Results 1 - 10 of 23
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[en] 2-Hydroxy-1-naphthaldehyde oxime (receptor 1) serves as a selective chemosensor for cyanide anion (CN"−). In the presence of CN"−, an enhanced fluorescent intensity and red-shift were observed. The observed complexation between receptor 1 and CN"− may cause by a hydrogen bonding interaction between the OH group of receptor 1 and CN"−. - Highlights: • 2-Hydroxy-1-naphthaldehyde oxime serves as a selective chemosensor for CN"−. • In the presence of CN"−, an enhanced fluorescent and red-shift were observed
[en] In the present work Ce3+-doped germanate glasses containing Gd2O3 and BaO or La2O3 were developed. The UV and VIS transmission spectra of these glasses were measured before and after irradiation at doses ranging between 3 and 277 Gy. The radiation induced absorption coefficient μ was calculated on the basis of the measured transmission spectra. From these results the cerium ions doping turns out to be effective in improving the radiation hardness of glasses with respect to their undoped matrices
[en] Graphical abstract: A series of novel β-Bi2O3-NiO/Ni composites were synthesized via one-step solution combustion method. The coupling of β-Bi2O3 with NiO/Ni promoted the catalytic activity under visible light irradiation, which can be ascribed to the increase of separation efficiency of electrons and holes over β-Bi2O3-NiO and the existence of metallic Ni. - Highlights: • β-Bi2O3-NiO/Ni composites were prepared via one-step solution combustion method. • The materials had excellent visible light absorption ability and narrow band gaps. • Ni may show a plasmonic property and increase the visible light absorption. • The photocatalytic mechanism of the β-Bi2O3-NiO/Ni composites was proposed. • The as-obtained samples could be recycled easily by magnetic separation. - Abstract: A series of novel β-Bi2O3-NiO/Ni heterojunctions were synthesized via one-step solution combustion method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis spectroscopy and terephthalic acid (TA) fluorescence. The obtained NiO/Ni samples showed visible light absorbance ability and had narrow band gap of ca. 2.20 eV. The coupling of β-Bi2O3 with NiO/Ni promoted the visible light catalytic performance. The enhanced activity could be ascribed to the increase of separation efficiency of electrons and holes and the existence of metallic Ni, which might show a plasmonic effect and could increase the light absorption ability. The scavengers’ tests demonstrated that hydroxyl radical and holes species played a major role for the methyl orange degradation. Furthermore, the as-obtained samples had magnetic properties and could be recycled easily by magnetic separation from the reaction system. Finally, the mechanism of the photocatalytic reaction over β-Bi2O3-NiO/Ni composites was proposed
[en] Highlights: ► Novel PAN nanofibers contained β-cyclodextrin and Ag nanoparticles. ► The composite nanofibers as antibacterial material. ► The composite nanofibers showed stronger antibacterial activity. - Abstract: Polyacrylonitrile (PAN) nanofibers containing β-cyclodextrin (β-CD) and Ag nanoparticles have been prepared by electrospinning technology. The silver nanoparticles were obtained from the AgNO3/PAN/DMF solution, in which AgNO3 acted as the precursor, DMF as reducing reagent, and PAN as protective agent. Then, β-CD was added to above solution and the resultant Ag/β-CD-PAN/DMF solution was directly electrospun to prepare Ag/β-CD-PAN nanofibers. The morphology of the nanofibers has been characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The antimicrobial properties were investigated by Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria, and the results indicated that the composite nanofibers showed stronger antibacterial activity.
[en] A simple boronic acid derivative was utilized as a reaction-based receptor for CN− in aqueous solution. The receptor showed a selective and sensitive response to CN− over other various anions via nucleophilic addition of CN− to the imine moiety of the boronic-based receptor.
[en] Highlights: • An analytical model for inductance of thin-film magnetic devices was developed. • Different device topologies and magnetic permeabilities were addressed. • Inductance of various topologies were calculated and compared with simulation. • The model predicts simulated values with excellent accuracy. - Abstract: A generic analytical model has been developed to fully describe the flux closure through magnetic inductors. The model was applied to multiple device topologies including solenoidal single return path and dual return path inductors as well as spiral magnetic inductors for a variety of permeabilities and dimensions. The calculated inductance values from the analytical model were compared with simulated results for each of the analyzed device topologies and found to agree within 0.1 nH for the range of typical thin-film magnetic permeabilities (∼102 to 103). Furthermore, the model can be used to evaluate behavior in other integrated or discrete magnetic devices with either non-isotropic or isotropic permeability and used to produce more efficient device designs in the future.
