2,805 research outputs found
History of the Creation of BESM: The First Computer of S.A. Lebedev Institute of Precise Mechanics and Computer Engineering
No full textInternational audienceSome aspects of the history of the first Soviet computer development are described. The idea of this work was offered by Sergey Lebedev who formulated the principles, wrote a plan and suggested the structure of the computer which was named BESM – Fast Electronic Calculating Machine. Some new documents are presented – a working notebook with Lebedev’s handwritten notes and a plan of a preliminary project draft development. BESM computer became the first in the long series of Soviet computers built under the leadership of Lebedev. It also was used as a prototype of the first Chinese computer built with the help of Soviet engineers
History of the Creation of BESM: The First Computer of S.A. Lebedev Institute of Precise Mechanics and Computer Engineering
No full textInternational audienceSome aspects of the history of the first Soviet computer development are described. The idea of this work was offered by Sergey Lebedev who formulated the principles, wrote a plan and suggested the structure of the computer which was named BESM – Fast Electronic Calculating Machine. Some new documents are presented – a working notebook with Lebedev’s handwritten notes and a plan of a preliminary project draft development. BESM computer became the first in the long series of Soviet computers built under the leadership of Lebedev. It also was used as a prototype of the first Chinese computer built with the help of Soviet engineers
An experimental investigation of the azimuthal structures formed during the ablation phase of wire array z-pinches
No full textA series of wire array implosion experiments have been carried out on MAGPIE, a 1.4MA peak current, 240ns
rise-time pulsed power generator located at Imperial College London. The aim of these experiments was to investigate
the azimuthal structure of ablation plasma produced during the early stages of wire array implosions. Previous
work [Lebedev, S.V., et al., PoP, 2001] has demonstrated that a significant portion of the implosion time is
dominated by the ablation phase, during which the dense wire cores remain at their initial radius and ablate
streams of plasma towards the array axis. This ablation plasma prefills the array, and its distribution forms the
initial conditions for the eventual snowplough-like implosion.
In order to carry out this investigation a new two-colour end-on interferometry system was constructed. A custom
software suite was developed in order to analyse the resulting data, enabling the conversion of the raw interferograms
into 2D electron density maps.
The experiments focused on cylindrical tungsten and aluminium arrays of between 8 and 128 wires. The structures
observed in aluminium arrays were dominated by collisional features. Networks of oblique shocks were
formed as the ablation streams interacted with their neighbours. Analysis of these shock structures allowed an
estimate to be made for the Mach number of the ablation streams, M=7.9-8.2. In contrast, the structures observed
in the tungsten experiments were characterised by smooth density profiles, consistent with relatively long
ion mean free paths. The quantitative nature of the dataset makes it ideal for comparison with the results of numerical
simulations.
Also reported in this thesis is the development of two CW laser diagnostics, a quadrature interferometer, and a
Faraday current diagnostic. The design of these diagnostics is discussed and some examples of the analysis are
presented
Victims of Soviet Terror in the Prose of Sergey Lebedev and Nikolay Kononov: The Prism of Postmemory
No full textThe article was submitted on 05.06.2021.This article discusses the prose of the Russian writers Sergey Lebedev and Nikolay V. Kononov, who address state terror and violence. The aforementioned authors take into account the experience of the post-Holocaust European culture of remembrance, which is constituted by the figure of the victim and tends to interpret the tragic events of the Soviet past using the concepts and theoretical frameworks of memory and trauma studies. In this article, Lebedev’s and Kononov’s prose is seen as an integral part of the Russian liberal-oriented memory project, which is based on late-Soviet dissident culture, the perestroika “culture of repentance,” and Western cultural models of “working through the past.” In rediscovering the topic of Stalinist terror, Lebedev and Kononov reassert its ideological and moral significance and attempt to place it on the current public agenda. Both writers proceed from the need to redress injustices against the victims of state violence, whose suffering was long silenced in the USSR. They work with documents, personal testimonies, and family history to tell stories of victims missing from the historical record and thus undermine the dominance of the state-supported heroic narrative. Such an approach brings Lebedev and Kononov closer to the tradition of Soviet camp prose, but this was prose of testimony, created by survivors of camps: the modern novelists have no such experience and rely on their imagination, documents, and previous representations of Stalinist terror. They consider the historical experience of state terror and the figure of the victim from the perspective of postmemory (M. Hirsch), which prompts them to postulate the existence of so-called “inherited trauma” and explore its social and emotional consequences in the lives of different generations. Thus, they observe the “post-existence of the GULAG” and paradoxical interactions between victims and perpetrators through the prism of “inherited” trauma and memory.В статье обсуждается проза Сергея Лебедева и Николая Кононова, которые обращаются к темам государственного террора и насилия. Они учитывают опыт европейской культуры памяти, конституированной после холокоста фигурой жертвы, и склонны интерпретировать трагические события советского прошлого, используя понятия и теоретические фреймы memory и trauma studies. Проза Лебедева и Кононова рассматривается автором как составная часть российского либерально ориентированного проекта памяти, который наследует позднесоветской диссидентской культуре, перестроечной «культуре покаяния» и западным культурным моделям «проработки прошлого». Переоткрывая тему сталинского террора, писатели заново утверждают ее идеологическую и моральную значимость и пытаются поместить ее в актуальную общественную повестку. Оба исходят из необходимости устранить несправедливость по отношению к жертвам террора, чьи страдания в СССР долгое время замалчивались. Они работают с документами, личными свидетельствами, семейными рассказами, чтобы показать истории жертв, отсутствующие в историческом архиве, и подорвать таким образом доминирование государственного героического нарратива. Подобный подход сближает их с советской лагерной прозой, но та, по мнению автора, была прозой свидетелей, выживших в лагерях, современные же романисты, не имея подобного опыта, опираются на воображение, документы и существующие репрезентации сталинского террора. Исторический опыт государственного террора и фигуру жертвы они воспринимают в перспективе постпамяти (М. Хирш), что побуждает их постулировать существование «унаследованной травмы» и исследовать ее социальные и эмоциональные эффекты в жизни нескольких поколений. Через призму «унаследованных» травмы и памяти они наблюдают «постсуществование ГУЛАГа» и парадоксальное взаимодействие жертв и палачей во времени
