Grothendieck ring of pretriangulated categories

We consider the abelian group $PT$ generated by quasi-equivalence classes of pretriangulated DG categories with relations coming from semi-orthogonal decompositions of corresponding triangulated categories. We introduce an operation of "multiplication" $\bullet$ on the collection of DG categories which makes this abelian group into a commutative ring. A few applications are considered: representability of "standard" functors between derived categories of coherent sheaves on smooth projective varieties and a construction of an interesting motivic measure.Comment: 33 page

The formation of stable hydrogen impermeable TiN-based coatings on zirconium alloy Zr1%Nb

TiN coatings were deposited by DC reactive magnetron sputtering (dcMS) method on Zr1%Nb substrates with different film thickness. The influence of crystalline structure and thickness of the coatings on hydrogen permeation was investigated. The results revealed that the increase in thickness of the film reduced hydrogen permeability. 1.54 [mu]m TiN deposited in N[2]/Ar gas mixture with a ratio of 3/1 reduces hydrogen permeation in more than two orders of magnitude at 350 °С. Adhesion strength decreased with increasing film thickness (0.55 to 2.04 [mu]m) from 7.92 to 6.65 N, respectively. The Ti underlayer applied by arc ion plating (AIP) leads to the formation of stable Ti/TiN coatings on Zr1%Nb under thermocycling conditions up to 800 °С. Meanwhile, hydrogen permeation rate of Ti/TiN deposited by combination of AIP and dcMS remains at the same level with TiN deposited by dcMS

Hydrogenation of Zr-2.5Nb alloy after plasma-immersion titanium implantation

The study results of the influence of plasma-immersion ion implantation of titanium in Zr-2.5Nb on hydrogenation are presented. The titanium implantation was carried out in two modes: with active plasma filtering (APF) and passive plasma filtering (PPF). The results of total hydrogen concentration, absorption rate, XRD analyses and depth distribution of elements revealed that modified surface layer after titanium ion implantation is formed hydrogen diffusion barrier reduces hydrogen absorption by Zr-2.5Nb

Mechanical Property Testing of Hydrogenated Zirconium Irradiated with Electrons

The mechanical properties of the hydrogenated zirconium alloy Zr-1Nb are studied underdifferent conditions for hydrogen removal by an electron beam and thermal heating. The mechanicaltesting of zirconium samples is analyzed during hydrogenation and irradiation with a low energyelectron beam. The plasticity of the samples is shown to be increased during the radiation stimulationof hydrogen removal from zirconium by even a weak electron beam. In this case, the tensile strength(ultimate strength) is practically not changed

Introduction of hydrogen into titanium by plasma methods

The introduction of hydrogen into titanium VT1-0 by the methods of plasma-immersion ion implantation (PIII) from the hydrogen plasma of a source with a heated cathode and into high-frequency discharge (HFD) plasma was studied. Modes of installations for introduction are chosen proceeding from the requirement of the maximum content of hydrogen in the samples. It is established that saturation from the HFD-plasma leads to a significant enrichment to a depth of 1.2 µm, at the introduction of hydrogen by the PIII this depth is 0.6 µm. The hydrogen content of 0.06 wt.% in the samples after saturation in the HFD plasma, and 0.049 wt.% after PIII. During PIIII (with an energy of 0.9-1.5 keV), hydrogen is strongly scattered by the surface of the sample and is captured predominantly by surface defects (including those created by the ions themselves), as well as by vacancies in the near-surface layers. Upon saturation from the HFD-plasma, hydrogen diffuses into the interior of the sample and settles in interstices and at grain boundaries. At the same time, saturation from the HFD plasma and PIII lead to significant change in the crystal parameters and the creation of hydride phases

Sign-based methods in linear statistical models

For nonparametric statistics, the last half of this century was the time when rank-based methods originated, were vigorously developed, reached maturity, and received wide recognition. The rank-based approach in statistics consists in ranking the observed values and using only the ranks rather than the original numerical data. In fitting relationships to observed data, the ranks of residuals from the fitted dependence are used. The signed-based approach is based on the assumption that random errors take positive or negative values with equal probabilities. Under this assumption, the sign procedures are distribution-free. These procedures are robust to violations of model assumptions, for instance, to even a considerable number of gross errors in observations. In addition, sign procedures have fairly high relative asymptotic efficiency, in spite of the obvious loss of information incurred by the use of signs instead of the corresponding numerical values. In this work, sign-based methods in the framework of linear models are developed. In the first part of the book, there are linear and factor models involving independent observations. In the second part, linear models of time series, primarily autoregressive models, are considered

Method of fluorescent control of plasma structure and treated surface in technique of downhole equipment anticorrosion protection

