Measurements of the Secondary Electron Emission from Rare Gases at 4.2K

Dependence of the secondary electron yield (SEY) from the primary beam incident energy and the coverage has been measured for neon, argon, krypton and xenon condensed on a target at 4.2K. The beam energy ranged between 100 eV and 3 keV, the maximal applied coverage have made up 12000, 4700, 2500 and 1400 monolayers correspondingly for neon, argon, krypton and xenon. The SEY results for these coverages can be considered as belonging only to investigated gases without influence of the target material. The SEY dependencies versus the primary beam energy for all gases comprise only an ascending part and therefore, the maximal measured SEY values have been obtained for the beam energy of 3keV and have made up 62, 73, 60.5 and 52 for neon, argon, krypton and xenon correspondingly. Values of the first cross-over have made up 21 eV for neon, 14 eV for argon, 12.5 eV for krypton and 10.5 eV for xenon. An internal field appearing across a film due to the beam impact can considerably affect the SEY measurements that demanded the beam current to be reduced till 9.0E-10A. Duration of the beam impact varied between 500 \mu sec and 250 \mu sec. It was found that reliable SEY measurements can also be taken on a charged surface if the charge was acquired due to beam impact with electrons of higher energy. All SEY measurements for once applied coverage have been carried out for whole range of incident energies from 3 keV down to 100 eV without renewing the film. Developing of pores inside of a deposited film can significantly increase the SEY as it was observed during warming up the target.Comment: 10 Pages - 25 figure

Measurements of the Secondary Electron Emission of Some Insulators

Charging up the surface of an insulator after beam impact can lead either to reverse sign of field between the surface and collector of electrons for case of thick sample or appearance of very high internal field for thin films. Both situations discard correct measurements of secondary electron emission (SEE) and can be avoided via reducing the beam dose. The single pulse method with pulse duration of order of tens microseconds has been used. The beam pulsing was carried out by means of an analog switch introduced in deflection plate circuit which toggles its output between "beam on" and "beam off" voltages depending on level of a digital pulse. The error in measuring the beam current for insulators with high value of SEE was significantly reduced due to the use for this purpose a titanium sample having low value of the SEE with DC method applied. Results obtained for some not coated insulators show considerable increase of the SEE after baking out at 3500C what could be explained by the change of work function. Titanium coatings on alumina exhibit results close to the ones for pure titanium and could be considered as an effective antimultipactor coating.Comment: 8 pages, 13 figure

The Influence of Air Exposures and Thermal Treatments on the Secondary Electron Yield of Copper

The variation of the secondary electron yield (SEY) of sputter-cleaned OFHC-copper has been studied as a function of air exposure duration at room temperature. After short air exposures of some seconds the maximum SEY (deltaMAX) of clean copper is reduced from 1.3 to less than 1.2, due to the oxidation of the copper surface. Prolonged air exposure increases the SEY steadily until, after about 8 days of atmospheric exposure, deltaMAX is higher than 2.Air exposures at higher temperatures have been found to be effective in reducing the SEY of technical copper surfaces. A 5-minute air exposure of copper at 350°C followed by a 350°C bake-out under vacuum reduces deltaMAX to about 1.05, which is lower than the value of pure copper and that of Cu2O

Study Of Oxidation Processes In Duck Meat With Application Of Rosemary And Grape Seed Extracts

The substantiation of the expedience of using antioxidants of a natural origin to decelerate oxidation processes in different meat products is an urgent direction of these studies. The prospective way of a solution of the problem of meat products oxidation spoilage is the use of vegetable extracts. The experimental studies of the effective use of the composition of rosemary and grape seed extracts in Peking duck forcemeat at the long storage were realized. Their influence on the dynamics of hydrolytic and peroxide oxidation of forcemeat lipids was studied. The analysis of oxidation secondary products accumulation was realized at the same time.The positive effect of the combined use of rosemary and grape seeds extracts on frozen Peking duck forcemeat was established, the optimal concentration of offered preparations was determined

Питання процесуального порядку повідомлення про підозру

Божко, Н. І. Питання процесуального порядку повідомлення про підозру / Наталія Іванівна Божко // Шляхи удосконалення досудового розслідування: організаційно-правові аспекти : матеріали наук.-практ. круглого столу (м. Харків, 24 жовт. 2019 р.) / МВС України ; Харків. нац. ун-т внутр. справ, Фак. № 1 (з підготовки слідчих), Каф. кримінал. процесу та організації досуд. слідства. - Харків, 2019. - С. 51-54.Розглянуті основні питання процесуального порядку повідомлення про підозру на етапі досудового розслідування.The main issues of the procedural order of notification of suspicion at the stage of pre-trial investigation are considered.Рассмотрены основные вопросы процессуального порядка уведомления о подозрении на этапе досудебного расследования

