256 research outputs found

    Генезис социальных медиа как предпосылка формирования новых маркетинговых коммуникаций

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    Досліджено зміну моделі споживчої поведінки під впливом появи соціальних мереж і соціальних медіа. Охарактеризовано відмінності соціальних медіа від традиційних засобів масової інформації. Виявлено основні чинники, складові та найвпливовіші аспекти, що обумовлюють розвиток сучасних маркетингових комунікацій у соціальних медіа. Доведено необхідність подальших досліджень маркетингового інструментарію у соціальних медіа для обґрунтування напрямів удосконалення маркетингового менеджменту та адаптації бізнес-моделей сучасних підприємств.The topic of the article is the genesis of social media as a precondition for the formation of new marketing communications. The purpose of the article is to study a systematic approach to the formation of modern theoretical and methodological basis for marketing communications in social media. The change models of consumer behavior influenced the emergence of social networking and social media. The characteristic differences of social media from traditional media. The study identified key factors and components of the most influential aspects that contribute to the development of modern marketing communication in social media. There is a necessity of further research into marketing tools for the study of social media marketing management areas of improvement and adaptation of business models of modern enterprises. The prospects for the further research in this direction is the development of the concept of marketing communication in social media,which is a scientific and practical response to the demands of the modern business environment and requires substantial theoretical and methodological mastery and perfection.Исследовано изменение модели потребительского поведения под влиянием появления социальных сетей и социальных медиа. Охарактеризованы различия социальных медиа от традиционных средств массовой информации. Выявлены основные факторы, составляющие и наиболее влиятельные аспекты, обуславливающие развитие современных маркетинговых коммуникаций в социальных медиа. Доказана необходимость дальнейших исследований маркетингового инструментария в социальных медиа для обоснования направлений совершенствования маркетингового менеджмента и адаптации бизнес-моделей современных предприятий

    Line-shape modeling in microwave spectroscopy of the positronium n=2 fine-structure intervals

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    We report numerical simulations of positronium experiments designed to measure the n = 2 fine-structure intervals. The simulations include all possible interference effects between all 20 states in the n = 1 and laser-excited n = 2 manifolds as well as representations of the electric and magnetic fields present in the waveguides used in the experiments. We find that rf wave reflection from the vacuum chamber walls is a possible explanation of previously observed line-shape distortions and shifts. We also characterized several systematic effects, including those arising from quantum interference, that are likely to be significant for future measurements

    On mutually diagonal nets on (confocal) quadrics and 3-dimensional webs

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    Canonical parametrisations of classical confocal coordinate systems are introduced and exploited to construct non-planar analogues of incircular (IC) nets on individual quadrics and systems of confocal quadrics. Intimate connections with classical deformations of quadrics which are isometric along asymptotic lines and circular cross-sections of quadrics are revealed. The existence of octahedral webs of surfaces of Blaschke type generated by asymptotic and characteristic lines which are diagonally related to lines of curvature is proven theoretically and established constructively. Appropriate samplings (grids) of these webs lead to three-dimensional extensions of non-planar IC nets. Three-dimensional octahedral grids composed of planes and spatially extending (checkerboard) IC-nets are shown to arise in connection with systems of confocal quadrics in Minkowski space. In this context, the Laguerre geometric notion of conical octahedral grids of planes is introduced. The latter generalise the octahedral grids derived from systems of confocal quadrics in Minkowski space. An explicit construction of conical octahedral grids is presented. The results are accompanied by various illustrations which are based on the explicit formulae provided by the theory

    Cutting the same fraction of several measures

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    We study some measure partition problems: Cut the same positive fraction of d+1d+1 measures in Rd\mathbb R^d with a hyperplane or find a convex subset of Rd\mathbb R^d on which d+1d+1 given measures have the same prescribed value. For both problems positive answers are given under some additional assumptions.Comment: 7 pages 2 figure

    Picropodophyllin causes mitotic arrest and catastrophe by depolymerizing microtubules via Insulin-like growth factor-1 receptor-independent mechanism

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    Picropodophyllin (PPP) is an anticancer drug undergoing clinical development in NSCLC. PPP has been shown to suppress IGF-1R signaling and to induce a G2/M cell cycle phase arrest but the exact mechanisms remain to be elucidated. The present study identified an IGF-1-independent mechanism of PPP leading to pro-metaphase arrest. The mitotic block was induced in human cancer cell lines and in an A549 xenograft mouse but did not occur in normal hepatocytes/mouse tissues. Cell cycle arrest by PPP occurred in vitro and in vivo accompanied by prominent CDK1 activation, and was IGF-1R-independent since it occurred also in IGF-1R-depleted and null cells. The tumor cells were not arrested in G2/M but in mitosis. Centrosome separation was prevented during mitotic entry, resulting in a monopolar mitotic spindle with subsequent prometaphase-arrest, independent of Plk1/Aurora A or Eg5, and leading to cell features of mitotic catastrophe. PPP also increased soluble tubulin and decreased spindle-associated tubulin within minutes, indicating that it interfered with microtubule dynamics. These results provide a novel IGF-1R-independent mechanism of antitumor effects of PPP

