Materials Literature
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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…
Growth and sinking rates varied over a 61.4‐h period for semicontinuous cultures of the marine diatom Coscinodiscus concinnus grown at light intensities of 48 and 9 µ Einst m −2 s −1 on a 12L : 12D cycle. The time‐course of sinking rates showed cyclic fluctuations, with sinking rates generally decreasing during the da…
Sintering of a fine‐grained polycrystalline diamond compact with grains less than 1 μm in size was successfully carried out by making a laminate on a WC/Co powder compact under sintering conditions of 5.8 GPa and 1430° to 1480°C for 30 min, in which small amounts of poly(ethylene glycol) and fine powder of cubic boron…
The corrosion resistance of titanium exposed in nitric acid vapor is generally inferior to that immersed in nitric acid solution because of an inhibitor effect of elements dissolved by corrosion of titanium in the solution.A new type corrosion testing apparatus, which would not be influenced by such dissolved elements…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA novel polymerization behavior of spiroorthoester: an equilibrium polymerizationSatoyuki Chikaoka, Toshikazu Takata, and Takeshi EndoCite this: Macromolecules 1991, 24, 1, 331–332Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published…
The conventional three-dimensional alternating-direction implicit (ADI) method is modified by introducing an f factor (0 < f < 1). This modification allows the time step limit to be increased by a factor of 1/f with the solutions remaining stable and high accuracy being retained. This new method is tested for two diff…
The effect of additions of iron on the corrosion behaviour of a 70Cu–30Ni alloy in sea water was studied by electrochemical methods and corrosion tests. Iron additions of 0·5 and 2% increased the average corrosion resistance of the alloy. This beneficial effect is due to the formation of a layer containing a large qua…
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…
LiCaPO4 has been synthesized and characterized by combined X-ray and neutron powder diffraction. The phase adopts the trigonal space group P31c, a= 7.5247(1)Å, c= 9.9657(2)Å. The structure is composed of a three-dimensional framework of vertex-sharing LiO4 and PO4 tetrahedra enclosing five-sided channels running paral…