1,305 research outputs found

    Transfer in Implicit Learning

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    The article describes the research, the aim of which is to discover the effect of transfer of the implicit knowledge of artificial grammar to solving of sensory-motor tasks. The article considers the role of implicit knowledge in actual cognitive activity. Forty volunteers took part in the experiment. Participants of the experiment wereimplicitly taught the rule of artificial grammar. At the control phase, the assignment consisted of solving the sensory-motor problem – to react to the appearance of the green or yellow circle by pressing a certain key. In the experimental group, the grammatical line always appeared before the green-colored circle was presented, and the ungrammatical line appeared before the yellow-colored circle. In the control group the color of the circle didn’t depend on the grammaticality of the line. As a result, we established the considerable reduction in the reaction time in the experimental group. Thus, the transfer of the implicitly learned knowledge of artificial grammar leads to enhancement of efficiency of sensory-motor activity. The implicit rule of artificialgrammar has acquired role of prime-stimulation. Keywords: implicit knowledge, implicit learning, artificial grammar learning, sensorymotor activity, transfer effect, primin

    The course of experimental staphylococcus infection in albino mice during action of certain factors of space flight

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    A study was made of the effect of certain factors of space flight, acceleration and hypokinesia, on the course of experimental staphylococcus infection in mice. Combined action of hypokinesia and acceleration caused a marked depression of the phagocytic activity of leukocytes and formation of a considerable amount of alpha toxin

    Temperature dependence of self-trapped exciton luminescence in nanostructured hafnia powder

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    The intrinsic optical properties and peculiarities of the energy structure of hafnium dioxide largely determine the prospects for applying the latter in new generation devices of optoelectronics and nanoelectronics. In this work, we have studied the diffuse reflectance spectra at room temperature for a nominally pure nanostructured HfO2HfO_2 powder with a monoclinic crystal structure and, as well its photoluminescence in the temperature range of 40 - 300 K. We have also estimated the bandgap EgE_g under the assumption made for indirect (5.31 eV) and direct (5.61 eV) allowed transitions. We have detected emission with a 4.2 eV maximum at T < 200 K and conducted an analysis of the experimental dependencies to evaluate the activation energies of thermal quenching (140 meV) and enhancement (3 meV) processes. Accounting for both the temperature behavior of the spectral characteristics and the estimation of the Huang-Rhys factor S >> 1 has shown that radiative decay of self-trapped excitons forms the mechanism of the indicated emission. In this case, the localization is mainly due to the interaction of holes with active vibrational modes of oxygen atoms in non-equivalent (O3fO_{3f} and O4fO_{4f}) crystal positions. Thorough study of the discussed excitonic effects can advance development of hafnia-based structures with a controlled optical response.Comment: 21 pages, 7 figures, 2 tables, 56 references. Keywords: hafnium dioxide, self-trapped exciton, F-center, thermal quenching of luminescence, luminescence enhacement, Huang-Rhys factor, effective phonon energy, bandgap widt

    Mutual Fund Theorem for continuous time markets with random coefficients

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    We study the optimal investment problem for a continuous time incomplete market model such that the risk-free rate, the appreciation rates and the volatility of the stocks are all random; they are assumed to be independent from the driving Brownian motion, and they are supposed to be currently observable. It is shown that some weakened version of Mutual Fund Theorem holds for this market for general class of utilities; more precisely, it is shown that the supremum of expected utilities can be achieved on a sequence of strategies with a certain distribution of risky assets that does not depend on risk preferences described by different utilities.Comment: 17 page

    A Chebyshev minimax technique oriented to aerospace trajectory optimization problems.

