294 research outputs found
Torsion free groups with indecomposable holonomy group I
We study the torsion free generalized crystallographic groups with the
indecomposable holonomy group which is isomorphic to either a cyclic group of
order or a direct product of two cyclic groups of order .Comment: 22 pages, AMS-Te
Selective deposition of polycrystalline diamond films using photolithography with addition of nanodiamonds as nucleation centers
A new method of selective deposition of polycrystalline diamond has been developed and studied. The diamond coatings with a complex, predetermined geometry and resolution up to 5 [mu]m were obtained. A high density of polycrystallites in the coating area was reached (up to 32·10{7} pcs/cm{2}). The uniformity of the film reached 100%, and the degree of the surface contamination by parasitic crystals did not exceed 2%. The technology was based on the application of the standard photolithography with an addition of nanodiamond suspension into the photoresist that provided the creation of the centers of further nucleation in the areas which require further overgrowth. The films were deposited onto monocrystalline silicon substrates using the method of "hot filaments" in the CVD reactor. The properties of the coating and the impact of the nanodiamond suspension concentration in the photoresist were also studied. The potential use of the given method includes a high resolution, technological efficiency, and low labor costs compared to the standard methods (laser treatment, chemical etching in aggressive environments)
Political Clubs and Press in Russia and England in the 20—30s of XIX Century: Russian Public Opinion about the Tory Party
The author examines the processes of institutionalization of such forms of public representation in Great Britain and Russia in the first third of the 19th century as the press and political clubs. The formation of criteria for a new type of communication characteristic of club culture is investigated: equality of participants, the quality of argumentation and problematization of public policy in relation to both countries. The relevance of the study is seen in conducting a comparative analysis and determining the features of the formation of public political discourse in Russia and Great Britain during the period under study. The novelty of the research lies in the placement of the problems considered in the article in a broader research context, as well as in the use of the methodology of critical conventionalism in the analysis of the role of the press and political clubs. Particular attention is paid to the presentation in the Russian press of the political situation in Great Britain in the first half of the 30s of the XIX century. The author’s vision of the role and place of the press in shaping public opinion in Russia in relation to the policy of the Tory party in 1831—1834 is presented. It is shown that the ideas of the Russian educated class about Tory politics during this period were fragmentary and poorly understood from the point of view of understanding British political realities. It is emphasized that the correctness of the assessment of the political situation in Great Britain in the first half of the 30s of the 19th century raises reasonable doubts in the Russian press
Regulating the international activities of Russian higher education institutions
One of the key conditions for increasing of Russian education competitiveness in the international market is the active involvement of universities in various international cooperation forms. For this purpose, an analysis of international, federal, local normative legal acts regulating the international activities of Russian higher education institutions was carried out. The international aspect was considered using a comparative legal analysis of agreements between Russia and other countries. The article presents the results of the analysis of the principles of international agreements regulating the educational process in Russian universities. According to the research, a model, regulating the international activities of Russia’s universities, was analysed. The study of regulatory legal acts in Russia’s higher education led to the conclusion about the legislation elaboration level, to outline the prospects for development and the possibility of expanding the domestic universities international activities
Long-term variability of the optical spectra of NGC 4151: I. Light curves and flux correlations
Results of a long-term spectral monitoring of the active galactic nucleus of
NGC 4151 are presented (11 years, from 1996 to 2006). High quality spectra
(S/N>50 in the continuum near Halpha and Hbeta) were obtained in the spectral
range ~4000 to 7500 \AA, with a resolution between 5 and 15 A, using the 6-m
and the 1-m SAO's telescopes (Russia), the GHAO's 2.1-m telescope (Cananea,
Mexico), and the OAN-SPM's 2.1-m telescope (San-Pedro, Mexico). The observed
fluxes of the Halpha, Hbeta, Hgamma and HeII emission lines and of the
continuum at the observed wavelength 5117 A, were corrected for the position
angle, the seeing and the aperture effects.