Актуальность. Надежность и целостность нефтедобывающего оборудования, сроки его эксплуатации обеспечиваются комплексом мер по борьбе с коррозией, в частности использованием технологий газопламенного напыления защитных покрытий на проектируемые или восстанавливаемые детали. В данных технологиях эффективным методом контроля за состоянием состава плазмы и качества напыляемой поверхности может служить явление гетерогенной хемилюминесценции. Гетерогенные хемилюминесцентные реакции обладают селективностью и высокой чувствительностью к типу поверхности и сорту возбуждающего газа. Использование оптических методов для изучения, контроля и управления в неравновесных системах газ–твердое тело открывает новые аналитические и аппаратурные возможности в физике поверхности, химии, плазмохимии, технологии полупроводников и люминофоров, в решении экологических проблем. Изучение процессов адсорбции–десорбции, диссоциации, диффузии, рекомбинации газовых частиц, дефектообразования и роста кристаллической решетки с использованием явления гетерогенной хемилюминесценции является актуальной задачей физики конденсированного состояния. Поскольку явление гетерогенной хемилюминесценции реализует возможности осуществления селективных экспресс-методов анализа при простом аппаратурном оснащении с пределом обнаружения свободных атомов, радикалов, примесей в газовой фазе и в составе поверхностных слоев конденсированных сред до 10–6 % (мол). Цель: исследование процессов в неравновесных системах газ – твердое тело и определение параметров этого взаимодействия на основе регистрации характеристик гетерогенной хемилюминесценции; разработка нестационарных методов определения параметров взаимодействия газ–твердое тело с использованием явления гетерогенной хемилюминесценции, контроль параметров газовой среды и состояния поверхности конденсированных сред. Объекты: атомно-молекулярные пучки водорода, кристаллофосфор ZnS–Mn2+, приповерхностные области взаимодействия газ – твердое тело. Методы: методы, основанные на явлении гетерогенной хемилюминесценции в атомарном водороде для определения скоростей адсорбции и рекомбинации атомов Н, десорбции молекул H2, энергии активации десорбции молекул водорода с поверхности ZnS–Mn2+. Методом «темновой» паузы определена скорость рекомбинации адсорбированных атомов водорода по механизму Лэнгмюра–Хиншелвуда. Результаты. Выполнено сравнительное исследование люминесценции ZnS–Mn2+ при возбуждении светом (фотолюминесценции) и атомарным водородом (гетерогенной хемилюминесценции). Изучены спектрально-кинетические характеристики люминесценции. Установлены механизмы и параметры взаимодействия атомов водорода с поверхностью сульфида цинка (сечения, частотные факторы, энергии активации) с использованием спектрально-кинетических характеристик гетерогенной хемилюминесценции. Показано, что люминофор ZnS–Mn2+ может служить экспресс датчиком восстановительной компоненты плазмы (водород). Явление гетерогенной хемилюминесценции составляет основу оперативных методов контроля начальных стадий модификации поверхности твердых тел в процессах пучково-плазменной обработки материалов.Relevance. Reliability and integrity of oil production equipment, its operation time are provided by a set of measures to combat corrosion, in particular, to use gas-plasma sputtering of protective coatings on designed or restored technology parts. In these technologies, the heterogeneous chemiluminescence phenomenon can serve as an effective method for monitoring plasma composition state and the sputtered surface quality. Heterogeneous chemiluminescence reactions has selectivity and high sensitivity to surface type and excitation gas grade. The use of optical methods to study and control in non-equilibrium gas-solid systems opens up new analytical possibilities in surface physics, chemistry, plasma chemistry, semiconductor and phosphor technology, and in solving environmental problems. Study of adsorption, desorption, dissociation, diffusion, gas particles recombination, defect formation and crystal lattice growth using heterogeneous chemiluminescence phenomenon is an urgent task in condensed matter physics, as the heterogeneous chemiluminescence phenomenon realizes the possibility of selective rapid analysis methods with simple hardware equipment at detection limit of free atoms, radicals, impurities in gas phase and the surface layers composition condensed matter to 10-6 % (mol). The main aim of the research is to study the processes in non-equilibrium systems gas-solid and to determine the interaction based on the registration of characteristics of heterogeneous chemiluminescence; to develop the methods for determining time-dependent interaction parameters of gas-solid using heterogeneous chemiluminescence phenomenon, to monitor the parameters of gaseous medium and the state of condensed matter surface. Objects: atomic-molecular hydrogen beams, crystalline phosphorus ZnS-Mn2+ , near-surface gas-solid interaction regions. Methods: methods based on heterogeneous chemiluminescence phenomenon in atomic hydrogen for determining adsorption rate and H atoms recombination, H2 molecules desorption rate, heat of hydrogen atoms desorption from ZnS-Mn2 + surface. Using the «dark» pause method, the recombination rate of adsorbed atoms was obtained by the Langmuir-Hinshelwood mechanism. Results. The authors have carried out the comparative study of ZnS-Mn2 + luminescence upon light (photoluminescence) and atomic hydrogen (heterogeneous chemiluminescence) excitation. Spectral-kinetic characteristics of luminescence were studied and mechanisms and parameters of interaction of hydrogen atoms with zinc sulfide surface (cross sections, frequency factors, activation energies) based on the kinetic characteristics of heterogeneous chemiluminescence were determined. It is shown that the ZnSCMn2+ phosphor can serve as an express sensor reducing plasma component (hydrogen). Heterogeneous chemiluminescence phenomenon is an effective method to control the initial step of modification and composition of solids surface in beam-plasma treatment of materials