On Two Complementary Types of Total Time Derivative in Classical Field Theories and Maxwell's Equations

Close insight into mathematical and conceptual structure of classical field theories shows serious inconsistencies in their common basis. In other words, we claim in this work to have come across two severe mathematical blunders in the very foundations of theoretical hydrodynamics. One of the defects concerns the traditional treatment of time derivatives in Eulerian hydrodynamic description. The other one resides in the conventional demonstration of the so-called Convection Theorem. Both approaches are thought to be necessary for cross-verification of the standard differential form of continuity equation. Any revision of these fundamental results might have important implications for all classical field theories. Rigorous reconsideration of time derivatives in Eulerian description shows that it evokes Minkowski metric for any flow field domain without any previous postulation. Mathematical approach is developed within the framework of congruences for general 4-dimensional differentiable manifold and the final result is formulated in form of a theorem. A modified version of the Convection Theorem provides a necessary cross-verification for a reconsidered differential form of continuity equation. Although the approach is developed for one-component (scalar) flow field, it can be easily generalized to any tensor field. Some possible implications for classical electrodynamics are also explored.Comment: no figure

Singlet-to-triplet ratio in the deuteron breakup reaction pd→pnppd\to pnp at 585 MeV

Available experimental data on the exclusive $pd\to pnp$ reaction at 585 MeV show a narrow peak in the proton-neutron final-state interaction region. It was supposed previously, on the basis of a phenomenological analysis of the shape of this peak, that the final spin-singlet $pn$ state provided about one third of the observed cross section. By comparing the absolute value of the measured cross section with that of $pd$ elastic scattering using the F\"aldt-Wilkin extrapolation theorem, it is shown here that the $pd\to pnp$ data can be explained mainly by the spin-triplet final state with a singlet admixture of a few percent. The smallness of the singlet contribution is compatible with existing $pN\to pN\pi$ data and the one-pion exchange mechanism of the $pd\to pnp$ reaction.Comment: 10 pages, Latex, 2 Postscript figure

"Background Field Integration-by-Parts" and the Connection Between One-Loop and Two-Loop Heisenberg-Euler Effective Actions

We develop integration-by-parts rules for Feynman diagrams involving massive scalar propagators in a constant background electromagnetic field, and use these to show that there is a simple diagrammatic interpretation of mass renormalization in the two-loop scalar QED Heisenberg-Euler effective action for a general constant background field. This explains why the square of a one-loop term appears in the renormalized two-loop Heisenberg-Euler effective action. No integrals need be evaluated, and the explicit form of the background field propagators is not needed. This dramatically simplifies the computation of the renormalized two-loop effective action for scalar QED, and generalizes a previous result obtained for self-dual background fields.Comment: 13 pages; uses axodraw.st

Analysis of the oxidation state of platinum particles in supported catalysts by double differentiation of XPS lines

In the work the double differentiation of functions describing the Pt4f7/2 band in the XPS spectra of model supported Pt/SiO2 catalysts is performed in order to determine the number of different chemical states of platinum particles. The functions for the differentiation are obtained by the deconvolution of the experimental spectral contour into two spin-orbit components. As a result of the performed analysis of the number and position of the minima of the second derivative of the function of Pt437/2 the conditions of the oxidation of platinum particles in the Pt/SiO2 sample on treating in a NO + O2 mixture and the reduction of platinum oxide particles on interacting of the PtOx/SiO2 sample with hydrogen are determined. © 2016, Pleiades Publishing, Ltd

Low-temperature electrical discharge through solid xenon

The uniform self-sustained electrical discharge through solid xenon has been realized and studied. The multiplication of electrons proceeds in the noble gas above the xenon crystal interface whereas a positive feedback is realized at the account of multiple exciton formation by excess electrons drifted through the crystal: molecular excitons emit VUV photons which knocked out secondary electrons from photosensitive cathode. The discharge was stimulated by short electrical spark along the sample axes. The discharge electrical properties as well as the spectra of solid xenon electroluminescence in UV and visible have been studied. Electric discharge in solid xenon was proved to be an effective source of UV radiation and a convenient tool to study the processes involving excitons and electrons in solid xenon at high pressures

