THERMAL RADIATION FROM MAGNETIZED NEUTRON STARS: A look at the Surface of a Neutron Star.

Surface thermal emission has been detected by ROSAT from four nearby young neutron stars. Assuming black body emission, the significant pulsations of the observed light curves can be interpreted as due to large surface temperature differences produced by the effect of the crustal magnetic field on the flow of heat from the hot interior toward the cooler surface. However, the energy dependence of the modulation observed in Geminga is incompatible with blackbody emission: this effect will give us a strong constraint on models of the neutron star surface.Comment: 10 pages. tar-compressed and uuencoded postcript file. talk given at the `Jubilee Gamow Seminar', St. Petersburg, Sept. 1994

Subexponential estimations in Shirshov's height theorem (in English)

In 1993 E. I. Zelmanov asked the following question in Dniester Notebook: "Suppose that F_{2, m} is a 2-generated associative ring with the identity x^m=0. Is it true, that the nilpotency degree of F_{2, m} has exponential growth?" We show that the nilpotency degree of l-generated associative algebra with the identity x^d=0 is smaller than Psi(d,d,l), where Psi(n,d,l)=2^{18} l (nd)^{3 log_3 (nd)+13}d^2. We give the definitive answer to E. I. Zelmanov by this result. It is the consequence of one fact, which is based on combinatorics of words. Let l, n and d>n be positive integers. Then all the words over alphabet of cardinality l which length is greater than Psi(n,d,l) are either n-divided or contain d-th power of subword, where a word W is n-divided, if it can be represented in the following form W=W_0 W_1...W_n such that W_1 >' W_2>'...>'W_n. The symbol >' means lexicographical order here. A. I. Shirshov proved that the set of non n-divided words over alphabet of cardinality l has bounded height h over the set Y consisting of all the words of degree <n. Original Shirshov's estimation was just recursive, in 1982 double exponent was obtained by A.G.Kolotov and in 1993 A.Ya.Belov obtained exponential estimation. We show, that h<Phi(n,l), where Phi(n,l) = 2^{87} n^{12 log_3 n + 48} l. Our proof uses Latyshev idea of Dilworth theorem application.Comment: 21 pages, Russian version of the article is located at the link arXiv:1101.4909; Sbornik: Mathematics, 203:4 (2012), 534 -- 55

Zero Frequency Current Noise for the Double Tunnel Junction Coulomb Blockade

We compute the zero frequency current noise numerically and in several limits analytically for the coulomb blockade problem consisting of two tunnel junctions connected in series. At low temperatures over a wide range of voltages, capacitances, and resistances it is shown that the noise measures the variance in the number of electrons in the region between the two tunnel junctions. The average current, on the other hand, only measures the mean number of electrons. Thus, the noise provides additional information about transport in these devices which is not available from measuring the current alone.Comment: 33 pages, 10 figure

Television pictures of Phobos: first results

In February-March 1989, 37 television images of the Martian satellite Phobos were obtained by the Phobos 2 spacecraft from distances of 200-1100 km. These images provide an important supplement to the TV data from the American Mariner 9 and Viking spacecraft in coverage of t4e surface of Phobos and in resolution in certain regions, in spectral range, and in range of phase angles. They make it possible to refine the figure and topographic and geological maps of the surface of Phobos, its spectral and angular reflective characteristics, the surface composition and texture, and characteristics of the orbital and librational motion

Study of effectiveness of antiviral drugs (umifenovir, triazavirin) against acute respiratory viral infections

Aim. Comparative study of clinical efficacy and safety of antiviral drug triazavirin and umifenovir in the treatment of patients with acute respiratory viral infections and influenza. Methods. The study included 100 patients aged 18 to 65 years diagnosed with moderate acute respiratory viral infection. Group 1 included 34 patients receiving umifenovir 200 mg 4 times a day for 5 days, and comparison group included 32 patients who received triazavirin 1 capsule (250 mg) 3 times a day for 5 days. Group 3 (control group) included 34 patients not treated with antiviral therapy. Efficacy and safety of the studied antiviral drugs were evaluated based on clinical symptoms in the disease course and were confirmed by adaptive reactions of the organism. Results. Among patients receiving triazavirin, recovery time and fever, headache and catarrhal syndrome resolution time were less than among patients who received umifenovir. On triazavirin treatment with favorable tolerability, symptomatic medications (antipyretics) were discontinued, and the duration of their use was less, than in patients receiving umifenovir. Evaluation of clinical efficacy of umifenovir and triazavirin for the treatment of acute respiratory viral infections and influenza demonstrated that the drugs effectively reverse the main symptoms of the disease (p <0.05), reduce complications incidence (18.1±2.1% vs. 55.9±3.2%, p <0.05) and contribute to the stabilization of adaptive reactions of the organism in contrast to the results of patients not receiving etiotropic therapy (6.9±2.9% vs. 12.8±2.7, p <0.05). During the use of umifenovir by day 4 and during the use of triazavirin by day 3 intoxication and catarrhal syndromes had been reversed, while in case of the absence of antiviral therapy, 55.8% of patients had continuing intoxication and catarrhal symptoms. Conclusion. The results of the study allow defining umifenovir and triazavirin as the first line of defense against acute respiratory viral infections with good efficacy and tolerability of the drugs