The arrays of ZnO nanorods were obtained on the sapphire substrates by means of pulsed laser deposition under the high pressure of argon. The conditions of synthesis were optimized, and their influence on the morphology of ZnO nanostructures were revealed. It is shown that the concentration of oxygen vacancies in ZnO nanorods can be changed by regulation of the synthesis temperature from 850 to 915 °. This process can be controlled by the ratio of intensities of the photoluminescence emission in the visible and ultraviolet regions. So, it allows to create nanostructures for UV photodetectors or chemosensors depending on the temperature choice.
Keywords: ZnO nanorods, laser deposition, PLD, photoluminescence
In this paper a systematic study of individual single-walled and multi-walled carbon nanotubes was performed by Raman spectroscopy and high-resolution electron microscopy. We have presented the geometrical and electronic structure analysis on the examples of two tubes: individual single-walled and double-walled nanotubes. The role of different environmental effects and their influence on the final structure assignment are discussed. Moreover, we have shown that the Raman spectroscopy gives reliable estimations of the nanotube diameters and the conductivity. Given a non-destructible character of Raman spectroscopy, we may conclude that it is one of the most efficient methods for structure analysis of carbon nanotubes.
Keywords: Carbon nanotubes, Raman spectroscopy, electron microscopy
Intracellular microinjection - a method of direct introduction of cellular organelles and solutions of substances into living cells. The technique of microinjection into nerve cells by puncturing their processes - axons , which are often surrounded by a dense glial sheath, are described. To puncture the sheath a special injector transmitting microvibrations of ultrasonic frequency on the injection capillary was designed. The results of using the proposed microinjection technique for introducing fluorescent marker in large axons of model object - crayfish ventral nerve cord, to visualize the morphology of axons, were shown.
Keywords: intracellular microinjection, neuron, axon, glial sheath, ultrasound vibration, piezoelectric transducer
The authors suggest two approaches to constructing hypotheses about the interactions of proteins on the basis of the results of tracking the changes in their levels during the studied biological process. The first approach is based on the use of machine mining of biological texts, which are freely available on the Internet. The second is related to the execution of database queries on binary protein-protein interactions . To specify the experimental context in obtained protein networks, filtering of the protein entities on the basis of needed ontology from database Gene Ontology was used.
Keywords: text mining, data base, protein-protein interaction, protein networks
The return coefficient task of determination of properties of a construction design by means of the device of neural networks is considered. As model the neural network in the form of a polutorasloyny predictor with possibility of iterative accumulation of volume is taken. Each subsequent step connected with addition of a new stream of neurons, is carried out only after training of the previous stream. Coefficients of synoptic communications pay off with the help of procedure of the return distribution from a condition of a minimum of function of an assessment. Algorithms of the solution of direct and return problems of multidimensional approximation are developed.
Keywords: neural network, approximation, synoptic communications, return distribution, construction designs
The paper discusses possible options for the use of genre classification results of Web documents in search engines. The proposed methods can improve the quality of search engines.
Keywords: Web document classification, text documents, search engines, search engine results page, search quality, diversity
Structure of surface acoustic waves(SAW) of CO sensor was developed. SAW sensor include transceiving IDT and catoptric IDT, which is loaded on the impedance of ZnO nanorods. Peak of reflection SAW from IDT clearly observed as result Fourier transformation of time function of pulsed response. IDT loaded on resistance paralleled ZnO nanorods, which depends on the concentration of CO.
Keywords: ZnO nanorods, device on SAW, CO sensor
Combined method which allows analyzing parameters of the nanoscale atomic and electronic structure of materials relying on three different methods (x-ray absorption spectroscopy (XAFS), x-ray diffraction (XRD) and Raman spectroscopy) was developed. The method was applied for the study of nickel oxide nanoparticles, which serve as an efficient catalyst for the artificial photosynthesis process.
Keywords: solar energy, artificial photosynthesis, NiO, Raman, x-ray diffraction, XAFS
`
Keywords:
In the present work we have carried out studies of the processes of growth of zinc oxide nanorods by hydrothermal method on silicon substrates. As sublayer catalyst used growth caused by laser deposition of zinc oxide, various thicknesses. Studied selective growth of nanorods on the microstructure of thin-film sub-layers of zinc oxide obtained by laser deposition. The optimal conditions for the synthesis of: the concentration of Zn (NO3) 2 - 0.4 mol / l, hexamethylenetetramine - 0.4 mol / l, the concentration of NH3 · H2O - 0,01 mol / L -0.01, process time 4:00, the process temperature is 80 ° C. Sublayer thickness of zinc oxide, as shown by experiment, the growth of the rods has no noticeable effect. Oriented arrays of nanorods were obtained up to 500 nm and a diameter of 60-150 nm.
Keywords: zinc oxide nanorods and micro-oriented arrays of nanorods, hydrothermal synthesis method, selective growth, thin film underlayer.
Keywords: