Long-term outdoor experiments were conducted to investigate the effects of elevated ultraviolet-B (UV-B, 280-320 nm) radiation on secondary metabolites (phenolics and terpenoids) and the main soluble sugars (sucrose, raffinose and glucose) in the bark of silver birch (Betula pendula Roth) saplings. Saplings were exposed to a constant 50% increase in erythemal UV irradiance (UV-B(CIE); based on ...

Arabidopsis thaliana UV RESISTANCE LOCUS8 (UVR8) is a UV-B-specific signaling component that binds to chromatin and regulates UV protection by orchestrating expression of a range of genes. Here, we studied how UV-B regulates UVR8. We show that UV-B stimulates the nuclear accumulation of both a green fluorescent protein (GFP)-UVR8 fusion and native UVR8. Nuclear accumulation leads to UV-B induct...

We review work done at UCSD on persistent photoconductivity and photoinduced superconductivity in REBa,Cu~O, thin films. It is shown that the resistivity, Hall coefficient and c-axis parameter change significantly upon illumination. All these effects require the presence of oxygen vacancies. The maximum enhancement of the conductivity with illumination occurs for fully deoxygenated ,samples (x=...

The crystal structures of different forms of TiO2 and those of BaTiO3, ZnO, SnO2, WO3, CuO, Fe2O3, Fe3O4, ZrO2 and Al2O3 nanoparticles have been deduced by powder X-ray diffraction. Their optical edges have been obtained by UV-visible diffuse reflectance spectra. The photocatalytic activities of these oxides and also those of SiO2 and SiO2 porous to oxidize iodide ion have been determined and c...

We report the fabrication of a double Schottky barrier (DSB) device by self-assembly of nanowires (NWs). The operating principle of the device is governed by the surface depletion effects of the NWs. High DSBs were formed at the contact interface of ZnO NWs self-assembled into bascule nanobridge (NB) structures. The bascule NB structures exhibited high sensitivity and fast response to UV illumi...

In2O3 nanostructure sensors were fabricated by arc-discharging a source composed of a graphite tube containing indium. The NO gas sensing properties, as well as the morphology, structure, and electrical properties, were examined at room temperature under UV light illumination. In particular, the response and recovery kinetics of the sensor at room temperature under various UV light intensities ...

ZnO film was deposited by the magnetron sputtering method. The thickness of ZnO film is approximately 2 μm. The influence of UV light illumination on C₂H₅OH sensing properties of ZnO film was investigated. Gas sensing results revealed that the UV-illuminated ZnO film displays excellent C₂H₅OH characteristics in terms of high sensitivity, excellent selectivity, rapid response/recovery, and low d...

Ultraviolet (UV) light photodetectors constructed from solely inorganic semiconductors still remain unsatisfactory because of their low electrical performances. To overcome this limitation, the hybridization is one of the key approaches that have been recently adopted to enhance the photocurrent. High-performance UV photodetectors showing stable on-off switching and excellent spectral selectivi...

In this study, the gas-sensing properties of nanocrystalline TiO 2 are enhanced by submitting the sensor system to UV light irradiation. TiO 2 gas sensing material based on nanosized particles is produced by gas condensation method. The crystal structure and ceramic microstructure of the powders are determined by TEM and XRD. Structural and morphological studies as well as UV irradiation are ca...