Materials Literature
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Ferromagnetism of ZnO-based magnetic semiconductors was investigated by ab initio calculations based on the local density approximation. In a system of Mn atom doped ZnO, the ferromagnetic ordering of Mn magnetic moments was induced by hole doping. It was also found that 3 d transition metal atoms of V, Cr, Fe, Co and…
As the sizes of electronic and mechanical devices are decreased to the micron and nanometre level, it becomes particularly important to predict the thermal transport properties of the components. Using molecular level theories, such predictions are particularly important for modelling nano-electronic devices where sca…
The characterization of native point defects in ZnO is still a question of debate. For example, experimental evidence for ZnO with an excess of Zn is inconclusive as to whether the dominant defects are metal interstitials or oxygen vacancies. This information is essential to understand the behavior of the material and…
We report a comprehensive spectroscopic study of KY 3 F 10 doped with trivalent praseodymium. Employing both infrared absorption and laser excited fluorescence spectroscopy, we have constructed an energy level scheme of 39 crystal-field states. A C 4v symmetry, conventional crystal-field analysis can well account for…
Measurements of the complex elastic Young's modulus of PZT ceramics as a function of the frequency of a triangular switching electric field and of an ac dynamic mechanical stress were performed. The results show that the electrostrictive character of the ceramics provides a complex elastic Young's modulus, which depen…
We have measured the inelastic neutron scattering spectra of the glasses of six mono- and polyalcohols; 1-propanol, ethylene glycol, propylene glycol, 1,3-propanediol, glycerol and threitol. Broad excitation peaks with peak top energy of 3-5 meV appeared in all of the S (2θ, E ) spectra. These peaks were identified as…
4,4'-Bis(N-tert-butyloxylamino)-2,2'-bipyridine (4) and its 1:1 complexes with bis(hexafluoroacetylacetonato)manganese(II), -copper(II), and -zinc(II) were prepared. An X-ray structure analysis of free ligand 4 reveals that the molecule has a trans conformation with Ci symmetry and the aminoxyl radical center has a sh…
Crystal structures of human and rabbit cytosolic serine hydroxymethyltransferase have shown that Tyr65 is likely to be a key residue in the mechanism of the enzyme. In the ternary complex of Escherichia coli serine hydroxymethyltransferase with glycine and 5-formyltetrahydrofolate, the hydroxyl of Tyr65 is one of four…
α-decay damage and recrystallization in natural zircon (with dose ranging from 0.06 to 23.3 × 10 18 α-events g -1 ) were studied using polarized reflection infrared spectroscopy. The experimental results show that α-decay damage leads to a gradual decrease in reflectivity and a loss of anisotropy of IR spectra. Recrys…
Three conjugated polymers containing oligothiophene units (from one to three thiophene rings) and aromatic 1,3,4-oxadiazole moieties have been successfully synthesized. The polymer structures were characterized and confirmed by (1)H and (13)C NMR, FT-IR, and elemental analysis. Thermogravimetric analysis demonstrated…
The formation of cristobalite and tridymite compounds is described in the system SiO 2 -V 2 O 5 -M 2 CO 3 (M = Na, K). Syntheses were performed with various vanadium concentrations at annealing temperatures between room temperature and 1000°C. Crystallization of cristobalite occurs at much lower temperatures (about 80…
An investigation was made of the potentialities of aperiodic multilayer structures (AMSs) optimised to obtain a preassigned reflection spectrum in the x-ray range (λ < 300 Å) and also starting from other criteria. It was found that among the multitude of realisations of AMSs there exist those which are superior to the…
Magnetostrictive FeCo films (thickness 300 nm) have been produced by RF magnetron sputter deposition. The effects of the substrate, composition and thermal treatment on the structural and magnetic properties of the films have been determined. Structural analysis was performed using transmission electron microscopy and…
The N -alkylation of polyaniline (PANi) was investigated by treating the fully reduced state (leucoemeraldine or LM) and the 50% oxidized state (emeraldine or EM) directly with various alkyl halides. The degree of alkylation of LM is low (<10%), while that of EM base is much higher (can be >30%), suggesting that the i…
The film-forming potential of isolate of sunflower proteins (ISFP) was investigated. Homogeneous films were obtained by dissolution of ISFP in alkaline water (pH 12), addition of a plasticizer, casting, and drying. Maximum protein solubilization and unfolding led to films with the highest elasticity. The effects of fi…
One selected composition within the system Na2O-Al2O3-B2O3-SiO2-H2O (NABSH) was studied with the aim of synthesizing the new tourmaline end member olenite with the theoretical formula NaAl3Al6 [Si6O18] (BO3)O3(OH). The starting material consisted of a gel with the anhydrous composition 0.625Na2O.4.5Al2O3.6SiO2, but wi…
Polypropylene copolymer (PP-cp) has a large number of applications and is preferred over the homopolymer due to its higher impact strength. These impact properties can be further improved by blending with polyolefinic elastomer (POE). Blends were prepared by using commercially available POE (Engage® EG 8150, Dupont–Do…
The reaction mechanism for the selective oxidation of methane with hydrogen peroxide was investigated for a H 4 PV 1 Mo 11 O 40 catalyst precursor, which has been reported to be the most active among various Keggin-type heteropolyacids and vanadium complexes in trifluoroacetic acid anhydride. The conversion vs selecti…
The syntheses and X-ray structures of novel porphyrinoids, “N-fused porphyrins (NFPs)”, and their reactivity were described. NFP was spontaneously produced from the bromo-substituted N-confused tetraarylporphyrin in a pyridine solution at room temperature. X-ray diffraction analyses revealed that the porphyrinoid core…
Alternating thin films of the anionic dye pyrenetetrasulfonic acid (4-PSA) and poly(allylamine hydrochloride) (PAH) were formed by the squential deposition of 4-PSA and PAH from aqueous solution onto solid substrates. Film growth was followed by absorption spectroscopy, and the resulting polyelectrolyte-dye multilayer…