Materials Literature
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In doped CuGeO3 systems, such as (Cu1-xZnx)GeO3 and Cu(Ge1-xSix)O3, the spin-Peierls (SP) ordering (Txc. They thus concluded that there is a compositional phase boundary between two distinct magnetic phases. To clarify the nature of two phases, we performed neutron-scattering measurements on (Cu1-xMgx)GeO3 single crys…
Neutron and synchrotron diffraction data provide the first observation of changes in the crystal symmetry at the metal-insulator transition in $R{\mathrm{NiO}}_{3}$ perovskites. At high temperatures, ${\mathrm{YNiO}}_{3}$ is orthorhombic and metallic but below ${T}_{\mathrm{MI}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule…
The thermal properties of blends of poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) prepared by screw extrusion were investigated by differential scanning calorimetry. From the thermal analysis of amorphous PEEK–PEI blends which were obtained by quenching in liquid nitrogen, a single glass transition tempe…
The emulsion polymerization of methyl methacrylate initiated by ultrasound has been studied at ambient temperature using sodium lauryl sulfate as the surfactant. The investigation includes the: (1) nature and source of the free radical for the initiation process; (2) effects of different types of cavitation; and (3) d…
Ab initio electronic structure theory has been applied to study the effects of β-halogenation on the structure, ionization potentials (IP), and electronic spectra of free-base (PH2) and zinc porphyrins (ZnP). Electronic and infrared (IR) spectra of β-octahalogenated free-base (β-PX8H2; X=F, Cl, Br) and zinc porphyrins…
Effects of hydrostatic pressure on Raman spectra have been investigated in mixed-valence (MV) gold complexes Cs2Au2X6 (X=Cl and Br). We have observed pressure-induced deactivation of the Raman-active Au-X stretching modes at various temperatures, indicating a pressure-induced phase transition from the MV state to a si…
Flavin reductases use flavins as substrates and are distinct from flavoenzymes which have tightly bound flavins. The reduced flavin can serve to reduce ferric complexes and iron proteins. In Escherichia coli, reactivation of ribonucleotide reductase is achieved by reduced flavins produced by flavin reductase. The crys…
Radial basis function (RBF) neural network models for the simultaneous estimation of flash point ( T f ) and boiling point ( T b ) based on 25 molecular functional groups and their first-order molecular connectivity index ( 1 χ) have been developed. The success of the whole modeling process depended on a network optim…
We report the results of P31 NMR measurements on trioctylphosphine oxide (TOPO) passivated InP quantum dots. The spectra show distinct surface-capping sites, implying a manifold of crystal–ligand bonding configurations. Two In 31P surface components are resolved and related to different electronic surroundings. With d…
The charge carrier mobility in a ladder-type poly(paraphenylene) (MeLPPP) and a phenylamino-substituted poly(phenylenevinylene) (PPV) derivative (PAPPV) has been studied in detail by using the time-of-flight (TOF) method. In most cases, the TOF signals feature characteristics of nondispersive charge transport in terms…
We propose a new method of calculating nonlinear optical responses of interacting electronic systems. In this method, the total Hamiltonian (system + system-pump interaction) is transformed into a different form that (apparently) does not have a system-pump interaction. The transformed Hamiltonian, which we call the p…
La0.7Ce0.3MnO3 is a relatively new addition in the family of colossal magnetoresistive manganites where the cerium ion is believed to be in the Ce4+ state. In this paper we report an extensive study the magnetotransport properties of laser ablated La0.7Ce0.3MnO3 films on LaAlO3 with variation in ambient oxygen pressur…
Adsorption of poly( N -3-sulfopropyl- N -methacrylooxyethyl- N, N -dimethyl ammonium betaine) (polysulfobetaine abbreviated as PSB), which is a neutral- and zwitterion-type polyampholyte, onto a silica surface from aqueous NaCl solutions was studied by adsorbance measurement and ellipsometry. Adsorbance A increases wi…
Hexagonal mesostructured mixed-valence oxovanadium phosphates [CTA] x VOPO 4 · z H 2 O, in short ICMUV-2, have been synthesized through a S + I - cooperative mechanism using cationic surfactant (cetyltrimethylammonium, CTAB) rodlike micelles as a template. On the lines of the hypothesis that the driving force leading…
Cereport (RMP-7) is a selective bradykinin B2 receptor agonist which increases the permeability of the 'blood-brain tumour barrier' (BBTB) to increase delivery of chemotherapeutic agents to brain tumours. A series of experiments was performed in an RG2 rodent model of glioma to evaluate and refine intravenous (i.v.) p…
The melting behavior of poly(ε-caprolactone)- block -polybutadiene (PCL- b -PB) copolymers, crystallized at various temperatures T c from the melt (homogeneous state or microphase-separated state), has been studied by small-angle X-ray scattering with synchrotron radiation (SR−SAXS). The strong SR−SAXS intensity peak…
Selective reduction of nitric oxide by ammonia over sulfated CuO/γ-Al 2 O 3 was carried out in a fixed-bed reactor. The optimum temperatures of the fresh and sulfated CuO/γ-Al 2 O 3 in the selective catalytic reduction of NO are found to be 350 and 450 °C, respectively. NO reduction with the sulfated catalyst is somew…
A general strategy has been developed for fabrication of ultrathin monolayer and multilayer composite films composed of nearly all kinds of polyoxometalates (POMs), including isopolyanions (IPAs), and heteropolyanions (HPAs). It involves stepwise adsorption between the anionic POMs and a cationic polymer on alkanethio…
Bulk samples of the layered ternary nitride Cr2GaN were observed to extrude filaments of pure elemental gallium at room temperature. This self-extrusion phenomenon is best described as a room-temperature deintercalation of gallium from the basal planes of porous Cr2GaN samples. The extruded filaments are single crysta…
An effective bosonic Hamiltonian of $1s$ excitons with ``spin'' degrees of freedom in two dimension is obtained through a projection procedure, starting from a conventional electron-hole Hamiltonian ${\cal H}_{eh}$. We first demonstrate that a straightforward transformation of ${\cal H}_{eh}$ into a Hamiltonian of bos…