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Abstract: Structural and photoluminescence properties of undoped and Ce3+-doped novel silicon-oxynitride phosphors of Ba4−z M z Si8O20−3x N2x (M=Mg, Sr, Ca) are reported. Single-phase solid solutions of Ba4−z M z Si8O20−3x N2x oxynitride were synthesized by partial substitutions of 3O2−→2N3− and Ba→M (M=Mg, Ca, Sr) in orthorhombic Ba2Si4O10. The influences of the type of alkaline earth ions of M, the Ce3+ concentration on the photoluminescence properties and thermal quenching behaviors of Ba3 MSi8O20−3x N2x (M=Mg, Ca, Sr, x=0.5) were investigated. Under excitation at about 330nm, Ba3 MSi8O20−3x N2x :Ce3+ (x=0.5) exhibits efficient blue emission centered at 400–450nm in the range of 350–650nm owing to the 5d→4f transition of Ce3+. The emission band of Ce3+ shifts to long wavelength by increasing the ionic size of M due to the modification of the crystal field, as well as the Ce3+ concentrations due to the Stokes shift and energy transfer or reabsorption of Ce3+ ions. Among the silicon-oxynitride phosphors of Ba3 MSi8O18.5N:Ce3+, M=Sr0.6Ca0.4 possesses the best thermal stability probably related to its high onset of the absorption edge of Ce3+. [Copyright &y& Elsevier]

Abstract: The photoluminescence properties of Eu2+, Ce3+ and Tb3+ doped α-Si3N4 have been studied and a possible structural model has been proposed on the basis of the Rietveld refinement of X-ray powder diffraction data. Nearly single phase rare earth doped α-Si3N4 was synthesized by a solid state reaction at 1600°C in N2–H2 atmosphere starting from amorphous Si3N4 and rare earth oxides or nitrides. Because of small crystal field splitting of the 5d levels, the excitation and emission bands of Eu2+ and Ce3+ are positioned at higher energies as isolated ions in comparison with that in Ca-α-Sialon. Both Eu2+- and Ce3+-doped α-Si3N4 show blue band emission peaking at about 470 and 450nm, respectively, under UV excitation. α-Si3N4:Tb3+ exhibits dominant green line emission mainly arising from 5D4→7F J (J=6–3) with weak 5D3→7F J (J=6–3) transitions of Tb3+ when excited by UV light. The thermal stability of α-Si3N4:Eu2+ is comparable with that of Ca-α-Sialon:Eu2+ and is much better than that of α-Si3N4:Ce3+. [Copyright &y& Elsevier]

Abstract: Photoluminescence properties and local electronic structures of rare earth (Eu3+ and Ce3+) activated Sr3AlO4F have been studied. X-ray powder diffraction data indicated that the activator ions of Eu3+ and Ce3+ can be incorporated into the Sr3AlO4F lattice and formed limited solid solutions of Sr3−2x Ln x Na x AlO4F (Ln=Eu, Ce) with Na+ as a charge compensator ion. The local structure around Sr sites was initially explored using Eu-activated Sr3AlO4F as a structural probe. Sr3AlO4F:Eu3+ exhibits orange-red emission ranging from 520 to 740nm with a maximum peak at about 619nm mainly originating from the 5D0 → 7FJ (J =0, 1, 2, 3, 4) transitions, indicating that Eu exists mainly in the trivalent state due to a strong oxidative lattice in Sr3AlO4F. Sr3AlO4F:Ce3+ shows an unusual long-wavelength 4f→5d excitation band of Ce3+ at about 405nm due to a large crystal field splitting of the 5d levels of Ce3+ in relation to its crystal structure. Under near-UV excitation in the range of 375–405nm, Sr3AlO4F:Ce3+ exhibits efficient blue-green emission at about 506nm. Given high absorption and efficient excitation in the near-UV region, Sr3AlO4F:Ce3+ demonstrates a potential blue-green emitting phosphor for applications in white LED lighting. [Copyright &y& Elsevier]

Abstract: The electronic structure of undoped and luminescence properties of Eu2+-doped Ca2BN2F have been investigated. First-principles calculations for Ca2BN2F show that the valence band is mainly composed of F and N 2p, B 2s and 2p orbitals, while the Ca 4s and 3d are almost empty, indicating that Ca2BN2F is a very ionic compound. The valence band close to the Fermi level is dominated by the N 2p states, and the bottom of the conduction band is determined by the Ca 3d and N/B 3s orbitals. The direct energy gap is calculated to be about 3.1eV, in fair agreement with the experimental data of ∼3.6eV derived from the diffuse reflection spectrum. Due to the high degree of ionic bonding of the coordinations of Eu with (N, F) on the Ca sites, Ca2BN2F:Eu2+ shows strong blue emission with a maximum at about 420nm upon UV excitation in the absorption range of 330–400nm. [Copyright &y& Elsevier]