Анализ геометрической разрешимости при сборке сложных изделий как задача принятия решений

Computer aided assembly planning (CAAP) of complex products is an important and urgent problem of state-of-the-art information technologies. A configuration of the technical system imposes fundamental restrictions on the design solutions of the assembly process. The CAAP studies offer various methods for modelling geometric constraints. The most accurate results are obtained from the studies of geometric obstacles, which prohibit the part movement to the appropriate position in the product, by the collision analysis methods. An assembly of complex technical systems by this approach requires very high computational costs, since the analysis should be performed for each part and in several directions.The article describes a method for minimizing the number of direct checks for geometric obstacle avoidance. Introduces a concept of the geometric situation to formalize such fragments of a structure, which require checking for geometric obstacle avoidance. Formulates two statements about geometric heredity during the assembly. Poses the task of minimizing the number of direct checks as a non-antagonistic two-person game on two-colour painting of an ordered set. Presents the main decision criteria under uncertainty. To determine the best criterion, a computational experiment was carried out on painting the ordered sets with radically different structural properties. All the connected ordered sets are divided into 13 subclasses, each of which includes structurally similar instances. To implement the experiment, a special program has been developed that creates a random ordered set in the selected subclass, implements a game session on its coloration, and also collects and processes statistical data on a group of the homogeneous experiments.The computational experiment has shown that in all subclasses of the partial orders, the Hurwitz criterion with a confidence coefficient of 2/3 and that of Bayes-Laplace demonstrate the best results. The Wald and Savage criteria have demonstrated the worst results. In the experiment, a difference between the best and worst results reached 70%. With increasing height (maximum number of levels) of an ordered set, this difference tends to grow rapidly. In the subclass of pseudo-chains, all criteria showed approximately equal results.The game model of geometric obstacles avoidance allows formalizing data on geometric heredity and obtaining data on the composition and the minimum number of configurations, the test of which objectifies all existing-in-the-product geometric constraints on the movements of parts during assembly.Автоматизация проектирования процессов сборки сложных изделий – это важная и актуальная проблема современной информационной технологии. Фундаментальные ограничения на проектные решения сборочного передела накладывает геометрия технической системы. В исследованиях по CAAP предложены различные методы моделирования геометрических связей. Самые точные результаты дает исследования геометрических препятствии, которые запрещают движение детали в служебное положение в изделии, методами анализа столкновений. Для сборки сложных технических систем данный подход требует очень высоких вычислительных затрат, поскольку анализ следует выполнить для каждой детали и в нескольких направлениях.В статье описан метод минимизации числа прямых проверок на геометрическую разрешимость. Введено понятие геометрической ситуации, которое формализует такие фрагменты конструкции, для которых требуется проверка геометрическую разрешимость. Сформулированы два утверждения о геометрической наследственности при сборке. Задача минимизации числа прямых проверок поставлена как неантагонистиченская игра двух лиц по окрашиванию упорядоченного множества в два цвета. Приведены основные критерии принятия решений в условиях неопределенности. Для определения лучшего критерия проведен вычислительный эксперимент по окрашиванию упорядоченных множеств с радикально различными структурными свойствами. Все связные упорядоченные множества разбиты на 13 подклассов, в каждый из которых входят структурно подобные экземпляры. Для реализации эксперимента создана специальная программа, которая создает случайное упорядоченное множество в выбранном подклассе, реализует игровой сеанс по его окрашиванию, а также собирает и обрабатывает статистические данные по группе однородных экспериментов.Вычислительный эксперимент показал, что во всех подклассах частичных порядков лучшие результаты у критериев Гурвица с коэффициентом доверия 2/3 и Байеса-Лапласа. Худшие результаты продемонстрировали критерии Вальда и Севиджа. Разница между лучшими и худшими результатами достигала в эксперименте 70%. Эта разница имеет тенденцию к быстрому росту с увеличением высоты (максимального числа уровней) упорядоченного множества. В подклассе псевдоцепей все критерии показали примерно равные результаты.Игровая модель геометрической разрешимости позволяет формализовать данные о геометрической наследственности и получить данные о составе и минимальном числе конфигураций, проверка которых объективирует все геометрические ограничения на движения деталей при сборке, существующие в изделии

Loss of Andreev Backscattering in Superconducting Quantum Point Contacts

We study effects of magnetic field on the energy spectrum in a superconducting quantum point contact. The supercurrent induced by the magnetic field leads to intermode transitions between the electron waves that pass and do not pass through the constriction. The latter experience normal reflections which couple the states with opposite momenta inside the quantum channel and create a minigap in the energy spectrum that depends on the magnetic field