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Ultra-long YCe x O y :Eu 3+ nanowire arrays(NWAs) have been synthesized in anodic aluminum oxide (AAO) templates by chemical co-deposition at negative pressure suction, which are amorphous, and possess precise dimension and homogeneous morphologies. The SEM, TEM, XRD and EDS were employed to investigate the morphology, structure and elemental composition of YCe x O y :Eu 3+ NWAs. The fluorescence properties of the YCe x O y :Eu 3+ NWAs were measured by fluorescence spectrometer (PerkinElmer LS-55) using Xenon discharge lamp as the excitation light source. There are two emission peaks at 615 nm and 702 nm with excitation wavelength of 394 nm, which corresponds to the 5 D 0 - 2 F 2 and 5 D 0 - 7 F 4 energy level transition of Eu 3+ , respectively. The fluorescence intensity of YCe x O y :Eu 3+ NWAs is related to the doping concentration of Eu 3+ ion, which reaches a maximum with doping concentration of Eu 3+ at 8%, and remarkably decreases at higher concentrations. Ce 3+ ion dominates the fluorescence activation in YCe x O y :Eu 3+ NWAs. [ABSTRACT FROM AUTHOR]

Abstract: Hollow AlPO4‐5 spheres (E‐AP and B‐AP) are synthesized ionothermally in tri‐substituted imidazolium bromide ionic liquids (ILs), that is, 1‐ethyl‐2,3‐dimethylimidazolium bromide and 1‐butyl‐2,3‐dimethylimidazolium bromide, respectively. Moreover, the morphologies of the hollow AlPO4‐5 particles vary with the type of ILs and the amounts of ILs, phosphoric acid, amine, and hydrofluoric acid. The thicknesses of the shells of the hollow spheres are substantially affected by the length of the alkyl chain on the imidazole ring of the ILs. The shell thicknesses significantly increase from 300–500 nm to 4–5 µm as the alkyl chain length increases, and solid AlPO4‐5 spheres (H‐AP) are generated in 1‐hexyl‐2,3‐dimethylimidazolium bromide IL. Furthermore, the experimental results suggest that the formation of hollow AlPO4‐5 spheres in an IL is consistent with Ostwald ripening theory. In addition, compared with ordinary solid AlPO4‐5 (S‐AP) prepared by hydrothermal methods, the hollow E‐AP particles are small and spherical. Moreover, the Co‐loaded hollow AlPO4‐5 (Co/E‐AP) catalyst exhibits excellent catalytic activities in the selective oxidation of tetralin. The reaction conversions are 73.5 and 5.7% over the Co/E‐AP catalyst and Co‐loaded solid AlPO4‐5 (Co/S‐AP) catalyst, respectively, which means that the hollow structure facilitates the mass transfer of the reactants and products in the catalytic reaction. [ABSTRACT FROM AUTHOR]

A solid acid boron phosphate (BP) has been prepared and characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The catalytic effects of BP on pyrolysis and flame retardancy of epoxy resins (EP) were studied by various methods. Transmission electron microscopy images suggested that BP was uniformly dispersed into the EP matrix. Differential scanning calorimetry illustrated that loading of BP could slightly reduce the glass transition temperature of EP. Thermogravimetric analysis and Fourier-transform infrared spectrometry indicated that BP catalyzed EP to pyrolysis at a lower temperature, leading to a reduction of flammable gas release and an increased residue yield. Limiting oxygen index (LOI) and UL 94 data showed that when the BP loading was increased, the LOI value increased accordingly. In addition, the UL 94 level was improved from no rating to a V-1 rating. In cone calorimeter measurements, a compact intumescent “honeycomb-like” char layer was found for the EP/BP composites, which led to considerable decreases in the maximum peak of heat release rate and total heat released. A possible catalytic flame retardant mechanism for the EP/BP composites is proposed. [ABSTRACT FROM AUTHOR]