Abstract: The photoluminescence properties of Eu2+-, Ce3+- and Tb3+-activated BaSi7N10 have been studied. The transitions of f↔d of the Eu2+ and Ce3+ ions occur at relatively high energies for nitrides which are principally attributed to weak bonding strength of Ba–N and small crystal field splitting of 5d excitation levels of Eu2+ and Ce3+ due to a large Ba crystallographic site in BaSi7N10. As a result, it was found that BaSi7N10:Eu2+ showed blue emission at about 475nm originating from the 4f65d1 →4f7 transition of Eu2+ upon UV excitation. While BaSi7N10:Ce3+, Li+ exhibited UV-blue emission with a maximum at about 400nm caused by the 5d→4f transition of Ce3+. In BaSi7N10:Tb3+, Li+, the luminescence spectrum of Tb3+ was dominated by green line emission arising from the 5D4 → 5F J (J =3, 4, 5, 6) transitions. [Copyright &y& Elsevier]

Abstract: The crystal and electronic structures, optical and magnetic properties of Tb4Al2O9 have been reported. Polycrystalline Tb4Al2O9 was synthesized by a solid state method at 1600°C for 4h under N2 atmosphere (0.48MPa) using AlN as an in situ reducing agent. Tb4Al2O9 is crystallized in the monoclinic crystal system having space group P21/c with a =0.74831(1)nm, b =1.05569(1)nm, c =1.11507(1)nm, β =108.96(1)0. Tb4Al2O9 was calculated to be a wide band gap semiconductor with indirect band gap energy of about 3.83eV in fair agreement with the experimental value ∼4.59eV obtained from the diffuse reflection spectrum. No photoluminescence of Tb3+ could be observed because of large effects of photoionization and concentration quenching of Tb3+ in Tb4Al2O9. Tb4Al2O9 exhibited weak antiferromagnetic interactions with an effective magnetic moment of near that of the Tb3+ free ion. [Copyright &y& Elsevier]

Abstract: AlN thin films with different orientation degrees, i.e., (0002) textured, (0002) textured with traces of non-(0002) components, and randomly oriented, were deposited by radio frequency magnetron sputtering. The films were comprehensively characterized using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The dependence of orientation degree on the nitrogen partial pressure during the deposition processes was revealed. Based on microstructural analysis with high-resolution transmission electron microscopy and photoluminescence measurements, the correlation between the orientation degree and photoluminescence was investigated. It was suggested that the defects induced in large-angle grain boundaries were possibly responsible for the enhanced non-band-edge emission. [Copyright &y& Elsevier]

Abstract: The influence of the replacement of Sr by Ca on structural and luminescence properties of Eu2+-doped Sr2Si5N8 is reported. The Rietveld refinement of the powder X-ray diffraction data shows that the Ca2+ ion preferentially occupies the larger Sr site in Sr2Si5N8:Eu2+. Although the excitation spectrum is hardly modified, the position of the emission band of Eu2+ can be tailored through partial replacement of Sr by Ca in Sr2Si5N8:Eu2+, resulting in red-emission shifting from 620 to 643nm. Furthermore, (Sr, Ca)2Si5N8:Eu2+ shows high potential as a conversion phosphor for white-light LED applications due to similar absorption, conversion efficiency and thermal quenching behaviour for 465nm excitation after the introduction of the Ca ion. [Copyright &y& Elsevier]

Summary: Introduction: There are many possible methods for penis reconstruction, among them, pedicled flaps, myocutaneous flaps, combined osseocutaneous flaps, and free skin flaps. This study evaluated the free scapular skin flap method for penile reconstruction. Methods: Fifteen men aged 20 to 48 underwent the procedure between March 2000 and February 2006, with follow-up examinations from 6 months to 5 years. Results: Fourteen of the reconstructions were successful, with patients enjoying good cosmetic results as well as functionality. Conclusion: The free scapular skin flap technique is a good method for penile reconstruction. [Copyright &y& Elsevier]