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76822/1/AIAA-6604-910.pd

    Developing Students’ Skills of Identifying Reliable Scientific Sources: The Role of a Librarian

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    Purpose. The purpose of this paper is to provide modes of teaching Russian undergraduate students fundamental critical analysis of scientifc papers and ways of identifying misinformation and disinformation in β€œAcademic Writing” discipline. design/methodology/approach. β€œAcademic Writing” discipline was taught to frst-year undergraduate students by scientifc library experts. At a starting period students were asked to complete a questionnaire and perform a test, and then write an essay to identify how students were able to assess Web scientifc literature and verify their β€œtolerance” to inaccurate and fake scientifc information. Then contact hours on theory and practice of identifying and assessing information were introduced into the curriculum. At the end of the semester lists of works cited in original essays and fnal assays were compared.Findings. The fndings reveal that entirely all frst year undergraduate students lack the ability to differentiate between qualitative certain scientifc information and misinformation and disinformation, and they willingly borrow anything from the Web. However, students acquired necessary skills to assess information critically using socio-technical systems infrastructures.This was demonstrated with list of literature analysis in students’ essays and peer-checking. originality. It is headline news and social networks when it is necessary to distinguish from authentic and inaccurate information. However, skills of critical assessment of scientifc publications are of vital importance at a starting period of studies. In publications of that sort falsifcations, fabrications and other fake discoveries can lead to reputational and fnancial risks, and then trigger unethical demeanour of future researchers. It is qualifed librarians being experts in electronic resources and data based use who are able to get students to β€œdigital hygiene”.Practical implications. The results of the paper can be used for teaching in university curriculum. Embedding information literacy and academic writing as well as involving information resources into students’ curriculum are aimed at the ability to identify misinformation and disinformation. Librarian-developed β€œAcademic writing” discipline component might be introduced into curriculum as a self-contained short course or a composing element of any students’ academic discipline. All this mitigate the risks of applying low-equality, unverifed and openly fake information in educational and scientifc works

    ΠœΠΎΡ€Ρ„ΠΎΠ»ΠΎΠ³ΠΈΡ ΠΈ экологичСскиС особСнности Sparganium Γ— longifolium (Typhaceae) Π² Ρ†Π΅Π½Ρ‚Ρ€Π΅ ЕвропСйской части России

