87 research outputs found
ROBUSTNESS AND RELIABILITY OF PARAMETERS OF TOWER OF ATTRACTION STRUCTURE
Investigation of robustness and reliability of parameters of tower of
attraction structure
Incomplete Quadratic Exponential Sums in Several Variables
We consider incomplete exponential sums in several variables of the form
S(f,n,m) = \frac{1}{2^n} \sum_{x_1 \in \{-1,1\}} ... \sum_{x_n \in \{-1,1\}}
x_1 ... x_n e^{2\pi i f(x)/p}, where m>1 is odd and f is a polynomial of degree
d with coefficients in Z/mZ. We investigate the conjecture, originating in a
problem in computational complexity, that for each fixed d and m the maximum
norm of S(f,n,m) converges exponentially fast to 0 as n grows to infinity. The
conjecture is known to hold in the case when m=3 and d=2, but existing methods
for studying incomplete exponential sums appear to be insufficient to resolve
the question for an arbitrary odd modulus m, even when d=2. In the present
paper we develop three separate techniques for studying the problem in the case
of quadratic f, each of which establishes a different special case of the
conjecture. We show that a bound of the required sort holds for almost all
quadratic polynomials, a stronger form of the conjecture holds for all
quadratic polynomials with no more than 10 variables, and for arbitrarily many
variables the conjecture is true for a class of quadratic polynomials having a
special form.Comment: 31 pages (minor corrections from original draft, references to new
results in the subject, publication information
Cаногенне мислення в структурі художньої творчості
У статті визначено поняття саногенного мислення, проаналізовано здобутки зарубіжних та вітчизняних науковців, що присвячені проблемі «саногенного мислення». Обґрунтовується актуальність вивчення проблеми саногенного мислення та його місця в художній творчості.
(The article defines the concept of sanohenic thinking, analyzes achievements of foreign and domestic scholars
whose works are devoted to the problem of «sanohenic thinking». The importance of studying the problem of sanohenic thinking and its place in art are reviewed)
About fracture behavior of steel 12Kh18N10T under repeating load in air separation plants
The results of investigations of nitrogen and oxygen regenerators metal after long
period of exploitation with analysis of change of mechanical properties and structural state
under the influence of the low temperatures and pulsating load are given in this paper. It is
shown the destruction of 12X18H10T steel occurs because of the undiffusion processes of
transition of austenite info martensite and of cracking on the borders of grains. The
destruction process of apparatus proceeds most intensively on the welded joints where the
most structural non-uniformity with presence of welding defects and residual stresses take
place
Strength of austenite steels at the combined action of vibration and corrosion
The results of investigations of influence the vibration on the rate of increasing the
intercrystallite corrosion of steel 12X18H10T is shown in given article. Given investigations
show that the vibration gives a great influence on the rate of increasing the intercrystallite
corrosion
Laser generation of CeAlO3 nanocrystals with perovskite structure
For the first time to the best of our knowledge, CeAlO3 nanocrystals with perovskite structure are synthesized by pulsed laser ablation technique. The morphological and optical properties of the obtained CeAlO3 nanocrystals are investigated. This work opens new prospects for the application of laser ablation methods for the generation of perovskite nanocrystals and development of novel nanocomposite structures, which can be applied for the fabrication of perovskite solar cells, scintillation detectors, catalysts, etc
ГАЗОХРОМАТОГРАФИЧЕСКИЙ АНАЛИЗ РОМАШКИ АПТЕЧНОЙ (Chamomilla recutita R.)
In this paper, we carried out the GC-MS study of volatile organic compounds of the gas phase of chamomile (Chamomilla recutita R.) using two sample preparation techniques: by direct headspace analysis and analysis using solid-phase microextraction with thermal desorption. The effect of temperature-controlled time of samples on the VOC content in the gas extract of chamomile (Chamomilla recutita R.) was studied. Comparative evaluation of the finding results with published data was carried out.Key words: Gas chromatography with mass selective detection(GC-MS), herbal raw materials, volatile organic compounds(VOC), headspace analysis (HS), solid phase microextraction (SPME). (Russian)DOI: http://dx.doi.org/10.15826/analitika.2013.17.1.009 L.V. Pavlova1, I.A. Platonov1,2, V.G. Arhipov2, V.A. Kurkin3, I.Y. Roschupkina1 1Samara State Aerospace University named after academician S.P.Korolyov (national research university), Samara, Russian Federation2Samara StateUniversity, Samara, Russian Federation3Samara State Medical University, Samara, Russian FederationПроведено ГХ-МС исследование состава летучих органических соединений газовой фазы ромашки аптечной (Chamomilla recutita R.) при использовании двух вариантов пробоподготовки: путем непосредственного анализа равновесной газовой фазы и анализа с применением твердофазной микроэкстракции с последующей термодесорбцией. Исследовано влияние времени термостатирования образцов на содержание летучих органических соединений в газовом экстракте ромашки аптечной (Chamomilla recutita R.). Проведена сравнительная оценка полученных результатов с литературными данными.Ключевые слова: газовая хроматография с масс-селективным детектированием (ГЖХ-МС), растительное лекарственное сырье, летучие органические соединения (ЛОС), парофазный анализ (ПФА), твердофазная микроэкстракция (ТФМЭ), характерные хроматограммыDOI: http://dx.doi.org/10.15826/analitika.2013.17.1.00
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