Software correlator for Radioastron mission

In this paper we discuss the characteristics and operation of Astro Space Center (ASC) software FX correlator that is an important component of space-ground interferometer for Radioastron project. This project performs joint observations of compact radio sources using 10 meter space radio telescope (SRT) together with ground radio telescopes at 92, 18, 6 and 1.3 cm wavelengths. In this paper we describe the main features of space-ground VLBI data processing of Radioastron project using ASC correlator. Quality of implemented fringe search procedure provides positive results without significant losses in correlated amplitude. ASC Correlator has a computational power close to real time operation. The correlator has a number of processing modes: "Continuum", "Spectral Line", "Pulsars", "Giant Pulses","Coherent". Special attention is paid to peculiarities of Radioastron space-ground VLBI data processing. The algorithms of time delay and delay rate calculation are also discussed, which is a matter of principle for data correlation of space-ground interferometers. During 5 years of Radioastron space radio telescope (SRT) successful operation, ASC correlator showed high potential of satisfying steady growing needs of current and future ground and space VLBI science. Results of ASC software correlator operation are demonstrated.Comment: 28 pages, 17 figure

Isolation of cationic and neutral (allenylidene)(carbene) and bis(allenylidene)gold complexes.

The one-electron reduction of a cationic (allenylidene)[cyclic(alkyl) (amino)carbene]gold(i) complex leads to the corresponding neutral, paramagnetic, formally gold(0) complex. DFT calculations reveal that the spin density of this highly robust coinage metal complex is mainly located on the allenylidene fragment, with only 1.8 and 3.1% on the gold center and the CAAC ligand, respectively. In addition, the first homoleptic bis(allenylidene)gold(i) complex has been prepared and fully characterized

Welding optimization of thin metal

Початкову матрицю планування експерименту оптимізовано за вартістю реалізації за допомогою програмного забезпечення. Отримано математичну модель процесу зварювання пластин. Визначено оптимальний режим проведення точкового зварювання пластин зі сталі електротехнічної малої товщини.Optimization of metal plates welding with small thickness was held using the methods of planning the experiment. The initial design of experiment matrix is optimized for the implementation cost using the search program of optimal combinatorial multilevel multifactor experiment plans. At the core of the program is the generation of combinatorial multifactor experiment plans, evaluation of their characteristics, the selection of the optimal implementation cost variant. Using the program the prize of the implementation cost of the experiment plan in 1,93 times as compared with the initial plan and in 3,00 times as compared with the plan that has a maximum value, is achieved. According to the obtained optimized plan a full factorial experiment was conducted. For each experiment matrix duplicate experiment was carried out to reduce random errors. As the factors that influence the value of capacitor, the rate of transformation, the pressure on the electrodes were considered. As the parameter of optimization the efforts gap of welded plates on tensile machine was elected. The mathematical model of plates welding is obtained. The adequacy of the obtained mathematical model is confirmed by the Fisher's exact test. Checking of the regression coefficients significance was performed using the Student's criterion. The coefficients of all the factors considered were significant. According to the mathematical models, a substantial change in the parameter optimization is caused by a change in value of capacitor, because it has the largest coefficient in absolute value. To increase the welded plates break efforts it is necessary to increase the value of capacitor and to reduce the rate of transformation and pressure on the electrodes. The search of the optimal parameters of welding process was carried out using a gradient method. The movement of the gradient is carried out by adding to the basic level of pitch variation for each factor. The calculation step is carried out by multiplying the coefficients of variation of the mathematical model for the interval of variation for each factor. The gradient motion series of experiments are obtained. The experiences that matter the most parameter optimization have been realized in practice. Obtained in practice parameter of optimization is close to the calculated using the mathematical model. The optimal mode of spot resistance welding of thin electrical steel plates is defined. To achieve the maximum strength spot welding of thin electrical steel plates it is recommended to set the following parameters: the value of capacitor – 140 uF, the coefficient of transformation – 75, the pressure on the electrodes – 10 N

X-ray variation statistics and wind clumping in Vela X-1

We investigate the structure of the wind in the neutron star X-ray binary system Vela X-1 by analyzing its flaring behavior. Vela X-1 shows constant flaring, with some flares reaching fluxes of more than 3.0 Crab between 20-60 keV for several 100 seconds, while the average flux is around 250 mCrab. We analyzed all archival INTEGRAL data, calculating the brightness distribution in the 20-60 keV band, which, as we show, closely follows a log-normal distribution. Orbital resolved analysis shows that the structure is strongly variable, explainable by shocks and a fluctuating accretion wake. Analysis of RXTE ASM data suggests a strong orbital change of N_H. Accreted clump masses derived from the INTEGRAL data are on the order of 5 x 10^19 -10^21 g. We show that the lightcurve can be described with a model of multiplicative random numbers. In the course of the simulation we calculate the power spectral density of the system in the 20-100 keV energy band and show that it follows a red-noise power law. We suggest that a mixture of a clumpy wind, shocks, and turbulence can explain the measured mass distribution. As the recently discovered class of supergiant fast X-ray transients (SFXT) seems to show the same parameters for the wind, the link between persistent HMXB like Vela X-1 and SFXT is further strengthened.Comment: 8 pages, 6 figures, accepted for publication in A&

Review of scientific topics for Millimetron space observatory

This paper describes outstanding issues in astrophysics and cosmology that can be solved by astronomical observations in a broad spectral range from far infrared to millimeter wavelengths. The discussed problems related to the formation of stars and planets, galaxies and the interstellar medium, studies of black holes and the development of the cosmological model can be addressed by the planned space observatory Millimetron (the "Spectr-M" project) equipped with a cooled 10-m mirror. Millimetron can operate both as a single-dish telescope and as a part of a space-ground interferometer with very long baseline.Comment: The translation of the original article in Physics Uspekhi http://ufn.ru/ru/articles/2014/12/c

THE MAIN DIRECTIONS OF THE DEFINITION OF REGIONAL DEVELOPMENT BENEFITS (FOR EXAMPLE, NIZHEGORODSKIY REGION)

Currently in a systemic crisis and the availability of sanctions in the first place is the problem of development of regions of Russia, therefore, the definition of the main socio-economic trends of development of regions is the most relevant. Research and analysis of fields of activity of separate regions enables determination of the trajectories of regional development in the whole country. The article identifies the main positive and negative trends in socio-economic development of Nizhniy Novgorod region, classified according to three main spheres of life: social, economic and information based on which the basic problems of territorial development, which are the causes of instability in the region

THE DEVELOPMENT OF REGIONAL ECONOMY IN TIMES OF CRISIS

Тhe article is devoted to the topical subject of a modern economy-development of regional economy in crisis, because of the need to determine the competitive status of the region (municipality), identification of factors of instability for further dynamic socio-economic development of the territory. The author of the article proposes an indicative list of factors for assessing the volatility of the regional economy in the context of a systemic crisis