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    The increasing impact of anthropogenic factors and climate change affect the growth of a number of taxa of hybrid nature. These taxa are widespread among various taxonomic groups of aquatic and semi-aquatic plants. The genus Sparganium L. Π’ is not an exception. In that regard, the aim of this study is to conduct biomorphological investigation of Sparganium Γ— longifolium Turcz. ex Ledeb., evaluate qualitative and quantitative criteria for the hybrid similarities and differences with its parental species, as well as to analyze data on its habitat characteristics. Samples were collected in 2014–2016 from waterbodies in European Russia (Tver and Yaroslavl oblasts). In the study on biomorphology of S.&nbsp;Γ— longifolium we used live and fixed materials, as well as herbarium funds of IBIW, MXA and MW. To establish and specify taxonomic features of the hybrid under study, indicating to its similarity with a certain ancestral species, our data on the morphology and ecology of S. emersum Rehm. and S. gramineum Georgi. are used. During field studies, the type of water object where the hybrid was detected, ecological characteristics of its habitat (type of soil, depth, water temperature and pH) are determined; the list of taxa which enter into the cenosis composition is compiled. The&nbsp;biomorphological investigation of S. Γ— longifolium shows that by life form this hybrid, as well as its parental species, is a vegetative-mobile evidently-polycentric annual or biennial plant of vegetative origin with a racemose root system. The following should be attributed to the characteristic features justifying the hybrid origin of S. Γ— longifolium: 1) a wider, slightly carinated lamina (as in S. emersum); 2) a branched inflorescence (as in S. gramineum); 3) the lower covering leaf of inflorescence, often exceeding the total length of the latter; 4) fruits with a straight (as in S. emersum) as well as bent (as in S. gramineum) style. Interestingly, some populations of S. Γ— longifolium are rich in terate forms that can be explained by back crossing with one of the parental species or pleiotropic mutation(s). It is established that S. Γ— longifolium is not widespread in European Russia, is a typically freshwater species, occurring in the littoral zone of mesotrophic and dystrophic waterbodies (usually in lakes of glacier origin). At present, its appearance in lake ecosystems is due to accelerated eutrophication caused by increasing human activities. Perhaps earlier this hybrid formation occurred in peripheral zones of the range of S. gramineum under cyclic climate changes. Observations suggest that S. Γ— longifolium exceeds S. gramineum in ecological potential. At the same time, habitat features of the latter have an effect on the hybrid’s distribution potential (limitation of habitat spectrum), which is hardly exceeds S. emersum in its ecological and coenotic characteristics.