5,280 research outputs found
Synthesis of aryl-substituted thieno[3,2-b]thiophene derivatives and their use for N,S-heterotetracene construction
Fiesselmann thiophene synthesis was applied for the convenient construction of thieno[3,2-b]thiophene derivatives. Thus, new 5- or 6-aryl-3-hydroxythieno[3,2-b]thiophene-2-carboxylates were obtained by condensation of 5- or 4-aryl-3-chlorothiophene-2-carbox-ylates, respectively, with methyl thioglycolate in the presence of potassium tert-butoxide. The saponification of the resulting esters, with decarboxylation of the intermediating acids, gave the corresponding thieno[3,2-b]thiophen-3(2H)-ones. The latter ketones were used to synthesize new N,S-heterotetracenes, namely 9H-thieno[2',3':4,5]thieno[3,2-b]indoles by their treatment with arylhydrazines in accordance with the Fischer indolization reaction. © 2019 Demina et al.; licensee Beilstein-Institut.Russian Foundation for Basic Research, RFBR: 18-33-20083This study was supported by the Russian Foundation for Basic Research, Grant No. 18-33-20083
Heavy Quark Production and PDF's Subgroup Report
We present a status report of a variety of projects related to heavy quark
production and parton distributions for the Tevatron Run II.Comment: Latex. 8 pages, 7 eps figures. Contribution to the Physics at Run II
Workshops: QCD and Weak Boson Physic
Cross MFF - Analysis in studying the obsessive-compulsive disorder
© Published under licence by IOP Publishing Ltd.There were demonstrated capabilities of the Memory Function Formalism (MFF) in analyzing cross correlations in human brain bioelectric activity at obsessive-compulsive disorder (OCD). To extract the information about collective phenomena in (electroencephalogram) EEG brain activity we use the power spectra of memory functions and the memory quantifiers. We discover the pairs of the electrodes with the greatest differences in dynamic and stochastic parameters for patients with the different condition. The high OCD condition is characterized by the influence of the memory effects. The MFF cross correlation analysis allow to describe the collective phenomena in EEG dynamics at OCD including the dynamic, spectral and stochastic behavior
The method for celestial bodies' center of mass position relative to their figures determination on the basis of harmonic analysis of the expansion in spherical functions in order to refine the physical libration parameters
© Published under licence by IOP Publishing Ltd. In this paper the problem of the lunar center of mass relative to the center of its figure determination on the basis of space observations is considered, since the Moon is the most studied celestial object and there is a complete database on it. The future prospects for lunar laser ranging and radio interferometry require development of adequate theoretical support for modern technologies. The aim of these studies is the distances' measurement between the Moon and the Earth with an accuracy of 1 mm. Thus, determination of the lunar center of mass position, represented in this paper, and development of the selenocentric system will allow to solve the above mentioned problem more accurately and reliably. The new values of the lunar center of mass relative to its center of figure in orthogonal selenographic coordinate system Δξ, Δη, Δζ have been determined; they are: -1.75, -0.75, 0.11 km respectively
Statistical analysis of collective phenomena in complex systems
© 2016, International Journal of Pharmacy and Technology. All rights reserved.The description of complex system evolution with the unique properties different from the sub-system properties is an important task of modern science. The solution of this problem is complicated not only by the absence of full information about the processes implemented in complex systems, but also by very diverse nature of the interaction between components. In this case, simplification is achieved in those approaches which allow “to abstract” from a studied system organization. Thus, the description of distributed system evolution is performed based on the extraction of information from the signals generated by them. This paper presents the possibilities of statistical analysis methods: the memory function formalism (MFF) and flicker-noise spectroscopy (FNS) during the study of synchronization phenomena. Using the example of a man’s magnetoencephalogram signal analysis (MEG) and radio emission of quasars examined the effects of coordination between the constituent parts of these systems are analyzed. MFF analysis of MEG signals mutual dynamics among healthy subjects led to the conclusion about the processes, compensating the abnormal collective activity of neurons in response to the third-party effects which are not observed in the case of photosensitive epilepsy. The effects of frequency-phase synchronization in the signals of quasar emission at different frequencies discovered within FNS contributed to the establishment of qualitatively distinct mechanisms concerning their disk accretion. The obtained results determine the possible ways of collective phenomena study in complex systems, as well as a key role of coordination effects in their evolution
The study of frequency behaviour and effects of statistical memory of eeg-signals of a man with bipolar affective disorder
