Electronic structure of carbon nanotubes with copper core

The electronic structure of copper-intercalated carbon nanotubes has been studied by quantum-chemical methods. The total and partial densities of states of nanotubes have been calculated by the linear augmented-cylindrical-wave method. The armchair (5,5) nanotubes with one, two, three, and four copper atoms per unit cell have been calculated The introduction of the metal is accompanied by a sharp increase in the density of states at the Fermi level of the nanowire, which determines the concentration of free electrons involved in charge transfer in the nanotube. The 3d electrons of the metal and the carbon shell are nearly equally involved in electron transport in intercalated wires.     

Structure of the correlation dependence of nonlinear stochastic functionals

Radiophysics and Quantum Electronics -     

Pseudospark switches for the power supply circuits of pulsed lasers

A family of sealed-off low-pressure spark gap switches developed at the Institute of High Current Electronics (Tomsk) and at the Plasma Scientific Research Institute (Ryazan) with participation of researchers from the Physical Institute of the University of Erlangen (Germany) is described. The devices are of cermet construction, are capable of switching pulsed currents over wide ranges of amplitudes and durations, and have a number of unique characteristics. The principle of operation of the spark gap switches is described and their designs are given. The triggering circuits of the switches are considered. Institute of High-Current Electronics, Siberian Division of the Russian Academy of Sciences. Plazma Scientific Research Institute of Gas-Discharge Devices. Physical Institute of the University of Erlangen. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 97–105, April, 2000.     

Detection of afobazole and its major metabolites using capillary gas chromatography-mass spectrometry

The possibility of detecting a target compound using Gas Chromatography-Mass Spectrometry has been demonstrated and the structure of these compounds has been confirmed. The possibility of sorption of these compounds in the chromatographic system has been analyzed. Results obtained using various sample injection modes have been compared. A highly sensitive method for detecting micromolar amounts of the compounds under investigation in samples with large volumes has been developed. The detection limits of the compounds studied equaled 5 × 10^?10 g in a sample of the model solution.     

Investigation of the charge distribution in the insulating envelope of a high-voltage vacuum device

Methods of measuring charges in the bulk and at the surface of the insulating envelope of a high-voltage vacuum device are developed as part of studies of a complex range of dielectric strength aspects. These methods were used to measure the charge distribution over the length of the envelope and to study how this distribution is influenced by the operating regimes of the device. Laws governing the formation of charges were identified and its correlation with the appearance of physical changes in the structure of the surface layers of the insulator was determined. Processes of structural change were studied and simulated and the change in the dielectric strength of the device was compared with changes in the magnitude and polarity of the surface and bulk charges. Zh. Tekh. Fiz. 69, 30–35 (June 1999)