&nbsp;154 &nbsp; На основС соврСмСнных ΠΏΠΎΠ΄Ρ…ΠΎΠ΄ΠΎΠ² ΠΊ Π°Π½Π°Π»ΠΈΠ·Ρƒ ΠΆΠΈΠ·Π½Π΅Π½Π½Ρ‹Ρ… Ρ„ΠΎΡ€ΠΌ рассмотрСна морфология Π²Π΅Π³Π΅Ρ‚Π°Ρ‚ΠΈΠ²Π½ΠΎΠΉ ΠΈ Π³Π΅Π½Π΅Ρ€Π°Ρ‚ΠΈΠ²Π½ΠΎΠΉ сфСры Sparangium Γ— longifolium Turcz. ex Ledeb. (S. emersum Rehm. Γ— S. gramineum Georgi). По ΠΆΠΈΠ·Π½Π΅Π½Π½ΠΎΠΉ Ρ„ΠΎΡ€ΠΌΠ΅ S. Γ— longifolium, ΠΊΠ°ΠΊ ΠΈ Π΅Π³ΠΎ Ρ€ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΡΠΊΠΈΠ΅ Π²ΠΈΠ΄Ρ‹, прСдставляСт собой Π²Π΅Π³Π΅Ρ‚Π°Ρ‚ΠΈΠ²Π½ΠΎ-ΠΏΠΎΠ΄Π²ΠΈΠΆΠ½Ρ‹ΠΉ явнополицСнтричСский ΠΌΠ°Π»ΠΎΠ»Π΅Ρ‚Π½ΠΈΠΊ Π²Π΅Π³Π΅Ρ‚Π°Ρ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ происхоТдСния с кистСвидной ΠΊΠΎΡ€Π½Π΅Π²ΠΎΠΉ систСмой. Π’ Ρ€Π°Π±ΠΎΡ‚Π΅ установлСн ΠΏΡ€ΠΎΠΌΠ΅ΠΆΡƒΡ‚ΠΎΡ‡Π½Ρ‹ΠΉ Ρ…Π°Ρ€Π°ΠΊΡ‚Π΅Ρ€ ΠΊΠΎΠ½ΠΊΡ€Π΅Ρ‚Π½Ρ‹Ρ… ΠΏΡ€ΠΈΠ·Π½Π°ΠΊΠΎΠ² Π³ΠΈΠ±Ρ€ΠΈΠ΄Π°, Π»ΠΈΠ±ΠΎ смСщСниС Ρ‚ΠΎΠ³ΠΎ ΠΈΠ»ΠΈ ΠΈΠ½ΠΎΠ³ΠΎ ΠΏΡ€ΠΈΠ·Π½Π°ΠΊΠ° Π² сторону ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΈΠ· Ρ€ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΡΠΊΠΈΡ… Π²ΠΈΠ΄ΠΎΠ². К Ρ…Π°Ρ€Π°ΠΊΡ‚Π΅Ρ€Π½Ρ‹ΠΌ особСнностям, ΠΏΠΎΠ΄Ρ‚Π²Π΅Ρ€ΠΆΠ΄Π°ΡŽΡ‰ΠΈΠΌ Π³ΠΈΠ±Ρ€ΠΈΠ΄Π½ΠΎΠ΅ происхоТдСниС S. Γ— longifolium, слСдуСт отнСсти: 1) Π½Π°Π»ΠΈΡ‡ΠΈΠ΅ Π±ΠΎΠ»Π΅Π΅ ΡˆΠΈΡ€ΠΎΠΊΠΎΠΉ, слСгка ΠΊΠΈΠ»Π΅Π²Π°Ρ‚ΠΎΠΉ листовой пластинки (ΠΊΠ°ΠΊ Ρƒ S. emersum); 2) Π½Π°Π»ΠΈΡ‡ΠΈΠ΅ Ρ€Π°Π·Π²Π΅Ρ‚Π²Π»Π΅Π½Π½ΠΎΠ³ΠΎ соцвСтия (ΠΊΠ°ΠΊ Ρƒ S. gramineum); 3) Π½ΠΈΠΆΠ½ΠΈΠΉ ΠΊΡ€ΠΎΡŽΡ‰ΠΈΠΉ лист соцвСтия, часто ΠΏΡ€Π΅Π²Ρ‹ΡˆΠ°ΡŽΡ‰ΠΈΠΉ ΠΎΠ±Ρ‰ΡƒΡŽ Π΄Π»ΠΈΠ½Ρƒ послСднСго; 4)&nbsp;Π½Π°Π»ΠΈΡ‡ΠΈΠ΅ ΠΏΠ»ΠΎΠ΄ΠΎΠ² ΠΊΠ°ΠΊ с прямым (ΠΊΠ°ΠΊ Ρƒ S. emersum), Ρ‚Π°ΠΊ ΠΈ с Π·Π°Π³Π½ΡƒΡ‚Ρ‹ΠΌ (ΠΊΠ°ΠΊ Ρƒ S. gramineum) столбиком. ΠžΡ‚Π΄Π΅Π»ΡŒΠ½Ρ‹Π΅ популяции S. Γ— longifolium ΠΈΠ·ΠΎΠ±ΠΈΠ»ΡƒΡŽΡ‚ Ρ‚Π΅Ρ€Π°Ρ‚Π½Ρ‹ΠΌΠΈ Ρ„ΠΎΡ€ΠΌΠ°ΠΌΠΈ, ΠΊΠΎΡ‚ΠΎΡ€Ρ‹Π΅ ΠΌΠΎΠ³ΡƒΡ‚ Π±Ρ‹Ρ‚ΡŒ ΠΎΠ±ΡŠΡΡΠ½Π΅Π½Ρ‹ Π½Π°Π»ΠΈΡ‡ΠΈΠ΅ΠΌ Π²ΠΎΠ·Π²Ρ€Π°Ρ‚Π½ΠΎΠ³ΠΎ скрСщивания, Π»ΠΈΠ±ΠΎ ΠΌΡƒΡ‚Π°Ρ†ΠΈΠΈ(ΠΉ) с ΠΏΠ»Π΅ΠΉΠΎΡ‚Ρ€ΠΎΠΏΠ½Ρ‹ΠΌ проявлСниСм. Анализ ΠΏΡ‹Π»ΡŒΡ†Ρ‹ Π³ΠΈΠ±Ρ€ΠΈΠ΄Π° Π½Π° ΠΆΠΈΠ·Π½Π΅ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡ‚ΡŒ ΠΏΠΎΠΊΠ°Π·Π°Π» ΠΏΡ€Π΅ΠΎΠ±Π»Π°Π΄Π°Π½ΠΈΠ΅ ΡΡ‚Π΅Ρ€ΠΈΠ»ΡŒΠ½ΠΎΠΉ ΠΏΡ‹Π»ΡŒΡ†Ρ‹ Π½Π°Π΄ Ρ„Π΅Ρ€Ρ‚ΠΈΠ»ΡŒΠ½ΠΎΠΉ. УстановлСно, Ρ‡Ρ‚ΠΎ S. Γ— longifolium – малораспространСнный Π½Π° Ρ‚Π΅Ρ€Ρ€ΠΈΡ‚ΠΎΡ€ΠΈΠΈ ЕвропСйской части России – Ρ‚ΠΈΠΏΠΈΡ‡Π½ΠΎ прСсноводный Π²ΠΈΠ΄, Π²ΡΡ‚Ρ€Π΅Ρ‡Π°ΡŽΡ‰ΠΈΠΉΡΡ Π² ΠΏΡ€ΠΈΠ±Ρ€Π΅ΠΆΠ½ΠΎΠΉ Π·ΠΎΠ½Π΅ ΠΌΠ΅Π·ΠΎΡ‚Ρ€ΠΎΡ„Π½Ρ‹Ρ… ΠΈ дистрофных Π²ΠΎΠ΄Π½Ρ‹Ρ… ΠΎΠ±ΡŠΠ΅ΠΊΡ‚ΠΎΠ² (ΠΎΠ±Ρ‹Ρ‡Π½ΠΎ Π² ΠΎΠ·Π΅Ρ€Π°Ρ… Π»Π΅Π΄Π½ΠΈΠΊΠΎΠ²ΠΎΠ³ΠΎ происхоТдСния). ПоявлСниС популяций Π³ΠΈΠ±Ρ€ΠΈΠ΄Π° Π² ΠΎΠ·Π΅Ρ€Π°Ρ… обусловлСно ΠΈΡ… ΡΡ‚Ρ€Π΅ΠΌΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠΉ эвтрофикациСй Π² Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Π΅ Π°Π½Ρ‚Ρ€ΠΎΠΏΠΎΠ³Π΅Π½Π½ΠΎΠΉ Π΄Π΅ΡΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ. Π Π°Π½Π΅Π΅ ΠΎΠ±Ρ€Π°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ этого Π³ΠΈΠ±Ρ€ΠΈΠ΄Π°, вСроятно, происходило Π² ΠΏΠ΅Ρ€ΠΈΡ„Π΅Ρ€ΠΈΠΉΠ½Ρ‹Ρ… частях Π°Ρ€Π΅Π°Π»Π° S. gramineum ΠΏΡ€ΠΈ цикличСских измСнСниях ΠΊΠ»ΠΈΠΌΠ°Ρ‚Π°. ВмСстС с Ρ‚Π΅ΠΌ, особСнности мСстообитания послСднСго Π½Π°ΠΊΠ»Π°Π΄Ρ‹Π²Π°ΡŽΡ‚ Β«ΠΎΡ‚ΠΏΠ΅Ρ‡Π°Ρ‚ΠΎΠΊΒ» Π½Π° ΠΏΠΎΡ‚Π΅Π½Ρ†ΠΈΠ°Π» распространСния Π³ΠΈΠ±Ρ€ΠΈΠ΄Π° (ΠΎΠ³Ρ€Π°Π½ΠΈΡ‡Π΅Π½Π½ΠΎΡΡ‚ΡŒ спСктра мСстообитаний), ΠΊΠΎΡ‚ΠΎΡ€Ρ‹ΠΉ вряд Π»ΠΈ ΠΌΠΎΠΆΠ΅Ρ‚ ΠΏΡ€Π΅Π²Π·ΠΎΠΉΡ‚ΠΈ ΠΏΠΎ своим эколого-цСнотичСским характСристикам S. emersum.&nbsp