    A search for massive neutral bosons in orthopositronium decay

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    We have searched for an exotic decay of orthopositronium into a single photon and a short-lived neutral boson in the hitherto unexplored mass region above 900 keV/c2{\rm keV}/{\it c}^{2}, by noting that this decay is one of few remaining candidates which could explain the discrepancy of the orthopositronium decay-rate. A high-resolution measurement of the associated photon energy spectrum was carried out with a germanium detector to search for a sharp peak from this two-body decay. Our negative result provides the upper-limits of\mbox{ }2.0×1042.0 \times 10^{-4} on the branching ratio of such a decay in the mass region from 847 to 1013 keV/c2{\rm keV}/{\it c}^{2}, and excludes the possibility of this decay mode explaining the discrepancy in the orthopositronium decay-rate.Comment: a LaTeX file (text 7 pages) and a uuencoded gz-compressed PostScript file (text 7 pages + figures 4 pages

    Influence of severe plastic deformation on the structure and mechanical properties of eutectic Al-Zn-Mg-Fe-Ni alloy

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    The structure and phase evolution of the new eutectic high strength aluminium alloy Nikalin were investigated under high pressure torsion (HPT) by several numbers of the revolution of the anvil. The chemical composition of the investigated Nikalin alloy was as follows: Al (base)- 7.22Zn-2.95 Mg-0.52 Fe-0.57 Ni-0.2 Zr. (wt.%). The initial material was a coarse grained cast ingot after homogenization. It was established that the HPT process resulted in the deformation dissolution of the nanosized T-phase precipitates and the formation of a supersaturated aluminum solid solution simultaneously with the strong refinement of the structure to the grain-subgrain size of 130-150 nm. Due to that, the yield stress of the HPT alloy increased by a factor of 1.5, the ultimate tensile strength increased by a factor of 1.4, while preserving good ductility of 6-7%. The observed effect of the additional supersaturated solution upon HPT relative to the homogenized state appeared upon post-deformation annealing at 140 °C. An increase in the microhardness of the HPT alloy due to the MgZn2 phase precipitation was observed at 0.5- hours of annealing. © Published under licence by IOP Publishing Ltd.Russian Foundation for Basic Research, RFBR: 18-03-00102Ministry of Science and Higher Education of the Russian Federation: АААА-А18-118020190116-6The research was carried out within the state assignment of the Ministry of Science and Higher Education of the Russian Federation (theme “Structura”, № АААА-А18-118020190116-6) supported in part by RFBR (project № 18-03-00102). The electron microscopy investigations were performed at the Center of Collaborative Access “Testing Center of Nanotechnologies and Advanced Materials” of the M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences

    INTERNET TECHNOLOGIES AS A FACTOR OF INCREASING THE COMPETITIVENESS AND COMPETITIVE STABILITY OF SERVICE ORGANIZATIONS

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    Presently, the use of Internet technologies is an absolute advantage on the way to the successful functioning of an enterprise in any sphere of economy. The increasing unpredictability of the external environment, the variability of consumer preferences are increasingly transforming competition in the markets of goods and services, from the industrial to the information plane. Under such conditions, the role of internal factors of enterprise competitiveness increases. In recent decades, the introduction of such technologies in service enterprises has become increasingly widespread, ranging from simple tools (e-mail or messengers) to global introduction in the business structure ( using electronic commerce or creating virtual enterprises). We are not even talking about the newest complex developments in the field of Internet technologies, but about the use of existing and simpler ones, which are increasingly used by enterprises. The basic directions of application of Internet technologies and advantages which a business entity in the service sector receives from it have been considered in the article

