed and described for performing three-dimensional finite element analysis of plain weave composites. This paper emphasizes aspects of the analysis that are different from analysis of traditional laminated composites, such as the mesh generation and representative unit cells. The analysis was use…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTModification of photochemical reactivity by zeolites. Preparation and spectroscopic characterization of polarons and bipolarons of thiophene oligomers within the channels of pentasil zeolites: the evolution of organic radical ions into conducting polymersJonathan V. Caspar,…
The transverse tensile behavior of a composite composed of unidirectional silicon-carbide fiber (Textron SCS-6) in a Ti-6AL-4V matrix is examined with emphasis on the effects of fiber-matrix interface strength. The residual stresses as a result of a mismatch in the coefficients of thermal expansion of silicon carbide…
Spin-polarized photoemission spectra at low photon energies from ferromagnetic ultrathin Fe layers on Cu(100) show a substantial polarization of the Cu 3d peaks. This is attributed to spin-dependent attenuation in the Fe overlayer. Values of the spin-dependent mean free path at low electron energies are obtained.
We report on an experimental investigation of porous silicon layer (PSL) formation and silicon/hydrofluoric acid interfaces, using internal‐reflection Fourier‐transform infrared spectroscopy and Fourier‐transform electrochemically modulated infrared spectroscopy. Low‐doping Si samples ( , resistivity ≈4 Ω cm) have bee…
The alkyl-substituted oligothiophenes with varying degree of polymerization have been characterized both in their neutral and in their doped forms. Large blade-shaped crystals of these compounds are readily accessible through recrystallization. Thin films of the oligothiophenes are also obtained from casting or vacuum…
The crystal stucture and phase transition of PrP5O14 have been studied by X-ray diffraction methode. The crystal belongs to monoclinic system at room temperature. The structure parameters are as follows: a = 8.777(l)?, b = 9.029(2)?, c= 13.068(2)?, β=90.35°(l), z=4. The space group is P21/c. The final R is 0.046. The…
Carbonatites are igneous rocks formed in the crust by fractional crystallization of carbonate-rich parental melts that are mostly mantle derived. They dominantly consist of carbonate minerals such as calcite, dolomite, and ankerite, as well as minor ...Read More
Among the boron rich materials, boron carbide B4C is presently the preferred neutron absorber for nuclear reactors but other boron‐rich compounds are of potential interest. We present here a study of some of the crucial properties for in‐reactor behavior: thermal conductivity and mechanical properties (Young modulus),…
Cells organize many of their biochemical reactions in non-membrane compartments. Recent evidence has shown that many of these compartments are liquids that form by phase separation from the cytoplasm. Here we discuss the basic physical concepts necessary ...Read More
The new ternary layer compounds Nb2Co2Te4 and TaCo2Te2 have been prepared by reaction of the elements at high temperature; isolated and condensed M2Co2(M = Nb or Ta) clusters are the structural key features of these unusual layer compounds, tight-binding band structure calculations indicate the importance of Nb–Co(Ta–…
The synthesis of {4′-[methyl(diphenyl)phosphonio]biphenyl-4-yl}triphenylborate (PBB) and 4′-(diphenylphosphino)biphenyl-4-yl(methyl)diphenylphosphonium hexafluorophosphate (PBP) is described. The properties of PBP and PBB are investigated by absorption and fluorescence spectroscopy. Diphenylphosphine is found to be a…
A practical conservation law related to isotropy is proposed for the deterministic Cahn-Hilliard equation, i.e., the order parameter conserving TDGL model. In order to examine it a dipole moment of the order parameter distribution in a two dimensional system is numerically calculated by using the cell-dynamics method…
The electrical, thermal, and multiple-stress (thermal and electrical) aging of cross-linked polyethylene (XLPE) cable models has been investigated in order to get information on aging effects and mechanisms. After endurance tests, XLPE cable models have been subjected to chemical, physical, electrical, and microstruct…
The effect of passivation and the influence of reactivation conditions on the metallic dispersion of nickel catalysts have been investigated. Catalysts were prepared on silica and alumina supports by different methods. After reduction, samples were passivated at room temperature with 1% O2 in an inert flow. The passiv…
Abstract Hydroxyl terminated polybutadine (HTPB) based composite solid propellants have gained prominence in advanced missiles and launch vehicles including the Space Shuttle's Inertial Upper Stage (IUS) motor (1). To achieve a blow‐hole free well performing casting, the knowledge of the processability characteristics…
The superplastic deformation of fine grained Ti–6Al–4V has been studied under uniaxial tensile test condition at temperatures of 750, 800 and 850°C and at strain rates in the range of 5×10−6–2×10−4 s−1. Constant strain rate and stepped true strain rate tensile tests were performed to determine the mechanical behavior…