190 research outputs found
I cambiamenti ambientali nella steppa Crimea per tutto il periodo romano di storia antica e di là
Insieme con l'integrazione di paleo suolo riferimento e archeologia, che permette efficiente ricostruzione paleogeografica dell'ambiente naturale nell'Olocene, ques ta zona integra lo studio del suolo in superficie, risalente metodi archeologici, e lo studio dei paesaggi antichi geoarcheologicayesБелгородский государственный университе
Частица со спином 1 в цилиндрическом базисе: метод проективных операторов
In this paper, the system of equations describing a spin 1 particle is studied in cylindric coordinates with the use of tetrad formalism and the matrix 10-dimension formalism of Duffin – Kemmer – Petieau. After separating the variables, we apply the method proposed by Fedorov – Gronskiy and based on the use of projective operators to resolve the system of 10 equations in the r variable. In the presence of an external uniform magnetic field, we construct in an explicit form three independent classes of wave functions with corresponding energy spectra. Separately the massless field with spin 1 is studied; there are found four linearly independent solutions, two of which are gauge ones, and other two do not contain gauge degrees of freedom. Meanwhile, the method of Fedorov – Gronskiy is also used.В настоящей работе система уравнений, описывающая частицу со спином 1, изучается в цилиндрических координатах с использованием тетрадного формализма и матричного 10-мерного формализма Даффина – Кеммера – Петье. После разделения переменных для решения системы 10 уравнений относительно переменной применяется метод, предложенный Федоровым – Гронским и основанный на применении проективных операторов. При наличии внешнего однородного магнитного поля построены в явном виде три независимых класса волновых функций с соответствующими энергетическими спектрами. Отдельно исследуется безмассовое поле со спином 1; найдено четыре линейно независимых решения, два из которых калибровочные, а остальные два не содержат калибровочных степеней свободы. При этом также используется метод Федорова – Гронского
Spin 3/2 Particle in External Magnetic Field, the Method of Projective Operators, Algebraic Approach
In the present paper, an algebraic method for solving the system of equations describing the spin 3/2 particle in presence of the uniform magnetic field has been elaborated. The method is based on decomposition of 16-components wave function with transformation properties of vector-bispinor in the sum of four constitutes, which are determined by four projective operators. With the use of formalism of elements of complete matrix algebra, the system is transformed to the form, in which only projective constituents Ψ±1/2(x), Ψ±3/2(x) enter. This system of equations is transformed to cylindric coordinates. On the wave functions three operators are diagonalized: the energy, the third projection of linear momentum and the third projection of the total angular momentum. After separating the variables, we derive 4 linked subsystems of equations for 16-component functions Ψ±1/2(r), Ψ±3/2(r). After performing needed calculations, the problem reduces to independent second order equations for 4 primary functions. This equations are solved in terms of confluent hypergeometric functions, 4 different energy spectra are found
Spin 2 Particle with Anomalous Magnetic Moment in Riemann Space-Time: A Massless Case with the Gauge Symmetry
The most of studies in the theory of spin 2 _field were performed with the use of the 2-nd order equations. The spin 2 particle theory proposed by F.I. Fedorov is based on the first order equations requires a 30-component set of tensors. Besides, by him and coauthors was elaborated a more general theory, which is based on 50-component set of tensors. In the
present paper, we consider this more general theory in presence of arbitrary electromagnetic fields and Riemannian space-time backgrounds. First we study the 50-component theory for a massive particle. In this case, there arises the non-minimal interaction with the curved space-time background through the Ricci and Riemann tensors. It is important that the theory under consideration allows for a new massless limit for the spin 2 field. This fact is of special interest, because the conventional Pauli - Fierz theory for the massless field does not possess gauge symmetry in the curved space-time, in particular, in models with the vanishing
Ricci tensor. We show that the generalized theory possesses such a gauge symmetry in all space-time models for which the Ricci tensor vanishes
GAPDH binders as potential drugs for the therapy of polyglutamine diseases: Design of a new screening assay
AbstractProteins with long polyglutamine repeats form a complex with glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which enhances aggregation and cytotoxicity in models of Huntington disease. The aim of this study was to develop a novel assay for the screening of anti-aggregation compounds with a focus on the aggregation-promoting capacity of GAPDH. The assay includes a pure Q58 polyglutamine fragment, GAPDH, and a transglutaminase that links the two proteins. The feasibility of the new assay was verified using two GAPDH binders, hydroxynonenal and −(−)deprenyl, and the benzothiazole derivative PGL-135 which exhibits anti-aggregation effect. All three substances were shown to reduce aggregation and cytotoxicity in the cell and in the fly model of Spinocerebellar ataxia