To explore the effect of Cu-Cu distance in the structure of copper complexes on their catechol oxidase and nuclease activity, six copper complexes with a similar coordination sphere but different Cu-Cu distances were synthesized and characterized with elemental analysis, single-crystal X-ray diffraction, molar conductivity measurements, IR and UV-visible spectroscopy. Complex 1 is a binuclear copper complex and complex 4 is a polynuclear complex with a Z-chain structure, as evidenced by their crystal structures. Complementary characterizations showed that complexes 2 and 3 have a similar binuclear structure to the complex 1; and complexes 5 and 6 are analogous to complex 4. The catechol oxidase activity of complexes 1, 2, 3 is quite akin to that of 4, 5, 6, suggesting that the catechol oxidase activity of the complexes was determined by the coordination environment of the copper center, when Cu-Cu distance is large. In contrast, DNA cleavage activity of the complexes 1, 2 and 3 are much higher than that of 4, 5 and 6, indicating that the planar ligand structure in the complexes 4, 5 and 6 is more critical than the copper coordination sphere and the Cu-Cu distance for their nuclease activity. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the factors responsible for molecular interactions leading to self-assembly between the molecules of sorbitol and polyhedral oligomeric silsesquioxane (POSS) carrying organic and inorganic side groups. The study also assessed the utility of such molecular adducts as processing aids which will aid preparation of polymer compounds, films, and spun fibers. Several POSS molecules containing silanol functionalities and alkyl and phenyl substituents were used to separately evaluate the effects of hydrogen bonding and π−π interactions on formation of molecular adducts. The molecular adducts were studied using differential scanning calorimetry, wide angle X-ray diffraction, scanning electron microscopy, mass spectrometry, oscillatory shear rheology, and molecular dynamics simulation. The study revealed that POSS-sorbitol self-assembled structures were formed only when hydrogen bonding and π−π interactions worked cooperatively. In addition, self-assembled molecules were of amorphous nature although POSS and sorbitol were crystalline. [Copyright &y& Elsevier]

Abstract: Superparamagnetic Fe3O4 nanoparticles were synthesized via a modified coprecipitation method, and were characterized with X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Zeta potential and FT-IR, respectively. The influences of different kinds of surfactants (sodium dodecyl benzene sulfonate, polyethyleneglycol, oleic acid and dextran), temperatures and pH values on the grain size and properties were also investigated. In this method, Fe3+ was used as the only Fe source and partially reduced to Fe2+ by the reducing agent with precise content. The following reaction between Fe3+, Fe2+ and hydroxide radical brought pure Fe3O4 nanoparticles. The tiny fresh nanoparticles were coated in situ with surfactant under the action of sonication. Comparing with uncoated sample, the mean grain size and saturation magnetization of coated Fe3O4 nanoparticles decrease from 18.4nm to 5.9–9.0nm, and from 63.89emug−1 to 52–58emug−1 respectively. When oleic was used as the surfactant, the mean grain size of Fe3O4 nanoparticles firstly decreases with the increase of reaction temperature, but when the temperature is exceed to 80°C, the continuous increase of temperature resulted in larger nanoparticles. the grain size decreases gradually with the increasing of pH values, and it remains unchanged when the PH value is up to 11. The saturation magnetization of as-prepared Fe3O4 nanoparticles always decreases with the fall of grain size. [Copyright &y& Elsevier]

Abstract: β-FeOOH nanowire arrays were assembled into porous anodized aluminum oxide (AAO) templates by electrochemical deposition in the mixture solution of FeCl3 and (NH4)2C2O4. In order to obtain well-crystallized α-Fe2O3 and other iron oxides nanowires, β-FeOOH nanowire arrays with amorphous crystal structure were heat-treated at different temperatures from 200 to 600 °C. The decomposition products were characterized by DTA, XRD, FTIR, and Mössbauer spectroscopy. When heat-treated at 200 °C, only 65% of β-FeOOH decomposed, whereas, when the temperature was up to 300 °C, it was completely decomposed and formed poorly crystallized β-Fe2O3. This transition temperature is higher than the 200 °C obtained on other β-FeOOH materials. However, when heated above 300 °C, the main products are characterized as poorly crystallized α-Fe2O3 nanowires, whereas, well-crystallized α-Fe2O3 nanowire arrays can be formed when the temperature was up to 600 °C, and this temperature is also higher compared with those temperatures observed on other β-FeOOH materials. From Mössbauer results, the α-Fe2O3 nanowires were composed of fine particles in which 66% of the particles are superparamagnetic. [Copyright &y& Elsevier]

