Materials Literature
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Copper oxide thin films deposited on Si (100) by a filtered cathodic vacuum arc with and without substrate bias have been studied by atomic force microscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The results show that the substrate bias significantly affects the surfac…
We demonstrate the epitaxial growth of optical-quality electrically-gated III-V ferromagnetic quantum structures. Photoluminescence spectroscopy reveals that initially unpolarized photoexcited holes in a GaAs quantum well become spin-polarized opposite to the magnetization of an adjacent digital ferromagnetic layer in…
Scheme and principle of operation of a spin gain transistor are proposed: a large unmagnetized current creates density sufficient for the ferromagnetic transition; a small magnetized current initiates spontaneous magnetization; large magnetized current is extracted. Therefore spin gain of more than 1000 is predicted.…
The electronic structure of AlN in wurtzite and zinc-blende phases is studied experimentally and theoretically. By using x-ray emission spectroscopy, the Al 3p, Al 3s and N 2p spectral densities are obtained. The corresponding local and partial theoretical densities of states (DOS), as well as the total DOS and the ba…
MgO exhibits activity for the reduction of CO 2 to CO under photoirradiation in the presence of H 2 or CH 4 as a reductant, although MgO is an insulating material. The present study clarified the mechanism of the CO 2 photocatalytic reduction in the presence of H 2 or CH 4 over MgO. The electron paramagnetic resonance…
A lead-free piezoelectric ceramic ternary system based on bismuth sodium titanate, (Bi 1/2 Na 1/2 )TiO 3 (BNT) - bismuth potassium titanate (Bi 1/2 K 1/2 )TiO 3 (BKT) - barium titanate BaTiO 3 (BT) near the morphotropic phase boundary (MPB) between the tetragonal and rhombohedral phases has been investigated. In the c…
Two types of aromaticity: Experimental and theoretical evidence shows that eight- and nine-atom boron clusters are perfectly planar molecular wheels, with a hepta- or octacoordinated central boron atom, respectively (see picture, B green). The radii of the miniature molecular wheels are found to be 1.8 and 2.0 Å. Anal…
With their bright, photostable fluorescence, semiconductor quantum dots (QDs) show promise as alternatives to organic dyes for biological labeling. Questions about their potential cytotoxicity, however, remain unanswered. While cytotoxicity of bulk cadmium selenide (CdSe) is well documented, a number of groups have su…
High-temperature solution phase reaction of iron(III) acetylacetonate, Fe(acac)(3), with 1,2-hexadecanediol in the presence of oleic acid and oleylamine leads to monodisperse magnetite (Fe(3)O(4)) nanoparticles. Similarly, reaction of Fe(acac)(3) and Co(acac)(2) or Mn(acac)(2) with the same diol results in monodispers…
The catalytic cracking of blends made up of polystyrene and polystyrene−butadiene with a light cycle oil (refinery stream) has been studied under the standard conditions of a FCC process. The catalysts used have been prepared based on HY zeolites of different acidity and porous structure. The results reveal the intere…
Stable cyclotriphosphazenes 5 and 6, with three and four carbon radical centers, have been prepared by condensation of (4-hydroxy-2,6-dichlorophenyl)bis(2,4,6-trichlorophenyl)methyl radical (4) with tetrachloro-2,2'-dioxybiphenylcyclotriphosphazene (7). EPR studies of both polyradicals in fluid solution suggest an ele…
Abstract Several, novel polyimide–polyurethane‐urea‐imide (PI‐PUI) copolymers with different polyimide (PI) contents were prepared by an in situ interpenetrating reaction between polyurethane‐urea‐imide (PUI) precursor and poly(amide acid). Changing the ratio of the PUI precursor and poly(amide acid) resulted in a cha…
Starch graft poly(methyl acrylate) (S-g-PMA) was prepared by ceric ion initiation of methyl acrylate in an aqueous corn starch slurry (prime starch) which maximized the accessibility of the starch for graft polymerization. A new ceric ion reaction sequence was established as starch-initiator-methyl acrylate followed b…
The molecular weight dependence of zero-shear viscosity (η 0 ) of polystyrene- block -polyisoprene (SI diblock) copolymer in the disordered state was investigated. For the investigation, a series of lamella-forming, nearly monodisperse SI diblock copolymers were synthesized via sequential anionic polymerization, and o…
The protein kinase family is a prime target for therapeutic agents, since unregulated protein kinase activities are linked to myriad diseases. Balanol, a fungal metabolite consisting of four rings, potently inhibits Ser/Thr protein kinases and can be modified to yield potent inhibitors that are selective-characteristi…
New power generation technologies are expected to reduce various environmental impacts of providing electricity to urban regions for some investment cost. Determining which power generation technologies are most suitable for meeting the demand of a particular region requires analysis of tradeoffs between costs and env…
Beamsplitting polarizer cubes consisting of two right angle prisms cemented together after one hypotenuse is coated have become important optical components in many optical systems. Usually the coating stack is of the MacNeille design. We present and compare an alternative coating structure consisting of a very fine w…
Abstract The effects of heat treatment below the melting point of 3,9‐bis{1,1‐dimethyl‐2[β‐(3‐ tert ‐butyl‐4‐hydroxy‐5‐methylphenyl)propionyloxy]ethyl}‐2,4,8,10‐tetraoxaspiro[5,5]‐undecane (AO‐80) on the thermal and dynamic mechanical properties and microstructure of chlorinated polyethylene (CPE) filled with vitrifie…
A convergent beam electron diffraction (CBED) study of Bi 2 La 2 Ti 3 O 12 was performed. As in the case of Bi 3 LaTi 3 O 12, it reveals a lowering of symmetry with respect to the idealized structure (space group I 4/ mmm ) of Aurivillius phases. The structure of Bi 4 - x La x Ti 3 O 12 ( x = 1 and 2) compounds has be…
A combination of experiments and theoretical calculations is used to develop an atomic-scale model of the grain boundary potential in perovskite oxides. More specifically, pristine $8\ifmmode^\circ\else\textdegree\fi{}$ and $58\ifmmode^\circ\else\textdegree\fi{}$ $[001]$ tilt grain boundaries in ${\mathrm{SrTiO}}_{3},…