[en] Highlights: → Chitosan/zinc sulfide (CS/ZnS) nano-composite films have been prepared by simulating bio-mineralization process.the sensing properties of nano-composite films to lead ions have been systematically investigated. → SEM and TEM observations showed that the size of ZnS particles in the CS films. → The fluorescence emission of the nanocomposite films is very sensitive to the presence of Pb ions and the emission is hardly affected by common ions in water, except for the iron ions. → The films may be developed as excellent sensing films for Pb ions in water. - Abstract: Chitosan/zinc sulfide (CS/ZnS) nano-composite films have been prepared by simulating bio-mineralization process. Factors affecting the hydrothermal stability and fluorescence properties of the films have been studied. Furthermore, the sensing properties of nano-composite films to lead ions have been systematically investigated. SEM and TEM observations showed that the size of ZnS particles is 70 nm, and the particles are evenly distributed within the CS films. The fluorescence emission of the nano-composite films indicates that the sizes of real fluorescing ZnS particles are less than 20 nm. This suggests that ZnS particles observed via SEM and TEM may be aggregates of smaller ZnS particles, and the smaller particles may be separated by the organics. The fluorescence emission (363 nm) of the nano-composite films is very sensitive to the presence of Pb ions. C(Pb2+) increased from 0 to 664.2 mg L-1 increases the emission dramatically. The emission is hardly affected by common ions in water, except for the iron ions. The films may be developed as excellent sensing films for Pb ions in water.
[en] Highlights: • A new fabrication method for silicon nanowires/micropillars structure is proposed. • The method is using lithography and metal-assisted chemical etching to fabricate silicon nanowires/micropillars structure. • The optimal light trapping properties of silicon nanowires structure were systemically investigated including etching concentration, etching time and etching temperature. • The average reflectance of silicon nanowires/micropillars structure was 1.96% in the wavelength range of 300–1000 nm. - Abstract: In this paper, a new fabrication method for silicon nanowires/micropillars structure is proposed. This method is using lithography and metal-assisted chemical etching to fabricate the structure of silicon nanowires/micropillars. In the experiment, to obtain the optimal light trapping properties of silicon nanowires/micropillars structure, the optimal light trapping properties of silicon nanowires were systemically investigated, including etching concentration, etching time and etching temperature. And then, a large-area uniform, controllable and optimal light trapping silicon nanowires/micropillars structure was fabricated using lithography and metal-assisted chemical etching method. This controllable and facile method for silicon nanowires/micropillars structure will expand its application in the field of optoelectronic devices and solar cells.
[en] To determine Z-score equations and reference ranges for Doppler flow velocity indices of cardiac outflow tracts in normal fetuses. A prospective cross-sectional echocardiographic study was performed in 506 normal singleton fetuses from 18 to 40 weeks. Twelve pulsed-wave Doppler (PWD) measurements were derived from fetal echocardiography. The regression analysis of the mean and the standard deviation (SD) for each parameter were performed against estimated fetal weight (EFW) and gestational age (GA), in order to construct Z-score models. The correlation between these variables and fetal heart rate were also investigated. Strong positive correlations were found between the twelve PWD indices and the independent variables. A linear-quadratic regression model was the best description of the mean and SD of most parameters, with the exception of the velocity time interval (VTI) of ascending aorta against EFW, which was best fitted by a fractional polynomial. Z-score equations and reference values for PWD indices of fetal cardiac outflow tracts were proposed against GA and EFW, which may be useful for quantitative assessment of potential hemodynamic alternations, particularly in cases of intrauterine growth retardation and structural cardiac defects.
[en] A pollution-free method to synthesize polyurethane (PU) was used. PU/CdS nanocomposite films were synthesized by simulating bio-mineralization process. The factors that affect the hydrothermal stability and fluorescence properties of the films were studied. Further, the sensing properties of the nanocomposite films to Ag(I) ions in water were systematically investigated. A scanning electron microscopy observation showed that the sizes of the CdS particles are around 60 nm, and the particles are evenly doped within the PU films. The fluorescence emission of nanocomposite films has been found to be very sensitive to the presence of Ag(I) ions, and a small amount of Ag(I) ions makes the emissions increase dramatically. The emission is hardly affected by other common ions in water except chloride and sulfate through their precipitation effects on Ag+ ions. The films are predicted to have the potential to be developed into excellent sensing films for Ag(I) ions in water.