The Work of Sergey Alekseevich Lebedev in Kiev and Its Subsequent Influence on Further Scientific Progress There
No full textInternational audienceThe paper represents the memories of an active participant of development of the first Soviet computers in Kiev, Ukraine. The process of creating electronic computing machines such as MECM, BESM and SESM is described in detail. The outstanding role of S.A. Lebedev (head of the research group) is specially stressed as well as his impact on subsequent progress
SERGEY YURIEVICH PREOBRAZHENSKY, SCHOLAR AND AUTHOR OF VERSES
No full textThe article is written in memoria of Sergey Yurievich Preobrahzhensky, linguist and poet. It tackles upon the scientific interests of the scholar, deals with his principal concepts in prosody and other spheres of poetics. Besides, It also contains a brief characteristics and examples of his own poetic work
Sergey Witte and his Foreign Investment Policy in the studies by English-speaking scholars
No full text. The article discusses the development of the interest of English-speaking historians in the foreign investment policy of Sergey Witte. The paper also examines the role of the Secret Memorandum of Sergey Wittein the understanding of the foreign investment in the Russian economy. The author shows that Russian and English-speaking historians, despite the political upheavals of the 20th century, were engaged in a scholarly conversation in their discussion of the subject
Cultural heritage protection in the globalization context
No full textThe article actualizes the problem of national identity through the preservation of the basis of the cultural heritage of peoples and ethnic groups in the era of globalization and the emergence of a large number of ‘melting pots’ that erase the edges of the uniqueness of individual peoples of the world. The author argues that for any emerging nation, the cultural heritage, even if artificial, determines to a large extent the ‘core culture’ and is one of the basic foundations of national identity. Consequently, an important role is played by the adaptation of immigrants, who bring and lobby their culture and traditions in new territories for themselves. It forces some countries seeking to preserve their history and cultural heritage to actively hinder the immigration process, even sacrificing the development of their ethnic group, which does not tend to reduce the birth rate. However, on other way, multiculturalism only contributes to the rooting of specific customs and traditions among immigrant diasporas, which finally turn into separate communities leading to a close existence. The author concludes that in conditions, when one’s cultural heritage is withering and the core culture is disintegrating, new cultural values belonging to new minorities begin to arise
An Investigation of Cylindrical Liner Z-pinches as Drivers for Converging Strong Shock Experiments
No full textA cylindrical liner z-pinch configuration has been used to drive converging radia-
tive shock waves into different gases. Experiments were carried out on the MAGPIE
(1.4 MA, 250 ns rise-time) pulsed-power device at Imperial College London [1]. On
application of the current pulse, a series of cylindrical shocks moving at typical
velocities of 20 km s-1 are consecutively launched from the inside liner wall into
an initially static gas- ll. The drive current skin depth calculated prior to resis-
tive heating was slightly less than the liner wall thickness and no bulk motion of
the liner occurred. Axial laser probing images show the shock fronts to be smooth
and azimuthally symmetric, with instabilities developing downstream of each shock.
Evidence for a radiative precursor ahead of the first shock was seen in laser inter-
ferometry imaging and time-gated spatially resolved optical spectroscopy.
In addition to investigating the shock waves themselves, the timing of the shocks
was used together with their trajectories to gain insight into launching mechanisms.
This provided information on the response of the liner to the current pulse, which
is useful for the benchmarking of magneto-hydrodynamics (MHD) codes. A new
load voltage diagnostic provided evidence for two phase transitions occurring within
the liner wall. The voltage probe was also fielded on various other z-pinch loads for
measurements of energy deposition and inductance. The response of magnetically
thick liners was found to differ significantly from the case where the liner wall was
thin with respect to the initial skin depth of the current. In the later case the
evolution of the liner is dominated by the ablation of plasma much like during the
ablation phase of a wire array z-pinch
Cyclization of 2-acyl- and 2-thioacylaminobenzylcyclopropanes in the gas phase and solution
No full textMass spectrometry proved itself to be a powerful tool to predict the directions and yields of mono-molecular reactions of organic compounds. Electron ionization (El) and electrospray ionization (ESIl were used to study possible transformations of N-(orthocyclopropylmethylphenyl)arylamides I and N-(ortho-cyclopropylmethylphenyl)arylthioamides II as well as their para-isomers III and IV in a mass spectrometer and to predict directions and yields of their acid catalyzed cyclization reactions. Several five-eight-membered heterocycles were proposed as possible products of intramolecular transformations of compounds I and II. Reactions of compounds I and 11 in sulfuric acid solutions were carried out and the results obtained were compared with mass spectrometric data. Surprisingly, El of the studied compounds mimics their solution reactions better than ESI
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