Abstract: The ZnO nanorods have been prepared on lime-glass substrate by doping Li+ and/or Mg2+ using a sol–gel method. The results show that the degree of C-orientation of Li/Mg doped ZnO nanorods is much high compared with that of Li doped and undoped ones. The individual nanorod exhibits an asymmetric hexagonal morphology with uniform diameter (50–80nm) along its length (300nm), and few abnormal ZnO rods (with about 3μm length) can be observed on the surface in the SEM images. The growth mechanism of ZnO nanorods has also been discussed. [Copyright &y& Elsevier]

Abstract: Isothermal oxidation behaviour of powdered boron carbide (B4C) with the fine (1.52μm), medium (22.5μm) and coarse (59.6μm) particle size has been studied in air ranging from 500 to 800°C. The oxidation rate strongly depends on the particle size of boron carbide and temperature. The smaller particle size the higher oxidation rate of B4C powder due to its larger surface area. When B4C powder is oxidized in air, a B2O3 glass film is formed on the surface of B4C grain which retards the further oxidation reaction. The oxidation kinetics is approximately fitted to the diffusion-controlled rate law which can be described by the Jander''s equation. The apparent activation energy for the fine-, medium- and coarse-B4C powders is 209.4±11.4, 212.7±35.8 and 219.2±45.3kJmol−1, respectively, slightly varying with the impurity content of B4C powders. The type of rate law suggests that the diffusion of oxygen through the oxide layer is the rate-limiting step in the oxidation reactions. In addition, the change in the oxidation process at higher oxidation fraction might associate with the B2O3 volatilization at higher temperatures. [Copyright &y& Elsevier]

Abstract: In this paper, the wind load distribution as well as its effects on single-layer reticulated cylindrical shells, which are widely used in practice, is investigated. At first, wind pressure distributions on three rigid cylindrical shell models considering different shape ratios are measured simultaneously in a wind tunnel. Some special characteristics of the measured wind pressure, especially its fluctuating component, are discussed. Then, considering the special structural mechanical behaviors, the effects of wind load, especially the fluctuating component, on the limit load-carrying capacity and the stability of the shells are investigated by both equivalent static analysis and dynamic analysis. Suitable methods to get a reasonable estimation of wind load effects in estimating the equivalent static wind load distribution for such shells are investigated. Finally, with comparison analyses using different methods mentioned in this paper, the efficiency of the method in estimating the effective wind load distribution presented by the authors previously for single-layer reticulated spherical shells is demonstrated, and some advices for estimating the wind load distribution on single-layer reticulated cylindrical shells is given for wind-resistant design in practice. [Copyright &y& Elsevier]

Abstract: The influence of the type of the alkaline-earth ion and the Eu2+ concentration on the luminescence properties of Eu2+-doped M2Si5N8 (M=Ca, Sr, Ba) has been investigated. XRD analysis shows that Eu2+-doped Ca2Si5N8 forms a limited solid solution with a maximum solubility of about 7mol% having a monoclinic lattice. The Eu2+ ion can be totally incorporated into Sr2Si5N8 and Ba2Si5N8 forming complete solid solutions with orthorhombic lattices. M2Si5N8:Eu2+ (M=Ca, Sr) shows typical broad band emission in orange to red spectral range (600–680nm) depending on the type of M and the europium concentration. Ba2Si5N8:Eu2+ shows yellow to red emission with maxima from 580 to 680nm with increasing Eu2+ content. The long-wavelength excitation and emission is attributed to the effect of a high covalency and a large crystal-field splitting on the 5d band of Eu2+ in the nitrogen environment. With increasing the europium concentration, the emission band shows a red-shift for all M2Si5N8:Eu2+ compounds due to changing Stokes shift and the reabsorption by Eu2+. The conversion (i.e. quantum) efficiency increases going from Ca to Ba and Sr under excitation at 465nm. In particular, Sr2Si5N8:Eu2+ with a quantum efficiency of 75–80% and a thermal quenching of only a few percent at 150°C, demonstrates to be a highly promising red-emitting conversion phosphor for white-LED applications. [Copyright &y& Elsevier]