Разработка системы точечного внесения жидких средств химизации на основе моделей сверточной нейронной сети
The authors showed that one of the reasons for the yield loss is poor-quality determination of the infection degree of agricultural crops by pathogens. They proposed a system of liquid chemicals point application. They identified the possibility of calculating the required amount of fertilizers and protective equipment. (Research purpose) To develop a system of liquid chemicals point application for plant protection and nutrition based on a convolutional neural network model. (Materials and methods) The authors analyzed the existing methods of machine learning. When developing the system, they used the U-net-algorithm of convolutional neural networks, as well as data displaying diseases of winter and spring wheat – brown rust and powdery mildew. Each image was cropped by hand and marked up using a specialized Python library. In the course of applying the architecture, the authors experimentally chose the optimal metrics (jaccard metric), the learning rate – 0.0001 seconds, the number of epochs – 300, and other indicators. (Results and discussion) The authors found that when a new, previously unavailable image was submitted to the algorithm, it recognized the disease in a few seconds and returned to the user not only the original image, but also a mask over it. The accuracy of applying the mask to the affected area was determined – 80 percent. They showed that the predicted error on the validation data was 0.18758. In practice, it could differ from the declared one by no more than 10-15 percent. The authors suggested using the algorithm with a vision system. (Conclusions) The authors showed that technical means imperfection for plants chemicalization increased the consumption up to 30 percent relative to the volume required for point application. They developed a neural network algorithm for identifying the affected areas of plants and proposed the concept of a point chemicals application in order to reduce the costs of processing crops. It was determined that the neural network was able to diagnose the affected areas of plants in 1 second.Показали, что одна из причин потери урожая – некачественное определение степени пораженности сельскохозяйственных культур патогенами. Предложили систему точечного внесения жидких средств химизации. Выявили возможность расчета необходимого объема удобрений и средств защиты. (Цель исследования) Разработать систему точечного внесения жидких средств для защиты и питания растений на основе модели сверточной нейронной сети. (Материалы и методы) Провели анализ существующих архитектур и методов машинного обучения. При разработке системы использовали U-net-алгоритм сверточных нейронных сетей, а также данные, отображающие заболевания озимой и яровой пшеницы – бурую ржавчину и мучнистую росу. Каждое изображение кадрировали вручную и размечали с помощью специализированной Python-библиотеки. В ходе применения архитектуры экспериментальным путем выбрали оптимальные метрики (jaccard metric), скорость обучения – 0,0001 секунды, количество эпох – 300, а также другие показатели. (Результаты и обсуждение) Установили, что при подаче алгоритму нового, ранее не доступного изображения, он за несколько секунд распознает болезнь и возвращает пользователю не только исходное изображение, но и маску поверх него. Определили точность наложения маски на больной участок – 80 процентов. Показали, что прогнозируемая ошибка на валидационных данных составила 0,18758. На практике она может отличаться от заявленной не более чем на 10-15 процентов. Предложили использовать алгоритм с системой технического зрения. (Выводы) Показали, что несовершенство технических средств для химизации растений повышает расход до 30 процентов относительно объема, необходимого для точечного внесения. Разработали нейросетевой алгоритм для определения пораженных участков растений и предложили концепцию точечного внесения средств химизации растений с целью сокращения затраты при обработке посевов. Определили, что нейросеть способна диагностировать пораженные участки растений за 1 секунду
Influence of Thermomechanical Treatment on Microstructure and Mechanical Properties of CoCr0,25FeNiMnСх (X = 0; 0,5; 1; 2) High Entropy Alloys
CoCr0,25FeNiMnСх alloys were rolled to a degree of deformation of 80 %, followed by annealing in the temperature range of 600–1000 °C for 1 hour. Alloying the alloy with carbon leads to the precipitation of carbides of the Me23C6 type, which provides significant hardening of the alloy after the application of heat treatment.Сплавы CoCr0,25FeNiMnСх были подвергнуты прокатке до степени деформации 80 % с последующим отжигом в интервале температур 600–1000 °C в течение 1 часа. Легирование сплава углеродом приводит к выделению карбидов типа Me23C6, что обеспечивает значительное упрочнение сплава после деформационно-термической обработки
Effect of carbon on cryogenic tensile behavior of CoCrFeMnNi-type high entropy alloys
Therefore in this work we examined cryogenic tensile behavior of the fcc high entropy alloys with different carbon content (0e2 at.%). The alloys had non-equiatomic proportions of principal elements, i.e. Co1Cr0.25Fe1Mn1Ni1. The lower Cr concentration in comparison with the equiatomic alloy led to the higher solubility of carbon confirmed by both ThermoCalc calculations and experimental results; only in the alloy with 2 at.% C a small (<1%) fraction of Crrich M7C3 carbides was found in the as-cast conditio
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