    Single and molecular ion irradiation-induced effects in GaN : experiment and cumulative MD simulations

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    An investigation of mechanisms of enhancement of irradiation-induced damage formation in GaN under molecular in comparison to monatomic ion bombardment is presented. Ion-implantation-induced effects in wurtzite GaN bombarded with 0.6 keV amu(-1) F, P, PF2, PF4, and Ag ions at room temperature are studied experimentally and by cumulative MD simulation in the correct irradiation conditions. In the low dose regime, damage formation is correlated with a reduction in photoluminescence decay time, whereas in the high dose regime, it is associated with the thickness of the amorphous/disordered layer formed at the sample surface. In all the cases studied, a shift to molecular ion irradiation from bombardment by its monatomic constituents enhances the damage accumulation rate. Implantation of a heavy Ag ion, having approximately the same mass as the PF4 molecule, is less effective in surface damage formation, but leads to noticeably higher damage accumulation in the bulk. The cumulative MD simulations do not reveal any significant difference in the total amount of both point defects and small defect clusters produced by light monatomic and molecular ions. On the other hand, increased production of large defect clusters by molecular PF4 ions is clearly seen in the vicinity of the surface. Ag ions produce almost the same number of small, but more large defect clusters compared to the others. These findings show that the higher probability of formation of large defect clusters is important mechanism of the enhancement of stable damage formation in GaN under molecular, as well as under heavy monatomic ion irradiation.Peer reviewe
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