Abstract: The luminescence properties of Ce3+, Li+ or Na+ co-doped alkaline-earth silicon nitride M2Si5N8 (M=Ca, Sr, Ba) are reported. The solubility of Ce3+ and optical properties of M2−2 x Ce x Li x Si5N8 () materials have been investigated as function of the cerium concentration by X-ray powder diffraction analysis and fluorescence spectroscopy. X-ray diffraction results show that the maximum solubility of Ce3+ in M2Si5N8 is about 2.5mol% () for both Ca2Si5N8 and Sr2Si5N8, and at 1.0mol% () for Ba2Si5N8. The Ce3+-activated M2Si5N8 phosphors exhibit broad emission bands with maxima at 470, 553 and 451nm for M=Ca, Sr, Ba, respectively, due to the 5d→4f transition of Ce3+. In addition, M2Si5N8:Ce3+, Li+ (M=Sr, Ba) obviously shows two Ce3+ emission centers due to the fact that the Ce3+ ions occupy two M sites. With increasing Ce3+ concentration, both absorption and emission intensity increase and the position of the emission bands show a slight red-shift (<10nm). The influence of using Na+ instead of Li+ ion as charge compensator on emission and excitation properties is small but Na+ enhances the emission intensity because of larger solubility of Ce3+ in M2Si5N8 (M=Ca, Sr). With increasing the ionic radius going from Ca to Sr and Ba, the ratio of the emission intensity to the absorption intensity of Ce3+ decreases related to a decreasing Ce3+ solubility. An intense absorption and excitation band in the blue range (370–450nm) in M2Si5N8:Ce, Li(Na) (M=Ca, Sr) points out that these materials are promising conversion phosphors for white-light LEDs. [Copyright &y& Elsevier]

BaYSi4N7 and its phosphors activated with Eu2+ and Ce3+ were synthesized by solid-state reaction at 1400–1650 °C under nitrogen mixed with hydrogen atmosphere. The crystal structure of BaYSi4N7 was solved by direct methods and refined by the Rietveld method from powder X-ray diffraction data. BaYSi4N7 crystallizes in the hexagonal space group P63mc (No.186), with a = 6.0550 (2) Å, c = 9.8567 (1) Å, V = 312.96 (2) Å3, and Z = 2, which is isotypic with BaYbSi4N7. The photoluminescence properties have been studied for the solid solutions of Ba1-xEuxYSi4N7 (x = 0 – 0.4) and BaY1-xCexSi4N7 (x = 0 – 0.1) at room temperature. Eu2+-doped BaYSi4N7 gives a broad green emission band centered between 503 and 527 nm depending on the Eu2+ concentration. The Eu2+ emission band shows a red-shift formulation with increasing Eu2+ concentration mainly caused by the change of the crystal field strength and Stokes shift. Concentration quenching of Eu2+ emission is observed for x = 0.05 due to energy transfer between Eu2+ ions by electric dipole–dipole interactions with a critical interaction distance of about 20 Å. Ce3+-doped BaYSi4N7 exhibits a bright blue emission band with a maximum at about 417 nm, which is independent of Ce3+ concentration. This is ascribed to a lower solubility of Ce3+ ions in BaYSi4N7 lattice as shown by X-ray powder diffraction analysis. [Copyright &y& Elsevier]

While gold and silver have high work functions, they are known to form relatively poor hole injecting contacts with organic semiconductors. We have found that inserting an ultrathin layer of plasma-polymerized fluorocarbon (CFx) between the metal and organic materials can substantially improve the hole injection. The working mechanism of the CFx interlayer was investigated with ultraviolet and x-ray photoemission spectroscopy and high resolution electron energy loss spectroscopy. The hole injection enhancement was caused by the reduced hole injection barrier, attributed to an interfacial electric field induced by the partial charge transfer from the metal to the CFx layer. Stability of the dipolar interface upon exposure to air was also demonstrated. [Copyright &y& Elsevier]

For a wide range of environmental pollutants, the aquatic ecosystem is the final sink, where nontarget aquatic organisms can be affected. On a worldwide scale, the emission of anthropogenic chemicals has resulted in long-term ecotoxicological effects. Aminophenols, which have three isomeric forms, including ortho-aminophenol (OAP), meta-aminophenol (MAP) and para-aminophenol (PAP), are commonly used in industrial chemical syntheses such as a dye intermediate, in dyeing hair, fur, and textiles, and as a photographic developer. Massive amounts of their discharges have had detrimental effects on the environment. Take PAP for example. As a parent material for the production of paracetamol, one of the most produced pharmaceuticals worldwide, PAP is applied most widely among three isomers. The amount of PAP increases 5% per year throughout the world and the yield is about 20kt annually in China (Sun and Wang 2001). In addition, these compounds are the metabolites of related xenobiotics such as nitrobenzene, aniline, phenacetin and acetaminophen. According to the results of studies, it is well known that PAP is a possible mutagen and teratogen (Yoshida et al. 1998). However, as far as we are aware, aquatic toxicity data for these three compounds are very limited or not available. The primary purpose of the present study was to investigate the toxic effects of three aminophenols on aquatic life, including the effects on embryo development of the zebrafish and genotoxic effects on kidney cells of carp. The possible contribution of the relative positions of the hydroxyl and amidogen substituents on the benzene ring to in vivo toxicity was also evaluated with the comparison among the three isomers. [ABSTRACT FROM AUTHOR]

