Growth of all-carbon horizontally aligned single-walled carbon nanotubes nucleated from fullerene-based structures

All-carbon single-walled carbon nanotubes (SWCNTs) were successfully synthesized, nucleated using a fullerene derivative. A systematic investigation into the initial preparation of C₆₀ fullerenes as growth nucleators for the SWCNTs was conducted. Enhancement in the yield of the produced SWCNT has been achieved with exploring different dispersing media for the fullerenes, the period, and environment of the initial thermal treatment of the fullerenes in addition to the use of different fullerene-based structures. The systematic studies significantly advance our understanding of the growth of the all-carbon catalyst-free single-walled carbon nanotubes. Field-effect transistors were fabricated using the catalyst-free SWCNT and then electrically characterized, showing current capacity as high as the well-studied catalyst-assisted nanotubes.     

Ignition of the Gas–Coal Dust Mixture. Pointwise Approximation

A mathematical model of ignition of a gas mixture with dust particles is constructed by methods of mechanics of reacting heterogeneous media. Some qualitative feature of the model are studied, which allow one to identify different characteristics variants of thermal dynamics of the mixture: heterogeneous ignition by means of oxidation of coke residue, homogeneous ignition caused by oxidation of volatiles in the gas phase, and hybrid ignition due to simultaneous action of surface and volume reactions. The model is verified using available experimental data on ignition delays of suspended coal particles in air and in oxygen in reflected shock waves.     

Microlens-Enhanced Substrate Patterning and MBE Growth of GaP Nanowires

Semiconductors - In this paper we demonstrate the results on selective area growth of GaP nanowires via self-catalyzed growth method using molecular beam epitaxy (MBE) technique on patterned...     

The influence of transition metals – Fe,Co, Cu on transformation of organic matters from Domanic rocks in hydrothermal catalytic system

Character of conversion of organic matter from Domanic rocks of Pervomaiskoye field (Tatarstan) of Semiluki horizon of upper Devonian deposits in the hydrothermal-catalytic system at temperature of 300?°C in carbon dioxide medium was studied with the application of complex of oil-soluble precursors of catalysts containing Fe, Co, and Cu. In presence of catalysts complex, content of organic extract increases, in which content of hydrocarbon fractions, saturated and aromatic hydrocarbons, increases 1.5 times, while resins content decreases by two times. As result of kerogen destruction in products of experiments, the content of asphaltenes and carbonaceous substances such as carbenes and carboides increase.     

Complex surface modification of carbide tool by Nb + Hf + Ti alloying followed by hardfacing (Ti + Al)N

The surface of the WC/Co carbide tool was modified by an electron beam with the magnetron sputtering of Nb + Hf + Ti alloy to obtain a gradient interlayer before hardfacing with (Ti + Al)N. The results of investigations of the composite using a scanning electron microscope equipped with a device for X-ray energy dispersion spectroscopy are given. The results of the comparative mechanical tests show reduced wear rate.     

Optimization of integral-code measuring systems for planar tomography constructed using extended pseudorandom sequences

A recently proposed new large class of one-dimensional binary sequences, called extended pseudorandom sequences, is investigated. It is shown that they enable one, in practice, to optimize a radiation-physical experiment and to solve problems of emission planar tomography more effectively using integral-code measurement systems.     

Results of U<Subscript>0.55</Subscript>Pu<Subscript>0.45</Subscript>N and U<Subscript>0.4</Subscript>Pu<Subscript>0.6</Subscript>N mixed mononitride fuel tests in a bor-60 reactor to burnup 12% h.a.

The results of post-reactor studies of U_0.55Pu_0.45N and U_0.4Pu_0.6N mixed mononitride fuel elements (density 85% of the theoretical value) and a helium sublayer are presented. The fuel elements are irradiated in a BOR-60 reactor to burnup 9.4 and 12.1% h.a., respectively, with power density 430 and 540 W/cm. All fuel elements remained hermetic; the ChS-68 steel cladding (20% cold deformation) retained excess plasticity. The maximum zone of interaction between the cladding and the fuel and fission products did not exceed 15 μm. The swelling rate of U_0.4Pu_0.6N and U_0.55Pu_0.45N fuel was 1.1 and 0.68%/% burnup, respectively. The gas release did not exceed 19.3 and 19%. The steel damage dose was 43 dpa. The character of the porosity distribution in the fuel affects the swelling and gas release.