Yang Hai-Tao

Controlled growth of large＇scale silver nanowires

Large-scale silver nanowires with controlled aspect ratio were synthesized via reducing silver nitrate with 1, 2-propanediol in the presence of poly (vinyl pyrrolidone) (PVP). Scanning electron microscopy, transmission electron microscopy and x-ray powder diffraction were employed to characterize these silver nanowires. The diameter of the silver nanowires can be readily controlled in the range of 100 to 400 nm by varying the experimental conditions. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results show that there exists no chemical bond between the silver and the nitrogen atoms. The interaction between PVP and silver nanowires is mainly through the oxygen atom in the carbonyl group.

Preparation and Properties of Al/Pb-Ag-Co Composite Anode Material for Zinc Electrowinning

The Al/Pb-0.3wt%Ag-0.01wt%Co and Al/Pb-0.3wt%Ag composite anode materials were prepared by electrodeposition. The electrochemical properties of the composite anode in 50 g/L Zn2+ and 150 g/L H2SO4 solutions were investigated by anode polarization curves, cyclic voltammetry (CV) curves and Tafel curves. The surface structure was characterized by SEM and EDS. The results show that the cobalt addition can reduce the oxygen evolution potential and improve the corrosion resistance. Compared with cast Pb-0.3wt%Ag, the anodized layer of the Al/Pb-0.3wt%Ag and Al/Pb-0.3wt%Ag-0.01wt%Co are more dense, the grains are finer.

Atomic Force Microscopy Studies of Barium Titanate Thin Films Prepared by Laser Molecular Beam Epitaxy

Laser molecular beam epitaxy (laser MBE) technique was utilized to grow the barium titanate (BaTiO3, BTO) thin films on SrTiO3(100) substrates. The surface morphology of the BaTiO3 thin films was studied by atomic force microscopy (AFM). Two- and three-dimensional AFM images were obtained. The root mean square surface roughness, the height profile, the histogram and the bearing ratio of the height distributions for the BaTiO3 thin films were analyzed in detail. The results indicate that the laser MBE thin films exhibit an atomically smooth surface.

Production of High-

Taking into account the effects of shadowing and jet quenching, the large transverse momentum distribution of K+, π+ and K+/π+ ratios at originating from resolved photoproduction processes is calculated based on perturbative quantum chromodynamics. It is found that the contribution of K+ and π+ produced by photoproduction processes is evident. The K+/π+ ratios in Au–Au collisions show an obvious enhancement compared with p–p collisions. The numerical results indicate that the photoproduction processes are good modification for kaon and pion production.

p_T

Monodispersive ZnO nanoparticles each with a hexagonal wurtzite structure are facilely prepared by the high-temperature organic phase method. The UV-visible absorption peak of ZnO nanoparticles presents an obvious blue-shift from 385 nm of bulk ZnO to 369 nm. Both the real part and the image part of the complex permittivity of ZnO nanoparticles from 0.1 GHz to 10 GHz linearly decrease without obvious resonance peak appearing. The real parts of intrinsic permittivity of ZnO nanoparticles are about 5.7 and 5.0 at 0.1 GHz and 10 GHz respectively, and show an obvious size-dependent behavior. The dielectric loss angle tangent (tanδ) of ZnO nanoparticles with a different weight ratio shows a different decreasing law with the increase of frequency.

Kaon and Pion in pp and Au–Au Collisions by Resolved Photoproduction Processes

CoPt3/Co multilayered nanowire (NW) arrays are synthesized by pulsed electrodeposition into nanoporous anodic aluminum oxide (AAO) templates. The electrochemistry deposition parameters are determined by cyclic voltammetry to realize the well control of the ratio of Co to Pt and the length of every segment. The x-ray diffraction (XRD) patterns show that both Co and CoPt3 NWs exhibit face-centered cubic (fcc) structures. In the UV-visible absorption spectra, CoPt3/Co NW arrays show a red-shift with respect to pure CoPt3NWs. Compared with the pure Co nanowire arrays, the CoPt3/Co multilayered nanowire arrays show a weak shape anisotropy and well-modulated magnetic properties. CoPt3/Co multilayered nanowires are highly encouraging that new families of bimetallic nanosystems may be developed to meet the needs of nanomaterials in emerging multifunctional nanotechnologies.