Electrical properties and phase structures of (Si+N)-codoped Ge2Sb2Te5 (GST) for phase change memory are investigated to improve the memory performance. Compared to the films with N or Si dopants only in previous reports, the (Si+N)-doped GST has a remarkable improvement of crystalline resistivity of about 104mOcm. The Fourier-transform infrared spectroscopy spectrum reveals the Si-N bonds formation in the film. X-ray diffraction patterns show that the grain size is reduced due to the crystallization inhibition of the amorphous GST by SiNx, which results in higher crystalline resistivity. This is very useful to reduce writing current for phase change memory applications. [ABSTRACT FROM AUTHOR]

B-site substituted Sr 2 Fe 1.4 X 0.1 Mo 0.5 O 6-δ (SFXM, X = Bi, Al and Mg) are evaluated as anode materials for hybrid direct carbon fuel cells (HDCFCs). The structure, morphology, conductivity and catalytic activity of the as-prepared SFXM anode are systematically investigated. Under a reducing atmosphere, the exsolution of metallic Fe from the SFXM perovskite lattice are demonstrated by the XRD, SEM and TEM observations. Further element valence analysis on reduced SFXM suggests the X doping significantly alters the Fe 3+ /Fe 2+ and Mo 6+ /Mo 5+ ratio, and thus beneficial to the intrinsic conductivity of SFXM. All these advantages are responsible for the good electrochemical performances of SFXM anodes. Meanwhile, among these SFXM anodes, the conductivity, catalytic activity and electrochemical performance all obey the order of SFBM > SFAM > SFMM. The maximum power densities of the La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3 electrolyte supported single cell with SFBM as the anode reaches 399, 287 and 141 mW cm −2 at 800 °C, 750 °C and 700 °C, respectively. Such designed B-site substitution perovskites have great potential to be applied as HDCFC anode materials. [ABSTRACT FROM AUTHOR]

Abstract: Two new mixed-ligand complexes [M(atdz)(DCA)(H2O)2]·2H2O, (M=Co(II), Zn(II); atdz=2-amino-1,3,4-thiadiazole, C2H3N3S; DCA=demethylcantharate, 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, C8H8O5) were prepared and characterized by elemental analysis. The structures of the complexes were determined by X-ray diffraction. The crystals have empirical formulas CoC10H19N3O9S (1) and ZnC10H19N3O9S (2), respectively. Complex 1 and 2 are monoclinic systems with space group P21/m. The structures of the complexes assume severely distorted octahedral geometries. The DNA binding properties of the complexes were investigated by electronic absorption spectra, thermal denaturation studies, fluorescence quenching studies and viscosity measurements. All the results showed the interaction modes between the complexes and DNA were partial intercalation. The results of agarose gel electrophoresis indicated the complexes could cleave supercoiled DNA. The antiproliferative activities testing revealed that all the complexes showed weak to moderate activities against human hepatoma cells (SMMC7721) and human breast cells (MCF-7) in vitro. [ABSTRACT FROM AUTHOR]

Nanosized LaCoxMn1−xO3 (x=0.3 and 0.4) oxide with perovskite structure was successfully synthesized at fairly low temperature in air by the decomposition of the amorphous precursor LaCoxMn1−x(DTPA)·6H2O (x=0.3 and 0.4). The precursor could completely decompose into oxide at temperature below 500 °C according to the DTA and TGA results. XPS and XRD demonstrated that the decomposed species was composed of LaCoxMn1−xO3 oxide and a perovskite structure was formed after being calcined at 500 °C for 2 h. TEM showed that LaCoxMn1−xO3 oxide existed as nanoparticles and the dispersion was homogeneous when the precursor was calcined at low temperature. The effect of the calcination temperature on the particle size and the specific surface area was much more serious than that of the calcination time. This method is effective and can be easily quantitatively controlled to synthesize nanosized perovskite oxides. [Copyright &y& Elsevier]

