Integrated Superconducting Submillimeter-Wave Receivers

We overview recent achievements in the field of cryogenic submillimeter-wave receivers based on superconductor–insulator–superconductor (SIS) tunnel junctions. The main attention is paid to the novel superconducting integrated receivers (SIRs) with an on-chip superconducting local oscillator. The single-chip microcircuit of the receiver, which integrates a quantum mixer based on the nonlinearity of a quasi-particle current in the SIS junction, a planar superconducting receiving antenna, and a cryogenic local oscillator, is described. Being dc-powered only by batteries, such a microcircuit operates as a submillimeter-wave superheterodyne receiver without any additional microwave equipment. Such receivers are very attractive for radioastronomical research, space communication systems, and monitoring of the environment from satellites, balloons, and special aircraft. A breadboard of a superconducting spectrometer with a phase-locked flux-flow oscillator (FFO) has been developed and tested. A frequency resolution better than 10 kHz was reached at a frequency of 365 GHz. We describe a balloon-borne 500-650 GHz integrated spectrometer for oblique atmospheric sounding, developed for the international Terahertz Limb Sounder (TELIS) project. The first flight is scheduled for 2005.     

Esters of nitromethane nitronic acid

Russian Chemical Bulletin - For the first time, O-methyl and O-ethyl esters of dinitromethane were isolated in an individual state. Their structures were confirmed by spectral methods, elemental...     

Extended formulations for convex heptagons

Results related to extended formulations for convex polygons are discussed. In particular, it turns out that six linear inequalities are sufficient to describe a convex heptagon up to linear projection.     

Yttrium Sesquioxide Ceramics Glow Under Irradiation with an Electron Beam

Russian Physics Journal - When various materials are used as radiators for Cherenkov detectors registering electron fluxes with energies of tens to hundreds of keV, cathodoluminescence negatively...     

Anharmonic Effects in the Theory of Finite Fermi Systems

Physics of Atomic Nuclei - Some results obtained by E.E. Saperstein and his coauthors in the theory of the ground state and low-lying excited states of magic and semimagic nuclei are...     

Drift motion of domain boundaries in garnet ferrites in an acoustic wave field

The drift motion of a 180° domain boundary in garnet ferrites with two nonequivalent sublattices is studied in an elastic stress field induced by an acoustic wave propagating in the domain boundary plane. The dependences of the drift velocity on the amplitude and polarization of the acoustic wave are obtained, and the drift motion conditions for a strip domain structure are determined.     

Correction to: Yttrium Sesquioxide Ceramics Glow under Irradiation with an Electron Beam

Russian Physics Journal - To the article “Yttrium Sesquioxide Ceramics Glow under Irradiation with an Electron Beam,” by E. Kh. Baksht, M. V. Erofeev, V. F. Tarasenko, M. I. Solomonov,...