Development of high-gain gaseous photomultipliers for the visible spectral range

We summarize the development of visible-sensitive gaseous photomultipliers, combining a semitransparent bi-alkali photocathode with a state-of-the-art cascaded electron multiplier. The latter has high photoelectron collection efficiency and a record ion blocking capability. We describe in details the system and methods of photocathode production and characterization, their coupling with the electron multiplier and the gaseous-photomultiplier operation and characterization in a continuous mode. We present results on the properties of laboratory-produced K$_2$CsSb, Cs$_3$Sb and Na$_2$KSb photocathodes and report on their stability and QE in gas; K$_2$CsSb photocathodes yielded QE values in Ar/CH$_4$(95/5) above 30% at wavelengths of 360-400 nm. The novel gaseous photomultiplier yielded stable operation at gains of 10$^5$, in continuous operation mode, in 700 Torr of this gas; its sensitivity to single photons was demonstrated. Other properties are described. The successful detection of visible light with this gas-photomultiplier pave ways towards further development of large-area sealed imaging detectors, of flat geometry, insensitive to magnetic fields, which might have significant impact on light detection in numerous fields.Comment: 22 pages, 12 figures, for submission to JINS

Further progress in ion back-flow reduction with patterned gaseous hole-multipliers

A new idea on electrostatic deviation and capture of back-drifting avalanche-ions in cascaded gaseous hole-multipliers is presented. It involves a flipped reversed-bias Micro-Hole & Strip Plate (F-R-MHSP) element, the strips of which are facing the drift region of the multiplier. The ions, originating from successive multiplication stages, are efficiently deviated and captured by such electrode. Experimental results are provided comparing the ion-blocking capability of the F-R-MHSP to that of the reversed-bias Micro-Hole & Strip Plate (R-MHSP) and the Gas Electron Multiplier (GEM). Best ion-blocking results in cascaded hole-multipliers were reached with a detector having the F-R-MHSP as the first multiplication element. A three-element F-R-MHSP/GEM/MHSP cascaded multiplier operated in atmospheric-pressure Ar/CH4 (95/5), at total gain of ~10^{5}, yielded ion back-flow fractions of 3*10^{-4} and 1.5*10^{-4}, at drift fields of 0.5 and 0.2 kV/cm, respectively. We describe the F-R-MHSP concept and the relevance of the obtained ion back-flow fractions to various applications; further ideas are also discussed.Comment: 17 pages, 11 figures, published in JINS

The Photon-Assisted Cascaded Electron Multiplier: a Concept for Potential Avalanche-Ion Blocking

We present a Photon-Assisted Cascaded Electron Multipliers (PACEM) which has a potential for ion back-flow blocking in gaseous radiation detectors: the avalanche from a first multiplication stage propagates to the successive one via its photons, which in turn induce photoelectron emission from a photocathode deposited on the second multiplier stage; the multiplication process may further continue via electron-avalanche propagation. The photon-mediated stage allows, by a proper choice of geometry and fields, complete blocking of the ion back-flow into the first element; thus, only ions from the latter will flow back to the drift region. The PACEM concept was validated in a double-MHSP (Micro-Hole & Strip Plate) cascaded multiplier operated in xenon, where the intermediate scintillation stage provided optical gain of ~60. The double-MHSP detector had a total gain above 10^4 and energy resolution of 18% FWHM for 5.9 keV x-rays.Comment: 13 pages, 5 figures. Submitted to JINST - electronic Journal of Instrumentation, June 25, 200

The methodology of calculation of sample size in “non-inferiority” comparative controlled clinical trials: a comparison of two proportions in parallel group

