The dislocation origin and model of excess tunnel current in GaP p-n structures

An excess tunnel current in GaP epitaxial nondegenerate p-n junctions on GaP and Si substrates was studied. An important experimental result is that the slope of exponential current-voltage (I–V) characteristic (in lnI–V coordinates) is independent of the width of the space-charge region, i.e., on n-and p-region doping levels. This fact is unexplained by existing models. A dislocation shunt model based on multihop tunneling through a dislocation line, which may be considered as a chain of parabolic potential barriers, is proposed. The density of dislocations predicted by this model is in agreement with the transmission electron microscopy (TEM) observations.     

Neutron-Physical Calculation of a Fresh Zone in the Natural Nuclear Reactor at Oklo

A full-scale computer model of zone 2 of the Oklo reactor with a realistic materials composition is constructed. Modern Monte Carlo programs are used to calculate the multiplication factor, the excess reactivity, and the neutron flux for the fresh reactor zone 2. The calculations are performed in a wide range of variation of the zone parameters: the uranium content in the contemporary Oklo zone is varied from 35 to 55 mass% and the water content from 0.355 to 455 g/cm³. The power effect is determined. The temperature of the fresh zone is found to be 725 ± 55 K, at which the reactor is critical and can operate in a stable manner for a long time. The power of the reactor is maintained by negative feedback. The neutron spectrum, over which the cross section of strong absorbers must be averaged, for example, ₆₂ ¹⁴⁹ Sm, in order to obtain the most accurate bounds on the possible shift of the samarium resonance as a result of a change in the fundamental constants, is found for 700 K.__________Translated from Atomnaya Energiya, Vol. 98, No. 4, pp. 306–316, April, 2005.     

Estimation of the parameters of an imminent seismic event focus by the free surface strains

Dilatancy zones generated by an active internal source of isolated force in a heterogeneous rock mass are studied. Based on the solution of an inverse problem, the method is proposed for locating and determining the source focus parameters using the measurement data on strains of the daylight surface. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 25–35, May–June, 2007.     

Measurement design for evaluation of measurement results characterized by dispersion

A measurement-design procedure for evaluation of measurement results characterized by dispersion is proposed. Russia. Translated from Izmeritel’naya Tekhnika, No. 12, pp. 12–15, December, 1999.     

Measurement planning for quality assurance with allowance for systematic error

We present a procedure for choosing optimal measurement plans for quality assurance with allowance for systematic error in the measurements. Translated from Izmeritel'naya Tekhnika, No. 8, pp. 3–9, August, 1998.     

Formation of dense electron beams in a gun with a plasma anode based on a reflecting discharge

A method of obtaining low-energy, high-current electron beams in a gun with a plasma anode based on a reflecting discharge is proposed and implemented for the first time. Pis’ma Zh. Tekh. Fiz. 23, 42–46 (May 26, 1997)     

Attribution of white-light emitting centers with carbonized surface in nano-structured SiO2:C layers

Carbon incorporated silicon oxide layers were fabricated by carbonization of porous silicon layer in acetylene atmosphere followed by oxidation in wet argon. The resulting porous SiO₂:C material exhibited a strong white photoluminescence. Subsequent thermal treatment in oxygen at 600 °C significantly decreased the green-yellow part of photoluminescence band while blue shoulder remained unchanged. Annealing at the same temperature in pure argon did not change light-emission properties indicating that the green-yellow light-emission sites originate from the surface. This study focuses on the interface of silicon oxide matrix and carbon inclusions by high-resolution scanning transmission electron microscopy (STEM) combined with electron energy loss spectroscopy (EELS). It is confirmed by EELS and STEM that the green-yellow emission band is associated with the carbonized interface in the porous layer.