Size effect in the oxidation-reduction processes of platinum particles supported onto silicon dioxide

The interaction of the Pt/SiO2 model catalysts as thin films on the surface of tantalum supports with a mixture of NO + O2 (1: 1) was studied by X-ray photoelectron spectroscopy. The pressure of the reaction mixture was varied from 6 to 64 mbar, and the temperature was varied from room temperature to 500°C. Two types of the catalysts, in which the Pt/Si atomic ratios were ~0.1 and ~0.3 (0.1-Pt/SiO2 and 0.3-Pt/SiO2, respectively) according to the XPS data, were studied. In 0.1-Pt/SiO2, the particles of platinum predominantly had a size from 1 to 2.5 nm; a wide Pt particle size distribution in a range from 1 to 15 nm with a maximum at ~4 nm was characteristic of 0.3-Pt/SiO2. The interaction of all of the samples with NO + O2 at room temperature led to the dissolution of oxygen atoms in the bulk of platinum metal particles. As the reaction temperature was increased, PtO x platinum oxide particles were formed: from small Pt particles in 0.1-Pt/SiO2 at 300°C and from larger particles in 0.3-Pt/SiO2 at 400-500°C. It was established that the reactivity of platinum oxide particles toward hydrogen also depended on the particle size. The small particles of platinum oxide were converted into platinum metal under the action of hydrogen (16 mbar) at 300°C. The coarse particles of PtO x in the samples of 0.3-Pt/SiO2 were reduced much more easily starting with room temperature. © 2015 Pleiades Publishing, Ltd

Search for light pseudoscalar sgoldstino in K- decays

A search for the light pseudoscalar sgoldstino production in the three body K- decay K-->pipi0P has been performed with the ISTRA+ detector exposed to the 25 GeV negative secondary beam of the U70 proton synchrotron. No signal is seen. An upper limit for the branching ratio Br(K->pipi0P), at 90% confidence level, is found to be around 9*10**-6 in the effective mass m(P) range from 0 till 200 MeV, excluding the region near m(pi0) where it degrades to 3.5*10**-5.Comment: 10 pages, LATEX, 8 EPS figures, revised version, to be published in Phys.Lett.

High statistic measurement of the K- -> pi0 e- nu decay form-factors

The decay K- -> pi0 e- nu is studied using in-flight decays detected with the ISTRA+ spectrometer. About 920K events are collected for the analysis. The lambda+ slope parameter of the decay form-factor f+(t) in the linear approximation (average slope) is measured: lambda+(lin)= 0.02774 +- 0.00047(stat) +- 0.00032(syst). The quadratic contribution to the form-factor was estimated to be lambda'+ = 0.00084 +- 0.00027(stat) +- 0.00031(syst). The linear slope, which has a meaning of df+(t)/dt|_{t=0} for this fit, is lambda+ = 0.02324 +- 0.00152(stat) +- 0.00032(syst). The limits on possible tensor and scalar couplings are derived: f_{T}/f_{+}(0)=-0.012 +- 0.021(stat) +- 0.011$(syst), f_{S}/f_{+}(0)=-0.0037^{+0.0066}_{-0.0056}(stat) +- 0.0041(syst).Comment: 11 pages, 8 figures. Accepted by Phys.Lett.

