Materials Literature
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Two chalcone-derivative isomers, 4,4′-diaminochalcone (4DAC) and 3,3′-diaminochalcone (3DAC), were synthesized and used as monomers together with tetracarboxylic dianhydrides to prepare novel photosensitive polyimides that contain a chalcone moiety in the main chain. The polyimides were characterized and their photoch…
SrRuO 3 epitaxial thin films were prepared by pulsed laser deposition (PLD) under a range of growth conditions to study the impact of bombardment on properties. Growth conditions favoring energetic bombardment resulted in SrRuO3 films with expanded in-plane and out-of-plane lattice constants. In particular, SrRuO3 fil…
The gene encoding the Escherichia coli Class I fructose-1, 6-bisphosphate aldolase (FBP aldolase) has been cloned and the protein overproduced in high amounts. This gene sequence has previously been identified as encoding an E. coli dehydrin in the GenBanktrade mark database [gene dhnA; entry code U73760; Close and Ch…
Small-size, high-density, and vertical-ordering Ge quantum dots are observed in strained Si/Ge short-period superlattices grown on Si(001) at low growth temperature by molecular-beam epitaxy. The photoluminescence (PL) peak position, the strong PL at room temperature, and the high exciton binding energy suggest an ind…
The hydrothermal reactions of molybdenum oxide starting materials with iron(II) and iron(III) halides in the presence of 2,2‘-bipyridine have afforded the three related one-dimensional solid materials [MoO 4 {Fe(III)Cl(2,2‘-bpy)}] ( 1 ), [Mo 3 O 12 {Fe(III)(2,2‘-bpy)} 2 ]·0.25H 2 O ( 2 ), and [Mo 4 O 15 {Fe(III)(2,2‘-…
Flux into the glycolytic pathway of most cells is controlled via allosteric regulation of the irreversible, committing step catalyzed by ATP-dependent phosphofructokinase (PFK) (ATP-PFK; EC 2.7.1.11), the key enzyme of glycolysis. In some organisms, the step is catalyzed by PPi-dependent PFK (PPi-PFK; EC 2.7.1.90), wh…
A new type of optical filter is predicted theoretically and verified experimentally. The filter operates under guided-mode resonance conditions in a thin-film waveguide grating. A high-efficiency reflection filter response is produced at the Brewster angle at which TM reflection is classically prohibited. Low-reflecta…
The efforts to reduce NOx pollutants have stimulated a large interest in the understanding of the elementary processes for NO transformation on transition metal surfaces. Periodic density-functional calculations have been performed for the molecular and dissociative chemisorption of NO on Pd and Rh(100) and (111) surf…
The electronic structures of the antiferromagnetic semiconductor FeS and ferrimagnetic metals ${\mathrm{Fe}}_{7}{\mathrm{S}}_{8}$ and ${\mathrm{Fe}}_{7}{\mathrm{Se}}_{8}$ have been studied by spin-integrated and spin-resolved photoemission spectroscopy and inverse-photoemission spectroscopy. The overall Fe $3d$ bandwi…
The electronic structure of LaTe 2 is calculated from the first principles using DV-Xα method. The Fermi surface of this material is mainly contributed from the Te square sheet in the crystal and it has several large parallel pieces that satisfy the nesting condition for CDW transition. Furthermore, the electronic str…
Iron dichalcogenides FeX 2 (X=S, Se and Te) attract interest as semiconducting material containing narrow 3 d band. FeS 2 crystallizes in a cubic pyrite-type structure, and both FeSe 2 and FeTe 2 in an orthorhombic marcasite-type one. Electrical resistivity (ρ), Hall coefficient ( R H ) and thermoelectric power ( S )…
In the framework of the effective-mass envelope-function theory, the electronic and optical properties of a spherical core-shell quantum-dot quantum well (QDQW) structure with one and two wells have been investigated. The results show that the energies of electron and hole states depend sensitively on the well thickne…
Metal deposition into a porous silicon (PS) layer by immersion plating has been studied. Ag and Cu were found to deposit on PS, while Ni was found not to deposit. The dependence of the amount of Cu deposition on Cu2+ concentration, halogen ion concentration, and immersion time was investigated using chelatometric titr…
A nanotube is phenomenologically modeled as a chain of atoms wrapped helically on a right circular cylinder. The semiclassical Hamiltonian of an electron is derived, using the Wannier approach for the Schr\"odinger equation, when the nanotube is exposed to both constant (dc) and high-frequency (ac) electromagnetic fie…
We have measured the dielectric relaxation of butylbenzene and of the glass-former propylbenzene in the frequency range 10−2 Hz to 2×1010 Hz in order to characterize the variation of relaxation times with temperature for these low loss liquids. Additionally, salol has been remeasured above 1 GHz with improved resoluti…
The magnetic-field dependence of optical spectra and their anisotropy have been investigated for a single crystal of ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3} \phantom{\rule{0ex}{0ex}}(x=0.4)$ at 30 K. The charge-ordered (CO) state is transformed into a ferromagnetic metallic state by a magn…
Measurements of the dynamic spall strength in aluminum, copper, and Metglas shocked by a high-power laser to hundreds of kilobars pressure are reported. The strain rates in these experiments are of the order of 107 s−1, which cannot be reached in impact experiments. The free-surface velocity behavior associated with s…
The enhanced features of a computer program (RREVM) for the estimation of copolymerization reactivity ratios using statistically sound techniques are illustrated with experimental and simulated case studies. In parallel, a literature review is given on the estimation of reactivity ratios. Both aspects are extensions b…
We study the \ensuremath{\pi}-band contribution to the optical properties of the carbon nanotubes based on the tight-binding model, including optical absorptions, optical rotatory power, and circular dichroism. By taking into account not only the interband contributions but also the free-carrier contributions, the die…
SiO 2 aerogels were prepared by a sol-gel method and supercritical drying. Introduction of nano-ZnO into nanopores of the SiO2 aerogels is performed by immersion, chemical reaction, and hydrolysis. Photoluminescence of these assemblies of nano-ZnO particles/SiO2 aerogels were systematically measured. For each assembly…