We found that the continuum and line fluxes varied strongly (up to a factor
6) during the monitoring period. The emission was maximum in 1996-1998, and
there were two minima, in 2001 and in 2005. The Halpha, Hgamma and He II fluxes
were well correlated with the Hbeta flux. We considered three characteristic
periods during which the Hbeta and Halpha profiles were similar: 1996-1999,
2000-2001 and 2002-2006. The line to continuum flux ratios were different; in
particular during the first period, the lines were not correlated with the
continuum and saturated at high fluxes. In the second and third period, where
the continuum flux was small, the Halpha and Hbeta fluxes were well correlated
to the continuum flux, meaning that the ionizing continuum was a good
extrapolation of the optical continuum. The CCFs are often asymmetrical and the
time lags between the lines and the continuum are badly defined indicating the
presence of a complex BLR, with dimensions from 1 to 50 light-days.Comment: A&A, accepte
USE OF CO2 FROM TPP FLUE GASES IN THE PRODUCTION OF SODA
Reducing greenhouse gas emissions caused by environmental concerns requires the development of economically viable technologies for capturing and using CO2. The modernization of the existing technology for the production of soda by the Solvay method is proposed, which consists in replacing mineral raw materials (limestone) with CO2 from the flue gases of TPP. The advantages of the proposed technology are the absence of waste due to the implementation of a closed chlorine cycle, as well as the readiness for practical use, due to the implementation of individual technological processes on an industrial scale.Вызванное экологическими проблемами сокращение эмиссии парниковых газов требует разработки экономически состоятельных технологий улавливания и использования CO2. Предложена модернизация существующей технологии производства соды по методу Сольве, заключающаяся в замене минерального сырья (известняка) на СО2 из дымовых газов тепловых электростанций (ТЭС). Преимуществами предлагаемой технологии являются отсутствие отходов за счет осуществления замкнутого цикла по хлору, а также готовность к практическому применению, обусловленная реализацией отдельных технологических процессов в промышленном масштабе
On the works of the Dokuchaev Soil Science Institute in Uzbekistan
The article considers the history of the work of the Dokuchaev Soil Science Institute researchers in Uzbekistan, conducted jointly with soil scientists from Uzbekistan. These works were started in 1930–1940s. They were especially active during the Great Patriotic War, when the Soil Institute was evacuated to Tashkent. During these years, both Russian and Uzbek soil scientists participated in joint work. Outstanding scientists can be named among Russian researchers: V.A. Kovda, A.A. Rode, A.N. Rozanov and many others who contributed to the study of Uzbekistan soils. The work of the researchers from the Dokuchaev Soil Science Institute, performed on the basis of a station in the Hungry Steppe (Mirzacho'l) in connection with the development of saline lands during the creation of new irrigation systems in Central Asia, is analyzed in particular detail. Various work areas of the station researchers are discussed in the article: issues of ameliorative development of saline soils, salinity mapping based on remote sensing methods, detailed study of the reclaimed soils properties using chemical, micromorphological, mineralogical and other research methods for the determination of salinity and gypsum content of soils in the New Irrigation Zone (NIZ) of Hungry and Jizzakh steppes. The results of the work were presented in a series of publications. In the 1990s, cooperation was temporarily ceased, but at the beginning of the 21st century it was resumed
State-dependent effects of transcranial oscillatory currents on the motor system during action observation