The absolute majority of clinical trials of generic drugs aimed to compare the therapeutic efficacy of the tested drug and the drug of an active control. It is necessary to estimate that the test drug is not less effective (or non-inferior) than the control drug. The designs of the aforementioned trials are called “non-inferiority” study; often, these are phase III of clinical trials. The primary criterions of effectiveness which are quite often used in the clinical trials are frequencies of signs, as a result of the analysis of binary data. Binary data are analyzed by comparing proportions. One of the most important conditions for a correct interpretation of the data obtained during the clinical trials — to provide necessary and suffi cient sample size. The purpose of this article is to show how to plan the study, how to provide necessary and sufficient sample size to ensure that the results and conclusions would be reliable; how to interpret the data in a comparative controlled study aimed to establish “non­inferiority” using proportions comparing in parallel groups

Dynamic model of elastoplastic normal collision of spherical particles under nonlocal plasticity

The problem of normal collision of a spherical particle with a half-space is considered with allowance for nonlocal plastic deformation in the case where the strength limit depends on the contact radius, as well as for the strengthening effect in the deformed material. The dimensionless coefficient of normal velocity restitution has been calculated numerically as a function of the initial velocity of the spherical particle. The obtained data coincide well with experimental results available in the literature

МОДЕЛИ СТРАТЕГИЧЕСКОГО УПРАВЛЕНИЯ ИНФОКОММУНИКАЦИНОННЫМ БИЗНЕСОМ

Consideration subject in this article are models of strategic management of large transnational information and communication business. The purpose of the presented work consists in formation of ideas of model of strategic management on the example of infocommunication business. For achievement of a goal the author of article carries out the analysis and synthesis of the existing practice of strategic management in infocommunication business. For achievement of a goal, as methodological base, the systems and logical analysis was selected. In water part of article the interrelation of a computerization of basic functions of a business management, by public and public institutions, growth of the enterprises of the information and communication sphere and formation of a pool of specially prepared labor with development of practice of a strategation is presented. In the main part of article practice of the organization of strategic management of infocommunication business in three leading fi rms of this branch of Microsoft, Dell, Intel is considered. Consideration is directly coordinated to evolution of the infocommunication branch defi ning regularities of strategic management. The model strategic management in the Microsoft company conceptually corresponds to strategy of growth and includes three elements: representation, participation and innovations. At the heart of model of strategic management of Intel there are two elements: fi rst, deduction of leader positions in the of a segment by means of development, productions and sales of the most eff ective and available goods at the price, secondly, is maximizing use value of the fi nal product of the company. Generally the model of strategic management of Dell includes three basic elements: development and use of the latest technologies, high quality of goods, eff ective interrelation in a value creation chain. As result of the experiment of strategic management of large information and communication business made in article of the analysis one general idea of formation of strategy of management of infocommunication business which consists in full recognition of inevitability of globalization processes in the modern world at the accelerated development of information technologies was selected. In these conditions, the companies use such strategic means of the competition, as: increase of productivity, mastering of the new markets, creation of new business models and attraction of talents on a global scale.Предметом рассмотрения в статье являются модели стратегического управления крупным транснациональным информационно-коммуникационным бизнесом. Цель статьи состоит в формировании представлений о модели стратегического управления на примере инфокоммуникационного бизнеса. Для достижения поставленной цели автор статьи проводит анализ и обобщение существующей практики стратегического управления в инфокоммуникационной бизнесе. В качестве методологической базы был выбран системный и логический анализ. В водной части статьи представлена взаимосвязь компьютеризации основных функций управления бизнесом, общественными и государственными учреждениями, рост предприятий информационно-коммуникационной сферы и формирование пула специально подготовленной рабочей силы с развитием практики стратегирования. В основной части статьи рассматривается практика организации стратегического управления инфокоммуникационным бизнесом в трех ведущих фирмах этой отрасли Microsoft, Dell, Intel. Рас-смотрение непосредственно увязано с эволюцией инфокоммуникационной отрасли, определяющей закономерности стратегического управления. Модель стратегического управление в компании Microsoft концептуально соответствует стратегиям роста и включает в себя три элемента: представительство, причастность и инновации. В основе модели стратегического управления Intel находятся два элемента: во-первых, удержание лидерских позиций в своем сегмента посредством разработки, производства и продажи наиболее эффективных и доступных по цене товаров, во-вторых, это максимизация потребительной ценности конечного продукта компании. Модель стратегического управления Dell включает в себя три основных элемента: разработка и использование новейших технологий, высокое качество товаров, эффективная взаимосвязь в цепочке создания стоимости. В качестве результата проведенного в статье анализа опыта стратегического управления крупным информационно-коммуникационным бизнесом была выделена одна общая идея формирования стратегии управления инфокоммуникационным бизнесом, которая состоит в полном признании неизбежности глобализационных процессов в современном мире при ускоренном развитии информационных технологий. В этих условиях, компании используют такие стратегические средства конкуренции, как: повышение производительности, освоение новых рынков, создание новых бизнес-моделей и привлечения талантов в глобальном масштабе

