Essential self-adjointness of magnetic Schr\"odinger operators on locally finite graphs

We give sufficient conditions for essential self-adjointness of magnetic Schr\"odinger operators on locally finite graphs. Two of the main theorems of the present paper generalize recent results of Torki-Hamza.Comment: 14 pages; The present version differs from the original version as follows: the ordering of presentation has been modified in several places, more details have been provided in several places, some notations have been changed, two examples have been added, and several new references have been inserted. The final version of this preprint will appear in Integral Equations and Operator Theor

New precise determination of the \tau lepton mass at KEDR detector

The status of the experiment on the precise $\tau$ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the $\tau^+\tau^-$ cross section behaviour around the production threshold. The preliminary result based on 6.7 pb$^{-1}$ of data is $m_{\tau}=1776.80^{+0.25}_{-0.23} \pm 0.15$ MeV. Using 0.8 pb$^{-1}$ of data collected at the $\psi'$ peak the preliminary result is also obtained: $\Gamma_{ee}B_{\tau\tau}(\psi') = 7.2 \pm 2.1$ eV.Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton Physics, Tau0

First experimental results obtained using the highpower free electron laser at the siberian center for photochemical research

The first lasing near the wavelength of 140 µm was achieved in April 2003 using a high-power free electron laser (FEL) constructed at the Siberian Center for Photochemical Research. In this paper we briefly describe the design of the FEL driven by an accelerator–recuperator. Characteristics of the electron beam and terahertz laser radiation, obtained in the first experiments, are also presented in the paper.У Сибірському центрі фотохімічних досліджень навесні 2003 року отримана генерація випромінювання з довжиною хвилі 140 мкм на потужному лазері на вільних електронах (ЛВЕ). У роботі коротко описана конструкція ЛВЕ на базі прискорювача рекуператора і представлені результати вимірювання деяких параметрів електронного пучка і терагерцового випромінювання.В Сибирском центре фотохимических исследований весной 2003 года получена генерация излучения с длиной волны 140 мкм на мощном лазере на свободных электронах (ЛСЭ). В работе кратко описана конструкция ЛСЭ на базе ускорителя рекуператора и представлены результаты измерения некоторых параметров электронного пучка и терагерцового излучения

Dependence of the Annual Asymmetry in NmF2 on Geomagnetic Latitude and Solar Activity

Abstract: The properties of the annual asymmetry in the electron density of the F2-layer maximum NmF2 at noon are analyzed based on the global empirical model of the F2-layer critical frequency median (SDMF2 model). As a characteristic of this asymmetry, we used the R index, i.e., the January/July ratio of the total (at a given and geomagnetically conjugate points) NmF2 density at noon averaged over all longitudes. It was found that the R index decreases with increasing solar activity at low geomagnetic latitudes (Φ < 31°–33°). At higher latitudes, the R index increases with an increase in solar activity. During low solar activity, the main R maximum is located at latitude Φ = 22°–24°. During high solar activity, this R maximum is located at Φ = 64°–66°. At latitude Φ = 22°–24° in the Northern and Southern hemispheres, the longitudinal average NmF2 density in January is higher than that in July for any level of solar activity. At Φ = 64°–66°, an increase in R with increasing solar activity is mainly caused by a January increase in NmF2 in the Northern Hemisphere. The global (average over all latitudes) R index increases with increasing solar activity. Additional analysis showed that the global R index decreases with increasing solar activity in the IRI model both with URSI option and, even more so, with CCIR option. This appears to be due to the limited amount of experimental data on the obtainment of the CCIR and URSI coefficients, especially over the oceans

Structures and catalytic properties of Cu(II) complex with chelating fluorinated ligands

Structure of Cu(II) complex with chelating fluorinated ligands were studied at 298 K and 90 K using CW X-band electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT). Spin-Hamiltonian and structural parameters have been determined and the latter were compared with the X-ray data showing good similarity. A phase transition occurred at 360 K in solid crystalline sample was observed by EPR and discussed. Qualitative kinetic analysis of the catalytic behavior of Cu(II) complex upon H2O2 decomposition in acetonitrile-aqueous solutions at 313 K was studied using EPR and UV–visible spectroscopy