Black Nb(4+) self-doped K4Nb6O17 microspheres were prepared for the first time through a facile UV light photoreduction method. By the introduction of Nb(4+), the defective K4Nb6O17 can harvest the full spectrum of visible light as well as near-infrared light. The black K4Nb6O17 microspheres showed improved visible-light-driven photocatalytic H2 production activity. Importantly, the present syn...

1. The amount of visible or long ultraviolet light (UV) required to photoreactivate Colpidium colpoda injured with known dosages of short UV (2654 A) was determined. 2. The effect of the short UV was tested by the delay in division of exposed animals compared to controls. Photoreactivation was tested by the effect of postillumination on the delay of division of treated colpidia compared to cont...

Kinetic studies of 2-chlorophenol photocatalytic degradation are carried out in a batch stirred built in quartz laboratory scale, using TiO2 as catalyst photoactived with ultraviolet light. Experimental design is performed using as independent variables or factors: catalyst concentration, catalyst calcinations temperature and initial concentration of 2-chlorophenol, to establish the best condit...

Production of extreme-ultraviolet radiation by high-order harmonic generation is demonstrated to yield unprecedented spectral purity of lambda/Delta lambda=2.5 x 10(5) at wavelengths covering the entire range 40-100 nm. Tunability and sub-cm(-1) bandwidth of the harmonics are demonstrated in recordings of the He (1s4p) and Ar (3p(5)3d') resonance lines at 52.2 and 86.6 nm. Frequency shift of th...

Irradiation of 5'-[32P]-phosphate labeled DNA fragments with ultraviolet light in the presence of primary amines followed by piperidine treatment resulted in base-specific cleavage of the DNA chain at T residues, accompanied by a less intensive G reaction. This simple, T greater than G cleavage offers an alternative method for determining T residues in chemical DNA sequencing.

Fluorescent guest molecules doped in polymers have been used to convert ultraviolet light into visible light for applications ranging from optical fibres to filters for the cultivation of plants. The wavelength conversion process involves the absorption of light at short wavelengths followed by fluorescence emission at a longer wavelength. However, a precise understanding of the light conversio...

We present a new interferometer technique based on the interference of high-order harmonic generation radiation from translatable successive gas jets. The phase shifts in the apparatus are shown to originate from the Gouy phase shift of the driving laser. The technique can be used to deliver time delays between light pulses and we demonstrate the unprecedented capability of delivering pulses of...

The purpose of this study was to determine the intranuclear distribution ofDNA repair synthesis (as measured by TdR-3 H3 incorporation) after exposure to a diverse group of direct-act ing chemical carcinogens and UV. Such an approach was thought to be useful since any DNA extraction procedure must, of necessity, result in some misrepresentation of nuclear structure (A good discussion of this pr...

Ozone-water complex has been thought to play a role in producing atmospheric OH radicals through its photolysis. Here, we re-examined the absorption cross-section of the ozone-water complex with a new method to tell whether the above speculation is valid. With argon solvation and photoionization by tunable vacuum ultraviolet light, we were able to selectively probe the ozone-water 1:1 complex. ...

30 mW continuous wave ultraviolet radiation is generated via a two-path geometry for cascaded frequency doubling and sun-frequency generation (SFG) at 18.9 W pump, where SFG is enabled by a third-order periodically poled