КОРПОРАТИВНЫЕ СТРАТЕГИИ МЕЖДУНАРОДНЫХ КОМПАНИЙ: АНАЛИЗ ЗАРУБЕЖНЫХ ИСТОЧНИКОВ

In article, based on a wide theoretical material of foreign researches, the author gives the review of a current state of degree of a readiness of a question of corporate strategies of the international companies.В статье на широком теоретическом материале из иностранных исследований автор даёт обзор современного состояния степени разработанности вопроса корпоративных стратегий международных компаний

Improving the Sphere of Customs Administration in Russia Based on the Chinese Experience

The widespread use of new technologies based on digitalization has recently intensified, due to the processes associated with changes in business organization. Serious attention is paid to this direction of development by business representatives engaged in economic activities in international trade and governments of the leading economies of the world, including China and Russia. The introduction of digitalization processes in various sectors of the economy has become a conscious necessity. In order to theoretically substantiate and subsequently achieve the necessary level of development of information technologies and communications, analytical studies and testing of changes in this area are being conducted in many countries. The economy based on the introduction of digital technologies determines the vector of development of the economies of countries for the long term.Aim. Analyze the digital transformation of the Chinese economy, identify positive experience in the application of digital solutions and their impact on the simplification of customs procedures and correlate the results with Russia.Tasks. Consider technological trends in digital transformation; to study the results of the policy in carrying out the digitalization of the economy of China and Russia; to consider possible promising areas for the development of cooperation between China and Russia in the field of digital.Methods. Statistical analysis of data and synthesis of the results obtained for comparison purposes.Results. As a result of the study, the following results were obtained: a) a comparative analysis of the changes in the values of indicators on the Global Connectivity Index (GCI) of China and Russia in 2020 compared to 2015 was carried out, the reasons for the changes that occurred were substantiated; b) the dynamics of exports and imports of China, as well as data on trade turnover between China and Russia for the period from 1991 to October 2021; c) the experience of customs administration in China is considered and possible directions of its application in Russia are determined.Conclusion. The positive experience of China’s customs administration in the light of the digitalization of economic processes can be used in Russia, which can certainly improve the current situation in the field of customs administration in our country

Multifractal analysis of stress time series during ultrathin lubricant film melting

Melting of an ultrathin lubricant film confined between two atomically flat surfaces is we studied using the rheological model for viscoelastic matter approximation. Phase diagram with domains, corresponding to sliding, dry, and two types of $stick-slip$ friction regimes has been built taking into account additive noises of stress, strain, and temperature of the lubricant. The stress time series have been obtained for all regimes of friction using the Stratonovich interpretation. It has been shown that self-similar regime of lubricant melting is observed when intensity of temperature noise is much larger than intensities of strain and stress noises. This regime is defined by homogenous distribution, at which characteristic stress scale is absent. We study stress time series obtained for all friction regimes using multifractal detrended fluctuation analysis. It has been shown that multifractality of these series is caused by different correlations that are present in the system and also by a power-law distribution. Since the power-law distribution is related to small stresses, this case corresponds to self-similar solid-like lubricant.Comment: 22 pages, 10 figures, 41 reference