Materials Literature
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New diamantane-based polyimides are synthesized by reacting of 4,9-bis[4-(4-aminophenoxy)phenyl]diamantane with various aromatic tetracarboxylic dianhydrides. Films of these polyimides have low dielectric constants, ranging from 2.58 to 2.74, and low moisture absorptions less than 0.3%. Four of these films have good s…
The effects of variations in salinity (5, 10, 15, 25, 35‰) and temperature (2, 5, 10, 15, 18, 22, 25°C) on growth, valve morphology, and toxicity were examined in the marine planktonic diatom Pseudo-nitzschia pseudodelicatissima (Hasle) Hasle from Danish waters. Growth rates were salinity and temperature dependent. Th…
A Bayesian treatment for phase calculation in the multiwavelength anomalous diffraction (MAD) technique is presented. This approach explicitly treats effects of errors correlated among measurements at different wavelengths and between Bijvoet pairs. The resulting method, which is called Bayesian correlated MAD phasing…
Lamellar domain spacings ( D ) of blends of a styrene-2-vinylpyridine (SP) diblock copolymer and homopolymers corresponding to the block polymers (S and/or P), of which molecular weights are lower than that of the block polymer, were examined by small-angle X-ray scattering (SAXS), and the dimensions of block chains i…
We have investigated the magnetic electronic structures of PtMnSb, NiMnSb, ${\mathrm{Ni}}_{2}\mathrm{MnSb},$MnSb, MnAlGe, and ${\mathrm{Mn}}_{2}\mathrm{Sb}$ by soft-x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) measurements in the Mn $2p$ core absorption region. Different degrees of the ele…
Abstract Stress relaxation experiments were performed on two grades of polycarbonate at room temperature. The tests were performed in uniaxial extension and compression at deformations from the small strain, linear viscoelastic regime to the highly nonlinear viscoelastic regime just below yield. Simultaneous to the co…
The fatigued state of Pt-PZT-Pt ferroelectric capacitors (FECAP) was investigated by means of piezoelectric coefficient, polarisation charge and permittivity measurements. The suppression of switching polarisation Pr S appears to be the result of freezing of ferroelectric domains without affecting the lattice dielectr…
Abstract Poly(triacetylene)s [PTAs, (CCCRCRCC) n –] are a new class of linearly conjugated polymers with a nonaromatic all‐carbon backbone. To explore structure–property relationships in PTAs, we prepared a series of monodisperse oligomers ranging from monomer to hexamer by oxidative Glaser–Hay coupling of a bif…
To synthesize nonlinear optical polyimides exhibiting high nonlinearity and high thermal stablity, a new monomer bearing phenylenediamine and a diazo benzene-type nonlinear optical chromophore (compound 1 ) was synthesized and polymerized with 4,4‘-(hexafluoroisopropylidene)diphthalic anhydride. This diazo chromophore…
A structured package for radiation analysis, SPRADIAN, is developed and its application is presented. This study is primarily motivated by necessity of a quantitative analysis of severe radiative environment which the MUSES-C capsule encounters during its reentry into the earth atmosphere. In comparison with other rad…
Resistivity and ac-susceptibility measurements demonstrate that the cation size mismatch at the $A$ site in perovskite manganites influences greatly the electrical and magnetic properties which are associated with colossal magnetoresistance. It has been reported that the Pr${}_{1\ensuremath{-}x}$Ca${}_{x}$MnO${}_{3}$…
The thermal behaviour and phase morphology of poly(3-hydroxybutyrate) (PHB) and starch acetate (SA) blends have been studied by differential scanning calorimetry, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy and polarizing optical microscopy. PHB/SA blends were immiscible. The melting t…
The electronic structure of In 2 O 3 has been studied for the first time using a first-principles calculation method based on the density functional theory. Although the complexity of the crystal structure of In 2 O 3 which contained 40 atoms in its unit cell had prevented studies of its electronic structure, we were…
PURPOSE: Thirteen male volunteers were studied to evaluate the MR imaging properties and pharmacokinetics of 10 mM mangafodipir trisodium infusion (MnDPDP, Teslascan). MATERIAL AND METHODS: Doses of 5 and 10 mumol/kg b.w. were administered by bolus injection (< 1 min) to 5 subjects, and by infusion (20 min) to 8 subje…
Tungsten erosion in the ASDEX Upgrade divertor has been measured by observing the WI emission at 400.9 nm. The sputtering yield is in the region of atoms/ion for typical divertor plasma conditions. By comparison of the measured sputtering yield with modelled sputtering yields one can conclude that tungsten erosion is…
We report the synthesis and morphological characterization of two triblock copolymers of the ABA type, where A is polystyrene (PS) and B polyisoprene (PI). The volume fraction of the minority component, PS or PI, is approximately 1/3. Cubic microdomain morphologies, already found in diblock and star block copolymers w…
This review describes the development and status of tracking research in Japan. First, the fundamentals of tracking and the influences of environmental stresses on tracking will be treated. Then, the principal tracking test methods currently in use will be characterized. Finally, some techniques for improving the trac…
Samples of soluble aromatic polyimides of varying chemical structure and molecular weight were synthesized in refluxing m-cresol at elevated temperatures through a one-step polymerization route. Modifications of the dianhydride and diamine monomers were designed to prepare aromatic polyimides having new architectures…
The reaction of ferrocene with molten imidazole at 150 °C yielded pale yellow crystals of composition [Fe 3 (imid) 6 (imidH) 2 ] x . Crystals of [Fe 3 (imid) 6 (imidH) 2 ] x are monoclinic, a = 10.5912(9), b = 12.958(2), c = 10.617(1) Å; β = 92.696(9)°; Z = 2; space group P 2 1 / c . The structure was solved by Patter…
Nuclear magnetic resonance and electrical conductivity measurements are conducted to study the dynamics of the ionic diffusion process in the crystalline ionic conductor ${\mathrm{Li}}_{0.5}{\mathrm{La}}_{0.5}{\mathrm{TiO}}_{3}.$ dc conductivity shows a non-Arrhenius temperature dependence, similar to the one recently…