A flexible organic light-emitting diode (FOLED) was fabricated on a steel foil. Stainless steel foil, spin-coated polyvinyl acetate (PVA) and silicon oxide were used as a flexible substrate, an insulating planarization layer and a buffer layer, respectively. Patterned indium tin oxide (ITO) was sputter-deposited on the buffer layer to form an anode. N,N′-bis-(1-naphthl)-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) and tris(8-quinolinolato) aluminum (Alq3) were used as a hole-transporting layer and a light-emitting/electron-transporting layer, respectively. A thin samarium layer was deposited on the organic stack to serve as a semitransparent cathode. The turn-on voltage of the resulting FOLED was 3 V, and the light-emitting efficiency reached 0.56 cd/A. The FOLED was shown to bend substantially without incurring detectable degradation. [Copyright &y& Elsevier]

Interfacial chemistry of samarium (Sm) with tris-(8-hydroxyquinoline) aluminum (Alq3) has been investigated. Photoelectron analysis revealed strong interactions at the Sm–Alq3 interface and limited Sm diffusion into Alq3. The lowest unoccupied molecular orbital of Alq3 was found to be 0.28 eV below the Fermi level of Sm at the Sm–Alq3 contact, implying lacking a barrier to electron-injection from the Sm to Alq3. Replacing Sm for MgAg as a cathode in organic electroluminescent devices considerably improved current–voltage characteristics, while the device efficiency was found to decrease by 40%. The reduction in efficiency is attributed to low optical reflectance at the Sm–Alq3 interface. [Copyright &y& Elsevier]

Abstract. Micro-bubbles have been stably trapped in liquid ethanol by a focused argon laser beam. Two equilibrium points where bubbles can be trapped are observed to be at the center and the rim of the laser beam. The light force is also able to push a bubble into the liquid to a position well below the liquid surface. Both the light-pressure force and the fluid force induced by the convection of the liquid medium are calculated. The results clearly show that these two kinds of forces account for the formation of trapping potential. [ABSTRACT FROM AUTHOR]

Proposes a technique for the fabrication and characterization of white-light organic electrochemical devices from multiheterostructures. Configuration for white-light emitting diodes;. Use of triphenyldiamine derivative as a hole-transporting layer; Maximum brightness and luminous efficiency of the device.

Examines the effect of Y[sub 2]O[sub 3] precipitates on critical current anisotropy in YBa[sub 2]Cu[sub 3]O[sub 7-x] thin films prepared by plasma-enhanced metalorganic vapor deposition. Use of the four-probe technique to measure the critical current density; Comparison of magnetic field positions in copper oxide planes; Function of precipitates as effective pinning centers.

Examines the thin films of yttrium-rich YBa[sub 2]Cu[sub 3]O[sub 7-x] with c-axis orientation prepared by plasma-enhanced chemical vapor deposition. Identification of yttria precipitates; Distribution of the yttria precipitates in the matrix; Effectiveness of the precipitates as flux pinning centers.

Prepares single-crystalline epitaxial YBa[sub 2]Cu[sub 3]O[sub 7-x] thin films by a plasma-enhanced metalorganic chemical vapor deposition (MOCVD). Formation of the films on lanthanum aluminum oxide substrates; Degree of epitaxial crystallinity of the films; Applications of MOCVD.

Studies oxygen decomposition in highly c-axis oriented YBa[sub 2]Cu[sub 3]O[sub 7-x] thin films deposited by plasma-enhanced metalorganic chemical vapor deposition. High transition temperature exhibited; Copper-rich precipitates on the surface; Reduction in transport properties observed in stoichiomeric films.

Discusses the preparation of YBCO superconducting thin films by metalorganic chemical vapor deposition process. Resistivity and magnetic susceptibility measurements of the as-deposited films; Measurement of the critical current densities by direct current transport method; Growth of films epitaxially with the c axis perpendicular to the surface of the substrate.