The ash fusion process of Jincheng anthracite ash, rice straw ash and coal-biomass ashes with different rice straw ash addition ratios during co-gasification under CO 2 atmosphere was elucidated by the ash fusion test, chemical analyses, optical heating stage microscopy (OHSM), X-ray diffraction and scanning electron microscopy equipped with energy-dispersive X-ray analyzer. Results showed that the initial sintering and initial melting temperatures of coal-biomass ashes observed by OHSM decreased with the addition of rice straw ash. The deformation temperatures determined by the ash fusion test were close to the initial melting temperatures. The biomass ash addition to coal ash introduced excessive amounts of alkaline compounds in the ash mixtures that led to lower initial temperatures of liquid phase formation. The ash fusion behavior of coal-biomass ashes with a rice straw ash addition ≤3 wt% was similar to that of coal ash and fits to the “softening-melting” ash fusion mechanism. In contrast, the ash fusion behavior of coal-biomass ashes with a greater addition of rice straw ash (>3 wt%) experienced dramatic changes at lower temperature and fits to the ‘‘melting-dissolution’’ ash fusion mechanism. [ABSTRACT FROM AUTHOR]

To study the transformation of organic structure and mineral matter in coal-biomass mixtures during co-gasification, the anthracite and rice straw addition with different ratios were isothermally gasified at 1100 °C under CO 2 atmosphere in a fixed bed reactor. The phase-mineral composition, morphology and organic structure of solid residues produced at different gasification time were analyzed by X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectrometer, Raman spectroscopy and other methods. Results revealed that the organic structure was changed in char as it became less ordered with the addition of biomass. The bulk concentrations of K and Na and their bearing minerals and phases in char increased with the addition of biomass during gasification process. The transformation of mineral matter played a significant role in promoting the coal gasification. [ABSTRACT FROM AUTHOR]

Ni modified Ce 0.6 Mn 0.3 Fe 0.1 O 2 (Ni-CMF) material is evaluated as an anode material for hybrid direct carbon fuel cell (HDCFC). The Temperature Programmed Reaction (TPR) and GC test results show that the Ni additive significantly promotes the oxidation of carbon and consequently accelerates the formation rate of CO. Moreover, the Ni-CMF material is found to show a high electrical conductivity compared to pure CMF in HDCFC operating conditions. Taking advantage of the excellent catalytic activity and high conductivity, the electrolyte-supported HDCFC with Ni-CMF anode shows a high maximum power density of 580.7 mW cm −2 at 800 °C, when activated carbon is used as the fuel. Furthermore, the cell displays good stability under galvanostatic operation at current density of 50 mA cm −2 at 750 °C. These results indicate that the designed Ni-CMF composite material has the potential to be developed as an alternative anode for HDCFCs. [ABSTRACT FROM AUTHOR]

Abstract: To improve the lattice structure of CeO2 and the transmission capacity of oxygen, Ce1−xFexO2(x≤0.2)solid solutions were prepared by a hydrothermal method and used in oxidative dehydrogenation of ethylbenzene to styrene with CO2. Ce1−xFexO2 solid solutions were characterized by powder X-ray diffraction, Raman spectroscopy, N2-adsorption, H2 temperature-programmed reduction and H2–O2 titration. Results showed that approximately 20% of Fe3+ could dissolve into the CeO2 lattice while portions of Fe2O3 were highly dispersed on the surface of the Ce1−xFexO2 solid solution. The formation of Ce–Fe solid solutions could create more oxygen vacancies to promote the absorption and activation of CO2, which improves the activity of the catalyst and increased ethylbenzene conversion by as much as 13%. [Copyright &y& Elsevier]