Asymmetrically substituted tetra(meso-aryl)porphyrins bearing peripheral 2,6-diisobornylphenol and 2,6-di-tert-butylphenol moieties

Russian Chemical Bulletin - Asymmetrically substituted tetra(meso-aryl)porphyrins bearing peripheral diisobornyl- phenol and di-tert-butylphenol moieties were synthesized by a mixed aldehyde...     

Upconversion nanoparticles for tumor imaging with near-infrared radiation

Prospects for using upconversion nanoparticles as markers for tumor optical imaging are discussed. Using a model of epidermoid Lewis lung carcinoma engrafted in mice, luminescent signals from nanoparticles delivered into the tumor tissue are registered in vivo.     

Specific character of the 119Sn thin films growth on amorphous Si by the CBPLD method

The research of the ¹¹⁹Sn thin films growth on amorphous Si that is important for the multilayer periodical spin-tunnel nanostructures creation have been investigated in this paper. The ¹¹⁹Sn mono-isotopic thin films on the silicon substrates (100) had been received by crossed-beam pulsed laser deposition method (CBPLD). Similarly the [Fe/Si/Sn/Si] multilayer periodical structures have been deposited. The received samples were investigated by atomic-force microscopy, electronic microscopy and X-ray reflectometry methods. It has been established that at ¹¹⁹Sn film thickness up to 3 nm it is possible to received atomic-smooth surfaces with 0.5 nm roughness.     

Fabrication of black multicrystalline silicon surface by nanosecond laser ablation

The optimal regimes for uniform texturing of a multicrystalline silicon (mc-Si) surface by pulsed laser radiation have been determined. The morphology and reflectance spectra of the texturized mc-Si have been studied. The laser-texturized mc-Si samples with reflectance of 2?C3% over a wide spectral region have been produced. The influence of subsequent chemical etching on the reflective properties of the texturized surface has been analyzed.     

Three-Dimensional Luminescence Tomographic Visualization of Biological Tissues

Optics and Spectroscopy - We propose a method for obtaining a fluorescence tomographic image for visualization and diagnosis of tissues of a living organism. The method is based on the excitation...     

Ternary alloys CdyZn1 ? yO and MgxZn1 ? xO as materials for optoelectronics

Thin films of Cd _y Zn_{1 − y} O and Mg _x Zn_{1 − x} O (y = 0−0.35, x = 0−0.45) ternary alloys have been grown by pulsed laser deposition onto sapphire substrates. The record solubility limits of Cd (y = 0.3) and Mg (x = 0.35) have been achieved in hexagonal zinc oxide. The mismatch of the lattice parameters a of Cd_0.2Zn_0.8O and Mg_0.35Zn_0.65O does not exceed 1%; in this case, the band gap discontinuity is 1.3 eV. The surface roughness of the films does not exceed 2.5 nm at x = 0−0.27 and y = 0−0.20.     

Synthesis and Estimation of Radical Scavenging Activity of Tetra(<Emphasis Type="Italic">meso</Emphasis>-aryl)porphyrins Containing 2,6-Dimethoxyphenol Unit

Tetra(meso-aryl)porphyrins containing 2,6-dimethoxyphenol unit distant from the macrocycle and adjacent to it have been prepared. Radical scavenging activity of the obtained compounds has been estimated in the model reaction of ethylbenzene oxidation initiated by azobisisobutyronitrile. It has been shown that the phenol hydroxy group ability to inhibit ethylbenzene oxidation depends on the environment of phenol group.     

Probe studies of laser erosion plume arising at silicon ablation in vacuum

An erosion plume arising at the ablation of silicon by a solid-state laser (λ = 1.06 μm) is studied with a Langmuir probe. The time-of-flight curves of the probe ion current are obtained for a plasma beam formed by intersecting plumes from two targets and for an erosion plume from one silicon target. The probe-target distance is varied in the range 40–157 mm. The time-of-flight curves for the ions of the erosion plume are sums of the velocity one-dimensional Maxwell distributions for four groups of ions. It is found that a plasma beam formed by intersecting plumes from two targets does not contain all groups of ions present in initial plumes.     

Modified crossed-beam PLD method for the control of ion energy spectrum

The modified crossed-beam pulsed laser deposition method, which allows wide-range variations in the energy of deposited particles, is presented for the first time. Time-of-flight curves (TFCs) of silicon ions that are formed by the crossed plumes from two silicon targets and the erosion plume from one silicon target are measured using the Langmuir probe technique. It is demonstrated that the TFCs of ions from the erosion plume are approximated by sums of the one-dimensional Maxwell velocity distributions. Variations in the ion concentrations that result from the interaction are measured. Transformations of the energy spectrum of the plasma beam formed by crossed plumes are determined using variations in the angle between the plumes.