© Research India Publications. The objective diagnostics of mental disorders at early developmental stages is obstructed due to absence of instrumental method of fixation, though relation of such disease to inevitable changes in the activity of separate areas of the brain cortex of a man seems evident, One of the limitations of instrumental diagnosis of psychiatric disturbances is a study of the signals of human brain activity: electroencephalogram (EEG), magnetoencephalogram (МEG), reflecting functional activity of different brain regions. Within the framework of formalism of memory functions (FMF) the present work analyses the spectral properties and effects of statistic memory of bioelectric activity of the cerebral cortex of healthy subjects and patients with bipolar affective disorder (BAD) for the purpose of determination of diagnostic criteria. FMF is a method that allows to bring in a complex of information measures for quantitative comparison of correlation fall time and existence of statistic memory in the dynamics under. In the course of FMF-analysis it has been discovered the characteristic forms of power spectra in the presence of BAD, and also the regions, for which the degree of manifestation of statistic memory in the dynamics of EEG-signals of healthy subjects and patients is cardinally discriminated. Substantial alterations of frequency behaviour of EEG-signals and effects of statistic memory for separate areas of human brain cortices can serve initial criteria for identification of BAD. The work observes the possibilities of using EEG-records in the development of objective methods of detection and identification of neuropsychopathy
Analysis of the terrestrial global digital model using fractal geometry and harmonic expansion into spherical functions
© 2018 by IOP Publishing Ltd. During the implementation of space missions on study of the Solar system a large amount of information on planets geophysics and their morphological properties has been obtained, that could be investigated using fractal geometry. The present paper describes the analysis of the GDEM terrestrial digital model built from the ASTER's observations. GDEM is global digital elevation model and ASTER is advanced spaceborne thermal emission and reflection radiometer. ASTER was installed on the platform of Terra (NASA) orbiter. In our study we used robust methods and fractal analysis. The fractal dimension values for the terrestrial surface, which has a heterogeneous structure, are obtained. The fractal dimensions are determined for geographical latitudes. Independent estimates of the Earth's macrostructure that could be used for a new interpretation of geophysical processes have been obtained as well
The fractal analysis of the topography and gravitational field of Venus
© Published under licence by IOP Publishing Ltd. The purpose of this paper is to present the results of structural analysis of gravitational and topographic parameters of Venus using the data from space missions, including "Magellan". The model gravitational potentials are presented as analytical functions of coordinates. The model is constructed on the basis of variations of Venus' artificial satellites orbits. As a result, fractal correlations of Venus' geoid anomalies and gravitational potential in both longitude and latitude as well as the mean value of fractal dimensions are calculated. The mean fractal dimension of Venus topographic model in latitude is D̄= 1.061, in longitude is D̄= 1.037; the mean fractal dimension of Venus gravitational potential model in latitude is D̄= 0.96, in longitude is D̄ = 1.053
The method of astronomical refraction anomalies analysis based on aerological data
© SGEM2017 All Rights Reserved. The aim of this article is to study astronomical refraction anomalies. Back in 1925 Grachev and Banahevich found systematic errors in meridian observations depending on zenithal distance. Grachev suggested that these refraction anomalies arise from the inclination of the Earth's surface to the South. The airstratas of the same density were considered as parallel to the Earth’s surface. But the analysis of latitude observations from the Bamberg and ZTL-180 telescopes showed there were significant systematic errors depending on zenithal distance and we suggested that these errors depended on inclination of the airstratas of the same density, which were independent of inclination of the Earth's surface. As a result, the method of calculating the inclinations of airstratas of the same density has been developed on the basis of aerological data. With this purpose isobaric surfaces (the surfaces of the same atmospheric pressure) in many points of the Earth’s surface were taken. Altitudes of each isobaric surface relative to the geoid were analyzed. It was found the impact of inclination of upper air layers of the same density on the refraction does not fully compensate the impact of inclination of lower atmospheric boundary layers. If inclination of the upper air layers starts from small altitude, then the impact of inclination of the lower atmospheric boundary layers on the refraction compensate approximately 50 % of the impact of inclination of the upper atmospheric boundary layers on the refraction. Therefore, it is necessary to introduce amendments to observations of refraction anomalies due to the impact of inclination of air layers of the same density; those amendments are particularly important for making observations by modern high-sensitive telescopes. Thus, if a pair of stars on different sides of the zenith is observed for example at zenithal distance of 70°, then the error in the latitude for anomalous refraction due to inclination of atmospheric boundary layers is about 0.1’. The present investigation allows explaining systematic differences between Hipparcos and modern star catalogues
Synchronization of EEG activity in patients with bipolar disorder
© Published under licence by IOP Publishing Ltd. In paper we apply the method based on the Flicker-Noise Spectroscopy (FNS) to determine the differences in frequency-phase synchronization of the cortical electroencephalographic (EEG) activities in patients with bipolar disorder (BD). We found that for healthy subjects the frequency-phase synchronization of EEGs from long-range electrodes was significantly better for BD patients. In BD patients a high synchronization of EEGs was observed only for short-range electrodes. Thus, the FNS is a simple graphical method for qualitative analysis can be applied to identify the synchronization effects in EEG activity and, probably, may be used for the diagnosis of this syndrome
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