Технологии комплексного интеллектуального анализа клинических данных

The paper presents the system for intelligent analysis of clinical information. Authors describe methods implemented in the system for clinical information retrieval, intelligent diagnostics of chronic diseases, patient’s features importance and for detection of hidden dependencies between features. Results of the experimental evaluation of these methods are also presented.Background: Healthcare facilities generate a large flow of both structured and unstructured data which contain important information about patients. Test results are usually retained as structured data but some data is retained in the form of natural language texts (medical history, the results of physical examination, and the results of other examinations, such as ultrasound, ECG or X-ray studies). Many tasks arising in clinical practice can be automated applying methods for intelligent analysis of accumulated structured array and unstructured data that leads to improvement of the healthcare quality.Aims: the creation of the complex system for intelligent data analysis in the multi-disciplinary pediatric center.Materials and methods: Authors propose methods for information extraction from clinical texts in Russian. The methods are carried out on the basis of deep linguistic analysis. They retrieve terms of diseases, symptoms, areas of the body and drugs. The methods can recognize additional attributes such as «negation» (indicates that the disease is absent), «no patient» (indicates that the disease refers to the patient’s family member, but not to the patient), «severity of illness», «disease course», «body region to which the disease refers». Authors use a set of hand-drawn templates and various techniques based on machine learning to retrieve information using a medical thesaurus. The extracted information is used to solve the problem of automatic diagnosis of chronic diseases. A machine learning method for classification of patients with similar nosology and the method for determining the most informative patients’ features are also proposed.Results: Authors have processed anonymized health records from the pediatric center to estimate the proposed methods. The results show the applicability of the information extracted from the texts for solving practical problems. The records of patients with allergic, glomerular and rheumatic diseases were used for experimental assessment of the method of automatic diagnostic. Authors have also determined the most appropriate machine learning methods for classification of patients for each group of diseases, as well as the most informative disease signs. It has been found that using additional information extracted from clinical texts, together with structured data helps to improve the quality of diagnosis of chronic diseases. Authors have also obtained pattern combinations of signs of diseases.Conclusions: The proposed methods have been implemented in the intelligent data processing system for a multidisciplinary pediatric center. The experimental results show the availability of the system to improve the quality of pediatric healthcare. Обоснование. Медицинские учреждения генерируют большой поток как структурированных, так и неструктурированных данных, содержащих важную информацию о пациентах. В структурированном виде, как правило, хранятся результаты анализов, однако подавляющее количество данных хранится в неструктурированной форме в виде текстов на естественном языке (анамнезы, результаты осмотров, описания результатов обследований, таких как УЗИ, ЭКГ, рентгеновских исследований и др.). Используя методы интеллектуальной обработки накопленных массивов структурированных и неструктурированных данных, можно автоматизировать решение многих задач, возникающих в клинической практике и повысить качество медицинской помощи.Цель исследования: создание комплексной системы интеллектуальной обработки данных в многопрофильном педиатрическом центре.Методы. Извлечение информации из клинических текстов на русском языке осуществляется на основе полного лингвистического анализа. Извлекаются упоминания заболеваний, симптомов, областей тела, лекарственных препаратов. В тексте также распознаются атрибуты заболеваний: «отрицание» (указывает на то, что заболевание отсутствует), «не пациент» (указывает на то, что заболевание относится не к пациенту, а к его родственнику), «тяжесть заболевания», «течение заболевания», «область тела, к которой относится заболевание». Для извлечения информации используются медицинские тезаурусы, набор вручную составленных шаблонов, а также различные методы на основе машинного обучения. Полученные из текстов данные используются для решения задачи автоматической диагностики хронических заболеваний. Предложен метод на основе машинного обучения для классификации пациентов со схожими нозологиями, а также метод для определения наиболее информативных признаков.Результаты. Экспериментальное исследование разработанных методов проводилось на обезличенных историях болезни пациентов педиатрического центра. Проведена оценка качества разработанных методов извлечения информации из клинических текстов на русском языке. Проведена экспериментальная оценка метода автоматической диагностики на данных пациентов с аллергическими заболеваниями и болезными органов дыхания, нефрологическими и ревматическими заболеваниями. Определены наиболее подходящие методы машинного обучения для классификации пациентов для каждой группы заболеваний, а также наиболее информативные признаки. Использование данных, извлеченных из клинических текстов совместно со структурированными данными, позволило повысить качество диагностики хронических заболеваний по сравнению с использованием лишь доступных структурированных данных. Получены также шаблонные комбинации признаков заболеваний.Заключение. Разработанные методы были реализованы в системе интеллектуальной обработки данных в многопрофильном педиатрическом центре. Проведенные исследования свидетельствуют о перспективности использования системы для повышения качества медицинской помощи пациентам детской возрастной категории