Specific features of transmutational doping of 30Si-enriched silicon crystals with phosphorus: Studies by the method of electron spin resonance

Electron spin resonance (ESR) is used to study the neutron transmutation doping of silicon crystals enriched with ³⁰Si isotope: phosphorus donors and radiation defects produced in the course of transmutational doping are observed. The ESR signals related to the phosphorus uncontrolled impurity in ³⁰Si before transmutational doping (the P concentration is ～10¹⁵ cm^?3) and phosphorus introduced by neutron irradiation with doses ～1 × 10¹⁹ cm^?2 and ～1 × 10²⁰ cm^?2 (the P concentrations are ～5 × 10¹⁶ and ～7 × 10¹⁷ cm^?3, respectively) are studied. As a result of drastic narrowing of the phosphorus ESR lines in ³⁰Si, the intensity of lines increased appreciably, which made it possible to measure the phosphorus concentration in the samples with a small volume (down to 10^?6 mm^?3). The methods for determining the concentration of P donors from hyperfine structure in the ESR spectra of isolated P atoms, exchange-related pairs, and clusters that consist of three, four, and more P donors are developed. In the region of high concentrations of P donors, in which case the hyperfine structure disappears, the concentration of P donors was estimated from the exchange-narrowed ESR line.     

The treatment of biological material by Falck's method and its modifications using a device of original design

Automation of the process of detecting adrenergic nerve structures helped obtain reliable positive results even in cases with low mediator concentration in body tissues. We have elaborated a new method of subsequent staining and microphotographing of biological specimens which permit registration of specific features of adrenergic nerve terminals histologic architecture and their cellular microenvironment.     

Standard impedance simulator

The principles of a method of isoperimetric high-frequency induction logging (IHIL) are described. Substantiation is provided for a procedure which uses an annular impedance simulator to check the metrological characteristics of IHIL equipment. The design of the simulator and the sequence of operations performed in using it are described, in addition to a method for testing the simulator. Values are given for the errors of the simulator's parameters. Translated from Izmeritel'naya Tekhnika, No. 10, pp. 57–59, October, 1998.     

Influence of temperature on the hydrodynamic resistance reduction effect

The effect of temperature on hydrodynamic resistance of aqueous solutions of polyethylene oxide is established experimentally.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 37, No. 6, pp. 1012–1014, December, 1979.