W18O49 Nanowires as Ultraviolet Photodetector

Photodetectors in a configuration of field effect transistor were fabricated based on individual W18O49 nanowires. Evaluation of electrical transport behavior indicates that the W18O49 nanowires are n-type semiconductors. The photodetectors show high sensitivity, stability and reversibility to ultraviolet (UV) light. A high photoconductive gain of 104 was obtained, and the photoconductivity is up to 60 nS upon exposure to 312 nm UV light with an intensity of 1.6 mW/cm2. Absorption of oxygen on the surface of W18O49 nanowires has a significant influence on the dark conductivity, and the ambient gas can remarkably change the conductivity of W18O49 nanowire. The results imply that W18O49 nanowires will be promising candidates for fabricating UV photodetectors

Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski, Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy), Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy

Physics Performance Report for PANDA: Strong Interaction Studies with Antiprotons

To study fundamental questions of hadron and nuclear physics in interactions of antiprotons with nucleons and nuclei, the universal PANDA detector will be built. Gluonic excitations, the physics of strange and charm quarks and nucleon structure studies will be performed with unprecedented accuracy thereby allowing high-precision tests of the strong interaction. The proposed PANDA detector is a state-of-the art internal target detector at the HESR at FAIR allowing the detection and identification of neutral and charged particles generated within the relevant angular and energy range. This report presents a summary of the physics accessible at PANDA and what performance can be expected.Comment: 216 page

Electrochemical Fabrication of Pt-Au-WO3 Electrodes for Direct Methanol Fuel Cell

Pt-Au-WO3 ternary electrodes with various compositions were synthesized by electrochemical method from a mixture of H2PtCl6 aqueous solution, HAuCl4 aqueous solution, and W-peroxo complex. Their electrocatalytic activities for methanol oxidation were investigated. Film composition was controlled by varying the concentration of each component in electrolytes. Morphology and compositional analyses of the synthesized films were performed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The catalytic activity and initial behavior of current density for methanol oxidation of the synthesized films were measured using cyclic voltammetry (CV) and chronoamperometry (CA) in a mixture of 0.5 M H2SO4 and 0.5 M CH3OH solution. Electrocatalytic activity for CO oxidation was also evaluated in 0.5 M H2SO4 solution. The activities of various electrodes for methanol oxidation were found to be strongly dependent on film composition. Pt-Au-WO3 electrodes exhibited higher activity for CO oxidation than pure Pt. The addition of proper amount of Au and WO3 significantly improved catalytic activity for methanol oxidation.