Anisotropic hybrid excitation modes in monolayer and double-layer phosphorene on polar substrates

We investigate the anisotropic hybrid plasmon-SO phonon dispersion relations in monolayer and double-layer phosphorene systems located on the polar substrates, such as SiO2, h-BN and Al2O3. We calculate these hybrid modes with using the dynamical dielectric function in the RPA by considering the electron-electron interaction and long-range electric field generated by the substrate SO phonons via Frohlich interaction. In the long-wavelength limit, we obtain some analytical expressions for the hybrid plasmon-SO phonon dispersion relations which represent the behavior of these modes akin to the modes obtaining from the loss function. Our results indicate a strong anisotropy in plasmon-SO phonon modes, whereas they are stronger along the light-mass direction in our heterostructures. Furthermore, we find that the type of substrate has a significant effect on the dispersion relations of the coupled modes. Also, by tuning the misalignment and separation between layers in double-layer phosphorene on polar substrates, we can engineer the hybrid modes.Comment: 10 pages, 7 figure

Genetic variability of Taenia saginata inferred from mitochondrial DNA sequences

Taenia saginata is an important tapeworm, infecting humans in many parts of the world. The present study was undertaken to identify inter- and intraspecific variation of T. saginata isolated from cattle in different parts of Iran using two mitochondrial CO1 and 12S rRNA genes. Up to 105 bovine specimens of T. saginata were collected from 20 slaughterhouses in three provinces of Iran. DNA were extracted from the metacestode Cysticercus bovis. After PCR amplification, sequencing of CO1 and 12S rRNA genes were carried out and two phylogenetic analyses of the sequence data were generated by Bayesian inference on CO1 and 12S rRNA sequences. Sequence analyses of CO1 and 12S rRNA genes showed 11 and 29 representative profiles respectively. The level of pairwise nucleotide variation between individual haplotypes of CO1 gene was 0.3–2.4 % while the overall nucleotide variation among all 11 haplotypes was 4.6 %. For 12S rRNA sequence data, level of pairwise nucleotide variation was 0.2–2.5 % and the overall nucleotide variation was determined as 5.8 % among 29 haplotypes of 12S rRNA gene. Considerable genetic diversity was found in both mitochondrial genes particularly in 12S rRNA gene. © 2015, Springer-Verlag Berlin Heidelberg

Investigation of presence different surfactant on morphologies of PbTe nanostructures

PbTe nanostructures were prepared by a hydrothermal method on presence of different surfactant. Results show that in constant condition by changing the capping agent the morphology of as-obtained PbTe were revolutionize PbTe nanostructures show a strong photoluminescence peak at 402 nm at room temperature, also optical absorption spectrum of PbTe nanostructures exhibit an extreme blue-shift, which is attributed to the quantum confinement of charge carriers in the nanostructures. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence spectroscopy, and Fourier transformed infrared spectroscopy were used to characterize the as-produced PbTe nanostructures

Investigation of presence different surfactant on morphologies of PbTe nanostructures

PbTe nanostructures were prepared by a hydrothermal method on presence of different surfactant. Results show that in constant condition by changing the capping agent the morphology of as-obtained PbTe were revolutionize PbTe nanostructures show a strong photoluminescence peak at 402 nm at room temperature, also optical absorption spectrum of PbTe nanostructures exhibit an extreme blue-shift, which is attributed to the quantum confinement of charge carriers in the nanostructures. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence spectroscopy, and Fourier transformed infrared spectroscopy were used to characterize the as-produced PbTe nanostructures

Novel precursors in preparation and characterization of nanosuperconductor YBa[2]Cu[3]O[7-y]

In order to prevent agglomeration of high temperature YBa2Cu3O7-x (YBCO) superconducting materials, the solid state processing method based on new and appropriate yttrium complex precursors that have high stability in air and compatibility in solution, was used without applying any surfactant. A new method of preparing yttrium precursors on the basis of coordination hydroxynaphthaldehydate, salicylaldehyde and acetylacetonate compounds has been suggested. These have been prepared by a reaction of yttrium acetate with three various coordination compounds for forming yttrium complex types. These techniques provide proper control on nanoparticles size distribution. The generated steric hindrance due to the structure of the novel precursors, acts like a protecting agent and prevents from agglomeration. We synthesized nanoparticles of a size about 30–50 nm with homogeneous grains distribution at high calcination temperature 920 °C. The maximum values of transition temperature into the superconducting state have been found to be Tc(0) = 84 K with a temperature interval of ∆T = 3 K for YBCO nanosuperconductor. The synthesized products were characterized by powder Xray diffraction, fourier transform infrared spectroscopy (FT-IR), transmission electron micrograph and scanning electronic microscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2066

Facile Surfactant-Free Preparation, Characterization and Investigation of Optical Properties of Zirconia Nanostructures

Zirconia nanostructures have been successfully synthesized through sonochemical-assisted rout. Zirconia nanostructures were synthesized by employing of the zirconyl nitrate and tetramethylethylenediamine (TMED) as starting materials. Here, TMED was used not only as precipitator, but also as capping agent to form zirconia nanostructures. The products were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible (UV–vis) spectroscopy and scanning electron microscopy (SEM). The obtained results demonstrated that utilizing of this precipitator is suitable choice for preparation of zirconia nanostructures with very uniform sphere-like morphology

Facile Solvent-Less Preparation, Characterization and Investigation of Photocatalytic Properties of Pr6O11 Nanostructures

Pr6O11 nanostructures were synthesized through a facile solvent-less method. Nanostructures were prepared by heat treatment in air, using [Pr L(NO3)2]NO3 (L bis-(salicyladehyde)-1,4-butadiimine Schiff base ligand), as new precursor, which was obtained by a solvent-free solid–solid reaction from praseodymium nitrate and Schiff base ligand. The as-obtained nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet–visible (UV–vis)spectroscopy. The obtained results demonstrated that utilizing of this precursor is suitable choice for preparation of Pr6O11 nanostructures with very uniform sphere-like morphology. The photocatalyst activity of as-obtained Pr6O11 was also examined by degradation of 2-naphthol as organic contaminant under ultraviolet light irradiation

Facile Solvent-Less Preparation, Characterization and Investigation of Photocatalytic Properties of Pr6O11 Nanostructures

Pr6O11 nanostructures were synthesized through a facile solvent-less method. Nanostructures were prepared by heat treatment in air, using [Pr L(NO3)2]NO3 (L bis-(salicyladehyde)-1,4-butadiimine Schiff base ligand), as new precursor, which was obtained by a solvent-free solid–solid reaction from praseodymium nitrate and Schiff base ligand. The as-obtained nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet–visible (UV–vis)spectroscopy. The obtained results demonstrated that utilizing of this precursor is suitable choice for preparation of Pr6O11 nanostructures with very uniform sphere-like morphology. The photocatalyst activity of as-obtained Pr6O11 was also examined by degradation of 2-naphthol as organic contaminant under ultraviolet light irradiation