Table of contents

The state of the art of research on the fabrication of semiconductor surface nanostructures using a scanning tunneling microscope (STM) is reviewed. The continuous atom transfer occurring due to directional surface diffusion initiated by the STM electric field and involving field-induced evaporation is analyzed. The effect of irradiation with an external electron beam on the tip–sample interaction is discussed, which consists in reducing the barrier for direct interatomic reactions and in changing the direction of the tip–sample atomic transfer. The possibilities of fabricating germanium and silicon nanostructures such as islands and lines and also making silicon windows on oxidized silicon surfaces are demonstrated.

Problems in the fields of neutrino astronomy and ultrahigh-energy astrophysics are reviewed. Neutrino fluxes produced in various astrophysical sources (bottom-up acceleration scenarios) and resulting from the decay of superheavy particles (top-down scenarios) are considered. Neutrino oscillation processes and the absorption and regeneration of neutrinos inside the earth are analyzed and some other factors affecting the intensity and flavor composition of astrophysical neutrino fluxes are discussed. Details of ultrahigh-energy neutrino interactions are discussed within the Standard Model, as well as using nonstandard scenarios predicting an anomalous increase in the inelastic neutrino–nucleon cross section. Ultrahigh-energy neutrino detection techniques currently in use in new-generation neutrino telescopes and cosmic ray detectors are also discussed.

Lectures introducing students to electromagnetic induction phenomena often feature the popular experiment in which a small magnet falling down a long conducting pipe is markedly decelerated by the retarding force due to Foucault eddy currents arising in the pipe. In this paper, a formula for the retarding force, valid both for low velocities (when the force is proportional to the velocity v of magnet motion) and high velocities (when it first decreases as v⁻¹ and then as v^−1/2), is derived. The last two regimes are analogous to the collisionless (and hence unbounded) acceleration of plasma electrons and have not been previously described in the literature. The calculation of the retarding force in the presence of a longitudinal cut in the pipe wall is carried out, and experiments to measure this force are discussed.

In the summer of 2005, a meeting of the Consultative Committee for Units of the International Committee on Weights and Measures took place. One of the topics discussed at the meeting was a possible redefinition of the kilogram in terms of fundamental physical constants — a question of relevance to a wide circle of specialists, from school teachers to physicists performing research in a great variety of fields. In this paper, the current situation regarding this question is briefly reviewed and its discussion at the Consultative Committee for Units and other bodies involved is covered. Other issues related to the International System of Units (SI) and broached at the meeting are also discussed.

A scientific session of the Physical Sciences Division of the Russian Academy of Sciences was held in the Conference Hall of the Lebedev Physics Institute, Russian Academy of Sciences, on 12 April 2006. The following reports were presented at the session:

(1) Khokhlov D R (Lomonosov Moscow State University) "High-sensitivity terahertz radiation detectors based on a new class of semiconductor materials"; (2) Mitin A V (Kazan State Technological University) "Modulation gamma-resonance spectroscopy"; (3) Kurochkin V E (Institute of Analytical Instrumentation, Russian Academy of Sciences, St. Petersburg) "Methods and tools for the express immunoassay. A new approach to solving the problem"; (4) Lukin V P (Institute of Atmospheric Optics, Siberian Division of the Russian Academy of Sciences, Tomsk) "Adaptive optical imaging in the atmosphere."

A brief presentation of the reports is given below. • High-sensitivity terahertz radiation detectors based on a new class of semiconductor materials, D R Khokhlov Physics-Uspekhi, 2006, Volume 49, Number 9, • Modulation gamma-resonance spectroscopy, A V Mitin Physics-Uspekhi, 2006, Volume 49, Number 9, • Methods and tools for the express immunoassay. A new approach to solving the problem, V E Kurochkin Physics-Uspekhi, 2006, Volume 49, Number 9, • Adaptive optical imaging in the atmosphere, V P Lukin Physics-Uspekhi, 2006, Volume 49, Number 9,

Comparatively recent theoretical and experimental research, which indicates the possible existence of electronic objects with a charge equal to a fraction of the electron charge (e/2, e/3, etc.), is briefly reviewed.