    РАСЧЕТ ФАЗОВЫХ ДИАГРАММ СИСТЕМ Al–Cu–Zn–Mg и Al–Cu–Zn–Mg–Fe–Si

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    Using the results of thermodynamic calculations with «Thermo-Сalc» software package, the fragments of the Al–Cu–Zn–Mg and Al–Cu–Zn–Mg–Fe–Si– (Mn) phase diagrams in the range of densities, (%): 4–6 Сu, 2–4 Zn, 0,5–2,0 Mg, 1,5–2,0 Fe, 1,5–5,0 Si have been built as well as the composition of the solid solution for a number of alloys of the Al–Cu–Zn–Mg–Fe–Si–(Mn) system has been calculated at temperatures near to the solidus line. The X-ray microspectral analysis was used for experimental proof of the thermodynamic calculations, which show the satisfactory precision of the calculated and experimental data. It is found that maximally alloyed aluminum solid solution can be produced at an iron and silicon density ratio of Fe/Si = 0,5 for the alloys of the Al–Cu–Zn–Mg–Fe–Si–(Mn) system.По результатам термодинамических расчетов с использованием пакета программ «Thermo-Сalc» построены фрагменты фазовых диаграмм Al–Cu–Zn–Mg и Al–Cu–Zn–Mg–Fe–Si–(Mn) в интервале концентраций (%) 4–6 Сu, 2–4 Zn, 0,5–2,0 Mg, 1,5–2,0 Fe, 1,5–5,0 Si, а также рассчитан состав твердого раствора для ряда сплавов системы Al–Cu–Zn–Mg–Fe–Si–(Mn) при температурах вблизи солидуса. Методом микрорентгеноспектрального анализа проведена экспериментальная проверка термодинамических расчетов, которая показала удовлетворительную сходимость расчетных и экспериментальных данных. Выявлено, что при соотношении концентраций железа и кремния Fe/Si = 0,5 для сплавов системы Al–Cu–Zn–Mg–Fe–Si–(Mn) возможно получение максимально легированного алюминиевого твердого раствора

    Экспериментальное изучение единичных треков, полученных из смеси порошков Ti и Al при варьируемых параметрах процесса селективного лазерного плавления

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    The paper studies the effect of the laser scanning speed (vs) on the morphology of single tracks obtained from a mixture of Ti and Al powders in a stoichiometric ratio of 1 : 1 in longitudinal and cross sections. Droplets of splashed liquid were found on the outer surface of the track obtained at vs = 300 mm/s. Their appearance is resulted most likely from the release of gas bubbles formed due to the evaporation of aluminum having a lower melting point. A distortion of a single track along its length was observed with an increase in vs values up to 600 mm/s. It was found that tracks loose stability as the laser beam speed increases with «balls» formed on the track surface due to the significant Marangoni convection and the capillary liquid instability in the molten bath. An increase in the laser speed led to the appearance of pores mainly concentrated in the formed balls, and also influenced the track morphology in the cross section, namely, the width and height of the track, as well as the depth of substrate fusion. An increase in the scanning speed from 300 to 900 mm/s led virtually no substrate fusion, and the track width decreased from 194 to 136 μm, while its height increased almost 4 times – from 21 to 88 μm. X-ray microanalysis was conducted and element distribution maps were obtained to assess the structure of the tracks under study. It was found that the degree of liquid mixing in the molten bath is insufficient at scanning speeds of 300 and 600 mm/s, which leads to the segregation of elements over the track cross section. The central zone turns out to be enriched in aluminum, while titanium predominates at the base and is practically absent in the extreme zone (4.57 at.% Ti). X-ray microanalysis revealed the presence of unmelted titanium powder particles at vs = 900 mm/s. Presumably, it may be caused by insufficient laser power at such a high scanning speed.В ходе исследований изучено влияние скорости сканирования лазера (vс) на морфологию единичных треков, полученных из смеси порошков Ti и Al в стехиометрическом соотношении 1 : 1 в продольном и поперечном сечениях. На наружной поверхности трека, полученного при vс= 300 мм/с, были обнаружены капли выплеснувшейся жидкости, появление которых скорее всего было вызвано выбросом пузырьков газа, образовавшихся из-за испарения более легкоплавкого алюминия. С ростом значений vс до 600 мм/с наблюдалось искажение единичного трека по длине. Было установлено, что с увеличением скорости лазерного луча треки перестают быть стабильными, и из-за значительной конвекции Марангони и нестабильности капиллярной жидкости в расплавленной ванне по поверхности трека формируются «шарики». Повышение скорости лазера привело к появлению пор, которые в основном сконцентрированы в образовавшихся шариках, а также оказало влияние на морфологию трека в поперечном сечении, а именно – на ширину, высоту трека и глубину проплавления подложки. С увеличением скорости сканирования с 300 до 900 мм/с проплавления подложки практически не наблюдалось, ширина трека уменьшилась с 194 до 136 мкм, а его высота увеличилась почти в 4 раза – с 21 до 88 мкм. Для оценки структуры изучаемых треков был проведен микрорентгеноспектральный анализ (МРСА) и получены карты распределения элементов. Установлено, что при скоростях сканирования 300 и 600 мм/с перемешивание жидкости в ванне расплава происходит в недостаточной степени, что приводит к ликвации элементов по сечению треков. Центральная зона оказывается обогащеной алюминием, в то время как в основании преобладает титан, а в крайней зоне он практически отсутствует (4,57 ат.% Ti). При vс = 900 мм/с, по данным МРСА, наблюдалось наличие нерасплавившихся частиц порошка титана. Предположительной причиной этого может являться недостаточная мощность лазера при столь высокой скорости сканирования
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