We applied transcranial alternating current stimulation (tACS) to the primary motor cortex (M1) at different frequencies during an index–thumb pinch-grip observation task. To estimate changes in the corticospinal output, we used the size of motor evoked potentials (MEPs) obtained by transcranial magnetic stimulation (TMS) of M1 using an online MRI-guided simultaneous TMS-tACS approach. The results of the beta-tACS confirm a non-selective increase in corticospinal excitability in subjects at rest; an increase was observed for both of the tested hand muscles, the first dorsal interosseous (FDI) and the abductor digiti minimi (ADM). However, during action observation of the pinch-grip movement, the increase of corticospinal excitability was only observed for the prime mover FDI muscle and took place during alpha-tACS, while gamma-tACS affected both the FDI and control muscle (ADM) responses. These phenomena likely reflect the hypothesis that the mu and gamma rhythms specifically index the downstream modulation of primary sensorimotor areas by engaging mirror neuron activity. The current neuromodulation approach confirms that tACS can be used to induce neurophysiologically detectable state-dependent enhancement effects, even in complex motor-cognitive tasks
Effect of Heat Treatment on Microstructure and Properties of High-Strength Steel
Изучены особенности структурообразования в стали 30Х2ГСН2ВМ (ВЛ-1) при реализации различных режимов изотермической обработки: ступенчатая закалка при температуре ниже Мн (quenching-partitioning), изотермическая закалка на бейнит. Показано, что расчетная оптимальная температура ступенчатой закалки не обеспечивает предсказанное количество стабильного остаточного аустенита в структуре исследуемой стали.The microstructure formation in steel 30Kh2GSN2VM are studied after the isothermal treatment: quenching-partitioning, austempering. It is shown that the calculated partitioning temperature does not provide the predicted amount of stable retained austenite in the structure of the steel under study.Исследование выполнено за счет средств гранта Российского научного фонда 22-29-00106.The research was carried out at the expense of the grant of the Russian science foundation 22-29-00106
The Holocene environmental history of a small coastal lake on the north-eastern Kamchatka Peninsula
© 2015. A radiocarbon and tephra-dated sediment core from Lifebuoy Lake, located on the north-east coast of Kamchatka Peninsula, was analysed for pollen, spores, diatoms, chironomids and tephra in order to uncover regional environmental history. The 6500-year environmental history of Lifebuoy Lake correlates with the broad regional patterns of vegetation development and climate dynamics with both diatoms and chironomids showing near-synchronous changes. Between ca. 6300 and 3900 cal. yr. BP, the lake ecosystem was naturally enriched, with several Stephanodiscus species dominating the diatom plankton. This natural eutrophication state is likely to be due to a combination of the base-rich catchment geology, the fertilisation effect of several fires in the catchment, silica input from tephra layers and, possibly, nitrogen input from seabirds. The substantial tephra deposit at about 3850 cal. yr. BP might have stopped sedimentary phosphorus from entering the lake water thus decreasing the trophic state of the lake and facilitating the shift in diatom composition to a benthic Fragiliariaceae complex. Both diatoms and chironomids showed simultaneous compositional changes, which are also reflected by statistically significant changes in their rates of change 300-400. years after the arrival of Pinus pumila in the lake catchment. The rapid increase in both total diatom concentration and the percentage abundance of the large heavy species, Aulacoseira subarctica might be a response to the change in timing and intensity of lake spring turn-over due to the changes in the patterns of North Pacific atmospheric circulation, most notably westward shift of the Aleutian Low. The two highest peaks in A. subarctica abundance at Lifebouy Lake occurred during opposite summer temperature inferences: the earlier peak (3500-2900. cal. yr. BP) coincided with warm summers and the latter peak (300. cal. yr. BP-present) occurred during the cold summer period. These imply that A. subarctica shows no direct response to the changes of summer air temperature. Instead, it appears to thrive during the periods of increased winter precipitation, thicker ice and late spring turn-over periods, i.e., shows indirect response to climate. The clearest effect of tephra deposition on the lake ecosystem is above 908 cm (ca. 3800 cal. yr. BP) where the tephra deposit might have caused the shift from Stephanodiscus-dominated planktonic assemblages to the Fragilariaceae complex of benthic species. Tephra deposits might have also contributed towards the development of eutrophic plankton from about 6300 cal. yr. BP. It is not certain if several tephra deposits influenced diatom and chironomid changes during the last 300 years
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